Lower C-reactive protein and IL-6 associated with vegetarian diets are mediated by BMI.

BACKGROUND AND AIMS: The mechanism by which vegetarian diets are associated with less inflammation is not clear. We investigated the role of BMI as a mediator in the relationship between vegetarian diet and concentrations of C-reactive protein (CRP), and the cytokines IL-6, IL-10 and TNF-α. METHODS AND RESULTS: We used data from participants of the Adventist Health Study 2 (AHS-2) Calibration (n = 893) and Biological Manifestations of Religion (n = 478) sub-studies. Vegetarian diet variations were determined based on reported intake of animal products assessed by FFQ. Combining all participants, the proportion of non-vegetarians (NVs), partial vegetarians (PVs), lacto-ovo vegetarians (LOVs), and strict vegetarians (SVs) was 44%, 16%, 31%, and 9%, respectively. NV and PV participants were older than other dietary groups, and non-vegetarians had the highest BMI. Mediation analyses supported the mediating effect of BMI in associations of vegetarian diet with CRP (p < 0.001 each for PV, LOV and SV), and with IL-6 (p < 0.05 each for PV, LOV and SV). Mediation by BMI was not evident between vegetarian diet and the biomarkers IL-10 and TNF-α. A direct pathway was significant only in the association between strict vegetarians and CRP (p = 0.017). CONCLUSION: The lower CRP and IL-6 concentrations among vegetarians may be mediated by BMI.

Relationship of vitamin D levels to blood pressure in a biethnic population.

BACKGROUND AND AIMS: Accumulating epidemiological and clinical studies have suggested that vitamin D insufficiency may be associated with hypertension. Blacks tend to have lower vitamin D levels than Whites, but it is unclear whether this difference explains the higher blood pressure (BP) observed in Blacks in a population with healthy lifestyle practices. METHODS AND RESULTS: We examined cross-sectional data in the Adventist Health Study-2 (AHS-2), a cohort of non-smoking, mostly non-drinking men and women following a range of diets from vegan to non-vegetarian. Each participant provided dietary, demographic, lifestyle and medical history data. Measurements of weight, height, waist circumference, percent body fat and blood pressure and fasting blood samples were obtained from a randomly selected non-diabetic sample of 284 Blacks and 284 Whites aged 30-95 years. Multiple regression analyses were used to assess independent relationships between blood pressure and 25(OH)D levels. Levels of 25(OH)D were inversely associated with systolic BP in Whites after control for age, gender, BMI, and use of BP-lowering medications (ß-coefficient -0.23 [95% CI, -0.43, -0.03; p = 0.02]). This relationship was not seen in Blacks (ß-coefficient 0.08 [95% CI, -0.14, 0.30; p = 0.4]). Results were similar when controlling for waist circumference or percentage body fat instead of BMI. No relationship between serum 25(OH)D and diastolic BP was seen. CONCLUSION: Systolic BP is inversely associated with 25(OH)D levels in Whites but not in Blacks. Vitamin D may not be a major contributor to the White-Black differential in BP.

Nutrition and vascular dementia.

OBJECTIVE: The objective of this review was to elucidate the relationship between VaD and various nutritional factors based on epidemiological studies. BACKGROUND: Vascular dementia (VaD) is the second most common type of dementia. The prevalence of VaD continues to increase as the US population continues to grow and age. Currently, control of potential risk factors is believed to be the most effective means of preventing VaD. Thus, identification of modifiable risk factors for VaD is crucial for development of effective treatment modalities. Nutrition is one of the main modifiable variables that may influence the development of VaD. METHODS: A systematic review of literature was conducted using the PubMed, Web of Science, and CINAHL Plus databases with search parameters inclusive of vascular dementia, nutrition, and vascular cognitive impairment (VCI). RESULTS: Fourteen articles were found that proposed a potential role of specific nutritional components in VaD. These components included antioxidants, lipids, homocysteine, folate, vitamin B12, and fish consumption. Antioxidants, specifically Vitamin E and C, and fatty fish intake were found to be protective against VaD risk. Fried fish, elevated homocysteine, and lower levels of folate and vitamin B12 were associated with increased VaD. Evidence for dietary lipids was inconsistent, although elevated midlife serum cholesterol may increase risk, while late-life elevated serum cholesterol may be associated with decreased risk of VaD. CONCLUSION: Currently, the most convincing evidence as to the relationship between VaD and nutrition exists for micronutrients, particularly Vitamin E and C. Exploration of nutrition at the macronutrient level and additional long term prospective cohort studies are warranted to better understand the role of nutrition in VaD disease development and progression. At present, challenges in this research include limitations in sample size, which was commonly cited. Also, a variety of diagnostic criteria for VaD were employed in the studies reviewed, indicating the need for constructing a correct nosological definition of VaD for consistency and conformity in future studies and accurate clinical diagnosis of VaD.

Influence of body mass index and serum lipids on the cholesterol-lowering effects of almonds in free-living individuals.

BACKGROUND AND AIMS: Short-term (4-9 weeks) human feeding trials have shown nut consumption to reduce serum total cholesterol (TC) and LDL-cholesterol (LDL). We hypothesized that individual levels of BMI, LDL, TC and triglycerides modify the cholesterol-lowering effect of almonds in a 24-week almond supplementation trial in a free-living population. METHODS AND RESULTS: We performed secondary analysis on data from a previously published study. Using a sequential study design, all participants followed their habitual diets during the first six months (control), and then consumed an almond-supplemented diet (habitual + almonds) for another six months. 100 adults enrolled; 19 were lost to attrition. Those who completed the study were men (n = 43) and women (n = 38) with mean (SD) age 49.4 (13.6) years. During almond supplementation, we found statistically significant changes in TC (-0.22 mmol/L), LDL (-0.22 mmol/L), TC:HDL (-0.35), and LDL:HDL (-0.28) in participants with baseline LDL levels ≥ 3.30 mmol/L, but not among normocholesterolemic individuals. Direction and magnitude of change were similar among individuals with TC ≥ 5.20 mmol/L but not in the lower strata. Tests of interaction (diet × TC and diet × LDL) were significant. Reductions in the ratios TC:HDL, and LDL:HDL were significant among those with BMI < 25 kg/m(2), but not in heavier individuals; however, formal tests of interaction did not reach significance. CONCLUSIONS: We provide strong evidence that the cholesterol-lowering effect of almonds is responsive among hypercholesterolemic individuals, and weak evidence that BMI modifies the effect of almonds on serum lipids.

Gender inequality in food intake and nutritional status of children under 5 years old in rural Eastern Kenya.

BACKGROUND/OBJECTIVE: Although gender inequality in nutritional status has been consistently reported in several parts of South Asia, in sub-Sahara Africa there is a paucity of data and conflicting conclusions. We conducted a study to assess if gender inequality in food intake and nutritional status is present in rural Eastern Kenya. SUBJECTS/METHODS: This was a descriptive cross sectional study conducted in the Mwingi and Makueni districts of Ukambani region in Eastern Kenya, two rural districts where grains are the main contributor of energy intake. There were 629 children aged <60 months, randomly selected for participation in the study. RESULTS: Boys consistently had higher energy intakes than girls (P = 0.005). More girls were stunted, underweight and wasted 51.7%, (49.9-53.5), 32.1%, (30.4-33.7), 4.6%, (3.9-5.4) than boys 35.9% (34.2-37.7), 14.6% (13.4-15.9) and 1.2% (0.8-1.6), respectively, P < 0.001. Of the total, 24.6% (23.1-26.2) of the girls were severely stunted compared with boys 16.3% (15.0-17.7). Boys had higher Z-score indices (height-for-age (HAZ) = -1.33 ± 1.86, weight-for-age (WAZ) = -0.60 ± 1.53 and weight-for-height (WHZ) = 0.25 ± 1.23) than girls (HAZ = -2.02 ± 1.94, WAZ = -1.37 ± 1.27 and WHZ = -0.10 ± 1.49), all P < 0.001. CONCLUSIONS: The prevalence of malnutrition among children in rural Eastern Kenya is sizable. However, girls were more stunted, underweight and wasted than boys at all age categories due to their consistent lower food intake. Further research is needed to expose the social and cultural determinants underlying gender discrimination in intra-household allocation of food.

Effect of n-3 fatty acid enriched eggs and organic eggs on serum lutein in free-living lacto-ovo vegetarians.

BACKGROUND/OBJECTIVE: Lutein is a xanthophyll found in the chloroplasts of dark green leafy vegetables, chromoplasts of fruits, and egg yolk. Dietary, serum and macular lutein are inversely related to the risk of age-related macular degeneration. Although the lutein from egg is known to be more bioavailable than that from spinach, not much is known about lutein bioavailability from n-3 fatty acid enriched eggs and organic eggs, both of which are increasingly available to consumers. SUBJECTS/METHODS: We determined the effects of feeding n-3 fatty acid-enriched eggs and organic eggs on serum lutein, zeaxanthin and ß-carotene in 20 healthy lacto-ovo-vegetarian (LOV) adults using a single-blind, randomized, crossover study design with a 4-week washout between treatments: six organic eggs or six n-3 fatty acid enriched eggs per week or no egg control for 8 weeks each. RESULTS: Serum lutein was significantly higher in both egg treatments (P<0.009) compared with the control, but was not different between the two egg treatments. Serum ß-carotene was also higher in the egg groups compared with control but only approached significance (P=0.066). Serum zeaxanthin increased in both egg treatments compared with control but did not reach statistical significance (P=0.139). CONCLUSION: n-3 fatty acid enriched eggs and organic eggs may both significantly increase serum lutein in healthy LOV consuming a predominately plant-based diet.