More Americans are eating "5 a day" but intakes of dark green and cruciferous vegetables remain low

What Do United States Adolescents Eat? Food Group Consumption Patterns and Dietary Diversity from a Decade of Nationally Representative Data

Background

Although the importance of adolescent nutrition has gained attention in the global nutrition community, there is a gap in research focused on adolescent dietary diversity and food group consumption.

Objectives

This study aimed to characterize population-level food group consumption patterns and quantify the extent of dietary diversity among United States adolescents using a large nationally representative sample of adolescents aged 10-19 y.

Methods

We used 24-h dietary recall data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2018 to construct the 10 food groups comprising the minimum dietary diversity for women (MDD-W) indicator and estimated the prevalence of intake of each food group. A composite metric adolescent dietary diversity score (ADDS) was derived for each adolescent where 1 point was awarded per food group. Both population scores and the distribution of individual scores were estimated. Differences in proportions of food groups consumed across sociodemographic categories were tested using the Rao-Scott χ² test, and pairwise comparisons were expressed as population prevalence differences and prevalence ratios.

Results

Food group consumption patterns were very similar across 2 d of dietary recall but varied significantly by sex, race/ethnicity, and income status. The food groups with the highest prevalence of consumption were grains, white, roots, and tubers (∼99%), milk products (∼92%), and meat, poultry, and fish (∼85%), whereas <15% of adolescents consumed key micronutrient-dense foods, such as vitamin A-rich fruits and vegetables and dark green vegetables. The mean ADDS was 4.69, with modest variation across strata.

Conclusions

On average, United States youth consumed fewer than 5 food groups on a given day. The lack of dietary variety and relatively low prevalence of consumption of several micronutrient-rich plant-based foods could pose a risk for adolescents' ability to achieve micronutrient adequacy in the United States.

A worldwide review of illness outbreaks involving mixed salads/dressings and factors influencing product safety and shelf life

The trends toward healthy living, vegetarianism, and busy schedules have increased salad popularity. Salads are usually consumed raw without any thermal treatment, and therefore, without proper care they can become major vehicles for foodborne illness outbreaks. This review examines the microbial quality of 'dressed' salads which contain two or more vegetables/fruits and salad dressings. The possible sources of ingredient contamination, recorded illnesses/outbreaks, and overall microbial quality observed worldwide, besides the antimicrobial treatments available are discussed in detail. Noroviruses were most frequently implicated in outbreaks. Salad dressings usually play a positive role in influencing microbial quality. However, this depends on several factors like the type of contaminating microorganism, storage temperature, dressing pH and ingredients, plus the type of salad vegetable. Very limited literature exists on antimicrobial treatments that can be used successfully with salad dressings and 'dressed' salads. The challenge with antimicrobial treatments is to find ones sufficiently broad in spectrum, compatible with produce flavour which can be applied at competitive cost. It is evident that renewed emphasis on prevention of produce contamination at the producer, processor, wholesale and retail levels plus enhanced hygiene vigilance at foodservice will have a major impact on reducing the risk of foodborne illnesses from salads.

Bitter taste receptors: Genes, evolution and health

Bitter taste perception plays vital roles in animal behavior and fitness. By signaling the presence of toxins in foods, particularly noxious defense compounds found in plants, it enables animals to avoid exposure. In vertebrates, bitter perception is initiated by TAS2Rs, a family of G protein-coupled receptors expressed on the surface of taste buds. There, oriented toward the interior of the mouth, they monitor the contents of foods, drinks and other substances as they are ingested. When bitter compounds are encountered, TAS2Rs respond by triggering neural pathways leading to sensation. The importance of this role placed TAS2Rs under selective pressures in the course of their evolution, leaving signatures in patterns of gene gain and loss, sequence polymorphism, and population structure consistent with vertebrates' diverse feeding ecologies. The protective value of bitter taste is reduced in modern humans because contemporary food supplies are safe and abundant. However, this is not always the case. Some crops, particularly in the developing world, retain surprisingly high toxicity and bitterness remains an important measure of safety. Bitter perception also shapes health through its influence on preference driven behaviors such as diet choice, alcohol intake and tobacco use. Further, allelic variation in TAS2Rs is extensive, leading to individual differences in taste sensitivity that drive these behaviors, shaping susceptibility to disease. Thus, bitter taste perception occupies a critical intersection between ancient evolutionary processes and modern human health.

Pre-diagnosis Cruciferous Vegetables and Isothiocyanates Intake and Ovarian Cancer Survival: A Prospective Cohort Study

Background: The associations of the consumption of cruciferous vegetables (CVs) and their bioactive components, isothiocyanates (ITCs), with ovarian cancer (OC) mortality have been unclear, owing to limited studies and inconsistent findings. To date, no studies have evaluated these associations among Chinese patients with OC. This study aims to provide more evidence indicating the relationships of pre-diagnosis CVs and ITC intake with OC survival.

Methods: We examined the associations of pre-diagnosis CV and ITC intake with OC mortality in a hospital-based cohort (n = 853) of Chinese patients with epithelial OC between 2015 and 2020. Pre-diagnosis dietary information was evaluated with a validated food frequency questionnaire. Deaths were ascertained until March 31, 2021 via medical records and active follow-up. The associations were examined with the Cox proportional hazards model, adjusted for potential confounders, and stratified by menopausal status, residual lesions, histological type, and body mass index (BMI).

Results: During a median follow-up of 37.2 months (interquartile: 24.7–50.2 months), we observed 130 deaths. The highest tertile of total CV intake was associated with better survival than the lowest tertile intake [hazard ratio (HR) = 0.57, 95% confidence interval (CI) = 0.33–0.98, p trend < 0.05]. In addition, higher intake of ITCs from CVs was associated with better survival (HR_T3VS.T1 = 0.59, 95% CI = 0.36–0.99, p trend = 0.06). Significant inverse associations were also observed for subgroup analyses stratified by menopausal status, residual lesions, histological type, and BMI, although not all associations showed statistical significance.

Conclusion: Increasing pre-diagnosis consumption of CVs and ITCs was strongly associated with better survival in patients with OC.

Influence of Green Leafy Vegetables in Diets with an Elevated ω-6:ω-3 Fatty Acid Ratio on Rat Blood Pressure, Plasma Lipids, Antioxidant Status and Markers of Inflammation

The typical Western dietary pattern has an elevated ω-6:ω-3 fatty acid ratio (FAR), which may exacerbate the risk of chronic disease. Conversely, the consumption of diets containing green leafy vegetables (GLVs) have been demonstrated to attenuate disease risk. This study investigated the effects of collard greens (CG), purslane (PL) and orange flesh sweetpotato greens (SPG) on measures of disease risk in rats fed diets with a 25:1 ω-6:ω-3 FAR. Male spontaneously hypertensive rats (SHRs) were randomly assigned to four dietary groups (n = 10/group) with a 25:1 ω-6:ω-3 FAR. Experimental diets contained 4% (dried weight) CG, PL or SPG. Dietary intake, body weight, blood pressure, plasma adiponectin, high sensitivity C-reactive protein (hsCRP), oxygen radical absorbance capacity and lipid profile were determined using standardized procedures. Following a 6-week consumption period, systolic blood pressure, plasma adiponectin, total and low-density lipoprotein (LDL) cholesterol decreased following the consumption of diets containing GLVs. While hsCRP increased in SHRs fed diets containing CG and PL, plasma antioxidant capacity was significantly reduced (p < 0.05) with the consumption of diets containing the GLVs. These findings suggest that CG, PL and SPG have the potential to decrease risks for cardiovascular disease (CVD) associated with the consumption of diets with an elevated ω-6:ω-3 FAR.

Cruciferous vegetable intake and colorectal cancer risk: Japan public health center-based prospective study

We aimed to assess the association between cruciferous vegetable intake and colorectal cancer (CRC) development among Japanese adults aged between 45 and 74 years in the Japan Public Health Center-based Prospective Study. During 1 325 853 person-years of follow-up, 2612 CRC cases were identified. The association of cruciferous vegetable intake with CRC risk was assessed using a Cox proportional hazard regression model to compute hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for potential confounders. No significant association was observed between the highest cruciferous vegetable intake quartile (compared with the lowest) and CRC risk in men (multivariate HRs: 1.08; 95% CI: 0.91, 1.29) and women (multivariate HRs: 0.99; 95% CI: 0.80, 1.22) and its subsites. Women showed a marginal negative association between cruciferous vegetable intake and the risk of colon cancer (CC) after excluding participants who developed CC in the first 3 years of follow-up (P for trend = 0.08); a positive association was found with proximal CC in men. Cruciferous vegetable intake does not have a significant association with CRC risk in the Japanese general population.

Cruciferous Vegetables, Isothiocyanates, and Bladder Cancer Prevention

Bladder cancer is a significant health burden due to its high prevalence, risk of mortality, morbidity, and high cost of medical care. Epidemiologic evidence suggests that diets rich in cruciferous vegetables, particularly broccoli, are associated with lower bladder cancer risk. Phytochemicals in cruciferous vegetables, such as glucosinolates, which are enzymatically hydrolyzed to bioactive isothiocyanates, are possible mediators of an anticancer effect. In vitro studies have shown inhibition of bladder cancer cell lines, cell cycle arrest, and induction of apoptosis by these isothiocyanates, in particular sulforaphane and erucin. Although not yet completely understood, many mechanisms of anticancer activity at the steps of cancer initiation, promotion, and progression have been attributed to these isothiocyanates. They target multiple pathways including the adaptive stress response, phase I/II enzyme modulation, pro-growth, pro-survival, pro-inflammatory signaling, angiogenesis, and even epigenetic modulation. Multiple in vivo studies have shown the bioavailability of isothiocyanates and their antitumoral effects. Although human studies are limited, they support oral bioavailability with reasonable plasma and urine concentrations achieved. Overall, both cell and animal studies support a potential role for isothiocyanates in bladder cancer prevention and treatment. Future studies are necessary to examine clinically relevant outcomes and define guidelines on ameliorating the bladder cancer burden.

Macular Xanthophylls Are Related to Intellectual Ability among Adults with Overweight and Obesity

Excess adiposity or obesity has been inversely related to cognitive function and macular xanthophyll status. However, whether the neuroprotective effects of macular xanthophylls on cognitive function are independent of excess adiposity is unclear. We investigated the relationship between macular xanthophylls and intellectual ability among adults (N = 114) between 25 and 45 years with overweight and obesity (≥25 kg/m²). Dual energy X-ray absorptiometry and heterochromatic flicker photometry were used to assess whole body adiposity (%Fat) and macular pigment optical density (MPOD), respectively. Dietary xanthophylls (lutein and zeaxanthin) were assessed using 7-day diet records. The Kaufman Brief Intelligence Test-2 (KBIT-2) was used to assess general intelligence (IQ) as well as fluid and crystallized intelligence. Bivariate correlations revealed that MPOD was inversely related to %Fat and positively associated with IQ and fluid intelligence. Although %Fat was inversely correlated to IQ and fluid intelligence, this relationship did not persist following adjustment for sex and MPOD. Further, MPOD was an independent predictor of IQ and fluid intelligence. However, no significant relationships were observed between MPOD and crystalized intelligence. These results suggest that macular xanthophylls are selectively related to fluid intelligence, regardless of degree of adiposity among adults with overweight and obesity.

The effect of educational intervention based on an Ecological-social model on consuming fruit and vegetables in women in Ilam

Background

The effect of instructional models on the changing behavior of consuming fruit and vegetables in the prevention of diseases caused by consumption of foods including rice, contaminated with toxic metals, has not been investigated in Iran yet.

Objective

To compare an Ecological-social model (ECO) group and Control group in increasing fruit and vegetable consumption.

Methods

This research involved implementation of a six-month randomized controlled educational interventionist program into a group of Ecological-social framework along with a control group, totally summing up to 160 women between 18 and 50 years of age in Ilam, Iran in 2014. The questionnaire included knowledge, social support construct (immediate family, relatives, friends, colleagues and neighbors.) and fruit and vegetable intake in both groups before and after the intervention was examined. Data were analyzed by SPSS version 16 using the signed ranks test, and repeated measures analysis of variance analysis, and confidence interval of 95% were employed.

Results

The results of the signed ranks test showed a significant increase in social support in the intervention group (p<0.001). This test showed a significant increase in fruit and vegetable consumption and a significant increase in the number of women using healthy rice (p<0.001), and a significant reduction in the number of women consuming unhealthy rice in the intervention group (p<0.001), that determines dietary intake improvement after the intervention compared with before the intervention (p<0.01). However, this improvement was not observed in the control group.

Conclusions

The results showed that ECO plays an effective role in improving fruit and vegetable consumption in women. Therefore, this model was implemented as a health protocol through health-care centers to conduct the prevention of complications resulting from the use of food contaminated with toxic metals.

The Effects of Liking Norms and Descriptive Norms on Vegetable Consumption: A Randomized Experiment

There is evidence that social norm messages can be used to promote the selection of fruit and vegetables in low habitual consumers of these foods but it is unclear whether this effect is sustained over time. It is also unclear whether information about others' liking for a food (liking norm) could have the same effect. Using a 2 × 5 × 2 experimental design we investigated the effects of exposure to various messages on later intake from a food buffet and whether any effects were sustained 24 h after exposure in both low and high consumers of vegetables. There were three factors: delay (immediate food selection vs. food selection 24 h after exposure), message type (liking norm, descriptive norm, health message, vegetable variety condition, and neutral control message), and habitual consumption (low vs. high). The buffet consisted of three raw vegetables, three energy-dense foods, and two dips. For vegetables and non-vegetables there were no main effects of message type, nor any main effect of delay. There was a significant message × habitual vegetable consumption interaction for vegetable consumption; however, follow up tests did not yield any significant effects. Examining each food individually, there were no main effects of message type, nor any main effect of delay, for any of the foods; however, there was a message × habitual vegetable consumption interaction for broccoli. Consumption of broccoli in the health message and descriptive norm conditions did not differ from the control neutral condition. However, habitually low consumers of vegetables increased their consumption of broccoli in the vegetable variety and liking norm conditions relative to habitual low vegetable consumers in the neutral control condition (p < 0.05). Further, investigation of the effects of the liking norm and vegetable variety condition on vegetable intake is warranted. This trial is listed as NCT02618174 at clinicaltrials.gov.

Pretreatment serum xanthophyll concentrations as predictors of head and neck cancer recurrence and survival

BACKGROUND

The purpose of this study was to examine associations of pretreatment serum carotenoids, tocopherols, and quercetin with prognosis in 154 patients newly diagnosed with head and neck cancer.

METHODS

Pretreatment blood and health surveys were collected. Serum micronutrients were measured by high performance liquid chromatography. Data on recurrence and death were collected annually. Cox proportional hazards models measured associations of serum nutrient concentrations with recurrence and overall survival.

RESULTS

During a median follow-up time of 37 months, there were 32 recurrences and 27 deaths. After controlling for covariates, subjects with high versus low serum xanthophyll and total carotenoid concentrations had significantly longer recurrence-free time (p = .002 and p = .02, respectively). Overall survival time was significantly longer in patients with high versus low serum xanthophyll concentrations (p = .02).

CONCLUSION

Future research should evaluate the possible benefits of interventions to increase intakes of rich food sources of xanthophylls in this patient population. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1591-E1597, 2016.

Associations between cruciferous vegetable intake and selected biomarkers among women scheduled for breast biopsies

OBJECTIVE

To examine the relationship between dietary cruciferous vegetable intake and selected tumour biomarkers for histone acetylation (H3K9ac, H3K18ac, HDAC3 and HDAC6), proliferation (Ki-67) and cell-cycle regulation (p21) from breast tissue.

DESIGN

The study used baseline data of women recruited to participate in a clinical trial of sulforaphane supplement. Dietary cruciferous vegetable intake was collected through a validated Arizona Cruciferous Vegetable Intake Questionnaire. Breast tissue was obtained from biopsy samples. Spearman correlations were calculated between intake of specific cruciferous vegetables and biomarkers. Tissue biomarkers were log2-transformed to obtain approximate normality. Linear regression analyses were conducted to examine associations between cruciferous vegetable intake and biomarkers adjusting for age and use of non-steroidal anti-inflammatory drugs. False discovery rate (FDR) was used to account for multiple comparisons.

SETTING

Clinical trial baseline.

SUBJECTS

Fifty-four women who had abnormal mammogram findings and were scheduled for breast biopsy.

RESULTS

Mean intake of total cruciferous vegetables from all food sources was 81·7 (sd 57·3) g/d. Mean urinary total sulforaphane metabolites was 0·08 (sd 0·07) µm/mm creatinine. Total cruciferous vegetable intake was inversely associated with Ki-67 protein expression in breast ductal carcinoma in situ (DCIS) tissue (β=-0·004; se=0·001; FDR q value=0·03), but not in benign or invasive ductal carcinoma (IDC) tissue. No association was found for other biomarkers measured (HDAC3, HDAC6, H3K9, H3K18 and p21) in all tissues examined (benign, DCIS and IDC).

CONCLUSIONS

The present study sought to provide additional evidence for the potential role of sulforaphane in histone acetylation and cell proliferation. Here, we report that total cruciferous vegetable intake is associated with decreased cell proliferation in breast DCIS tissue.

Lifestyle Modifications and Colorectal Cancer

Many studies suggest that Western lifestyle and dietary factors may be responsible for the high incidence of colorectal cancer in industrialized countries. Consumption of high amounts of red and processed meat and low intake of fiber and multiple protective phytochemicals found in fruits, vegetables, and whole grains might be responsible for the high incidence of this neoplasm in the Western world. Additionally, obesity, lack of physical activity, tobacco and alcohol use, sleep deprivation, and other factors have been proven to further increase the risk of colorectal cancer. Identifying and understanding the mechanisms through which they impact colon carcinogenesis is needed for the introduction of protective lifestyle recommendations.

Understanding African American women's decisions to buy and eat dark green leafy vegetables: an application of the reasoned action approach

OBJECTIVE

Examine intentions to buy and eat dark green leafy vegetables (DGLV).

DESIGN

Cross-sectional survey assessing demographics, behavior, intention, and Reasoned Action Approach constructs (attitude, perceived norm, self-efficacy).

SETTING

Marion County, Indiana.

PARTICIPANTS

African American women responsible for buying and preparing household food.

MAIN OUTCOME MEASURE(S)

Reasoned Action Approach constructs explaining intentions to buy and eat DGLV.

ANALYSIS

Summary statistics, Pearson correlations, and multiple regression analyses.

RESULTS

Among participants (n = 410, mean age = 43 y), 76% and 80%, respectively, reported buying and eating DGLV in the past week. Mean consumption was 1.5 cups in the past 3 days. Intentions to buy (r = 0.20, P < .001) and eat (r = 0.23, P < .001) DGLV were positively associated with consumption. Reasoned Action Approach constructs explained 71.2% of the variance in intention to buy, and 60.9% of the variance in intention to eat DGLV. Attitude (β = .63) and self-efficacy (β = .24) related to buying and attitude (β = .60) and self-efficacy (β = .23) related to eating DGLV explained significant amounts of variance in intentions to buy and eat more DGLV. Perceived norm was unrelated to either intention to buy or eat DGLV.

CONCLUSIONS AND IMPLICATIONS

Interventions designed for this population of women should aim to improve DGLV-related attitudes and self-efficacy.

In nutrition, can we "see" what is good for us?

The selection of foods to eat is a complex interplay of vision, taste, smell, and texture. In addition to micro- and macronutrients, plant-based foods also contain several classes of phytochemicals. In many cases, the phytochemicals account for the various colors of foods. Although aesthetically pleasing, the color of foods may mislead consumers as to their phytochemical content, which is particularly true with regard to polyphenols. Polyphenols are a broad class of compounds with antioxidant and other health benefits. Human vision is limited to a small window (390-765 nm) of the electromagnetic spectrum. Many important phytochemicals (e.g., vitamin C) have no absorbance in this range. Therefore, the human eye cannot directly judge the vitamin C content of foods. Being able to see in the ultraviolet range allows bees to locate the pollen-rich region of flowers, whereas pit vipers locate their prey by being able to "see" them in the infrared range. Assessing the impact of phytochemicals on human health depends on several factors. Colorless phytochemicals in unprocessed foods may be lost during the cooking process because no visual guide exists to ensure their retention. The molecular structures of phytochemicals influence the extent to which they are altered by cooking processes and the methods by which they are absorbed from the gastrointestinal tract. Extensive metabolism by phase I/II enzymes and by the gut microbiome may also create compounds that the eye is never allowed to appreciate.

Contributions of white vegetables to nutrient intake: NHANES 2009-2010

Vegetables, especially white potatoes, provide significant levels of key nutrients of concern, such as potassium and dietary fiber. Per capita availability (PCA) data for vegetables-often used as a proxy for vegetable consumption-show that vegetable consumption, including consumption of white potatoes, declined in the past decade. Using dietary data for participants in the NHANES 2009-2010, we examined total vegetable, white potato, and French-fried potato consumption among all age-gender groups as well as mean energy, potassium, and dietary fiber intakes. Mean total energy intake for the US population (≥2 y old) was 2080 kcal/d, with white potatoes and French-fried potatoes providing ∼4% and ∼2% of total energy, respectively. Individuals who consumed white potatoes had significantly higher total vegetable and potassium intakes than did nonconsumers. In addition, the proportion of potassium and dietary fiber contributed by white potatoes was higher than the proportion that they contributed to total energy. Among white potato consumers aged 14-18 y, white potatoes provided ∼23% of dietary fiber and ∼20% of potassium but only ∼11% of total energy in the diet. The nutrient-dense white potato may be an effective way to increase total vegetable consumption and potassium and dietary fiber intake.

Salient beliefs about eating and buying dark green vegetables as told by Mid-western African-American women

Vegetables in the dark green group are the most nutritious, yet intake is low. Studies suggest that an increase in fruit and vegetables may improve diet-related health outcomes of African Americans. The aim of this exploratory study was to use the Reasoned Action Approach (RAA) to qualitatively assess salient, top-of-the-mind, beliefs (consequences, circumstances and referents) about eating and buying more dark green leafy vegetables each week over the next 3months. Adult (n=30), Midwestern African-American women, who buy and prepare food for their household participated in a face-to-face salient belief elicitation. A content analysis of verbatim text and a descriptive analysis were conducted. Findings suggest that the RAA can be used to identify salient consequences, circumstances and referents about eating and buying more dark green leafy vegetables. The use of the RAA allowed for the extraction of specific beliefs that may aid in the development of nutrition education programs that consider the varying priorities, motivators and barriers that subgroups within the population have in regard to buying and consuming dark green leafy vegetables.

Prioritizing health and community food security through the farm bill

Food security and health are complex interrelated issues. Individual characteristics exist within the physical and built environments. Title IV of the Food, Conservation, and Energy Act of 2008 is analyzed in terms of how it addresses systemic food insecurity and the opportunities the policy has for improving public health by increasing support for the availability of affordable local produce to low-income households. Structural changes need to occur for programs to be equitable, efficient, and effective. Interdisciplinary leadership within government agencies, school systems, social service agencies, health care agencies, and nonprofit networks is necessary to ensure food security and health for all Americans. Social work and public health practitioners have the opportunity to change the status quo, encourage community-level interventions, advocate for producers and consumers, and encourage more equitable distribution of food to create a healthier low-income population.

Carotenoids and total phenolic contents in plant foods commonly consumed in Korea

Phytochemicals are reported to provide various biological functions leading to the promotion of health as well as the reduced risk of chronic diseases. Fat-soluble plant pigments, carotenoids, are extensively studied micronutrient phytochemicals for their potential health benefits. It is noteworthy that specific carotenoids may be responsible for different protective effects against certain diseases. In addition, each carotenoid can be obtained from different types of plant foods. Considering the fact that the phytochemical content in foods can vary according to, but not limited to, the varieties and culture conditions, it is important to establish a database of phytochemicals in locally produced plant foods. Currently, information on individual carotenoid content in plant foods commonly consumed in Korea is lacking. As the first step to support the production and consumption of sustainable local plant foods, carotenoids and total phenolic contents of plant foods commonly consumed in Korea are presented and their potential biological functions are discussed in this review.

Mapping QTL, epistasis and genotype × environment interaction of antioxidant activity, chlorophyll content and head formation in domesticated lettuce (Lactuca sativa)

Fruits and vegetables are rich sources of antioxidants in human diets and their intake is associated with chronic disease prevention. Lettuce (Lactuca sativa L.) is a common vegetable in diets worldwide, but its nutritional content is relatively low. To elucidate the genetic basis of antioxidant content in lettuce, we measured the oxygen radical absorbance capacity (ORAC) and chlorophyll (Chl) content as a proxy of β-carotene in an F(8) recombinant inbred line (RIL) in multiple production cycles at two different production sites. Plants were phenotyped at the open-leaf stage to measure genetic potential (GP) or at market maturity (MM) to measure the influence of head architecture ('head' or 'open'). Main effect quantitative trait loci (QTL) were identified at MM (three Chl and one ORAC QTL) and GP (two ORAC QTL). No main effect QTL for Chl was detected at GP, but epistatic interaction was identified in one pair of marker intervals for each trait at GP. Interactions with environment were also detected for both main and epistatic effects (two for main effect, and one for epistatic effect). Main effect QTL for plant architecture and nutritional traits at MM colocated to a single genomic region. Chlorophyll contents and ORAC values at MM were significantly higher and Chl a to Chl b ratios were lower in 'open' types compared to 'head' types. The nutritional traits assessed for GP showed a significant association with plant architecture suggesting pleiotropic effects or closely linked genes. Taken together, the antioxidant and chlorophyll content of lettuce is controlled by complex mechanisms and participating alleles change depending on growth stage and production environment.

Impact of a community-based intervention on serving and intake of vegetables among low-income, rural Appalachian families

OBJECTIVE

To evaluate the effectiveness of a community-based intervention promoting the serving and eating of deep-orange, cruciferous, and dark-green leafy vegetables.

DESIGN

Randomized, parallel-group, community-based intervention with a baseline/postintervention/3-month follow-up design.

SETTING AND PARTICIPANTS

Low-income food preparers (n = 50) and their partners (n = 50) in rural Appalachia Pennsylvania.

INTERVENTION

Experimental food preparers attended 8 weekly interactive lessons; control food preparers received 8 weekly mailings that included similar recipes and handouts.

MAIN OUTCOME MEASURES

Target vegetable intake and frequency of serving by experimental and control treatment groups and by high and low meal diary scores, a measure of recipe acceptability.

ANALYSIS

Linear mixed-model analysis with repeated measures.

RESULTS

No significant differences resulted between the original experimental and control treatment groups. When grouped by high and low meal diary scores, more experimental families had high scores than in controls. High scores were associated with significant changes in frequency of serving and intake of the target vegetables.

CONCLUSIONS AND IMPLICATIONS

Meal diary use may foster food preparer negotiation with partners and children to become involved in vegetable dish evaluation. Tools to help the trained food preparer draw family members into recipe evaluation, such as the meal diary, are useful and needed.

Increasing access and affordability of produce improves perceived consumption of vegetables in low-income seniors

High cost and limited access to food have been associated with lower intake of fruits and vegetables in limited-income individuals. The Veggie Mobile is a van that carries fresh produce and travels in low-income neighborhoods, selling fruits and vegetables at a fraction of regular supermarket prices. The purpose of this study was to determine whether participation in the Veggie Mobile increases fruit and vegetable intake in a group of seniors. The intervention, buying fruits and vegetables from the Veggie Mobile, was implemented between April and October 2008 in two senior housing sites that had not previously received Veggie Mobile services. Participants were asked about fruit and vegetable intake using a modified six-item questionnaire based on the Behavioral Risk Factor Surveillance System at preintervention and again at 3 to 5 months. The post-survey also included questions about perceived benefits and barriers to using the Veggie Mobile. The two cross-sections of seniors were matched using date of birth. Wilcoxon signed rank test and paired samples t tests examined change in pre- and post-intervention variables. Seventy-nine older adults completed the baseline survey and 63 completed the post-survey. Of these, 43 participants completed both surveys (70% white [n=30], mean age 69 ± 9 years). Mean intake of fruits and vegetables after using the Veggie Mobile increased by 0.37 servings/day. Vegetable intake alone increased from 1.98 ± 1.71 servings/day to 2.58 ± 1.4 servings/day (P=0.027), half of which was potatoes. Change in fruit intake was not significant (P=0.358). At post-intervention, seniors visited the supermarket less often (P=0.001) and spent an average of $14.92 less during their last visit. The majority of participants who completed the post-survey (62 of 63) indicated being satisfied with the program. The Veggie Mobile provides an example of a simple community intervention that has potential to lead to positive behavior change among low-income seniors.

Consumption of Purple/Blue Produce Is Associated With Increased Nutrient Intake and Reduced Risk for Metabolic Syndrome: Results From the National Health and Nutrition Examination Survey 1999-2002

To determine the effect of consuming purple/blue fruit and vegetables (P/B) on nutrient intakes and physiological parameters, a secondary analysis of National Health and Nutrition Examination Survey (NHANES) 1999-2002 data for children aged 5 to 18 years (n = 6345) and adults 19+ years (n = 8827) was conducted. Compared with nonconsumers (n = 13 304), P/B consumers (n = 1559) had increased intakes of total fruit (P < .0001), dietary fiber (P ≤ .0001), vitamin C (P < .001), and potassium (P < .0001) and decreased intakes of added sugar (P < .0001). P/B consumers had higher energy intakes (P < .001), but among children, there were no differences in weight or body mass index (BMI) for age between groups; among adults, lower weight and BMI (P < .0001) were found as compared with nonconsumers. Adult P/B consumers had significantly reduced risk for 3 of the 5 risk factors that define the metabolic syndrome (MetS): elevated blood pressure, low HDL cholesterol, and increased waist circumference. An additional analysis for the subgroup of 100% grape juice (GJ) consumers was conducted. GJ consumers (n = 270) also had higher intakes of fruit (P < .001), vitamin C (P < .001), and potassium (P < .005) and lower intakes of added sugar (P < .01) compared with GJ nonconsumers (n = 14 902), with no differences in weight, BMI, or waist circumference. Consumption of P/B produce was associated with increased fruit and nutrient intakes and with reduced risk for MetS. GJ consumption was also associated with increased nutrient intake.

Associations between neighborhood availability and individual consumption of dark-green and orange vegetables among ethnically diverse adults in Detroit

Diets rich in dark-green and orange vegetables have been associated with a reduction in chronic diseases. However, most Americans do not consume the number of daily servings recommended by the 2005 Dietary Guidelines for Americans. An increasing number of studies suggest that changes to the neighborhood food environment may be critical to achieving population-wide improvements in eating. The objective of this study was to examine the relationship between observed neighborhood availability and individual consumption of dark-green and orange vegetables among low- to moderate-income and ethnically diverse adults in Detroit. This study used a cross-sectional design that drew upon a 2002-2003 community survey and 2002 in-person audit of food stores. A total of 919 adults (mean age 46.3 years, 52.2% female) including African Americans (56.7 %), Latinos (22.2%), and whites (18.7%) residing in three Detroit communities participated in the survey. Two-level weighted, hierarchical linear regression was used to analyze the data. On average, survey respondents ate 0.61 daily servings of dark-green and orange vegetables. Residents of neighborhoods with no stores carrying five or more varieties of dark-green and orange vegetables were associated with an average of 0.17 fewer daily servings of these foods compared with residents of neighborhoods with two stores carrying five or more varieties of dark-green and orange vegetables (P=0.047). These findings suggest that living in a neighborhood with multiple opportunities to purchase dark-green and orange vegetables may make an important contribution toward meeting recommended intakes.

Colorectal cancer prevention through dietary and lifestyle modifications

Several studies indicate that Western dietary and lifestyle factors are responsible for the high incidence of colorectal cancer in industrialized countries. Diets rich in red and processed meat, refined starches, sugar, and saturated and trans-fatty acids but poor in fruits, vegetables, fiber, omega-3 fatty acids and whole grains are closely associated with an increased risk of colorectal cancer. Other main features of the western lifestyle, such as excess body mass and sedentary behaviours, are also strongly associated with higher risk of developing this cancer. Modifications of the western diet, notably increasing consumption of foods from plant origin and reducing that of red meat intake, and maintenance of physical activity and appropriate body mass could substantially reduce colorectal cancer incidence and mortality.

Sweet potato leaves: properties and synergistic interactions that promote health and prevent disease

Sweet potato (Ipomoea batatas) leaves provide a dietary source of vitamins, minerals, antioxidants, dietary fiber, and essential fatty acids. Bioactive compounds contained in this vegetable play a role in health promotion by improving immune function, reducing oxidative stress and free radical damage, reducing cardiovascular disease risk, and suppressing cancer cell growth. Currently, sweet potato leaves are consumed primarily in the islands of the Pacific Ocean and in Asian and African countries; limited consumption occurs in the United States. This comprehensive review assesses research examining the nutritional characteristics and bioactive compounds within sweet potato leaves that contribute to health promotion and chronic disease prevention. Research has affirmed the potential cardioprotective and chemopreventive advantages of consuming sweet potato leaves, thus indicating that increased consumption of this vegetable should be advocated. Since reducing the prevalence of chronic diseases is of public health concern, promoting the consumption of sweet potato leaves warrants further and more intensive research investigation.

Men, food, and prostate cancer: gender influences on men's diets

Although healthy eating might enhance long-term survival, few men with prostate cancer make diet changes to advance their well-being. Men's typically poor diets and uninterest in self-health may impede nutrition interventions and diet change. Food choice behavior is complex involving many determinants, including gender, which can shape men's health practices, diets, and prostate cancer experiences. Developing men-centered prostate cancer nutrition interventions to engage men (and where appropriate their partners) in promoting healthy diets can afford health benefits. This article presents an overview and synthesis of current knowledge about men's food practices and provides an analysis of diet and diet change behaviors for men with prostate cancer. Masculinity and gender relations theory are discussed in the context of men's food practices, and suggestions for future applications to nutrition and prostate cancer research and diet interventions are made.

Family members' influence on family meal vegetable choices

OBJECTIVE

Characterize the process of family vegetable selection (especially cruciferous, deep orange, and dark green leafy vegetables); demonstrate the usefulness of Exchange Theory (how family norms and experiences interact with rewards and costs) for interpreting the data.

DESIGN

Eight focus groups, 2 with each segment (men/women vegetable likers/dislikers based on a screening form). Participants completed a vegetable intake form.

SETTING

Rural Appalachian Pennsylvania.

PARTICIPANTS

Sixty-one low-income, married/cohabiting men (n = 28) and women (n = 33).

ANALYSIS

Thematic analysis within Exchange Theory framework for qualitative data. Descriptive analysis, t tests and chi-square tests for quantitative data.

RESULTS

Exchange Theory proved useful for understanding that regardless of sex or vegetable liker/disliker status, meal preparers see more costs than rewards to serving vegetables. Experience plus expectations of food preparer role and of deference to family member preferences supported a family norm of serving only vegetables acceptable to everyone. Emphasized vegetables are largely ignored because of unfamiliarity; family norms prevented experimentation and learning through exposure.

CONCLUSIONS AND IMPLICATIONS

Interventions to increase vegetable consumption of this audience could (1) alter family norms about vegetables served, (2) change perceptions of experiences, (3) reduce social and personal costs of serving vegetables, and (4) increase tangible and social rewards of serving vegetables.

Validation of a semi-quantitative food frequency questionnaire measuring dietary vitamin K intake in elderly people

The study objective was to validate a semi-quantitative food frequency questionnaire (FFQ) specifically designed to measure dietary vitamin K intake. A 50-item FFQ was interviewer-administered and compared with data previously obtained from 5-day food records. Thirty-nine community-dwelling healthy men and women aged 65 to 85 years were recruited from the Montréal metropolitan area. Absolute and relative agreements between methods were assessed. Vitamin K intake measured by the vitamin K FFQ (mean+/-standard deviation; 222+/-186 microg/day) was significantly higher than that obtained by food records (135+/-153 microg/day; P<0.001). Bland-Altman analysis on log(10)-transformed data indicated that vitamin K intake from vitamin K FFQ was 2.26 times (95% confidence interval: 1.90 to 2.67) higher than food records, limits of agreement ranging from 0.80 to 6.35. However, correlation between methods was strong and highly significant (r=0.83; P<0.001). Cross-classification also showed that 72% of participants were correctly classified into thirds and only 8% were grossly miscategorized. Weighted kappa value (kappa=0.60) also indicated a good relative agreement. In light of these results, the vitamin K FFQ is a valid tool for ranking individuals according to their vitamin K intake. The poor absolute agreement likely results from the inability for food records to adequately measure the usual intake of episodically consumed foods, particularly those high in vitamin K. The vitamin K FFQ will be useful in large-scale, population-based research on vitamin K and disease as well as in clinical practice, especially that focusing on anticoagulant therapy.

Supplementation with lutein or lutein plus green tea extracts does not change oxidative stress in adequately nourished older adults

Epigallocatechin gallate, a major component of green tea polyphenols, protects against the oxidation of fat-soluble antioxidants including lutein. The current study determined the effect of a relatively high but a dietary achievable dose of lutein or lutein plus green tea extract on antioxidant status. Healthy subjects (50-70 years) were randomly assigned to one of two groups (n=20 in each group): (1) a lutein (12 mg/day) supplemented group or (2) a lutein (12 mg/day) plus green tea extract (200 mg/day) supplemented group. After 2 weeks of run-in period consuming less than two servings of lightly colored fruits and vegetables in their diet, each group was treated for 112 days while on their customary regular diets. Plasma carotenoids including lutein, tocopherols, flavanols and ascorbic acid were analyzed by HPLC-UVD and HPLC-electrochemical detector systems; total antioxidant capacity by fluorometry; lipid peroxidation by malondialdehyde using a HPLC system with a fluorescent detector and by total hydroxyoctadecadienoic acids using a GC/MS. Plasma lutein, total carotenoids and ascorbic acid concentrations of subjects in either the lutein group or the lutein plus green tea extract group were significantly increased (P<.05) at 4 weeks and throughout the 16-week study period. However, no significant changes from baseline in any biomarker of overall antioxidant activity or lipid peroxidation of the subjects were seen in either group. Our results indicate that an increase of antioxidant concentrations within a range that could readily be achieved in a healthful diet does not affect in vivo antioxidant status in normal healthy subjects when sufficient amounts of antioxidants already exist.

GST polymorphism and excretion of heterocyclic aromatic amine and isothiocyanate metabolites after Brassica consumption

Brassica vegetable intake has been associated with decreased risk and well-done meat intake has been associated with increased risk of cancers at multiple organ sites in epidemiologic studies. Experimental studies suggest a role of modulation of phase I and phase II metabolizing enzymes as one mechanism for these associations. Heterocyclic aromatic amines (HAAs) are carcinogens formed in meat that has been cooked to well-done and at high temperatures. Phase I metabolizing enzymes catalyze the activation of HAAs, and phase II metabolizing enzymes serve to detoxify the active carcinogens. The glutathione S-transferases (GSTs) are a family of phase II metabolizing enzymes that are induced by, and act to conjugate, isothiocyanates (ITCs), phytochemicals found in Brassica vegetables. This review summarizes the results of feeding studies in humans that examine effects of polymorphisms in GSTs on ITC metabolite excretion, reviews the evidence for modulation of HAA mutagenicity by ITCs, and discusses the need for feeding studies examining potential interactions among polymorphic genes encoding phase I and phase II metabolizing enzymes, meat intake, and Brassica intake to elucidate their role in cancer etiology.

Correlates of fruit and vegetable intakes in US children

The objective of this study was to assess the quality of the current intakes of fruits and vegetables compared to the Dietary Guidelines for Americans in US children and adolescents and identify factors related to low fruit and vegetable intake. This descriptive study examined differences in fruit and vegetable intakes by age, sex, ethnicity, poverty level, body mass index, and food security status utilizing data from the 1999-2002 National Health and Nutrition Examination Survey. Six thousand five hundred thirteen children and adolescents ages 2 to 18 years, who were respondents to the 1999-2002 National Health and Nutrition Examination Survey. Mean fruit and vegetable intakes were computed using 24-hour recalls for individuals and compared using analysis of variance. Leading contributors to fruit and vegetable intake were identified using frequency analysis. Children aged 2 to 5 years had significantly higher total fruit and juice intakes than 6- to 11- and 12- to 18-year-olds. Total vegetable and french fry intake was significantly higher among 12- to 18-year-old adolescents. Regarding sex differences, boys consumed significantly more fruit juice and french fries than girls. In addition, non-Hispanic African-American children and adolescents consumed significantly more dark-green vegetables and fewer mean deep-yellow vegetables than Mexican-American and non-Hispanic white children and adolescents. Total fruit consumption also differed significantly among race/ethnicities and household income. Children and adolescents most at risk for higher intakes of energy-dense fruits and vegetables (fruit juice and french fries) were generally boys, and adolescents, at risk for overweight or overweight and living in households below 350% of the poverty level.

Low-income young adults report increased variety in fruit and vegetable intake after a stage-tailored intervention

The objective of this study was to determine if a fruit and vegetable (FV) intervention, previously demonstrated to increase amount of FV per day, also increased the variety consumed. Variety in FV intake was assessed using a 26-item FV (12 fruit and 14 vegetable) food frequency questionnaire on 1255 low-income adults, with ages from 18 to 24 years (control = 684 vs experimental = 571), after completion of a stage-tailored intervention to increase FV intakes. The food frequency questionnaire was administered at 12 months to assess how often and how much participants ate of each item over the previous year. Variety was defined as the number of different types of fruits and vegetables consumed. At completion, the experimental group vs the control group had significantly greater variety in number of fruit items (9.5 +/- 0.1 vs 9.1 +/- 0.1, P < or = .001) and vegetable items (11.5 +/- 0.1 vs 11.2 +/- 0.1, P < .01) as well as greater total intake of fruits (2.73 +/- 0.09 vs 2.33 +/- 0.11 cups, P < .01) and vegetables (1.87 +/- 0.10 vs 1.62 +/- 0.01 cups, P < or = .001) and a greater consumption of the categories of seasonal fruits (P < .05), juices (P < .01), and high-beta-carotene vegetables (P < or = .001). This is one of the first studies to document an increase in FV variety as a result of an educational intervention for low-income young adults.

Serum carotenoid concentrations in postmenopausal women from the United States with and without osteoporosis

Antioxidant defenses may be compromised in osteoporotic women. Little is known about fruit and vegetable or carotenoid consumption among postmenopausal women. The primary carotenoids in human serum are alpha- and beta-carotene, lycopene, beta-cryptoxanthin, lutein, and zeaxanthin. This study investigated the interrelationships among serum carotenoid concentrations, fruit and vegetable intake, and osteoporosis in postmenopausal women (n = 59, 62.7 +/- 8.8 y). Bone density was assessed by dual energy x-ray absorptiometry and osteoporosis diagnosis was based upon T-scores. Serum samples (n = 53) and three-day diet records (n = 49) were analyzed. Logistic regression analyzed differences between carotenoids after adjusting for serum retinol; supplement usage; milk, yogurt, fruit, and vegetable intake; and body mass index (BMI). Pearson statistics correlated carotenoids with specific fruit or vegetable intake. Serum lycopene concentrations were lower in the osteoporosis group than controls (p = 0.03). Beta-cryptoxanthin intake was higher in the osteoporosis group (p = 0.0046). Total fruit and vegetable intakes were correlated with serum lycopene and beta-cryptoxanthin (p = 0.03, 0.006, respectively). Serum alpha-carotene concentration was associated with carrot intake, and zeaxanthin and beta-cryptoxanthin with lettuce intake. Carotenoids that may have beneficial skeletal effects are lower in women with osteoporosis. Research is needed to identify potential protective mechanisms or utilization of carotenoids during osteoporosis.

Plasma and dietary carotenoids are associated with reduced oxidative stress in women previously treated for breast cancer

Dietary carotenoids show numerous biological activities, including antioxidant activity, induction of apoptosis, and inhibition of mammary cell proliferation. Studies examining the role of carotenoid consumption in relation to breast cancer recurrence are limited and report mixed results. We tested the hypothesis that breast cancer survivors with high dietary and plasma carotenoids would show significantly lower levels of oxidative stress than breast cancer survivors with low dietary and plasma carotenoid levels. Two hundred seven postmenopausal breast cancer survivors from the Women's Healthy Eating and Living Study volunteered for this ancillary study. Dietary data were analyzed by the Arizona Food Frequency Questionnaire and plasma carotenoids alpha-carotene, beta-carotene, lutein plus zeaxanthin, lycopene, and beta-cryptoxanthin and quantified with high-performance liquid chromatography, and immunoaffinity chromatography-monoclonal antibody-based ELISAs were used to analyze the urine samples for 8-hydroxy-2'-deoxyguanosine (8-OhdG) and 8-iso-prostaglandin-F2alpha (8-iso-PGF2alpha). The correlations between dietary and plasma carotenoids were 0.34 for beta-carotene, 0.46 for alpha-carotene, 0.39 for beta-cryptoxanthin, 0.27 for lycopene, 0.30 for lutein plus zeaxanthin, and 0.30 for total carotenoids. The 8-OHdG oxidative stress biomarker was significantly reduced at the highest quartile of total plasma carotenoid concentrations (P = 0.001) and 8-iso-PGF2alpha was moderately reduced (P = 0.088). Dietary carotenoid levels were not significantly associated with oxidative, stress indicators, although dietary lycopene and lutein/zeaxanthin were modestly associated with 8-OHdG levels (P = 0.054 and 0.088, respectively). Key findings include a significant inverse association between total plasma carotenoid concentrations and oxidative stress as measured by urinary 8-OHdG and a moderately significant inverse association with 8-iso-PGF2alpha, a protective association that was not shown for dietary carotenoid intake.

Head and neck cancer: a case for inhibition by isothiocyanates and indoles from cruciferous vegetables

Chemical carcinogens derived from cigarettes and other tobacco products, as well as betel quid, paan, and alcohol consumption, are commonly associated with head and neck cancer risk. This is a particularly debilitating cancer, with a high recurrence rate and long-term treatment comorbidities affecting health and lifestyle. Controlling tobacco access or use may be an ideal prevention strategy but may also be challenging or undesired. Individuals, however, may be able to reduce their risk through simple and focused dietary change. Results from epidemiologic studies, basic research, and clinical investigations suggest that a diet rich in cruciferous vegetables may increase carcinogen metabolism, induce apoptosis, and reduce the risk of developing a primary head and neck tumor. This review briefly summarizes head and neck cancer nutritional epidemiology, and then describes the biochemical and epidemiologic literature describing the effects of crucifer consumption on head and neck carcinogenesis. To translate these findings, the strengths and limitations of specific intervention models are discussed, including differences in target populations and the choice of a food-based or pill-based approach for intervention. Addressing these factors in a future intervention may define a low-cost and non-toxic approach to reduce the burden of head and neck cancer.

Increase in cruciferous vegetable intake in women previously treated for breast cancer participating in a dietary intervention trial

Consumption of cruciferous vegetables has been associated with reduced breast cancer risk mechanistically and in population-based studies, although evidence has been inconsistent. This inconsistency may be related to limitations in quantifying and qualifying cruciferous vegetable exposure using standard instruments for dietary assessment (for example, food-frequency questionnaires, FFQs) or due to low levels of intake demonstrated among U.S. population samples. Cruciferous vegetable intake data are presented from a longitudinal study of a high-vegetable dietary intervention to reduce breast cancer recurrence among breast cancer survivors (n=1,156; 536 intervention and 620 comparison group subjects). Intake was assessed using repeat administration of an FFQ and cross-sectional administration of a cruciferous vegetable-specific FFQ (CVFFQ). Mean intake in the intervention group assessed using the standard FFQ was 37.7 g/day at baseline and increased to 57.1 g/day at 12 mo (P=0.0001) and was sustained through 48 mo. Broccoli and cabbage were the most commonly consumed cruciferous vegetables, regardless of the instrument used to assess intake. Differences in intake by group assignment were shown for raw cruciferous vegetables (30.2 g/day vs. 24.6 g/day, assessed using the CVFFQ), suggesting increased exposure to biologically active, cancer-preventive food constituents. These data suggest that this study population will be the first U.S. population sample to provide ample quantity and variety in cruciferous intake to examine whether these vegetables are protective against breast cancer recurrence.

Cruciferous vegetable intake questionnaire improves cruciferous vegetable intake estimates

OBJECTIVE

To develop a validated, focused Cruciferous Vegetable Food Frequency Questionnaire (FFQ) as an assessment tool for specific quantification of dietary cruciferous vegetable exposure.

DESIGN/METHODS

Participants (n=107; 18 to 76 years old) completed a standard FFQ and the Cruciferous Vegetable FFQ twice over a 2-week period. Repeat dietary recalls were collected on 3 days over the same 2-week period. Urinary dithiocarbamate was determined as a biomarker of cruciferous vegetable intake.

STATISTICAL ANALYSES

Descriptive statistics of intake; paired t tests and sign tests for comparison of intake estimates between instruments; Spearman correlations to assess reliability and associations between diet instruments and urinary dithiocarbamate.

RESULTS

Cruciferous vegetable intake was significantly correlated between the two FFQs (r(s)=0.58), although the Cruciferous Vegetable FFQ estimated intake 35 g higher than the standard FFQ. The Cruciferous Vegetable FFQ was reliable, with a repeated measures correlation of 0.69 (P</=0.01). Urinary dithiocarbamate excretion correlated with cruciferous vegetable intake from the Cruciferous Vegetable FFQ (r(s)=0.26, P<0.01), and from the standard FFQ (r(s)=0.19, P=0.06).

CONCLUSIONS

The Cruciferous Vegetable FFQ provided a reproducible, valid estimate of cruciferous vegetable exposure and improved the relationship between crucifer consumption and urinary dithiocarbamate, a biomarker of cruciferous vegetable exposure. The nearly twofold difference in exposure estimates between the Cruciferous Vegetable FFQ and the standard FFQ could change the statistical significance of risk estimates in the context of epidemiological research. This questionnaire is an appropriate research tool to evaluate cruciferous vegetable intake more accurately than a standard FFQ, particularly in the context of dietary intervention studies that promote increased vegetable intake to reduce the risk for chronic disease.

Women Participating in a Dietary Intervention Trial Maintain Dietary Changes Without Much Effect on Household Members

This study examined whether subjects who participated in a 12-mo intervention would maintain their diets 1 yr after the study ended and whether the diets of household members were affected. Premenopausal women, who had at least one first-degree relative with breast cancer (n = 122), were randomized to one of four diets: control, low fat (15% of energy), high fruit and vegetable (FV, nine servings per day), and combination low fat, high FV. Study subjects and one household member were asked to complete the Block '95 food-frequency questionnaire (FFQ) at baseline, 1 yr, and 2 yr. Study subjects also completed 24-h recalls and 4-day food records at baseline and Year 1. Fat and FV intakes by all three assessment methods compared reasonably well except that fat intakes by FFQ were somewhat higher. FV intakes by FFQ in the high-FV and combination arms increased significantly from 4 servings per day to about 10 servings per day at Year 1 and 7 servings per day at Year 2. FV intakes increased much more modestly in the low-fat and control arms. Fat intakes in the low-fat and combination arms were lower at Year 1 than Year 2, but mean Year 2 fat intakes of 26-28% were still significantly lower than those at baseline. In household members, the only significant change was a small decrease in energy from fat at Year 1 in the household members of subjects who were in the combination arm. These results indicate that study subjects were making large dietary changes independently of their household members and that fat and FV intakes in study subjects 1 yr after intervention stopped were still substantially different from intakes at baseline.

Orange juice ingestion and supplemental vitamin C are equally effective at reducing plasma lipid peroxidation in healthy adult women

OBJECTIVE

To directly examine the contribution of vitamin C to the antioxidant potential of fruits and vegetables, the antioxidant effect of orange juice consumption (8 and 16 fl. oz.) was compared to the antioxidant effect of supplemental vitamin C (dosage equivalent to that supplied by 8 fl. oz. of orange juice).

METHODS

Subjects (n = 11; 28.6 +/- 2.1 years) received each treatment in a 3 x 3 randomized crossover design, and each two-week treatment was preceded by a two-week washout. During the entire trial, subjects restricted fruit and vegetable consumption to < or =3 servings per day except the vitamin C-rich foods (items containing >20 mg/serving), which were restricted to < or =3 servings per week. A fasting blood sample was collected at the end of each washout and each treatment period.

RESULTS

Following washouts, plasma vitamin C and lipid peroxidation (plasma TBARS) were similar by treatment group and averaged 25.4 +/- 3.6 micromol/L and 3.82 +/- 0.10 nmol/mL respectively. Plasma vitamin C concentrations were similar following each treatment period, 37.9 +/- 8.1, 45.8 +/- 9.4, and 38.3 +/- 12.4 micromol/L for the 8 and 16 fl. oz. orange juice treatments and the supplement treatment, respectively. All intervention treatments reduced plasma TBARS as compared to pretreatment values: -47% (p = 0.013), -40% (p = 0.083), and -46% (p = 0.015) for the 8 and 16 fl. oz. orange juice treatments and supplement treatment respectively.

CONCLUSIONS

These data indicate that the regular consumption of 8 fl. oz. orange juice or supplemental vitamin C ( approximately 70 mg/day) effectively reduced a marker of lipid peroxidation in plasma.