Low-carbohydrate, high-protein diet score and risk of incident cancer; a prospective cohort study

The Association of Low-Carbohydrate Diet and HECTD4 rs11066280 Polymorphism with Risk of Colorectal Cancer: A Case-Control Study in Korea

Background

Glucose is a main source of energy for tumor cells. Thus, a low-carbohydrate diet (LCD) is thought to make a significant contribution to cancer prevention. In addition, LCD and HECT domain E3 ubiquitin protein ligase 4 (HECTD4) gene may be related to insulin resistance.

Objectives

We explored whether LCD score and HECTD4 rs11066280 are etiological factors for colorectal cancer (CRC) and whether LCD score interacts with HECTD4 rs11066280 to modify CRC risk.

Methods

We included 1457 controls and 1062 cases in a case-control study. The LCD score was computed based on the proportion of energy obtained from carbohydrate, protein, and fat, as determined by a semiquantitative food frequency questionnaire. We used unconditional logistic regression models to explore the association of HECTD4 with CRC prevention and interaction of LCD score and HECTD4 polymorphism with CRC preventability.

Results

Individuals with AA/AT genotypes who carried a minor allele (A) of HECTD4 rs11066280 exhibited a decreased CRC risk [odds ratio (OR) = 0.75, 95% confidence interval (CI): 0.62, 0.91]. In addition, a protective effect of high LCD score against CRC development was identified (OR = 0.52, 95% CI: 0.40, 0.68, P for trend <0.001). However, the effect of LCD depended on individual's genetic background, which appears only in participants with TT genotype of HECTD4 rs11066280 [OR = 0.49 (0.36-0.68), P interaction = 0.044].

Conclusions

Our findings suggest a protective effect of LCD and a minor allele of HECTD4 rs11066280 against CRC development. In addition, we provide an understanding of the interaction effect of LCD and HECTD4 rs11066280 on CRC, which may be helpful for establishing diet plans regarding cancer prevention.

High-protein diet scores, macronutrient substitution, and breast cancer risk: insights from substitution analysis

BACKGROUND

Evidence from recent studies suggested that variation in the quantity and quality of macronutrients in the diet may potentially play a role in predicting the risk of breast cancer (BC). In the current study, we aimed to assess the association of different high-protein diet scores and replacing fats and carbohydrate (CHO) with protein in the diet with the BC risk among Iranian women.

METHODS

The current hospital-based case-control study was conducted on 401 participants, aged ≥ 30 years old, including 134 women in the case group who had been diagnosed with histologically confirmed BC and 267 women in the control group. Dietary intake data was collected using a validated food frequency questionnaire, and high protein diet scores were determined. Logistic regression models were used to determine the odds ratios (OR) and 95% confidence interval (CI) of BC across tertiles of high protein diet scores. Also, we assessed how substituting protein with other macronutrients affected BC odds while adjusting for the various confounding variables.

RESULTS

Participants' mean ± SD of age and body mass index were 47.9 ± 10.3 years and 29.4 ± 5.5 kg/m2, respectively. The scores of high-protein-low-CHO and fat diet, high-protein and CHO-low-fat diet, and high-protein and fat-low-CHO diet in participants were 16.5 ± 3.8, 16.5 ± 6.7, and 16.4 ± 5.9, respectively. In the multivariable model, individuals in the highest tertile of high-protein-low-CHO and fat diet score (OR:0.71;95%CI:0.56-0.90) and high-protein and CHO-low-fat diet (OR:0.76;95%CI:0.60-0.97) had lower odds of BC compared to those in the lowest tertile (P < 0.05). However, no significant association was found between high-protein and fat-low-CHO diet and BC risk. Our results showed that replacing fat by protein (ORdifferences:-0.40;95%CI:-0.73,-0.07) and also replacing refined-CHO by plant protein (ORdifferences:-0.66;95%CI:-1.26,-0.07) in the diet are associated inversely with risk of BC(P < 0.05).

CONCLUSIONS

The results of our study suggested that higher adherence to a high-protein-low-CHO and fat diet, characterized by a higher intake of plant proteins and a lower intake of refined grains and saturated fat can play a protective role against the odds of BC.

Dietary patterns and risk of colorectal cancer: a comparative analysis

BACKGROUND

Although several dietary patterns have been associated with incident colorectal cancer (CRC), it is unclear which diet is optimal.

METHODS

Participants included 48 409 men and 169 772 women from three USA-based prospective cohort studies. We compared the associations of 18 dietary patterns with CRC risk, including two reference scores. The reference scores were derived based on the dietary recommendations for cancer prevention and CRC-specific dietary risk factors mentioned in the 2018 World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR) Third Expert Report. Multivariable Cox proportional hazards models were fitted to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

Most dietary patterns showed moderate correlations with the WCRF dietary score (absolute values of Spearman correlation coefficients: 0.45-0.63), except the Plant-based diet index, low-carbohydrate diets, the Empirical dietary index for hyperinsulinemia (EDIH) and Empirical dietary inflammation pattern (EDIP). HR for the 10th-90th percentile difference in the score was 0.86 (95% CI: 0.78-0.94) for the Dietary Approaches to Stop Hypertension score (DASH), 1.15 (1.06-1.26) for Western dietary pattern, 1.20 (1.10-1.31) for EDIH and 1.23 (1.13-1.34) for EDIP. These associations between patterns and CRC risk persisted after adjusting for the two reference scores.

CONCLUSIONS

Although further research is needed to improve the WCRF/AICR dietary recommendations, our comprehensive assessment of dietary patterns revealed that the DASH, Western dietary pattern, EDIH and EDIP may be the most relevant diets for preventing CRC.

Low-carbohydrate diet score is associated with improved blood pressure and cardio-metabolic risk factors among obese adults

Obesity is associated with numerous co-morbidities and diet, is one of the modifiable risk factors for prevention against these obesity-related metabolic disorders. In the current study, we aimed to evaluate the association between adherence to low carbohydrate diet (LCD) score and serum lipids, glycemic markers, blood pressure, and anthropometric parameters among obese individuals. The current cross-sectional study is a combination of two projects with total participants of 359 obese individuals (body mass index [BMI] ≥ 30 kg/m2 ) aged 20-50 years were included. Dietary intake was assessed by a validated semi-quantitative food frequency questionnaire (FFQ) of 132 food items. Low carbohydrate diet score was estimated by deciles of dietary intakes. Metabolic syndrome (MetS) was defined based on the guidelines of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III). Enzymatic methods were used to assess serum lipids, glucose, and insulin concentrations. Blood pressure was measured by sphygmomanometer and body composition with bioelectrical impedance analysis (BIA). Higher adherence to LCD score was associated with significantly lower DBP and triglyceride (TG) concentrations and increased high density lipoprotein (HDL)-C levels after adjustment for the confounders (p < 0.05). A non-significant reduction in systolic blood pressure (SBP) and total cholesterol (TC) values were also observed. Also, high adherence to LCD score was associated with reduced prevalence of metabolic syndrome (p < 0.05). Higher BMI, fat mass, and lower fat-free mass were also accompanied with higher adherence to LCD score. According to our study, low carbohydrate diet score was associated with more favorable cardio-metabolic risk factors independent of some confounders like age, BMI, sex, and physical activity level. Further studies in different communities will help for generalization of our findings.

Low-carbohydrate diet and risk of cancer incidence: The Japan Public Health Center-based prospective study

Epidemiological evidence on the effects of a long‐term low‐carbohydrate diet (LCD) on cancer incidence remains sparse. We investigate the association between LCD and the risk of overall and specific cancer site incidence in a Japanese population‐based prospective cohort study among 90 171 participants aged 45‐74. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During a median 17.0 y of follow‐up, we identified 15 203 cancer cases. A higher overall LCD score was associated with increased overall cancer risk (HR = 1.08 [CI: 1.02‐1.14], P‐trend = .012), while it was associated with decreased gastric cancer (GC) risk (0.81 [0.71‐0.93], P‐trend = .006). A higher animal‐based LCD score was associated with higher risk of overall cancer (1.08 [1.02‐1.14], P‐trend = .003), colorectal cancer (CRC) (1.11 [0.98‐1.25], P‐trend = .018), rectal cancer (RC) (1.24 [1.00‐1.54], P‐trend = .025), lung cancer (LC) (1.16 [1.00‐1.34], P‐trend = .042), and lower risk of GC (0.90 [0.79‐1.01], P‐trend = .033). Furthermore, we found that plant‐based LCD score was related to lower GC incidence (0.87 [0.77‐0.99], P‐trend = .031). Additionally, adjusted for plant fat intake amplified the adverse associations (overall cancer: 1.08 [1.02‐1.14] vs. 1.11 [1.05‐1.18]; CRC: 1.08 [0.95‐1.22] vs. 1.13 [0.99‐1.30]; LC: 1.14 [0.98‐1.33] vs. 1.19 [1.01‐1.41]). We conclude that LCD enriching with animal products was associated with increased overall cancer, CRC, and LC incidence. These adverse associations could be attenuated by plant fat consumption. LCD reduces the risk of developing GC. Long‐term adherence to LCD without paying attention to the balance between animal and plant food source consumption might cause adverse overall cancer incidence consequences.

Low-carbohydrate diets and the risk of pancreatic cancer: a large prospective cohort study

Low-carbohydrate diets have become a popular approach for weight loss in recent years. However, whether low-carbohydrate diets are associated with the risk of pancreatic cancer remains to be elucidated. Hence, we examined the association of low-carbohydrate diets with the risk of pancreatic cancer in a US population. A population-based cohort of 95 962 individuals was identified. A low-carbohydrate-diet score was calculated to quantify adherence to this dietary pattern, with higher scores indicating greater adherence. Cox regression was used to calculate risk estimate for the association of the low-carbohydrate-diet score with the risk of pancreatic cancer. Subgroup analysis was used to identify the potential effect modifiers. After an average follow-up of 8.87 years (875856.9 person-years), we documented a total of 351 pancreatic cancer cases. In the fully adjusted model, the highest versus the lowest quartiles of the overall low-carbohydrate-diet score were found to be associated with a reduced risk of pancreatic cancer (hazard ratioquartile 4 versus 1: 0.61; 95% confidence interval: 0.45, 0.82; Ptrend < 0.001). Subgroup analysis found that the inverse association of low-carbohydrate diets with the risk of pancreatic cancer was more pronounced in individuals aged ≥65 years than in those aged <65 years (Pinteraction = 0.015). Similar results were obtained for animal and vegetable low-carbohydrate-diet scores. In conclusion, low-carbohydrate diets, regardless of the type of protein and fat, are associated with a lower risk of pancreatic cancer in the US population, suggesting that adherence to low-carbohydrate diets may be beneficial for pancreatic cancer prevention. Future studies should validate our findings in other populations.

Adherence to the low carbohydrate diet and the risk of breast Cancer in Iran

Background

Previous studies on the link between macronutrients and breast cancer have mostly focused on individual macronutrients rather than their combination. This study investigates the association between adherence to a low carbohydrate diet and odds of breast cancer among women.

Methods

This hospital-based case-control study was carried out on 412 women with pathologically confirmed breast cancer within the past year and 456 apparently healthy controls that were matched in terms of age and residential place. Dietary data was collected using a 168-item validated FFQ. Participants were classified in terms of quintiles of percentages of energy intake from carbohydrates, proteins, and fats. Then, individuals in the highest quintile of fat and protein intake were given a score of 5 and those in the lowest quintile of these macronutrients were given a score of 1. Participants in the other quintiles of these macronutrients were given the corresponding score. In terms of carbohydrate intake, those in the highest quintile received a score of 1 and those in the lowest quintile received 5. The scores were then summed up to calculate the total low carbohydrate diet (LCD) score, which varied from 3 to 15. A higher score meant greater adherence to a low carbohydrate diet.

Results

The mean age of study participants was 45.2 y and mean BMI was 28.4 kg/m². Mean LCD score of participants was 8.9 ± 2.5 (8.9 ± 2.6 in cases and 9.0 ± 2.5 in controls). Although no significant association was observed between adherence to the LCD score and odds of breast cancer in the study population, a trend toward significant positive association was seen between consumption of LCD and odds of breast cancer in postmenopausal women; after controlling for several potential confounders, individuals in the third quartile of LCD score were 1.94 times more likely to have breast cancer than those in the lowest quartile (95% CI: 1.00, 3.76). This association strengthened after controlling for dietary variables (2.50; 1.18–5.32). Even after further adjustment for BMI, this association remained significant (2.64, 1.23–5.67). No significant relationship was observed in premenopausal women, either before or after controlling for confounders.

Conclusion

Adherence to LCD may be associated with increased odds of breast cancer in postmenopausal women. Prospective cohort studies are needed to confirm these findings.

Association of low-carbohydrate diet score with overweight, obesity and cardiovascular disease risk factors: a cross-sectional study in Iranian women

Introduction: This study aimed to determine the association of low-carbohydrate-diet score with overweight, obesity and cardiovascular risk factors among Iranian women. Methods: In healthy Iranian women 20-50 years, demographics, anthropometrics, physical activity, blood pressure, fasting blood glucose, blood lipids, and dietary intake (using a validated food frequency questionnaire) were assessed. Participants were divided into deciles of macronutrient intakes. Women in the lowest decile of carbohydrate intake received a score of 9 and women in the highest decile received a score of 0. For protein and fat intakes, women in the lowest decile received a score of 0 for that macronutrient and those in the highest decile received the score of 9. Macronutrient scores were summed to create the low-carbohydrate diet score and women were grouped into tertiles based on these scores. Continuous and qualitative variables were compared among the low-carbohydrate-diet score by one-way ANOVA and chi-square test, respectively. Logistic regression was used to determine the association of low-carbohydrate-diet score and cardiovascular risk factors. Results: A total of 209 women were included in the study. Socioeconomic status significantly increased from tertile 1 to 3 of the low-carbohydrate diet score (P = 0.02). Total dietary glycemic index (GI) significantly differed among tertiles (tertile 1 GI: 63.1 ±0.50, tertile 2 GI: 61.9 ± 0.5, tertile 3 GI: 59.5 ± 0.5; P < 0.001). The odds ratios for overweight, obesity and cardiovascular risk factors were not significantly different among the tertiles of low-carbohydrate diet score. Conclusion: In Iranian women, diets lower in carbohydrate and higher in protein and fat were not associated with overweight, obesity and cardiovascular risk factors.

Comparison of the Body Composition of Caucasian Young Normal Body Mass Women, Measured in the Follicular Phase, Depending on the Carbohydrate Diet Level

Background and objectives: Some publications indicate the possibility of the influence of meal nutritional value on results of bioelectrical impedance, and of the relation between the long-term carbohydrate intake and body composition. The aim of the presented study was to evaluate the influence of long-term intake of carbohydrates on body composition results assessed using the bioelectrical impedance of Caucasian young women with normal body mass, who were in the follicular phase of their menstrual cycle. Materials and Methods: Body composition was assessed in 100 women (18–30 years), according to strict rules, to minimize the influence of disturbing factors and by using two types of bioelectrical impedance device of the same operator to eliminate the influence of measurement (BIA 101/SC and BIA 101/ASE by Akern Srl, Firenze, Italy with the Bodygram 1.31 software and its equations by Akern Srl, Firenze, Italy). The analysis included validation of reproducibility of body composition assessment (fat, fat-free, body cell and muscle mass, water, extracellular water, and intracellular water content), and comparison of body composition for groups characterized by carbohydrate content <50% (n = 55) and >50% of the energy value of the diet (n = 45). Results: Analysis conducted using Bland–Altman method, analysis of correlation, analysis of quartile distribution, and weighted κ statistic revealed a positively validated reproducibility, but extracellular water associations were the weakest. Depending on the device, participants characterized by higher carbohydrate intake had significantly higher intracellular water content (p = 0.0448), or close to significantly higher (p = 0.0851) than those characterized by lower carbohydrate intake, whose extracellular water content was close to significantly lower (p = 0.0638) or did not differ. Conclusions: The long-term, moderately reduced, carbohydrate intake may cause the shift of intracellular water to the extracellular space and, as a result, influence the body composition results.

Diet Quality Scores Inversely Associated with Postmenopausal Breast Cancer Risk Are Not Associated with Premenopausal Breast Cancer Risk in the California Teachers Study

Background

Evidence for the association between diet and breast cancer risk is inconsistent Thus, research that compares indexes of overall diet quality may provide new insight.

Objective

We examined the association between diet quality indexes and pre- and postmenopausal breast cancer risk in a large prospective cohort.

Methods

This was a prospective analysis of 96,959 women, aged 22-104 y, in the California Teachers Study cohort (1995-2011). Diet quality was characterized by 4 different indexes. Specifically, we examined Alternate Mediterranean Diet (aMED), Alternative Healthy Eating Index-2010 (AHEI-2010), Dietary Approaches to Stop Hypertension (DASH), and Paleolithic index (PALEO) scores with the risk of developing breast cancer. We used multivariable Cox proportional hazards regression models to derive HRs and 95% CIs for breast cancer risk.

Results

In the analysis of 42,517 women at risk of premenopausal breast cancer, there was no association between any of the indexes and incident breast cancer (346 cases). In the analysis of 54,442 women at risk of postmenopausal breast cancer at baseline, higher AHEI-2010, aMED, and DASH scores were inversely associated with incident breast cancer (3523 incident cases). Respectively, HRs (95% CIs) comparing quintile 5 to quintile 1 (reference) for AHEI-2010, aMED, and DASH indexes were 0.87 (0.78, 0.97; P-trend = 0.004), 0.91 (0.82, 1.02; P-trend = 0.03), and 0.89 (0.80, 1.00; P-trend = 0.03). The PALEO score was not associated with postmenopausal breast cancer (HR for quintile 5 compared with quintile 1: 1.05; 95% CI: 0.94, 1.17).

Conclusions

Diet quality indexes that emphasize intake of whole grains, vegetables, fruits, legumes, and nuts and seeds and de-emphasize red and processed meats and sugar-sweetened beverages were modestly associated with a lower risk of incident postmenopausal breast cancer risk. However, they were not associated with premenopausal breast cancer, and the PALEO score was not associated with cancer risk regardless of menopausal status.

Foods and beverages and colorectal cancer risk: a systematic review and meta-analysis of cohort studies, an update of the evidence of the WCRF-AICR Continuous Update Project

Objective

As part of the World Cancer Research Fund International Continuous Update Project, we updated the systematic review and meta-analysis of prospective studies to quantify the dose-response between foods and beverages intake and colorectal cancer risk.

Data sources

PubMed and several databases up to 31 May 2015.

Study selection

Prospective studies reporting adjusted relative risk estimates for the association of specific food groups and beverages and risk of colorectal, colon and rectal cancer.

Data synthesis

Dose-response meta-analyses using random effect models to estimate summary relative risks (RRs).

Results

About 400 individual study estimates from 111 unique cohort studies were included. Overall, the risk increase of colorectal cancer is 12% for each 100 g/day increase of red and processed meat intake (95% CI = 4-21%, I2=70%, pheterogeneity (ph)<0.01) and 7% for 10 g/day increase of ethanol intake in alcoholic drinks (95% CI = 5-9%, I2=25%, ph = 0.21). Colorectal cancer risk decrease in 17% for each 90g/day increase of whole grains (95% CI = 11-21%, I2 = 0%, ph = 0.30, 6 studies) and 13% for each 400 g/day increase of dairy products intake (95% CI = 10-17%, I2 = 18%, ph = 0.27, 10 studies). Inverse associations were also observed for vegetables intake (RR per 100 g/day =0.98 (95% CI = 0.96-0.99, I2=0%, ph = 0.48, 11 studies) and for fish intake (RR for 100 g/day = 0.89 (95% CI = 0.80-0.99, I2=0%, ph = 0.52, 11 studies), that were weak for vegetables and driven by one study for fish. Intakes of fruits, coffee, tea, cheese, poultry and legumes were not associated with colorectal cancer risk.

Conclusions

Our results reinforce the evidence that high intake of red and processed meat and alcohol increase the risk of colorectal cancer. Milk and whole grains may have a protective role against colorectal cancer. The evidence for vegetables and fish was less convincing.

The effects of whey and soy proteins on growth performance, gastrointestinal digestion, and selected physiological responses in rats

The objective of this work was to identify the nutritional and physiological effects of commercial soy and whey protein preparations. Wistar rats were fed with soy (S), whey (W), or casein (C) preparations as the sole dietary protein source. The nitrogen balance, body composition, changes in caecal microbiota, mucosal and bacterial enzyme activities, and allergenic potential of the preparations were analysed. The whey diet elicited greater skeletal muscle anabolism than the soy diet. Rats from the S group had the lowest values of body weight, fat, and lean mass gain. Compared to casein, soy and whey preparations decreased the protein efficiency ratio, increased N in the urine, and triggered the reduction of ammonia levels in the caecum. Changes in β-glucuronidase and β-galactosidase activities in the small intestine, caecum, and colon between experimental groups were observed. Significant differences were noted in the total counts of anaerobic bacteria and sulphite reducing bacteria during soy and whey treatments. This probably affected the short chain fatty acid level in caecal digesta resulting in the lowest propionic acid and total putrefactive short chain fatty acid levels during S treatment. Generally, whey preparations are a good choice for rapid bodybuilding (skeletal muscles), whereas soy preparations are more helpful during mass reduction.

Changes in Anthropometry and Selected Metabolic Parameters in Young Men During Their First Year of Study at a University of Physical Education

This study aims to determine main health-related anthropometric and metabolic parameters in young physically active male students in their first year of study. Sixty one male students from a Polish university of physical education were studied twice–at the beginning of their first and second academic years. Body weight, height, waist circumference, and body composition were measured. Plasma levels of thyroid-stimulating hormone (TSH), leptin, cortisol, and insulin, as well as insulin resistance (IR) using the homeostatic model assessment (HOMA) were determined. In 64% of the participants body weight and body mass index (BMI) significantly increased during the study. An average students’ weight gain amounted to 1.2 kg. In most of the subjects it resulted from the increase of fat-free mass (r = .886, p < .001). TSH and leptin levels did not change, but a significant increase of cortisol levels and a tendency toward decreased insulin levels and also HOMA-IR values were observed. However, there were no significant correlations identified between the changes in anthropometric and biochemical parameters. The study revealed that body weight gain seen in male students during their first year at the university of physical education was mainly due to the increase in fat-free mass. Apart from anthropometrics, changes in their insulin and cortisol levels were also detected, but further studies are required to evaluate these findings. The documented insufficient energy and carbohydrates consumption in physically active male students proves the need for nutritional education among them.

Index-Based Dietary Patterns and the Risk of Prostate Cancer

Prostate cancer is the second leading cause for cancer incidence in male. Although this high incidence is due to prostate specific antigen screening, other risk-factors, such as diet, might also be involved. The results of previous studies on the association between prostate cancer risk and individual dietary components have been conflicting. Thus, evaluation by dietary pattern analysis rather than individual dietary factors is suggested. The purpose of this study was to review the association of prostate cancer with a priori dietary indices, which are less studied and reviewed to date compared to a posteriori indices. Studies reviewed in this research were published from January 1997 to March 2017. Seventeen studies with nine indices were selected. In Mediterranean Diet Score (MDS), all four studies were non-significant. In Dietary Inflammatory Index (DII), 3 out of 4 studies significantly increased risk by 1.33–2.39 times, suggesting that a higher pro-inflammatory diet may be a possible prostate cancer risk factor. In Oxidative Balance Score (OBS), 2 out of 5 studies had decreased risk by 0.28 and 0.34 times, whereas 1 study had increased risk by 1.17 times. Among other indices, Healthy Eating Index (HEI) and prostate cancer dietary index were associated with decreased risk, while the results from 2 studies of Low Carbohydrate, High Protein Diet (LCHP) score were conflicting. In conclusion, we observed that it is insufficient to support the association between a priori indices and prostate cancer risk, except for MDS and DII, which had relatively constant results among studies. Therefore, further studies are required to identify consistent criteria for each a priori index, and should be conducted actively in various populations.

Animal Proteins as Important Contributors to a Healthy Human Diet

Adequate protein intake is critical for health and development. Generally, protein of animal origin is of higher quality for humans owing to its amino acid pattern and good digestibility. When administered in mixtures it can enhance the quality of plant proteins, but its availability is often low in low-income communities, especially in young children, the elderly, and pregnant and lactating women, who have increased requirements and in whom high-quality protein also stimulates (bone) growth and maintenance. Although high protein intake was associated with increased type 2 diabetes mellitus risk, milk and seafood are good sources of branched chain amino acids and taurine, which act beneficially on glucose metabolism and blood pressure. However, high consumption of protein-rich animal food is also associated with adverse health effects and higher risk for noncommunicable diseases, partly related to other components of these foods, like saturated fatty acids and potential carcinogens in processed meat but also the atherogenic methionine metabolite homocysteine. In moderation, however, animal proteins are especially important for health maintenance in vulnerable persons.

MicroRNA biomarkers predicting risk, initiation and progression of colorectal cancer

Colorectal cancer is a major global cause of morbidity and mortality. Current strategies employed to increase detection of early, curable stages of this disease are contributing to a reduction of the negative health impact from it. While there is a genetic component to the risk of disease, diet and environment are known to have major effects on the risk of an individual for developing the disease. However, there is the potential to reduce the impact of this disease further by preventing disease development. Biomarkers which can either predict the risk for or early stages of colorectal cancer could allow intervention at a time when prospects could be modified by environmental factors, including lifestyle and diet choices. Thus, such biomarkers could be used to identify high risk individuals who would benefit from lifestyle and dietary interventions to prevent this disease. This review will give an overview on one type of biomarker in the form of microRNAs, which have the potential to predict an individual’s risk for colorectal cancer, as well as providing a highly sensitive and non-invasive warning of disease presence and/or progression. MicroRNA biomarkers which have been studied and whose levels look promising for this purpose include MiR-18a, MiR-21, MiR-92a, MiR-135b, MiR-760, MiR-601. Not only have several individual microRNAs appeared promising as biomarkers, but panels of these may be even more useful. Furthermore, understanding dietary sources and ways of dietary modulation of these microRNAs might be fruitful in reducing the incidence and slowing the progression of colorectal cancer.

Diet Quality and Cancer Outcomes in Adults: A Systematic Review of Epidemiological Studies

Dietary patterns influence cancer risk. However, systematic reviews have not evaluated relationships between a priori defined diet quality scores and adult cancer risk and mortality. The aims of this systematic review are to (1) describe diet quality scores used in cohort or cross-sectional research examining cancer outcomes; and (2) describe associations between diet quality scores and cancer risk and mortality. The protocol was registered in Prospero, and a systematic search using six electronic databases was conducted through to December 2014. Records were assessed for inclusion by two independent reviewers, and quality was evaluated using a validated tool. Sixty-four studies met inclusion criteria from which 55 different diet quality scores were identified. Of the 35 studies investigating diet quality and cancer risk, 60% (n = 21) found a positive relationship. Results suggest no relationship between diet quality scores and overall cancer risk. Inverse associations were found for diet quality scores and risk of postmenopausal breast, colorectal, head, and neck cancer. No consistent relationships between diet quality scores and cancer mortality were found. Diet quality appears to be related to site-specific adult cancer risk. The relationship with cancer mortality is less conclusive, suggesting additional factors impact overall cancer survival. Development of a cancer-specific diet quality score for application in prospective epidemiology and in public health is warranted.

Impact of Weight Loss on Plasma Leptin and Adiponectin in Overweight-to-Obese Post Menopausal Breast Cancer Survivors

Women who are obese at the time of breast cancer diagnosis have higher overall mortality than normal weight women and some evidence implicates adiponectin and leptin as contributing to prognostic disadvantage. While intentional weight loss is thought to improve prognosis, its impact on these adipokines is unclear. This study compared the pattern of change in plasma leptin and adiponectin in overweight-to-obese post-menopausal breast cancer survivors during weight loss. Given the controversies about what dietary pattern is most appropriate for breast cancer control and regulation of adipokine metabolism, the effect of a low fat versus a low carbohydrate pattern was evaluated using a non-randomized, controlled study design. Anthropometric data and fasted plasma were obtained monthly during the six-month weight loss intervention. While leptin was associated with fat mass, adiponectin was not, and the lack of correlation between leptin and adiponectin concentrations throughout weight loss implies independent mechanisms of regulation. The temporal pattern of change in leptin but not adiponectin was affected by magnitude of weight loss. Dietary pattern was without effect on either adipokine. Mechanisms not directly related to dietary pattern, weight loss, or fat mass appear to play dominant roles in the regulation of circulating levels of these adipokines.

Association of decrease in carbohydrate intake with reduction in abdominal fat during 3-month moderate low-carbohydrate diet among non-obese Japanese patients with type 2 diabetes

OBJECTIVE

The effectiveness of a moderate low-carbohydrate diet (M-LCD) has been demonstrated in terms of glycemic control, body weight and serum lipid profiles. We investigated the effect of a 3-month M-LCD on visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), and examined an association between decrease in carbohydrate intake and reduction in abdominal fat among patients with Type 2 diabetes mellitus (T2DM).

METHODS

Seventy-six patients (45 men and 31 women; mean age ± SD: 59.5 ± 11.1 years) with T2DM were instructed to follow an M-LCD for 3 months. We assessed abdominal fat distribution using computed tomography and macronutrient intakes from 3-day dietary records at baseline and after 3 months.

RESULTS

The patients complied well with the M-LCD - %carbohydrate: %fat: %protein at baseline and after 3 months were 51:27:15 and 41:33:18 in men and 54:27:16 and 42:37:19 in women, respectively. VAT and SAT significantly decreased during the 3 months (P for time < 0.001 for both). Decrease in carbohydrate intake (g/day) and %carbohydrate were correlated with decrease (%) in VAT. The correlations were significant in men (Spearman correlation coefficient r = 0.469 for carbohydrate intake (g) and r = 0.402 for %carbohydrate) but not in women (r = 0.269 and 0.278, respectively). The correlations in men remained significant in multiple regression analysis adjusted for age and changes in energy intake.

CONCLUSIONS

In men, decrease in carbohydrate intake was significantly correlated with VAT loss during a 3-month M-LCD, independently of reduction in energy intake.

Can we say what diet is best for health?

Diet is established among the most important influences on health in modern societies. Injudicious diet figures among the leading causes of premature death and chronic disease. Optimal eating is associated with increased life expectancy, dramatic reduction in lifetime risk of all chronic disease, and amelioration of gene expression. In this context, claims abound for the competitive merits of various diets relative to one another. Whereas such claims, particularly when attached to commercial interests, emphasize distinctions, the fundamentals of virtually all eating patterns associated with meaningful evidence of health benefit overlap substantially. There have been no rigorous, long-term studies comparing contenders for best diet laurels using methodology that precludes bias and confounding, and for many reasons such studies are unlikely. In the absence of such direct comparisons, claims for the established superiority of any one specific diet over others are exaggerated. The weight of evidence strongly supports a theme of healthful eating while allowing for variations on that theme. A diet of minimally processed foods close to nature, predominantly plants, is decisively associated with health promotion and disease prevention and is consistent with the salient components of seemingly distinct dietary approaches. Efforts to improve public health through diet are forestalled not for want of knowledge about the optimal feeding of Homo sapiens but for distractions associated with exaggerated claims, and our failure to convert what we reliably know into what we routinely do. Knowledge in this case is not, as of yet, power; would that it were so.

Dietary patterns and prostate cancer risk: report from the population based ULSAM cohort study of Swedish men

Dietary pattern analyses have increased the possibilities to detect associations between diet and disease. However, studies on dietary pattern and prostate cancer are scarce. Food intake data in the Uppsala Longitudinal Study of Adult Men cohort was determined by 7-day food records. Adherence to a modified Mediterranean Diet Score (mMDS) and a low carbohydrate-high protein (LCHP) score were grouped as low, medium, or high in the whole study population (n = 1,044) and in those identified as adequate reporters of energy intake (n = 566), respectively. Prostate cancer risk was analyzed with Cox proportional hazard regression (median follow-up 13 years) and competing risk of death was considered. There were no associations between dietary patterns and prostate cancer (n = 133) in the whole study population. Among adequate reporters the mMDS was not associated with prostate cancer (n = 72). The LCHP score was inversely related to prostate cancer in adequate reporters, adjusted hazard ratios; 0.55 (0.32-0.96) for medium and 0.47 (0.21-1.04) for high compared to low adherent participants (P-for-trend 0.04). Risk relations were not attributable to competing risk of death. In this study, a LCHP diet was associated with lower prostate cancer incidence. Relations emerged in adequate reporters, underscoring the importance of high-quality dietary data.