Changes in Coffee Intake, Added Sugar and Long-Term Weight Gain - Results from Three Large Prospective US Cohort Studies.

BACKGROUND: Consumption of both caffeinated and decaffeinated coffee has been reported to attenuate long-term weight gain. Whether the association between coffee consumption and weight gain depends on the addition of sugar, cream, or coffee whitener remains unclear. OBJECTIVE: We aimed to study the associations between changes in coffee consumption, caffeine intake, and weight changes by considering the addition of sugar, cream, or a nondairy coffee whitener. METHODS: We used 3 large prospective cohorts - the Nurses' Health Study (1986 - 2010), Nurses' Health Study II (1991 - 2015) and Health Professional Follow-up Study (1991 - 2014). We applied multivariable linear regression models with robust variance estimators to assess the association of changes in coffee habits within each 4-y interval with concurrent weight changes. Results across the 3 cohorts were pooled using inverse-variance weights. RESULTS: After multivariable adjustment, each 1 cup per day increment in unsweetened caffeinated coffee was associated with a reduction in 4-y weight gain of -0.12 kg (95 % CI: -0.18, -0.05 kg) and of -0.12 kg (95 % CI: -0.16, -0.08 kg) for unsweetened decaffeinated coffee. The habits of adding cream or nondairy coffee whitener were not significantly linked to weight changes. Adding a teaspoon of sugar was associated with a 4-y weight gain of +0.09 kg (0.07, 0.12 kg). Stratified analyses suggested stronger magnitude of the observed associations with younger age and higher baseline BMI. Neither caffeine nor coffee modified the association of adding sugar to any food or beverage with weight changes. CONCLUSIONS: An increase in intake of unsweetened caffeinated and decaffeinated coffee was inversely associated with weight gain. The addition of sugar to coffee counteracted coffee's benefit for possible weight management. To the contrary, adding cream or coffee whitener was not associated with greater weight gain.

Increase from low to moderate, but not high, caffeinated coffee consumption is associated with favorable changes in body fat.

BACKGROUND & AIMS: Higher consumption of coffee and caffeine has been linked to less weight gain and lower body mass index in prospective cohort studies. The aim of the study was to longitudinally assess the association of changes in coffee and caffeine intake with changes in fat tissue, in particular, visceral adipose tissue (VAT) using dual x-ray absorptiometry (DXA). METHODS: In the setting of a large, randomized trial of Mediterranean diet and physical activity intervention, we evaluated 1483 participants with metabolic syndrome (MetS). Repeated measurements of coffee consumption from validated food frequency questionnaires (FFQ) and DXA measurements of adipose tissue were collected at baseline, 6 months, 12 months and 3 years of follow-up. DXA-derived measurements of total and regional adipose tissue expressed as % of total body weight were transformed into sex-specific z-scores. Linear multilevel mixed-effect models were used to investigate the relationship between changes in coffee consumption and corresponding concurrent changes in fat tissue during a 3-year follow-up. RESULTS: After adjustment for intervention group, and other potential confounders, an increase in caffeinated coffee consumption from no or infrequent consumption (≤3 cups/month) to moderate consumption (1-7 cups/week) was associated with reductions in total body fat (Δ z-score: -0.06; 95% CI: -0.11 to -0.02), trunk fat (Δ z-score: -0.07; 95% CI: -0.12 to -0.02), and VAT (Δ z-score: -0.07; 95% CI: -0.13 to -0.01). Neither changes from no or infrequent consumption to high levels of caffeinated coffee consumption (>1 cup/day) nor any changes in decaffeinated coffee consumption showed significant associations with changes in DXA measures. CONCLUSIONS: Moderate changes in the consumption of caffeinated coffee, but not changes to high consumption, were associated with reductions in total body fat, trunk fat and VAT in a Mediterranean cohort with MetS. Decaffeinated coffee was not linked to adiposity indicators. Moderate consumption of caffeinated coffee may be part of a weight management strategy. TRIAL REGISTRATION: The trial was registered at the International Standard Randomized Controlled Trial (ISRCTN: http://www.isrctn.com/ISRCTN89898870) with number 89898870 and registration date of 24 July 2014, retrospectively registered.

Vitamin D in Cancer Prevention: Gaps in Current Knowledge and Room for Hope.

Intensive epigenome and transcriptome analyses have unveiled numerous biological mechanisms, including the regulation of cell differentiation, proliferation, and induced apoptosis in neoplastic cells, as well as the modulation of the antineoplastic action of the immune system, which plausibly explains the observed population-based relationship between low vitamin D status and increased cancer risk. However, large randomized clinical trials involving cholecalciferol supplementation have so far failed to show the potential of such interventions in cancer prevention. In this article, we attempt to reconcile the supposed contradiction of these findings by undertaking a thorough review of the literature, including an assessment of the limitations in the design, conduct, and analysis of the studies conducted thus far. We examine the long-standing dilemma of whether the beneficial effects of vitamin D levels increase significantly above a critical threshold or if the conjecture is valid that an increase in available cholecalciferol translates directly into an increase in calcitriol activity. In addition, we try to shed light on the high interindividual epigenetic and transcriptomic variability in response to cholecalciferol supplementation. Moreover, we critically review the standards of interpretation of the available study results and propose criteria that could allow us to reach sound conclusions in this field. Finally, we advocate for options tailored to individual vitamin D needs, combined with a comprehensive intervention that favors prevention through a healthy environment and responsible health behaviors.