Person:

Malik, Vasanti

Background: The prevalence of type 2 diabetes has been reaching epidemic proportions across the globe, affecting low/middle-income and developed countries. Two main contributors to this burden are the reduction in mortality from infectious conditions and concomitant negative changes in lifestyles, including diet. We aimed to depict the current state of type 2 diabetes worldwide in light of the undergoing epidemiologic and nutrition transition, and to posit that a key factor in the nutrition transition has been the shift in the type and processing of staple foods, from less processed traditional foods to highly refined and processed carbohydrate sources. Discussion We showed data from 11 countries participating in the Global Nutrition and Epidemiologic Transition Initiative, a collaborative effort across countries at various stages of the nutrition-epidemiologic transition whose mission is to reduce diabetes by improving the quality of staple foods through culturally-appropriate interventions. We depicted the epidemiologic transition using demographic and mortality data from the World Health Organization, and the nutrition transition using data from the Food and Agriculture Organization food balance sheets. Main staple foods (maize, rice, wheat, pulses, and roots) differed by country, with most countries undergoing a shift in principal contributors to energy consumption from grains in the past 50 years. Notably, rice and wheat products accounted for over half of the contribution to energy consumption from staple grains, while the trends for contribution from roots and pulses generally decreased in most countries. Global Nutrition and Epidemiologic Transition Initiative countries with pilot data have documented key barriers and motivators to increase intake of high-quality staple foods. Summary Global research efforts to identify and promote intake of culturally-acceptable high-quality staple foods could be crucial in preventing diabetes. These efforts may be valuable in shaping future research, community interventions, and public health and nutritional policies.

Objective: Whether dietary habits early in life can affect risk of type 2 diabetes (T2DM) in adulthood is unknown. We evaluated the relationship between dietary patterns during adolescence and risk of T2DM in midlife. Research design and methods: We examined the 7-year incidence of T2DM in relation to dietary patterns during high school among 37,038 participants in the Nurses’ Health Study II cohort, who completed a food-frequency questionnaire about their diet during high school. Dietary patterns were derived by factor analysis. Cox proportional hazards regression was used to estimate relative risk (RR) and 95% CI. Results: The prudent pattern, characterized by healthy foods, was not associated with risk of T2DM. The Western pattern, characterized by desserts, processed meats, and refined grains, was associated with 29% greater risk of T2DM (RR 1.29; 95% CI 1.00–1.66; P trend 0.04), after adjusting for high school and adult risk factors comparing extreme quintiles, but was attenuated after adjusting for adult weight change (1.19; 0.92–1.54). Women who had high Western pattern scores in high school and adulthood had an elevated risk of T2DM compared with women who had consistent low scores (1.82; 1.35–2.45), and this association was partly mediated by adult BMI (1.15; 0.85–1.56). Conclusions: A Western dietary pattern during adolescence may increase risk of T2DM in later life, partly through adult weight gain. Preventive measures should be aimed at developing healthy dietary habits that begin in early life and continue through adulthood.

Background: Evidence regarding the consumption of soy foods and isoflavones in relation to risk of type 2 diabetes (T2D) is scarce. Objective: Our study was to evaluate the association between soy food and isoflavone consumption and risk of T2D in US men and women. Methods: We followed 63,115 women in the Nurses’ Health Study (1998-2012), 79,061 women in the Nurses’ Health Study II (1999-2013), and 21,281 men in the Health Professionals Follow-Up Study (2002-2010). Diet was assessed by a validated food-frequency questionnaire, and was updated every 4 y. Self-reports of incident T2D was confirmed by a validated supplementary questionnaire. Results: During 1,966,321 person-years of follow-up, 9,185 incident T2D cases were documented. After multivariate adjustment for covariates, consumption of soy foods (tofu and soy milk) was not associated with a lower T2D risk. Compared to non-consumers of soy foods, the hazard ratio (HR) was 1.00 (95% CI: 0.93, 1.07) for <1 serving/week, and 0.93 (95% CI: 0.83, 1.03) for ≥1 serving/week of soy foods (P for trend = 0.14). In contrast, intake of total isoflavones was inversely associated with T2D risk. Comparing extreme quintiles of isoflavones, the HR was 0.89 (95% CI: 0.83, 0.96; P for trend = 0.009). Inverse associations were also found for consumption of major individual isoflavones, including daidzein and genistein, with risk of T2D. Conclusions: Intake of isoflavones was associated with a modestly lower T2D risk in US men and women who typically consumed low to moderate amounts of soy foods. These findings warrant replications in other populations with similar soy intake levels.

Objective: To examine the long-term relationship between changes in water and beverage intake and weight change. Subjects Prospective cohort studies of 50 013 women aged 40-64 in the Nurses’ Health Study (NHS, 1986-2006), 52 987 women aged 27-44 in the NHS II (1991-2007), and 21 988 men aged 40-64 in the Health Professionals Follow-up Study (1986-2006) without obesity and chronic diseases at baseline. Measures We assessed the association of weight change within each 4-year interval with changes in beverage intakes and other lifestyle behaviors during the same period. Multivariate linear regression with robust variance and accounting for within-person repeated measures were used to evaluate the association. Results across the three cohorts were pooled by an inverse-variance-weighted meta-analysis. Results: Participants gained an average of 1.45 kg (5th to 95th percentile, −1.87 to 5.46) within each 4-year period. After controlling for age, baseline body mass index, and changes in other lifestyle behaviors (diet, smoking habits, exercise, alcohol, sleep duration, TV watching), each 1-cup/d increment of water intake was inversely associated with weight gain within each 4-year period (−0.13 kg; 95% CI: −0.17, −0.08). The associations for other beverages were: SSBs (0.36 kg; 0.24, 0.48), fruit juice (0.22 kg; 0.15, 0.28), coffee (−0.14 kg; −0.19, −0.09), tea (−0.03 kg; −0.05, −0.01), diet beverages (−0.10 kg; −0.14, −0.06), low-fat milk (0.02 kg; −0.04, 0.09), and whole milk (0.02 kg; −0.06, 0.10). We estimated that replacement of 1 serving/d of SSBs by 1 cup/d of water was associated with 0.49 kg (95% CI: 0.32, 0.65) less weight gain over each 4-year period, and the replacement estimate of fruit juices by water was 0.35 kg (95% CI: 0.23, 0.46). Substitution of SSBs or fruit juices by other beverages (coffee, tea, diet beverages, low-fat and whole milk) were all significantly and inversely associated with weight gain. Conclusion: Our results suggest that increasing water intake in place of SSBs or fruit juices is associated with lower long-term weight gain.

Aims/hypothesis Studies suggest a potential link between low-grade metabolic acidosis and type 2 diabetes. A western dietary pattern increases daily acid load but the association between diet-dependent acid load and type 2 diabetes is still unclear. This study aimed to assess whether diet-dependent acid load is associated with the risk of type 2 diabetes. Methods: We examined the association between energy-adjusted net endogenous acid production (NEAP), potential renal acid load (PRAL) and animal protein-to-potassium ratio (A:P) on incident type 2 diabetes in 67,433 women from the Nurses’ Health Study, 84,310 women from the Nurses’ Health Study II and 35,743 men from the Health Professionals’ Follow-up Study who were free from type 2 diabetes, cardiovascular disease and cancer at baseline. Study-specific HRs were estimated using Cox proportional hazards models with time-varying covariates and were pooled using a random effects meta-analysis. Results: We documented 15,305 cases of type 2 diabetes during 4,025,131 person-years of follow-up. After adjustment for diabetes risk factors, dietary NEAP, PRAL and A:P were positively associated with type 2 diabetes (pooled HR [95% CI] for highest (Q5) vs lowest quintile (Q1): 1.29 [1.22, 1.37], ptrend <0.0001; 1.29 [1.22, 1.36], ptrend <0.0001 and 1.32 [1.24, 1.40], ptrend <0.0001 for NEAP, PRAL and A:P, respectively). These results were not fully explained by other dietary factors including glycaemic load and dietary quality (HR [95% CI] for Q5 vs Q1: 1.21 [1.09, 1.33], ptrend <0.0001; 1.19 [1.08, 1.30] and 1.26 [1.17, 1.36], ptrend <0.0001 for NEAP, PRAL and A:P, respectively). Conclusions/interpretation This study suggests that higher diet-dependent acid load is associated with an increased risk of type 2 diabetes. This association is not fully explained by diabetes risk factors and overall diet quality.