Perspective: Beyond the Mediterranean Diet-Exploring Latin American, Asian, and African Heritage Diets as Cultural Models of Healthy Eating

The Mediterranean diet is a well-studied cultural model of healthy eating, yet research on healthy models from other cultures and cuisines has been limited. This perspective article summarizes the components of traditional Latin American, Asian, and African heritage diets, their association with diet quality and markers of health, and implications for nutrition programs and policy. Though these diets differ in specific foods and flavors, we present a common thread that emphasizes healthful plant foods and that is consistent with high dietary quality and low rates of major causes of disability and deaths. In this perspective, we propose that nutrition interventions that incorporate these cultural models of healthy eating show promise, though further research is needed to determine health outcomes and best practices for implementation.

Role of Polyunsaturated Fat in Modifying Cardiovascular Risk Associated With Family History of Cardiovascular Disease: Pooled De Novo Results From 15 Observational Studies

BACKGROUND

It is unknown whether dietary intake of polyunsaturated fatty acids (PUFA) modifies the cardiovascular disease (CVD) risk associated with a family history of CVD. We assessed interactions between biomarkers of low PUFA intake and a family history in relation to long-term CVD risk in a large consortium.

METHODS

Blood and tissue PUFA data from 40 885 CVD-free adults were assessed. PUFA levels ≤25th percentile were considered to reflect low intake of linoleic, alpha-linolenic, and eicosapentaenoic/docosahexaenoic acids (EPA/DHA). Family history was defined as having ≥1 first-degree relative who experienced a CVD event. Relative risks with 95% CI of CVD were estimated using Cox regression and meta-analyzed. Interactions were assessed by analyzing product terms and calculating relative excess risk due to interaction.

RESULTS

After multivariable adjustments, a significant interaction between low EPA/DHA and family history was observed (product term pooled RR, 1.09 [95% CI, 1.02-1.16]; P=0.01). The pooled relative risk of CVD associated with the combined exposure to low EPA/DHA, and family history was 1.41 (95% CI, 1.30-1.54), whereas it was 1.25 (95% CI, 1.16-1.33) for family history alone and 1.06 (95% CI, 0.98-1.14) for EPA/DHA alone, compared with those with neither exposure. The relative excess risk due to interaction results indicated no interactions.

CONCLUSIONS

A significant interaction between biomarkers of low EPA/DHA intake, but not the other PUFA, and a family history was observed. This novel finding might suggest a need to emphasize the benefit of consuming oily fish for individuals with a family history of CVD.

Diet-Attributable Greenhouse Gas Emissions and Acute Myocardial Infarction in Costa Rica Heart Study

Adopting sustainable dietary patterns is essential for planetary and human health. As data to address this issue are lacking in Latino populations, this study examined the association between diet-attributable greenhouse gas emissions (GHGEs) and myocardial infarction (MI) in a Costa Rica Heart Study. This analysis included 1817 cases of a first non-fatal acute MI during hospitalization and their matched population-based controls, by age, sex, and area of residence. A validated food frequency questionnaire was used to quantify habitual dietary intake and diet-attributable GHGEs (kg CO2 equivalent (eq.)/year). Due to the matching design, conditional logistic regression was used. Red meat consumption contributed approximately 50% to the total diet-attributable GHGEs among both cases and controls. Higher diet-attributable GHGEs were associated with increased odds of acute MI. The odds of MI were 63% higher (OR = 1.63; 95% CI 1.20-2.21) among participants in the highest quintile (median diet-attributable GHGEs = 6247 kg CO2 eq./year) compared to the lowest quintile (median diet-attributable GHGEs = 2065 kg CO2 eq./year). An increasing linear trend in the odds of acute MI and diet-attributable GHGEs was detected (p-trend 0.0012). These findings highlight the importance of reducing red meat consumption to sustainably mitigate the incidence of MI and improve planetary health.

A prospective analysis of red blood cell membrane polyunsaturated fatty acid levels and risk of non-Hodgkin lymphoma

Published studies report inconsistent associations of polyunsaturated fatty acid (PUFA) intake with non-Hodgkin lymphoma (NHL) risk. We conducted a nested case-control study in Nurses' Health Study and Health Professionals Follow-Up Study participants to evaluate a hypothesis of inverse association of pre-diagnosis red blood cell (RBC) membrane PUFA levels with risk of NHL endpoints. We confirmed 583 NHL cases and matched 583 controls by cohort/sex, age, race and blood draw date/time. We estimated odds ratios (OR) and 95% confidence intervals (CI) for risk of NHL endpoints using logistic regression. RBC PUFA levels were not associated with all NHL risk; cis 20:2n-6 was associated with follicular lymphoma risk (OR [95% CI] per one standard deviation increase: 1.35 [1.03-1.77]), and the omega-6/omega-3 PUFA ratio was associated with diffuse large B-cell lymphoma risk (2.33 [1.23-4.43]). Overall, PUFA did not demonstrate a role in NHL etiology; the two unexpected positive associations lack clear biologic explanations.

Associations between sleep duration and Mediterranean diet score in Costa Rican adults

Both insufficient and excessive sleep duration have been associated with lower-quality diets in adult populations. However, investigations in Latin America, where different sleep norms may exist (e.g., daily napping), are scarce. Therefore, we examined whether weekday sleep duration and inconsistencies between weekday and weekend sleep duration were related to adherence to the Mediterranean diet among Costa Rican adults. The study population included 2169 controls (74% men) from a population-based case-control study. Usual sleep duration (weekday versus weekend) was self-reported and defined as short, recommended, and long (<7 h, 7-9 h, >9 h, respectively). Inconsistent weekday-weekend sleep duration was defined as >1-h difference. Diet was assessed with a food frequency questionnaire, and adherence to the Mediterranean diet was calculated with the Alternative Mediterranean Diet Score (AMED). Sex-stratified linear regression models were conducted with AMED score as a continuous outcome and sleep variables as categorical or dichotomous exposures (in separate models). Models were adjusted for age, area of residence, education, napping, caffeine intake, smoking status, type 2 diabetes mellitus, hypertension, and physical activity. Average (SD) hours of sleep per night reported were 7.0 (1.4) on weekdays and 7.3 (1.6) on weekends for men, and 7.0 (1.5) on weekdays and 7.2 (1.6) on weekends for women. Among women, sleep duration <7-h per night was associated with a lower AMED score compared to those with recommended sleep duration (β: -0.35, CI: -0.63 to -0.07). Unstratified models showed a suggestive association between inconsistent weekday-weekend sleep and lower AMED scores that did not vary by sex (β: -0.08, CI: -0.16, 0.006; P, interaction with sex = 0.93). Lastly, the napping frequency was not associated with AMED scores in any model. In conclusion, short and inconsistent sleep duration may affect the dietary patterns of Costa Ricans.

Starchy Vegetables and Metabolic Syndrome in Costa Rica

Only a few studies primarily examined the associations between starchy vegetables (other than potatoes) and metabolic syndrome (MetS). We aimed to evaluate the association between starchy vegetables consumption and MetS in a population-based sample of Costa Rican adults. We hypothesized that a higher overall intake of starchy vegetables would not be associated with higher MetS prevalence. In this cross-sectional study, log-binomial regression models were used to estimate prevalence ratios (PRs) of MetS across quintiles of total, unhealthy, healthy starchy vegetables, and individual starchy vegetables (potatoes, purple sweet potatoes, etc.), among 1881 Costa Rican adults. Least square means and 95% confidence intervals (CIs) from linear regression models were estimated for each MetS component by categories of starchy vegetable variables. Higher intakes of starchy vegetables were associated with a higher prevalence of MetS in crude models, but no significant trends were observed after adjusting for confounders. A significant inverse association was observed between total starchy and healthy starchy vegetables consumption and fasting blood glucose. In this population, starchy vegetables might be part of a healthy dietary pattern.

Breakfast Frequency Is Inversely Associated with Weight Gain in a Cohort of Mexican Women

BACKGROUND

Food timing affects circadian rhythms involved in weight control. Regular consumption of breakfast may affect body weight.

OBJECTIVE

We examined the relation between breakfast frequency with weight change in middle-age women over a 3-y period.

METHODS

We used data from 65,099 nonpregnant women aged >20 y participating in the Mexican Teachers' Cohort (MTC) who at baseline (2006-2008) were cancer free and for whom self-reported breakfast frequency at baseline was available. We analyzed body weight change between baseline and the first follow-up (2011) according to breakfast frequency. Participants were classified according to baseline breakfast frequency 0, 1-3, 4-6, or 7 d/wk and meal frequency 1-2, 3-4, or ≥5 meals/d. We used linear and modified Poisson regression to analyze body weight change as a continuous variable and for weight gain ≥5 kg (yes/no), respectively. Models were adjusted for sociodemographic and lifestyle confounders.

RESULTS

At baseline, 25% of participants were daily breakfast consumers and 18.4% of women increased ≥5 kg between 2008 and 2011. The prevalence of weight gain ≥5 kg among daily breakfast consumers was 7% lower than among those who skipped breakfast (prevalence ratio: 0.93; 95% CI: 0.89, 0.97; P-trend = 0.02). The association was stronger among normal-weight women at baseline with a corresponding estimate of 0.87 (95% CI: 0.79, 0.97; P-trend = 0.02).

CONCLUSION

Daily breakfast consumption was inversely associated with weight gain ≥5 kg over 3 y in middle-aged Mexican women. Regular breakfast may be an important dietary factor for body weight change.

Coexistence of genetically modified seed production and organic farming in Chile

The seed industry in Chile has thrived since the implementation of a stringent, voluntarily self-imposed coexistence strategy between genetically modified organisms (GMOs) and non-GMO seed activities. GMO varieties of maize, soybean, and canola represent the vast majority of biotech seeds produced in Chile. Chile’s exports of genetically modified (GM) seeds and organically grown food products (which excludes GM seeds and materials) continue to expand. Organic Chilean farmers predominantly produce and export fruits such as blueberries, wine grapes, and apples. Under normal agricultural conditions, the inadvertent presence of GMOs in non-GMO or organic crops cannot be ruled out. Producers of organic foods are required to implement stringent measures to minimize contact with any non-organic crop, regardless of whether these crops are GM. Only very small amounts of organic maize, soybean, and canola – if any – have been produced in Chile in recent years. Given the characteristics and nature of Chile’s agriculture, the direct impact of the GM seed industry on organic farming in Chile is likely to be negligible. The Chilean experience with coexistence between GM seed and organic industries may inform other countries interested in providing its farmers with alternative agricultural production systems.

Red blood cell membrane trans fatty acid levels and risk of non-Hodgkin lymphoma: a prospective nested case-control study

BACKGROUND

Trans fatty acid (TFA) intake persists in much of the world, posing ongoing threats to public health that warrant further elucidation. Published evidence suggests a positive association of self-reported TFA intake with non-Hodgkin lymphoma (NHL) risk.

OBJECTIVES

To confirm those reports, we conducted a prospective study of prediagnosis RBC membrane TFA levels and risk of NHL and common NHL histologic subtypes.

METHODS

We conducted a nested case-control study in Nurses' Health Study and Health Professionals Follow-Up Study participants with archived RBC specimens and no history of cancer at blood draw (1989-1090 and 1994-1995, respectively). We confirmed 583 incident NHL cases (332 women and 251 men) and individually matched 583 controls on cohort (sex), age, race, and blood draw date/time. We analyzed RBC membrane TFA using GLC (in 2013-2014) and expressed individual TFA levels as a percentage of total fatty acids. We used unconditional logistic regression adjusted for the matching factors to estimate ORs and 95% CIs for overall NHL risk per 1 SD increase in TFA level and assessed histologic subtype-specific associations with multivariable polytomous logistic regression.

RESULTS

Total and individual TFA levels were not associated with risk of all NHL or most subtypes. We observed a positive association of total TFA levels with diffuse large B cell lymphoma (DLBCL) risk [n = 98 cases; OR (95% CI) per 1 SD increase: 1.30 (1.05, 1.61); P = 0.015], driven by trans 18:1n-9(ω-9)/elaidic acid [OR (95% CI): 1.34 (1.08, 1.66); P = 0.007], trans 18:1n-7/vaccenic acid [OR (95% CI): 1.28 (1.04, 1.58); P = 0.023], and trans 18:2n-6t,t [OR (95% CI): 1.26 (1.01, 1.57); P = 0.037].

CONCLUSIONS

Our findings extended evidence for TFA intake and DLBCL risk but not for other NHL subtypes. Reduced TFA consumption through dietary choices or health policy measures may support prevention of DLBCL, an aggressive NHL subtype.

Comparison of the Utility of Total Plasma Fatty Acids Versus those in Cholesteryl Ester, Phospholipid, and Triglyceride as Biomarkers of Fatty Acid Intake

Total plasma fatty acids or those in cholesteryl ester and phospholipids are often used to reflect fatty acid intake in epidemiological studies, but their relative performance as biomarkers of intake has not been clearly evaluated within a single population. The assessment of fatty acids in plasma fractions is more labor intensive. Thus, their use as biomarkers of dietary intake needs to be justified. Dietary intake was assessed in 200 population-based controls from a case-control study of diet and heart disease in Costa Rica by a validated food frequency questionnaire (FFQ). Fatty acids in fasting whole plasma and plasma fractions (cholesteryl ester, phospholipid, and triglyceride + free fatty acid) were measured in the 200 controls by the same laboratory using gas chromatography with flame ionization detection (GC-FID). We compared the plasma and plasma fractions data with the FFQ and adipose fatty acid profile using partial Spearman correlations to assess utility as biomarkers of intake and exposure. We found that whole plasma was equally or more strongly correlated with the FFQ and adipose fatty acid profile than either cholesteryl ester or phospholipid in most of the established markers of dietary intake, including dairy (15:0 and 17:0) and seafood (eicosapentaenoic acid and docosahexaenoic acid). Of the three plasma fractions, only fatty acids in the plasma triglyceride + free fatty acid fraction had stronger correlations with dietary intake than whole plasma. In our study population, fatty acids measured in fasting whole plasma perform as good as or better than those measured in plasma fractions as biomarkers for dietary fatty acid intake. Thus, the fractionation of plasma to evaluate long-term fatty acid intake may not be warranted.

Biomarkers of Dietary Omega-6 Fatty Acids and Incident Cardiovascular Disease and Mortality

BACKGROUND

Global dietary recommendations for and cardiovascular effects of linoleic acid, the major dietary omega-6 fatty acid, and its major metabolite, arachidonic acid, remain controversial. To address this uncertainty and inform international recommendations, we evaluated how in vivo circulating and tissue levels of linoleic acid (LA) and arachidonic acid (AA) relate to incident cardiovascular disease (CVD) across multiple international studies.

METHODS

We performed harmonized, de novo, individual-level analyses in a global consortium of 30 prospective observational studies from 13 countries. Multivariable-adjusted associations of circulating and adipose tissue LA and AA biomarkers with incident total CVD and subtypes (coronary heart disease, ischemic stroke, cardiovascular mortality) were investigated according to a prespecified analytic plan. Levels of LA and AA, measured as the percentage of total fatty acids, were evaluated linearly according to their interquintile range (ie, the range between the midpoint of the first and fifth quintiles), and categorically by quintiles. Study-specific results were pooled using inverse-variance-weighted meta-analysis. Heterogeneity was explored by age, sex, race, diabetes mellitus, statin use, aspirin use, omega-3 levels, and fatty acid desaturase 1 genotype (when available).

RESULTS

In 30 prospective studies with medians of follow-up ranging 2.5 to 31.9 years, 15 198 incident cardiovascular events occurred among 68 659 participants. Higher levels of LA were significantly associated with lower risks of total CVD, cardiovascular mortality, and ischemic stroke, with hazard ratios per interquintile range of 0.93 (95% CI, 0.88-0.99), 0.78 (0.70-0.85), and 0.88 (0.79-0.98), respectively, and nonsignificantly with lower coronary heart disease risk (0.94; 0.88-1.00). Relationships were similar for LA evaluated across quintiles. AA levels were not associated with higher risk of cardiovascular outcomes; in a comparison of extreme quintiles, higher levels were associated with lower risk of total CVD (0.92; 0.86-0.99). No consistent heterogeneity by population subgroups was identified in the observed relationships.

CONCLUSIONS

In pooled global analyses, higher in vivo circulating and tissue levels of LA and possibly AA were associated with lower risk of major cardiovascular events. These results support a favorable role for LA in CVD prevention.

Sugar-Sweetened Soda Consumption Increases Diabetes Risk Among Mexican Women

BACKGROUND

Epidemiological evidence supports an association between sugar-sweetened soda consumption and diabetes. However, evidence regarding this association is limited in countries that have recently undergone a nutritional transition.

OBJECTIVE

We estimated the association between sugar-sweetened soda consumption and incident diabetes. We also determined if the association between sugar-sweetened soda and diabetes differs as a result of early life factors and potential genetic susceptibility.

METHODS

We used data from the Mexican Teachers' Cohort including 72,667 women aged ≥25 y, free of diabetes, cardiovascular disease, and cancer at baseline. We assessed sugar-sweetened soda consumption using a validated food frequency questionnaire (FFQ) at baseline. Diabetes was self-reported. We used Cox proportional hazard regression models to estimate the association between quintiles of sugar-sweetend soda and diabetes. We also estimated the associaiton by increasing one serving per day (355 mL) of sugar-sweetened soda. We conducted prespecified subgroup analysis by potential effect modifiers, namely markers of energy balance of early life factors, family history of diabetes, and Amerindian admixture.

RESULTS

During a median follow-up of 2.16 y (IQR 0.75-4.50) we identified 3,155 incident cases of diabetes. The median consumption of sugar-sweetened soda was 1.17 servings per day (IQR 0.47- 4.00). In multivariable analyses, comparing extreme quintiles showed that higher sugar-sweetened soda consumption was associated with diabetes incidence (HR = 1.32; 95% CI: 1.17, 1.49), and each additional serving per day of sugar-sweetened soda was associated with an increase of 27% in diabetes incidence (HR = 1.27; 95% CI: 1.16, 1.38). The soda-diabetes association was stronger among women who experienced intrauterine and childhood over-nutrition (high birth weight, no short stature, higher adiposity in premenarche, and higher adiposity at age 18-20 y old).

CONCLUSION

Sugar-sweetened soda consumption is associated with an increased risk of diabetes among Mexican women in a magnitude similar to that reported in other populations. The stronger association among individuals with markers of early life over-nutrition reinforce the need for early life interventions.

A Prospective Analysis of Red Blood Cell Trans Fatty Acid Levels and Risk of Non-Hodgkin Lymphoma

To confirm previous reports of increased non-Hodgkin lymphoma (NHL) risk with higher intake of dietary trans fatty acids (TFA), we conducted the first prospective study of pre-diagnosis red blood cell (RBC) TFA levels and risk of NHL and common NHL histologic subtypes (diffuse large-B cell lymphoma (DLBCL), follicular lymphoma, chronic lymphocytic lymphoma/small lymphocytic leukemia, other B-cell NHL, T-cell NHL). Methods: We conducted a nested case-control study in Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS) participants with archived RBC specimens and no history of cancer at sample collection (NHS: 1989–90; HPFS: 1994–5). We confirmed 583 NHL cases (332 women in NHS, 251 men in HPFS) and matched 583 controls by cohort (sex), age, race/ethnicity and blood draw date/time. We analyzed RBC TFAs using gas-liquid chromatography; individual TFA levels were expressed as a percentage of total fatty acids. We used unconditional logistic regression, adjusted for the matching factors, to estimate odds ratios (OR) and 95% confidence intervals (CI) for overall NHL risk per 1 standard deviation (SD) unit increase in TFA level. We fitted multivariate polytomous logistic regression models to assess associations for the specific subtypes listed above. Results: Total and individual RBC TFAs were not associated with overall NHL risk or risk of most histologic subtypes. However, we observed a positive association of total RBC TFA with DLBCL risk (n = 86 cases; OR [95% CI] per 1 SD: 1.29 [1.02, 1.64]), driven primarily by 18:1 TFAs (1.35 [1.07, 1.72]). Among 18:1 TFA isomers, we found a positive association for trans 18:1 n-9 (elaidic acid; 1.33 [1.05, 1.68]) but not for other isomers. Conclusions: We observed significant positive associations for RBC TFA levels with DLBCL risk. These findings are consistent with published studies of self-reported TFA intake; further, previous studies have shown that TFA levels – particularly trans 18:1n-9, which is industrially-derived – are positively correlated with biomarkers of inflammation and immune activation, supporting the biologic plausibility of our findings. Food industry and public health measures to diminish TFA intake may help to reduce risk of NHL, and particularly of DLBCL.

Adipose tissue palmitoleic acid is inversely associated with nonfatal acute myocardial infarction in Costa Rican adults

BACKGROUND AND AIMS

Animal models have shown that adipose-derived palmitoleic acid may act as a lipokine by conferring resistance to diet-induced obesity; however, human epidemiologic studies investigating this relationship thus far have not provided data in support of this hypothesis. Because metabolic syndrome and cardiovascular disease are intricately linked with the former being a major risk factor for the latter, we hypothesized that adipose-derived palmitoleic acid may be inversely associated with myocardial infarction. We examined whether adipose tissue palmitoleic acid was associated with nonfatal acute myocardial infarction in a representative population of Costa Rican adults.

METHODS AND RESULTS

Odds ratios of nonfatal acute myocardial infarction by quintiles of adipose tissue palmitoleic acid were calculated using conditional logistic regression in a case-control study of 1828 cases and 1828 controls matched by age, sex, and area of residence. We observed an inverse relationship between nonfatal acute myocardial infarction and adipose tissue palmitoleic acid (OR for highest quintile compared to lowest quintile of palmitoleic acid: 0.55; 95% CI: 0.41, 0.75; P for trend: <0.0001). We additionally observed a significant positive association between adipose tissue palmitoleic acid and high-density lipoprotein cholesterol.

CONCLUSION

These data demonstrate an inverse association between adipose tissue palmitoleic acid and nonfatal acute myocardial infarction; however, further research is required in order to better understand the opposing associations between palmitoleic acid and high-density lipoprotein cholesterol and systolic blood pressure.

A prospective analysis of circulating saturated and monounsaturated fatty acids and risk of non-Hodgkin lymphoma

Circulating saturated (SFA) and monounsaturated fatty acids (MUFA), which are predominantly derived from endogenous metabolism, may influence non-Hodgkin lymphoma (NHL) risk by modulating inflammation or lymphocyte membrane stability. However, few biomarker studies have evaluated NHL risk associated with these fats. We conducted a prospective study of 583 incident NHL cases and 583 individually matched controls with archived pre-diagnosis red blood cell (RBC) specimens in the Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS). RBC membrane fatty acid levels were measured using gas chromatography. Using multivariable logistic regression, we estimated odds ratios (OR) and 95% confidence intervals (CI) for risk of NHL and major NHL subtypes including T cell NHL (T-NHL), B cell NHL (B-NHL) and three individual B-NHLs: chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma. RBC SFA and MUFA levels were not associated with NHL risk overall. However, RBC very long chain SFA levels (VLCSFA; 20:0, 22:0, 23:0) were inversely associated with B-NHLs other than CLL/SLL; ORs (95% CIs) per standard deviation (SD) increase in level were 0.81 (0.70, 0.95) for 20:0, 0.82 (0.70, 0.95) for 22:0 and 0.82 (0.70, 0.96) for 23:0 VLCSFA. Also, both VLCSFA and MUFA levels were inversely associated with T-NHL [ORs (95% CIs) per SD: VLCSFA, 0.63 (0.40, 0.99); MUFA, 0.63 (0.40, 0.99)]. The findings of inverse associations for VLCSFAs with B-NHLs other than CLL/SLL and for VLCSFA and MUFA with T-NHL suggest an influence of fatty acid metabolism on lymphomagenesis.

Snail knockdown reverses stemness and inhibits tumour growth in ovarian cancer

To develop effective therapies for advanced high grade serous ovarian cancer (HGSOC), understanding mechanisms of recurrence and metastasis is necessary. In this study, we define the epithelial/mesenchymal status of cell lines that accurately model HGSOC, and evaluate the therapeutic potential of targeting Snai1 (Snail), a master regulator of the epithelial/mesenchymal transition (EMT) in vitro and in vivo. The ratio of Snail to E-cadherin (S/E index) at RNA and protein levels was correlated with mesenchymal morphology in four cell lines. The cell lines with high S/E index (OVCAR8 and COV318) showed more CSC-like, motile, and chemoresistant phenotypes than those with low S/E index (OVSAHO and Kuramochi). We tested the role of Snail in regulation of malignant phenotypes including stemness, cell motility, and chemotherapy resistance: shRNA-mediated knockdown of Snail reversed these malignant phenotypes. Interestingly, the expression of let-7 tumour suppressor miRNA was upregulated in Snail knockdown cells. Furthermore, knockdown of Snail decreased tumour burden in an orthotopic xenograft mouse model. We conclude that Snail is important in controlling HGSOC malignant phenotypes and suggest that the Snail/Let-7 axis may be an attractive target for HGSOC treatment.

Fried food intake and risk of nonfatal acute myocardial infarction in the Costa Rica Heart Study

Economic development in middle-income countries has led to a noticeable rise in the availability of commercial deep fried foods and lifestyles that require eating meals “on the go” and outside of the home. Yet, data from these countries where fried foods were traditionally prepared at home are scarce, despite several studies showing the potential adverse effects of fried food consumption on risk for heart disease. We aimed to examine whether consumption of fried foods inside or outside of the home is associated with an increased risk of myocardial infarction (MI) among Hispanic/Latinos living in Costa Rica. Participants were incident cases of a first acute MI (n = 2,154) and randomly selected controls matched for age, sex, and residence (n = 2,154). After adjustment for traditional cardiovascular risk factors, including history of diabetes, history of hypertension, smoking, abdominal obesity, income, educational years, occupation, alcohol intake, dietary intakes of saturated fatty acid, fiber intake, and total energy intake, the multivariable-adjusted odds ratio (OR, 95% CI) for risk of MI were 1.00 (reference), 1.02 (0.86–1.21), 1.26 (0.81–1.95), and 1.58 (1.08–2.30) for intake of fried foods outside of the home <1/week, 1-3/week, 4-6/week, and 1/day, respectively (P trend = 0.02); and 1.00, 0.81 (0.65–1.00), 0.81 (0.61–1.09), and 0.93 (0.72–1.19), respectively (P for trend = 0.65) for intake of fried foods inside the home. The data suggest that consumption of fried foods outside of the home, a practice that has been associated with economic development, could have adverse effects on cardiovascular disease.

Erythrocyte membrane fatty acids and breast cancer risk: a prospective analysis in the nurses' health study II

The roles of specific fatty acids in breast cancer etiology are unclear, particularly among premenopausal women. We examined 34 individual fatty acids, measured in blood erythrocytes collected between 1996 and 1999, and breast cancer risk in a nested case-control study of primarily premenopausal women in the Nurses' Health Study II. Breast cancer cases diagnosed after blood collection and before June 2010 (n = 794) were matched to controls and conditional logistic regression was used to estimate OR's (95% CI's) for associations of fatty acids with breast cancer; unconditional logistic regression was used for stratified analyses. Fatty acids were not significantly associated with breast cancer risk overall; however, heterogeneity by body mass index (BMI) was observed. Among overweight/obese women (BMI ≥ 25), several odd-chain saturated (SFA, e.g. 17:0, OR_Q4vsQ1 (95% CI) =1.85 (1.18-2.88), p_trend =0.006 p_int <0.001), trans (TFA, e.g. 18:1, OR_Q4vsQ1 (95% CI) =2.33 (1.45-3.77), p_trend <0.001, p_int =0.007) and dairy-derived fatty acids (SFA 15:0 + 17:0 + TFA 16:1n-7t; OR_Q4vsQ1 (95% CI) =1.83(1.16-2.89), p_trend =0.005, p_int <0.001) were positively associated, and n-3 polyunsaturated fatty acids (n-3 PUFA, e.g. alpha-linolenic acid; OR_Q4vsQ1 (95% CI) =0.57 (0.36-0.89), p_trend =0.017, p_int =0.03) were inversely associated with breast cancer. Total SFA were inversely associated with breast cancer among women with BMI < 25 (OR_Q4vsQ1 (95% CI) =0.68 (0.46-0.98), p_trend =0.05, p_int =0.01). Thus, while specific fatty acids were not associated with breast cancer overall, our findings suggest positive associations of several SFA, TFA and dairy-derived fatty acids and inverse associations of n-3 PUFA with breast cancer among overweight/obese women. Given these fatty acids are influenced by diet, and therefore are potentially modifiable, further investigation of these associations among overweight/obese women is warranted.

Habitual coffee consumption and genetic predisposition to obesity: gene-diet interaction analyses in three US prospective studies

BACKGROUND

Whether habitual coffee consumption interacts with the genetic predisposition to obesity in relation to body mass index (BMI) and obesity is unknown.

METHODS

We analyzed the interactions between genetic predisposition and habitual coffee consumption in relation to BMI and obesity risk in 5116 men from the Health Professionals Follow-up Study (HPFS), in 9841 women from the Nurses' Health Study (NHS), and in 5648 women from the Women's Health Initiative (WHI). The genetic risk score was calculated based on 77 BMI-associated loci. Coffee consumption was examined prospectively in relation to BMI.

RESULTS

The genetic association with BMI was attenuated among participants with higher consumption of coffee than among those with lower consumption in the HPFS (P _interaction  = 0.023) and NHS (P _interaction  = 0.039); similar results were replicated in the WHI (P _interaction  = 0.044). In the combined data of all cohorts, differences in BMI per increment of 10-risk allele were 1.38 (standard error (SE), 0.28), 1.02 (SE, 0.10), and 0.95 (SE, 0.12) kg/m² for coffee consumption of < 1, 1-3 and > 3 cup(s)/day, respectively (P _interaction  < 0.001). Such interaction was partly due to slightly higher BMI with higher coffee consumption among participants at lower genetic risk and slightly lower BMI with higher coffee consumption among those at higher genetic risk. Each increment of 10-risk allele was associated with 78% (95% confidence interval (CI), 59-99%), 48% (95% CI, 36-62%), and 43% (95% CI, 28-59%) increased risk for obesity across these subgroups of coffee consumption (P _interaction  = 0.008). From another perspective, differences in BMI per increment of 1 cup/day coffee consumption were 0.02 (SE, 0.09), -0.02 (SE, 0.04), and -0.14 (SE, 0.04) kg/m² across tertiles of the genetic risk score.

CONCLUSIONS

Higher coffee consumption might attenuate the genetic associations with BMI and obesity risk, and individuals with greater genetic predisposition to obesity appeared to have lower BMI associated with higher coffee consumption.

PCSK9 variant, long-chain n-3 PUFAs, and risk of nonfatal myocardial infarction in Costa Rican Hispanics

Background: Previous studies have indicated that the cardioprotective effects of long-chain (LC) n-3 (ω-3) polyunsaturated fatty acids (PUFAs) may vary across various ethnic populations. Emerging evidence has suggested that the gene-environment interaction may partly explain such variations. Proprotein convertase subtilisin/kexin type 9 (PCSK9) was shown to have a mutually regulating relation with LC n-3 PUFAs and also to reduce the risk of cardiovascular diseases (CVDs). Therefore, we hypothesized that certain PCSK9 genetic variants may modify the association between LC n-3 PUFA intake and CVD risk.Objective: We determined whether a PCSK9 variant (rs11206510), which has been identified for early onset myocardial infarction (MI), modified the association of LC n-3 PUFAs with nonfatal MI risk in Costa Rican Hispanics.Design: We analyzed cross-sectional data from 1932 case subjects with a first nonfatal MI and 2055 population-based control subjects who were living in Costa Rica to examine potential gene-environment interactions. Two-sided P values <0.05 were considered significant.Results: We observed a significant interaction between the PCSK9 rs11206510 genotype and LC n-3 PUFA intake on nonfatal MI risk (P-interaction = 0.012). The OR of nonfatal MI was 0.84 (95% CI: 0.72, 0.98) per 0.1% increase in total energy intake from LC n-3 PUFAs in protective-allele (C-allele) carriers, whereas the corresponding OR (95% CI) in non-C-allele carriers was 1.02 (95% CI: 0.95, 1.10). Similar results were observed when we examined the association between docosahexaenoic acid, which is one type of LC n-3 PUFA, and nonfatal MI risk (P-interaction = 0.003).Conclusion: LC n-3 PUFA intake is associated with a lower risk of nonfatal MI in C-allele carriers of PCSK9 rs11206510 (n = 799) but not in non-C-allele carriers (n = 3188).

Challenges and opportunities in establishing a collaborative multisite observational study of chronic diseases and lifestyle factors among adults in Puerto Rico

Background

Prevalence of chronic diseases and unhealthy lifestyle behaviors among the adult population of Puerto Rico (PR) is high; however, few epidemiological studies have been conducted to address these. We aimed to document the methods and operation of establishing a multisite cross-sectional study of chronic diseases and risk factors in PR, in partnership with academic, community, clinical, and research institutions.

Methods

The Puerto Rico Assessment of Diet, Lifestyle and Diseases (PRADLAD) documented lifestyle and health characteristics of adults living in PR, with the goal of informing future epidemiological and intervention projects, as well as public health, policy, and clinical efforts to help improve the population’s health. The study was conducted in three primary care clinics in the San Juan, PR metropolitan area. Eligible volunteers were 30–75y, living in PR for at least 10 months of the previous year, and able to answer interviewer-administered questionnaires without assistance. Questions were recorded electronically by trained interviewers, and included socio-demographic characteristics, lifestyle behaviors, self-reported medically-diagnosed diseases, and psychosocial factors. Waist and hip circumferences were measured following standardized protocols. A subset of participants answered a validated food frequency questionnaire, a legumes questionnaire, and had medical record data abstracted. Process and outcome evaluation indicators were assessed.

Results

The study screened 403 participants in 5 months. Of these, 396 (98%) were eligible and 380 (94%) had reliable and complete information. A subset of 242 participants had valid dietary data, and 236 had medical record data. The mean time to complete an interview was 1.5 h. Participants were generally cooperative and research collaborators were fully engaged. Having multiple sites helped enhance recruitment and sociodemographic representation. Diagnosed conditions were prevalent across sites. Challenges in data monitoring, interviewer training, and scheduling were identified and corrected, and should be addressed in future studies.

Conclusions

Epidemiological studies in PR can be successfully implemented in partnership with multiple institutions. Effective recruitment and implementation requires concerted planning and continued involvement from partners, frequent quality control, brief interviews, reasonable incentives, and thorough training/re-training of culturally-sensitive interviewers. Further studies are feasible and needed to help address highly prevalent chronic conditions in PR.

Lifestyle Cardiovascular Risk Score, Genetic Risk Score, and Myocardial Infarction in Hispanic/Latino Adults Living in Costa Rica

Background

A lifestyle cardiovascular risk score (LCRS) and a genetic risk score (GRS) have been independently associated with myocardial infarction (MI) in Hispanics/Latinos. Interaction or joint association between these scores has not been examined. Thus, our aim was to assess interactive and joint associations between LCRS and GRS, and each individual lifestyle risk factor, on likelihood of MI.

Methods and Results

Data included 1534 Costa Rican adults with nonfatal acute MI and 1534 matched controls. The LCRS used estimated coefficients as weights for each factor: unhealthy diet, physical inactivity, smoking, elevated waist:hip ratio, low/high alcohol intake, low socioeconomic status. The GRS included 14 MI‐associated risk alleles. Conditional logistic regressions were used to calculate adjusted odds ratios. The odds ratios for MI were 2.72 (2.33, 3.17) per LCRS unit and 1.13 (95% CI 1.06, 1.21) per GRS unit. A significant joint association for highest GRS tertile and highest LCRS tertile and odds of MI was detected (odds ratio=5.43 [3.71, 7.94]; P<1.00×10⁻⁷), compared to both lowest tertiles. The odds ratios were 1.74 (1.22, 2.49) under optimal lifestyle and unfavorable genetic profile, and 5.02 (3.46, 7.29) under unhealthy lifestyle but advantageous genetic profile. Significant joint associations were observed for the highest GRS tertile and the highest of each lifestyle component risk category. The interaction term was nonsignificant (P=0.33).

Conclusions

Lifestyle risk factors and genetics are jointly associated with higher odds of MI among Hispanics/Latinos. Individual and combined lifestyle risk factors showed stronger associations. Efforts to improve lifestyle behaviors could help prevent MI regardless of genetic susceptibility.

ω-3 Polyunsaturated Fatty Acid Biomarkers and Coronary Heart Disease: Pooling Project of 19 Cohort Studies

IMPORTANCE

The role of ω-3 polyunsaturated fatty acids for primary prevention of coronary heart disease (CHD) remains controversial. Most prior longitudinal studies evaluated self-reported consumption rather than biomarkers.

OBJECTIVE

To evaluate biomarkers of seafood-derived eicosapentaenoic acid (EPA; 20:5ω-3), docosapentaenoic acid (DPA; 22:5ω-3), and docosahexaenoic acid (DHA; 22:6ω-3) and plant-derived α-linolenic acid (ALA; 18:3ω-3) for incident CHD.

DATA SOURCES

A global consortium of 19 studies identified by November 2014.

STUDY SELECTION

Available prospective (cohort, nested case-control) or retrospective studies with circulating or tissue ω-3 biomarkers and ascertained CHD.

DATA EXTRACTION AND SYNTHESIS

Each study conducted standardized, individual-level analysis using harmonized models, exposures, outcomes, and covariates. Findings were centrally pooled using random-effects meta-analysis. Heterogeneity was examined by age, sex, race, diabetes, statins, aspirin, ω-6 levels, and FADS desaturase genes.

MAIN OUTCOMES AND MEASURES

Incident total CHD, fatal CHD, and nonfatal myocardial infarction (MI).

RESULTS

The 19 studies comprised 16 countries, 45 637 unique individuals, and 7973 total CHD, 2781 fatal CHD, and 7157 nonfatal MI events, with ω-3 measures in total plasma, phospholipids, cholesterol esters, and adipose tissue. Median age at baseline was 59 years (range, 18-97 years), and 28 660 (62.8%) were male. In continuous (per 1-SD increase) multivariable-adjusted analyses, the ω-3 biomarkers ALA, DPA, and DHA were associated with a lower risk of fatal CHD, with relative risks (RRs) of 0.91 (95% CI, 0.84-0.98) for ALA, 0.90 (95% CI, 0.85-0.96) for DPA, and 0.90 (95% CI, 0.84-0.96) for DHA. Although DPA was associated with a lower risk of total CHD (RR, 0.94; 95% CI, 0.90-0.99), ALA (RR, 1.00; 95% CI, 0.95-1.05), EPA (RR, 0.94; 95% CI, 0.87-1.02), and DHA (RR, 0.95; 95% CI, 0.91-1.00) were not. Significant associations with nonfatal MI were not evident. Associations appeared generally stronger in phospholipids and total plasma. Restricted cubic splines did not identify evidence of nonlinearity in dose responses.

CONCLUSIONS AND RELEVANCE

On the basis of available studies of free-living populations globally, biomarker concentrations of seafood and plant-derived ω-3 fatty acids are associated with a modestly lower incidence of fatal CHD.

Seasoning ingredient variety, but not quality, is associated with greater intake of beans and rice among urban Costa Rican adults

Exposure to a variety of flavors may promote food enjoyment, but few studies have examined the relationship between food seasoning and food intake. We hypothesized that using a higher variety (number) of 11 seasonings to prepare 2 staple foods (beans, white rice) would be associated with intake of those foods in a population-based case-control study of Costa Rican adults in urban vs rural areas (n=1025), where cooking and dietary practices differ. Participants were surveyed about the variety of seasoning ingredients added when preparing beans or rice. Ingredients were also categorized by their dietary quality (healthfulness), and scores for seasoning variety and quality were created. Multivariable linear regression was used to determine the association between variety and quality scores (continuously and in tertiles (T)) and intake of each staple food. Seasoning variety was positively associated with daily servings of beans (β=.02, P=.01; 1.31 and 1.23 servings/day in T2 and T3 versus 1.02 servings/day in T1, P<.05) and rice (β=.04, P=.005) in the urban areas only. No differences in ingredient quality across increasing intakes of beans or rice were noted, and the joint associations between variety and quality were not significant. In conclusion, a greater variety, but not quality, of seasoning ingredients was positively associated with intakes of beans and rice in urban Costa Rican adults. Our results suggest that increasing the variety of seasonings added to beans may be a culturally-appropriate strategy to improve intake of this healthy staple food among urban Costa Rican adults.

Sugar-sweetened beverage intake, chromosome 9p21 variants, and risk of myocardial infarction in Hispanics

BACKGROUND

Chromosome 9p21 variants are among the most robust genetic markers for coronary artery disease (CAD), and previous studies have suggested that genetic effects of this locus might be modified by dietary factors. Intake of sugar-sweetened beverages (SSBs), which are the main dietary source of added sugar, has been shown to interact with genetic factors in affecting CAD risk factors such as obesity.

OBJECTIVE

We aimed to test whether SSB intake modified the association between chromosome 9p21 variants and CAD risk in Hispanics living in Costa Rica.

DESIGN

The current study included 1560 incident cases of nonfatal myocardial infarction (MI) and 1751 population-based controls. Three independent single nucleotide polymorphisms (SNPs) at the chromosome 9p21 locus were genotyped. SSB intake was assessed with the use of a food-frequency questionnaire and was defined as the frequency of intake of daily servings of sweetened beverages and fruit juice.

RESULTS

We showed a significant interaction between SSB intake and one of the 3 variants (i.e., rs4977574) on MI risk. The per–risk allele OR (95% CI) of rs4977574 for MI was 1.44 (1.19, 1.74) in participants with higher SSB consumption (>2 servings/d), 1.21 (1.00, 1.47) in those with average consumption (1–2 servings/d), and 0.97 (0.81, 1.16) in subjects with lower consumption (<1 serving/d; P-interaction = 0.005). A genetic risk score derived from the sum of risk alleles of the 3 SNPs also showed a significant interaction with SSB intake on MI risk (P-interaction = 0.03).

CONCLUSION

Our data suggest that unhealthy dietary habits such as higher intake of SSBs could exacerbate the effects of chromosome 9p21 variants on CAD.

Circulating Biomarkers of Dairy Fat and Risk of Incident Diabetes Mellitus Among Men and Women in the United States in Two Large Prospective Cohorts

BACKGROUND

In prospective studies, the relationship of self-reported consumption of dairy foods with risk of diabetes mellitus is inconsistent. Few studies have assessed dairy fat, using circulating biomarkers, and incident diabetes mellitus. We tested the hypothesis that circulating fatty acid biomarkers of dairy fat, 15:0, 17:0, and t-16:1n-7, are associated with lower incident diabetes mellitus.

METHODS AND RESULTS

Among 3333 adults aged 30 to 75 years and free of prevalent diabetes mellitus at baseline, total plasma and erythrocyte fatty acids were measured in blood collected in 1989 to 1990 (Nurses' Health Study) and 1993 to 1994 (Health Professionals Follow-Up Study). Incident diabetes mellitus through 2010 was confirmed by a validated supplementary questionnaire based on symptoms, diagnostic tests, and medications. Risk was assessed by using Cox proportional hazards, with cohort findings combined by meta-analysis. During mean±standard deviation follow-up of 15.2±5.6 years, 277 new cases of diabetes mellitus were diagnosed. In pooled multivariate analyses adjusting for demographics, metabolic risk factors, lifestyle, diet, and other circulating fatty acids, individuals with higher plasma 15:0 had a 44% lower risk of diabetes mellitus (quartiles 4 versus 1, hazard ratio, 0.56; 95% confidence interval, 0.37-0.86; P-trend=0.01); higher plasma 17:0, 43% lower risk (hazard ratio, 0.57; 95% confidence interval, 0.39-0.83; P-trend=0.01); and higher t-16:1n-7, 52% lower risk (hazard ratio, 0.48; 95% confidence interval, 0.33-0.70; P-trend <0.001). Findings were similar for erythrocyte 15:0, 17:0, and t-16:1n-7, although with broader confidence intervals that only achieved statistical significance for 17:0.

CONCLUSIONS

In 2 prospective cohorts, higher plasma dairy fatty acid concentrations were associated with lower incident diabetes mellitus. Results were similar for erythrocyte 17:0. Our findings highlight the need to better understand the potential health effects of dairy fat, and the dietary and metabolic determinants of these fatty acids.

High Fiber and Low Starch Intakes Are Associated with Circulating Intermediate Biomarkers of Type 2 Diabetes among Women

BACKGROUND

Carbohydrate quality has been consistently related to the risk of type 2 diabetes (T2D). However, limited information is available about the effect of carbohydrate quality on biomarkers related to T2D.

OBJECTIVE

We examined the associations of carbohydrate quality measures (CQMs) including carbohydrate intake; starch intake; glycemic index; glycemic load; total, cereal, fruit, and vegetable fiber intakes; and different combinations of these nutrients with plasma concentrations of adiponectin, C-reactive protein (CRP), and glycated hemoglobin (HbA1c).

METHODS

This is a cross-sectional analysis of 2458 diabetes-free women, ages 43-70 y, in the Nurses Health Study. CQMs were estimated from food-frequency questionnaires, and averages from 1984, 1986, and 1990 were used. Plasma biomarkers were collected in 1990. Multiple linear regression models were used to assess the associations between CQMs and biomarkers.

RESULTS

After age, body mass index, lifestyle, and dietary variables were adjusted, 1) total fiber intake was positively associated with adiponectin (P-trend = 0.004); 2) cereal fiber intake was positively associated with adiponectin and inversely associated with CRP, and fruit fiber intake was negatively associated with HbA1c concentrations (all P-trend < 0.03); 3) starch intake was inversely associated with adiponectin (P-trend = 0.02); 4) a higher glycemic index was associated with lower adiponectin and higher HbA1c (both P-trend < 0.05); 5) a higher carbohydrate-to-total fiber intake ratio was associated with lower adiponectin (P-trend = 0.005); 6) a higher starch-to-total fiber intake ratio was associated with lower adiponectin and higher HbA1c (both P-trend < 0.05); and 7) a higher starch-to-cereal fiber intake ratio was associated with lower adiponectin (P-trend = 0.002).

CONCLUSIONS

A greater fiber intake and a lower starch-to-fiber intake ratio are favorably associated with adiponectin and HbA1c, but only cereal fiber intake was associated with CRP in women. Further research is warranted to understand the potential mechanism of these associations in early progression of T2D.

Carbohydrate quality and quantity and risk of type 2 diabetes in US women

BACKGROUND

Carbohydrate quality may be an important determinant of type 2 diabetes (T2D); however, relations between various carbohydrate quality metrics and T2D risk have not been systematically investigated.

OBJECTIVE

The purpose of this study was to prospectively examine the association between carbohydrates, starch, fibers, and different combinations of these nutrients and risk of T2D in women.

DESIGN

We prospectively followed 70,025 women free of cardiovascular disease, cancer, and diabetes at baseline from the Nurses' Health Study (1984-2008). Diet information was collected with the use of a validated questionnaire every 4 y. Cox regression was used to evaluate associations with incident T2D.

RESULTS

During 1,484,213 person-years of follow-up, we ascertained 6934 incident T2D cases. In multivariable analyses, when extreme quintiles were compared, higher carbohydrate intake was not associated with T2D (RR = 0.98; 95% CI: 0.89, 1.08; P-trend = 0.84), whereas starch was associated with a higher risk (RR = 1.23; 95% CI: 1.12, 1.35; P-trend <0.0001). Total fiber (RR = 0.80; 95% CI: 0.72, 0.89; P-trend < 0.0001), cereal fiber (RR = 0.71, 95% CI: 0.65, 0.78; P-trend < 0.0001), and fruit fiber (RR = 0.79; 95% CI: 0.72, 0.85; P-trend < 0.0001) were associated with a lower T2D risk. The ratio of carbohydrate to total fiber intake was marginally associated with a higher risk of T2D (RR = 1.09; 95% CI: 1.00, 1.20; P-trend = 0.04). On the other hand, we found positive associations between the ratios of carbohydrate to cereal fiber (RR = 1.28; 95% CI: 1.17, 1.39; P-trend < 0.0001), starch to total fiber (RR = 1.12; 95% CI: 1.02, 1.23; P-trend = 0.03), and starch to cereal fiber (RR = 1.39; 95% CI: 1.27, 1.53; P-trend < 0.0001) and T2D.

CONCLUSIONS

Diets with high starch, low fiber, and a high starch-to-cereal fiber ratio were associated with a higher risk of T2D. The starch-to-cereal fiber ratio of the diet may be a novel metric for assessing carbohydrate quality in relation to T2D.

Diet, interleukin-17, and childhood asthma in Puerto Ricans

BACKGROUND

Dietary patterns might influence the pathogenesis of asthma in Puerto Ricans, the ethnic group most affected by this disease in the United States.

OBJECTIVE

To examine the association among diet, T-helper cell type 17 cytokines, and asthma in Puerto Rican children.

METHODS

As part of a case-control study of 678 Puerto Rican children 6 to 14 years old in San Juan, participants completed a 75-item questionnaire on the child's food consumption in the prior week. Foods were aggregated into 7 groups: fruits, vegetables, grains, protein foods, dairy, fats, and sweets. Logistic regression was used to evaluate consumption frequency of each group, plasma T-helper cell type 17 cytokine levels, and asthma. Based on this analysis, a food score (range -2 [unhealthy diet: high consumption of dairy products and sweets, low consumption of vegetables and grains] to +2 [healthy diet: high consumption of grains and vegetables, low consumption of dairy and sweets]) was created to identify dietary patterns.

RESULTS

High consumption of grains was associated with lower odds of asthma (adjusted odds ratio [aOR] 0.52, 95% confidence interval [CI] 0.33-0.82), whereas frequent consumption of dairy products (aOR 1.93, 95% CI 1.32-2.84) or sweets (aOR 1.82, 95% CI 1.08-2.72) was associated with higher odds of asthma. A healthier diet (each 1-point increment in food score) was associated with lower levels of interleukin-17F (β = -1.48 pg/mL, 95% CI -1.78 to -1.20) and with 36% decreased odds of asthma (aOR 0.64, 95% CI 0.53-0.77).

CONCLUSION

A healthy diet, with frequent consumption of vegetables and grains and low consumption of dairy products and sweets, was associated with lower levels of interleulin-17F and decreased odds of childhood asthma in Puerto Ricans.

Abstract 1872: Plasma carotenoids and breast cancer risk in the Cancer Prevention Study II Nutrition Cohort

Background: Several plasma carotenoids have been inversely associated with postmenopausal breast cancer risk in large cohort studies and a pooled analysis. Whether associations differ by tumor or participant characteristics is unclear. We investigated the associations of plasma carotenoids with postmenopausal breast cancer risk overall and by estrogen receptor (ER) status, tumor stage, smoking status and body mass index in a case-control study nested in the Cancer Prevention Study II Nutrition Cohort.

Methods: A total of 561 breast cancer cases diagnosed between blood draw in 1998-2001 and June 30, 2007 and matched 1:1 with controls on race, birth date and blood draw date were included. Multivariable-adjusted conditional and unconditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

Results: Plasma α-carotene was inversely associated with breast cancer risk even after adjustment for total fruit and vegetable intake (4th vs. 1st quartile OR = 0.58, 95% CI: 0.40, 0.85, P-trend = 0.03). This inverse association was stronger among ever smokers (P-interaction&lt;0.05), and obese women (P-interaction = 0.02), but did not differ by tumor stage (P-heterogeneity = 0.61). Although there was an inverse trend between α-carotene and ER+ (P-trend = 0.01) but not ER- breast cancer (P-trend = 0.99), the test for heterogeneity by ER status was not statistically significant (P-heterogeneity = 0.28). There was some evidence of an inverse association with total carotenoids but this association was nonlinear.

Conclusions: These results suggest that higher plasma α-carotene is associated with lower risk of breast cancer, and this association was even stronger in smokers and obese women.

Citation Format: Ying Wang, Susan M. Gapstur, Mia M. Gaudet, Jeremy D. Furtado, Hannia Campos, Marjorie L. McCullough. Plasma carotenoids and breast cancer risk in the Cancer Prevention Study II Nutrition Cohort. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1872. doi:10.1158/1538-7445.AM2015-1872

Abstract 1871: Circulating cis- and trans- palmitoleic acid in relation to prostate cancer-specific mortality among prostate cancer patients

Background: Palmitoleic acid (16:1n-7c), a lipokine, and its trans isomer (16:1n-7t), a fatty acid found in foods of ruminant origin, have been associated with metabolic regulation and insulin sensitivity, which have in turn been related to prostate cancer progression and survivorship.

Objective: To investigate whether circulating cis- and trans-palmitoleate, measured before and after prostate cancer diagnosis, are related to prostate cancer-specific mortality among men diagnosed with non-metastatic prostate cancer.

Methods: We employed a prospective study using pre-diagnostic whole blood samples collected in 1982 in 518 men who were later diagnosed with prostate cancer and followed for mortality. Proportional hazards regression was used to estimate relative risk (RR) and 95% confidence interval (CI) of prostate cancer-specific mortality across quartiles of pre-diagnostic palmitoleate concentrations. The multivariable model was adjusted for age at diagnosis, BMI, smoking status, clinical characteristics and time interval between blood drawn and prostate cancer diagnosis. Using a nested case-control design, we also assayed 148 post-diagnostic red blood cell samples collected in 1997 among 74 patients who subsequently died of the disease and 74 survivors, matched with age at diagnosis and risk scores. Conditional logistic regression was used to estimate the RR (95%CI) of prostate cancer-specific mortality across tertiles of post-diagnostic palmitoleate levels after adjusting for BMI and smoking status. trans- and cis-palmitoleic acid concentrations were measured by gas chromatography.

Results: Pre-diagnostic whole blood trans-palmitoleic acid and post-diagnostic red blood cell trans-palmitoleic acid levels were associated with lower prostate cancer-specific mortality. The adjusted RR (95%CI) of prostate cancer-specific mortality comparing top to bottom quartiles of pre-diagnostic 16:1n-7t was 0.35 (0.16-0.79; p-trend = 0.03). The adjusted RR (95%CI) comparing top to bottom tertiles of post-diagnostic 16:1n-7t levels was 0.26 (0.08-0.84; p-trend = 0.02). In contrast, cis-palmitoleic acid levels measured before and after prostate cancer diagnosis were unrelated to disease-specific mortality. The pre-diagnostic cis-isomer, however, was significantly correlated with a lower level of adiponectin and higher levels of C-peptide, insulin-like growth factor binding protein 3, and pro-insulin.

Conclusions: Pre- and post- diagnostic circulating trans-palmitoleic acid, but not cis-palmitoleic acid, was associated with lower prostate cancer-specific mortality among prostate cancer patients.

Citation Format: Meng Yang, Stacey A. Kenfield, Hannia Campos, Howard D. Sesso, Jing Ma, Meir J. Stampfer, Jorge E. Chavarro. Circulating cis- and trans- palmitoleic acid in relation to prostate cancer-specific mortality among prostate cancer patients. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1871. doi:10.1158/1538-7445.AM2015-1871

Circulating Very-Long-Chain Saturated Fatty Acids and Incident Coronary Heart Disease in US Men and Women

BACKGROUND

Circulating very-long-chain saturated fatty acids (VLCSFAs) may play an active role in the origin of cardiometabolic diseases.

METHODS AND RESULTS

We measured 3 VLCSFAs (C20:0, C22:0, and C24:0) in plasma and erythrocytes using gas-liquid chromatography among 794 incident coronary heart disease (CHD) cases who were prospectively identified and confirmed among women in the Nurses' Health Study (NHS; 1990-2006) and among men in the Health Professionals Follow-Up Study (HPFS; 1994-2008). A total of 1233 CHD-free controls were randomly selected and matched to cases in these 2 cohorts. Conditional logistic regression was used to estimate hazard ratios and 95% confidence intervals. Plasma VLCSFAs were correlated with favorable profiles of blood lipids, C-reactive protein, and adiponectin in the NHS and HPFS and with fasting insulin and C-peptide levels in a nationally representative US comparison population. After multivariate adjustment for lifestyle factors, body mass index, diet, and long-chain n-3 and trans fatty acids, total VLCSFAs in plasma were associated with a 52% decreased risk of CHD (pooled hazard ratio, 0.48; 95% confidence interval, 0.32-0.72, comparing extreme quintiles; Ptrend<0.0001). For VLCSFAs in erythrocytes, a nonsignificant inverse trend with CHD risk was observed (pooled hazard ratio, 0.66; 95% confidence interval, 0.41-1.06, comparing extreme quintiles; Ptrend=0.16).

CONCLUSIONS

In US men and women, plasma VLCSFAs were independently associated with favorable profiles of blood lipids and other cardiovascular disease risk markers and a lower risk of CHD. Erythrocyte VLCSFAs were associated with nonsignificant trends of lower CHD risk. Future studies are warranted to elucidate the underlying biological mechanisms.

Reducing the global burden of type 2 diabetes by improving the quality of staple foods: The Global Nutrition and Epidemiologic Transition Initiative

BACKGROUND

The prevalence of type 2 diabetes has been reaching epidemic proportions across the globe, affecting low/middle-income and developed countries. Two main contributors to this burden are the reduction in mortality from infectious conditions and concomitant negative changes in lifestyles, including diet. We aimed to depict the current state of type 2 diabetes worldwide in light of the undergoing epidemiologic and nutrition transition, and to posit that a key factor in the nutrition transition has been the shift in the type and processing of staple foods, from less processed traditional foods to highly refined and processed carbohydrate sources.

DISCUSSION

We showed data from 11 countries participating in the Global Nutrition and Epidemiologic Transition Initiative, a collaborative effort across countries at various stages of the nutrition-epidemiologic transition whose mission is to reduce diabetes by improving the quality of staple foods through culturally-appropriate interventions. We depicted the epidemiologic transition using demographic and mortality data from the World Health Organization, and the nutrition transition using data from the Food and Agriculture Organization food balance sheets. Main staple foods (maize, rice, wheat, pulses, and roots) differed by country, with most countries undergoing a shift in principal contributors to energy consumption from grains in the past 50 years. Notably, rice and wheat products accounted for over half of the contribution to energy consumption from staple grains, while the trends for contribution from roots and pulses generally decreased in most countries. Global Nutrition and Epidemiologic Transition Initiative countries with pilot data have documented key barriers and motivators to increase intake of high-quality staple foods. Global research efforts to identify and promote intake of culturally-acceptable high-quality staple foods could be crucial in preventing diabetes. These efforts may be valuable in shaping future research, community interventions, and public health and nutritional policies.

Study design and methods for a randomized crossover trial substituting brown rice for white rice on diabetes risk factors in India

India has the second largest number of people with diabetes in the world following China. Evidence indicates that consumption of whole grains can reduce the risk of type 2 diabetes. This article describes the study design and methods of a trial in progress evaluating the effects of substituting whole grain brown rice for polished (refined) white rice on biomarkers of diabetes risk (glucose metabolism, dyslipidemia, inflammation). This is a randomized controlled clinical trial with a crossover design conducted in Chennai, India among overweight but otherwise healthy volunteers aged 25-65 y with a body mass index ≥23 kg/m(2) and habitual rice consumption ≥200 g/day. The feasibility and cultural appropriateness of this type of intervention in the local environment will also be examined. If the intervention is efficacious, the findings can be incorporated into national-level policies which could include the provision of brown rice as an option or replacement for white rice in government institutions and food programs. This relatively simple dietary intervention has the potential to substantially diminish the burden of diabetes in Asia and elsewhere.

Serum tocopherol levels and vitamin E intake are associated with lung function in the normative aging study

BACKGROUND & AIMS

The results of studies assessing relationships between vitamin E intake and status and lung function are conflicting. This study aimed to evaluate the effect of vitamin E intake and serum levels of tocopherol isoforms on lung function in a cross-sectional sample of 580 men from the Normative Aging Study, a longitudinal aging study.

METHODS

Regression models were used to look at associations of serum tocopherol isoform levels and vitamin E intake with lung function parameters after adjustment for confounders. Vitamin E intake was measured using a food frequency questionnaire and serum levels of γ, α, and δ-tocopherol levels were measured using high-performance liquid chromatography.

RESULTS

After adjustment for potential confounders, serum γ-tocopherol had a significant inverse association with forced vital capacity (β = -0.10, p = 0.05). Alpha and δ-tocopherol were not associated with any lung function parameter. After classifying COPD status according to Global Initiative for Obstructive Lung Disease (GOLD) stage criteria, serum levels of δ-tocopherol were lower in participants with more severe COPD (p = 0.01). Serum levels of δ-tocopherol were also lower in participants with greater levels of smoking (p = 0.02). Both vitamin E intake (β = 0.03, p = 0.02; β = 0.03, p = 0.01) and use of vitamin E supplements (β = 0.05, p = 0.03; β = 0.06. p = 0.02) were positively associated with FEV1 and FVC, after adjusting for confounders. Subjects who took vitamin E supplements had significantly higher α-tocopherol levels (p < 0.0001) and lower γ-tocopherol levels (p < 0.0001) than non-users.

CONCLUSION

In this study, there is a positive association between dietary vitamin E intake and lung function, and evidence of an inverse relationship between serum levels of γ-tocopherol and lung function.

Physical activity patterns and metabolic syndrome in Costa Rica

OBJECTIVE

To examine whether total physical activity or activity patterns are associated with metabolic syndrome and its components.

METHODS

Participants include 1994 controls from a case-control study of non-fatal myocardial infarction in Costa Rica (1994-2004). Physical activity was assessed via self-administered questionnaire and patterns were identified using principal components analysis. Metabolic syndrome was assessed via blood samples and anthropometry measurements from in-home study visits. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were calculated using log binomial regression. Adjusted least squares means of metabolic syndrome components were calculated by quintile of total activity and pattern scores.

RESULTS

Four activity patterns were identified: rest/sleep, agricultural, light indoor activity, and manual labor. Total activity was not associated with metabolic syndrome. Metabolic syndrome prevalence was 20% lower in participants with the highest scores on the agricultural job pattern compared to those with the lowest (PR: 0.80, 95% CI: 0.68-0.94). Higher total activity was associated with lower triglycerides and lower HDL cholesterol. Higher scores on each pattern were inversely associated with metabolic syndrome components, particularly waist circumference and fasting blood glucose.

CONCLUSIONS

Patterns or types of physical activity may be more strongly associated with metabolic syndrome and its components than total activity levels.

Circulating biomarkers of dairy fat and risk of incident stroke in U.S. men and women in 2 large prospective cohorts

BACKGROUND

Previous observational studies of self-reported dairy product consumption and stroke risk have reported mixed findings. Few studies have used circulating biomarkers that provide objective measures of dairy fat intake.

OBJECTIVES

We tested the hypothesis that the circulating biomarkers of dairy fat, pentadecanoic acid (15:0), heptadecanoic acid (17:0), and trans palmitoleate (trans 16:1n-7), were associated with lower incidence of stroke, especially ischemic stroke. Secondarily, we evaluated 14:0, which is obtained from dairy products and beef, and also endogenously synthesized.

DESIGN

In participants from 2 large US cohorts (the Health Professionals Follow-Up Study: 51,529 men; the Nurses' Health Study: 121,700 women) with stored blood samples in 1993-1994 (n = 18,225) and 1989-1990 (n = 32,826), respectively, we prospectively identified 594 incident stroke cases (median follow-up: 8.3 y) and matched them 1:1 to risk-set-sampled control subjects by age, sex, race, and smoking. Total plasma and red blood cell (RBC) fatty acids were measured by using gas-liquid chromatography. Covariates were assessed by using validated questionnaires. Stroke events and subtypes were adjudicated by using medical records or other supporting documentation. We used conditional logistic regression to estimate associations of fatty acids with incident stroke, and cohort-specific findings were combined by inverse-variance weights.

RESULTS

After adjustment for demographic characteristics, lifestyle, cardiovascular disease risk factors, diet, and other circulating fatty acids, no significant associations with total stroke were seen for plasma 15:0 (pooled HR for highest compared with lowest quartiles: 0.85; 95% CI: 0.54, 1.33), 17:0 (0.99; 0.67, 1.49), trans 16:1 n-7 (0.89; 0.55, 1.45), or 14:0 (1.05; 0.62, 1.78). Results were similar for ischemic and hemorrhagic stroke subtypes, for RBC fatty acids, and in several different sensitivity analyses.

CONCLUSION

In 2 large prospective cohorts, circulating biomarkers of dairy fat were not significantly associated with stroke.

Adipose tissue n-3 fatty acids and metabolic syndrome

Background

Evidence regarding the relationship of n-3 fatty acids (FA) to type 2 diabetes (T2D) and metabolic syndrome components (MetS) is inconsistent.

Objective

To examine associations of adipose tissue n-3 FA with MetS.

Design

We studied 1611 participants without prior history of diabetes or heart disease who were participants in a population-based case-control study of diet and heart disease (The Costa Rica Heart Study). We calculated prevalence ratios (PR) and 95% confidence intervals (CI) for MetS by quartile of n-3 FA in adipose tissue derived mainly from plants [α-Linolenic acid (ALA)], fish [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)], or metabolism [docosapentaenoic acid (DPA), as well as the EPA:ALA ratio, a surrogate marker of delta-6 desaturase activity].

Results

N-3 FA levels in adipose tissue were associated with MetS prevalence in opposite directions. The PR (95% CI) for the highest compared to the lowest quartile adjusted for age, sex, BMI, residence, lifestyle, diet and other fatty acids were 0.60 (0.44, 0.81) for ALA, 1.43 (1.12, 1.82) for EPA, 1.63 (1.22, 2.18) for DPA, and 1.47 (1.14, 1.88) for EPA:ALA, all p for trend <0.05. Although these associations were no longer significant (except DPA) after adjustment for BMI, ALA and DPA were associated with lower glucose and higher triglyceride levels, p<0.05 (respectively).

Conclusions

These results suggest that ALA could exert a modest protective benefit, while EPA and DHA are not implicated in MetS. The positive associations for DPA and MetS could reflect higher delta-6 desaturase activity caused by increased adiposity.

Docosahexaenoic Acid and Periodontitis in Adults: A Randomized Controlled Trial

Periodontitis is a common chronic inflammatory disease initiated by bacteria, resulting in bone resorption, tooth loss, and systemic inflammation. Long-chain omega-3 fatty acids such as docosahexaenoic acid (DHA) reduce periodontitis in animals. We aimed to determine whether DHA supplementation with low-dose aspirin would reduce periodontitis in humans. We conducted a double-blind placebo-controlled parallel trial lasting 3 mo. Fifty-five adults with moderate periodontitis were randomized to 2,000 mg of DHA or identical soy/corn oil capsules. All participants received 81 mg of aspirin but received no other treatments. We analyzed the primary outcome of per-pocket change in pocket depth using mixed models among teeth with pocket depth ≥5 mm. Secondary outcomes assessed with generalized estimating equations included gingival index, plaque index, and bleeding on probing. Gingival crevicular fluid samples were analyzed for changes in high-sensitivity C-reactive protein (hsCRP) and interleukins 6 and 1β (IL-6 and IL-1β). Plasma was analyzed for changes in systemic inflammatory markers, including hsCRP. We confirmed adherence with erythrocyte fatty acid measurement. Forty-six participants completed the trial. While similar at baseline, the proportion of DHA in red blood cell plasma membranes increased from 3.6% ± 0.9% to 6.2% ± 1.6% in the intervention group but did not change among controls. DHA supplementation decreased mean pocket depth (-0.29 ± 0.13; p = .03) and gingival index (-0.26 ± 0.13; p = .04). Plaque index and bleeding on probing did not change. Significant adjusted differences were found between DHA and control for both gingival crevicular fluid hsCRP (-5.3 ng/mL, standard error [SE] = 2.4, p = .03) and IL-1β (-20.1 pg/mL, SE = 8.2, p = .02) but not IL-6 (0.02 pg/mL, SE = 0.71, p = .98) or systemic hsCRP (-1.19 mg/L, SE = 0.90, p = .20). In this randomized controlled trial, aspirin-triggered DHA supplementation significantly improved periodontal outcomes in people with periodontitis, indicating its potential therapeutic efficacy (clinicaltrials.gov NCT01976806).

Blood levels of saturated and monounsaturated fatty acids as markers of de novo lipogenesis and risk of prostate cancer

De novo lipogenesis has been implicated in prostate carcinogenesis, and blood levels of specific saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) could reflect activity of this pathway. We used gas chromatography to measure blood SFA and MUFA levels in prediagnostic samples from 476 incident prostate cancer cases (1982-1995) in the Physicians' Health Study and an equal number of controls matched on age and smoking status. Five tagging polymorphisms in the fatty acid synthase (FASN) gene (rs1127678, rs6502051, rs4246444, rs12949488, and rs8066956) were related to blood SFA and MUFA levels. Conditional logistic regression was used to estimate the rate ratios, with 95% confidence intervals, of prostate cancer across quintiles of blood fatty acid levels. The polymorphisms rs6502051 and rs4246444 were associated with lower levels of 14:1n-5, 16:1n-7, and 18:1n-9. Blood levels of 16:1n-7 were associated with higher prostate cancer incidence, with rate ratios for men in increasing quintiles of 1.00, 1.40, 1.35, 1.44, and 1.97 (95% confidence interval: 1.27-3.06; Ptrend = 0.003). Furthermore, 16:1n-7 levels were positively related to incidence of high-grade (Gleason score ≥7) tumors (rate ratioQ5-Q1 = 3.92; 95% confidence interval: 1.72-8.94) but not low-grade tumors (rate ratioQ5-Q1 = 1.51; 95% confidence interval: 0.87-2.62) (Pheterogeneity = 0.02). Higher activity of enzymes involved in de novo lipogenesis, as reflected in blood levels of 16:1n-7, could be involved in the development of high-grade prostate cancer.

A novel fatty acid lipophilic index and risk of CHD in US men: the health professionals follow-up study

Few epidemiological studies have examined the association between an overall fatty acid (FA) profile and CHD risk. The aim of the present study was to examine a novel index that summarises individual FA levels based on FA affinity and fluidity in relation to CHD risk in men. In a prospective nested case–control study, FA in plasma and erythrocytes were measured in 459 CHD cases and 879 matched controls. Lipophilic index (LI) was computed by summing the products between FA levels and melting point of each FA to reflect the overall FA lipophilicity. Among controls, higher plasma LI was significantly correlated with adverse profiles of blood lipids, inflammatory markers and adiponectin. After multivariate adjustment for age, smoking, BMI and other CHD risk factors, plasma LI was significantly associated with an increased risk of CHD: the relative risk was 1·61 (95% CI 1·03, 2·53; P for trend¼0·04) comparing extreme quintiles. This association was attenuated to 1·21 (95% CI 0·48, 3·09; P for trend¼0·77) after adjusting for plasma levels of total trans-FA, long-chain n-3 FA and polyunsaturated:saturated fat ratio. Erythrocyte LI was not significantly associated with CHD risk. The present data indicate that a novel LI is associated with an adverse profile of cardiovascular risk markers and increased risk of CHD in men; its usefulness as a complement of individual FA in assessing disease risk needs to be elucidated in future studies.

A novel fatty acid profile index--the lipophilic index--and risk of myocardial infarction

The lipophilic index (LI), a mean measure of fatty acid melting points, has been proposed to capture overall fatty acid profile and may play an important role in the etiology of coronary heart disease. We aimed to determine the association between LI in diet and in adipose tissue and metabolic risk factors for myocardial infarction (MI) and risk of MI. We used a population-based, matched case-control study of nonfatal first acute MI conducted in Costa Rica between 1994 and 2004, with 1,627 case-control pairs. The LI is defined as the mean of the melting points of specific fatty acids in diet or adipose tissue. LIs in diet and adipose tissue were significantly associated with higher plasma triglyceride concentrations, low-density lipoprotein cholesterol concentrations, and low-density:high-density lipoprotein cholesterol ratio. Comparing extreme quintiles for the LI in diet or adipose tissue, the odds ratios for MI were 1.57 (95% confidence interval: 1.22, 2.02; P for trend < 0.001) for dietary LI and 1.30 (95% confidence interval: 1.00, 1.69; P for trend = 0.02) for adipose tissue LI in the multivariable models. We hypothesize that a higher LI in diet and in adipose tissue represents decreased fatty acid fluidity and could play an important role in the etiology of coronary heart disease.

A case-control study of physical activity patterns and risk of non-fatal myocardial infarction

Background

The interactive effects of different types of physical activity on cardiovascular disease (CVD) risk have not been fully considered in previous studies. We aimed to identify physical activity patterns that take into account combinations of physical activities and examine the association between derived physical activity patterns and risk of acute myocardial infarction (AMI).

Methods

We examined the relationship between physical activity patterns, identified by principal component analysis (PCA), and AMI risk in a case-control study of myocardial infarction in Costa Rica (N=4172), 1994-2004. The component scores derived from PCA and total METS were used in natural cubic spline models to assess the association between physical activity and AMI risk.

Results

Four physical activity patterns were retained from PCA that were characterized as the rest/sleep, agricultural job, light indoor activity, and manual labor job patterns. The light indoor activity and rest/sleep patterns showed an inverse linear relation (P for linearity=0.001) and a U-shaped association (P for non-linearity=0.03) with AMI risk, respectively. There was an inverse association between total activity-related energy expenditure and AMI risk but it reached a plateau at high levels of physical activity (P for non-linearity=0.01).

Conclusions

These data suggest that a light indoor activity pattern is associated with reduced AMI risk. PCA provides a new approach to investigate the relationship between physical activity and CVD risk.

Changes in dietary intake and food sources of saturated and cis and trans unsaturated fatty acids in Costa Rican adolescents: 1996 versus 2006

OBJECTIVE

To identify how dietary intake and food sources of saturated (SFA) and cis (PUFA) and trans (TFA) unsaturated fatty acids in the diet of Costa Rican adolescents changed from 1996 to 2006--a period with several public health nutrition changes.

METHODS

Cross-sectional comparisons used data from measured food records of 133 adolescents (ages 12-17 y) surveyed in 1996 and a similar group of adolescents surveyed in 2006. Values obtained in 1996 and 2006 were compared with the current World Health Organization guidelines for chronic disease prevention.

RESULTS

Adolescents surveyed in 2006 reported a significantly higher mean daily energy intake from linoleic acid (LA) and alpha-linolenic acid (ALA) (0.9% and 7.8%, respectively) compared with the 1996 cohort, whereas SFA and TFA were significantly lower (9.5% and 1.3%, respectively). Food sources of fat also changed. In 2006, 2% of SFA in the diet came from palm shortening (compared with 34% in 1996); 39% of TFA came from ruminant-derived foods (in 1996, soybean oil was the main contributor of TFA, 34%), and bakery products (mainly pre-packaged cookies) provided 25% of the source of TFA, compared with only 11% in 1996. Dietary fatty intake of Costa Rican adolescents in 2006 is closer to WHO guidelines compared with 1996.

CONCLUSIONS

After public health initiatives that changed fatty acid profile of most foods, intakes of TFA, SFA, and food sources of fatty acids in adolescents' diets improved. Public health nutrition efforts should continue to strengthen diets that are low in SFA and TFA and higher in ALA content among Costa Rican adolescents.

Circulating carotenoids and risk of breast cancer: pooled analysis of eight prospective studies

BACKGROUND

Carotenoids, micronutrients in fruits and vegetables, may reduce breast cancer risk. Most, but not all, past studies of circulating carotenoids and breast cancer have found an inverse association with at least one carotenoid, although the specific carotenoid has varied across studies.

METHODS

We conducted a pooled analysis of eight cohort studies comprising more than 80% of the world's published prospective data on plasma or serum carotenoids and breast cancer, including 3055 case subjects and 3956 matched control subjects. To account for laboratory differences and examine population differences across studies, we recalibrated participant carotenoid levels to a common standard by reassaying 20 plasma or serum samples from each cohort together at the same laboratory. Using conditional logistic regression, adjusting for several breast cancer risk factors, we calculated relative risks (RRs) and 95% confidence intervals (CIs) using quintiles defined among the control subjects from all studies. All P values are two-sided.

RESULTS

Statistically significant inverse associations with breast cancer were observed for α-carotene (top vs bottom quintile RR = 0.87, 95% CI = 0.71 to 1.05, P(trend) = .04), β-carotene (RR = 0.83, 95% CI = 0.70 to 0.98, P(trend) = .02), lutein+zeaxanthin (RR = 0.84, 95% CI = 0.70 to 1.01, P(trend) = .05), lycopene (RR = 0.78, 95% CI = 0.62 to 0.99, P(trend) = .02), and total carotenoids (RR = 0.81, 95% CI = 0.68 to 0.96, P(trend) = .01). β-Cryptoxanthin was not statistically significantly associated with risk. Tests for heterogeneity across studies were not statistically significant. For several carotenoids, associations appeared stronger for estrogen receptor negative (ER(-)) than for ER(+) tumors (eg, β-carotene: ER(-): top vs bottom quintile RR = 0.52, 95% CI = 0.36 to 0.77, P(trend) = .001; ER(+): RR = 0.83, 95% CI = 0.66 to 1.04, P(trend) = .06; P(heterogeneity) = .01).

CONCLUSIONS

This comprehensive prospective analysis suggests women with higher circulating levels of α-carotene, β-carotene, lutein+zeaxanthin, lycopene, and total carotenoids may be at reduced risk of breast cancer.