To review the contribution of the Nurses' Health Studies (NHS and NHS II) in addressing hypotheses regarding risk factors for and consequences of obesity.
Narrative review of the publications of the ...NHS and NHS II between 1976 and 2016.
Long-term NHS research has shown that weight gain and being overweight or obese are important risk factors for type 2 diabetes, cardiovascular diseases, certain types of cancers, and premature death. The cohorts have elucidated the role of dietary and lifestyle factors in obesity, especially sugar-sweetened beverages, poor diet quality, physical inactivity, prolonged screen time, short sleep duration or shift work, and built environment characteristics. Genome-wide association and gene-lifestyle interaction studies have shown that genetic factors predispose individuals to obesity but that such susceptibility can be attenuated by healthy lifestyle choices. This research has contributed to evolving clinical and public health guidelines on the importance of limiting weight gain through healthy dietary and lifestyle behaviors.
The NHS cohorts have contributed to our understanding of the risk factors for and consequences of obesity and made a lasting impact on clinical and public health guidelines on obesity prevention.
BACKGROUND:Americans have a shorter life expectancy compared with residents of almost all other high-income countries. We aim to estimate the impact of lifestyle factors on premature mortality and ...life expectancy in the US population.
METHODS:Using data from the Nurses’ Health Study (1980–2014; n=78 865) and the Health Professionals Follow-up Study (1986–2014, n=44 354), we defined 5 low-risk lifestyle factors as never smoking, body mass index of 18.5 to 24.9 kg/m, ≥30 min/d of moderate to vigorous physical activity, moderate alcohol intake, and a high diet quality score (upper 40%), and estimated hazard ratios for the association of total lifestyle score (0–5 scale) with mortality. We used data from the NHANES (National Health and Nutrition Examination Surveys; 2013–2014) to estimate the distribution of the lifestyle score and the US Centers for Disease Control and Prevention WONDER database to derive the age-specific death rates of Americans. We applied the life table method to estimate life expectancy by levels of the lifestyle score.
RESULTS:During up to 34 years of follow-up, we documented 42 167 deaths. The multivariable-adjusted hazard ratios for mortality in adults with 5 compared with zero low-risk factors were 0.26 (95% confidence interval CI, 0.22–0.31) for all-cause mortality, 0.35 (95% CI, 0.27–0.45) for cancer mortality, and 0.18 (95% CI, 0.12–0.26) for cardiovascular disease mortality. The population-attributable risk of nonadherence to 5 low-risk factors was 60.7% (95% CI, 53.6–66.7) for all-cause mortality, 51.7% (95% CI, 37.1–62.9) for cancer mortality, and 71.7% (95% CI, 58.1–81.0) for cardiovascular disease mortality. We estimated that the life expectancy at age 50 years was 29.0 years (95% CI, 28.3–29.8) for women and 25.5 years (95% CI, 24.7–26.2) for men who adopted zero low-risk lifestyle factors. In contrast, for those who adopted all 5 low-risk factors, we projected a life expectancy at age 50 years of 43.1 years (95% CI, 41.3–44.9) for women and 37.6 years (95% CI, 35.8–39.4) for men. The projected life expectancy at age 50 years was on average 14.0 years (95% CI, 11.8–16.2) longer among female Americans with 5 low-risk factors compared with those with zero low-risk factors; for men, the difference was 12.2 years (95% CI, 10.1–14.2).
CONCLUSIONS:Adopting a healthy lifestyle could substantially reduce premature mortality and prolong life expectancy in US adults.
IMPORTANCE Epidemiologic studies have suggested that higher intake of added sugar is associated with cardiovascular disease (CVD) risk factors. Few prospective studies have examined the association ...of added sugar intake with CVD mortality. OBJECTIVE To examine time trends of added sugar consumption as percentage of daily calories in the United States and investigate the association of this consumption with CVD mortality. DESIGN, SETTING, AND PARTICIPANTS National Health and Nutrition Examination Survey (NHANES, 1988-1994 III, 1999-2004, and 2005-2010 n = 31 147) for the time trend analysis and NHANES III Linked Mortality cohort (1988-2006 n = 11 733), a prospective cohort of a nationally representative sample of US adults for the association study. MAIN OUTCOMES AND MEASURES Cardiovascular disease mortality. RESULTS Among US adults, the adjusted mean percentage of daily calories from added sugar increased from 15.7% (95% CI, 15.0%-16.4%) in 1988-1994 to 16.8% (16.0%-17.7%; P = .02) in 1999-2004 and decreased to 14.9% (14.2%-15.5%; P < .001) in 2005-2010. Most adults consumed 10% or more of calories from added sugar (71.4%) and approximately 10% consumed 25% or more in 2005-2010. During a median follow-up period of 14.6 years, we documented 831 CVD deaths during 163 039 person-years. Age-, sex-, and race/ethnicity–adjusted hazard ratios (HRs) of CVD mortality across quintiles of the percentage of daily calories consumed from added sugar were 1.00 (reference), 1.09 (95% CI, 1.05-1.13), 1.23 (1.12-1.34), 1.49 (1.24-1.78), and 2.43 (1.63-3.62; P < .001), respectively. After additional adjustment for sociodemographic, behavioral, and clinical characteristics, HRs were 1.00 (reference), 1.07 (1.02-1.12), 1.18 (1.06-1.31), 1.38 (1.11-1.70), and 2.03 (1.26-3.27; P = .004), respectively. Adjusted HRs were 1.30 (95% CI, 1.09-1.55) and 2.75 (1.40-5.42; P = .004), respectively, comparing participants who consumed 10.0% to 24.9% or 25.0% or more calories from added sugar with those who consumed less than 10.0% of calories from added sugar. These findings were largely consistent across age group, sex, race/ethnicity (except among non-Hispanic blacks), educational attainment, physical activity, health eating index, and body mass index. CONCLUSIONS AND RELEVANCE Most US adults consume more added sugar than is recommended for a healthy diet. We observed a significant relationship between added sugar consumption and increased risk for CVD mortality.
Due to the rapidly increasing availability of metabolomics data in prospective studies, an update of the meta evidence on metabolomics and type 2 diabetes risk is warranted.
To conduct an updated ...systematic review and meta-analysis of plasma, serum, and urine metabolite markers and incident type 2 diabetes.
We searched PubMed and Embase until 6 March 2021.
We selected prospective observational studies where investigators used high-throughput techniques to investigate the relationship between plasma, serum, or urine metabolites and incident type 2 diabetes.
Baseline metabolites per-SD risk estimates and 95% CIs for incident type 2 diabetes were extracted from all eligible studies.
A total of 61 reports with 71,196 participants and 11,771 type 2 diabetes cases/events were included in the updated review. Meta-analysis was performed for 412 metabolites, of which 123 were statistically significantly associated (false discovery rate-corrected P < 0.05) with type 2 diabetes risk. Higher plasma and serum levels of certain amino acids (branched-chain, aromatic, alanine, glutamate, lysine, and methionine), carbohydrates and energy-related metabolites (mannose, trehalose, and pyruvate), acylcarnitines (C4-DC, C4-OH, C5, C5-OH, and C8:1), the majority of glycerolipids (di- and triacylglycerols), (lyso)phosphatidylethanolamines, and ceramides included in meta-analysis were associated with higher risk of type 2 diabetes (hazard ratio 1.07-2.58). Higher levels of glycine, glutamine, betaine, indolepropionate, and (lyso)phosphatidylcholines were associated with lower type 2 diabetes risk (hazard ratio 0.69-0.90).
Substantial heterogeneity (I2 > 50%, τ2 > 0.1) was observed for some of the metabolites.
Several plasma and serum metabolites, including amino acids, lipids, and carbohydrates, are associated with type 2 diabetes risk.
Prospective associations between n-3 fatty acid biomarkers and type 2 diabetes (T2D) risk are not consistent in individual studies. We aimed to summarize the prospective associations of biomarkers of ...α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) with T2D risk through an individual participant-level pooled analysis.
For our analysis we incorporated data from a global consortium of 20 prospective studies from 14 countries. We included 65,147 participants who had blood measurements of ALA, EPA, DPA, or DHA and were free of diabetes at baseline. De novo harmonized analyses were performed in each cohort following a prespecified protocol, and cohort-specific associations were pooled using inverse variance-weighted meta-analysis.
A total of 16,693 incident T2D cases were identified during follow-up (median follow-up ranging from 2.5 to 21.2 years). In pooled multivariable analysis, per interquintile range (difference between the 90th and 10th percentiles for each fatty acid), EPA, DPA, DHA, and their sum were associated with lower T2D incidence, with hazard ratios (HRs) and 95% CIs of 0.92 (0.87, 0.96), 0.79 (0.73, 0.85), 0.82 (0.76, 0.89), and 0.81 (0.75, 0.88), respectively (all
< 0.001). ALA was not associated with T2D (HR 0.97 95% CI 0.92, 1.02) per interquintile range. Associations were robust across prespecified subgroups as well as in sensitivity analyses.
Higher circulating biomarkers of seafood-derived n-3 fatty acids, including EPA, DPA, DHA, and their sum, were associated with lower risk of T2D in a global consortium of prospective studies. The biomarker of plant-derived ALA was not significantly associated with T2D risk.
Recent attention has focused on fructose as having a unique role in the pathogenesis of cardiometabolic diseases. However, because we rarely consume fructose in isolation, the major source of ...fructose in the diet comes from fructose-containing sugars, sucrose and high fructose corn syrup, in sugar-sweetened beverages and foods. Intake of sugar-sweetened beverages has been consistently linked to increased risk of obesity, type 2 diabetes, and cardiovascular disease in various populations. Putative underlying mechanisms include incomplete compensation for liquid calories, adverse glycemic effects, and increased hepatic metabolism of fructose leading to de novo lipogenesis, production of uric acid, and accumulation of visceral and ectopic fat. In this review we summarize the epidemiological and clinical trial evidence evaluating added sugars, especially sugar-sweetened beverages, and the risk of obesity, diabetes, and cardiovascular disease and address potential biological mechanisms with an emphasis on fructose physiology. We also discuss strategies to reduce intake of fructose-containing beverages.
Plant-based diets are recommended for coronary heart disease (CHD) prevention. However, not all plant foods are necessarily beneficial for health.
This study sought to examine associations between ...plant-based diet indices and CHD incidence.
We included 73,710 women in NHS (Nurses’ Health Study) (1984 to 2012), 92,329 women in NHS2 (1991 to 2013), and 43,259 men in Health Professionals Follow-up Study (1986 to 2012), free of chronic diseases at baseline. We created an overall plant-based diet index (PDI) from repeated semiquantitative food-frequency questionnaire data, by assigning positive scores to plant foods and reverse scores to animal foods. We also created a healthful plant-based diet index (hPDI) where healthy plant foods (whole grains, fruits/vegetables, nuts/legumes, oils, tea/coffee) received positive scores, whereas less-healthy plant foods (juices/sweetened beverages, refined grains, potatoes/fries, sweets) and animal foods received reverse scores. To create an unhealthful PDI (uPDI), we gave positive scores to less-healthy plant foods and reverse scores to animal and healthy plant foods.
Over 4,833,042 person-years of follow-up, we documented 8,631 incident CHD cases. In pooled multivariable analysis, higher adherence to PDI was independently inversely associated with CHD (hazard ratio HR comparing extreme deciles: 0.92; 95% confidence interval CI: 0.83 to 1.01; p trend = 0.003). This inverse association was stronger for hDPI (HR: 0.75; 95% CI: 0.68 to 0.83; p trend <0.001). Conversely, uPDI was positively associated with CHD (HR: 1.32; 95% CI: 1.20 to 1.46; p trend <0.001).
Higher intake of a plant-based diet index rich in healthier plant foods is associated with substantially lower CHD risk, whereas a plant-based diet index that emphasizes less-healthy plant foods is associated with higher CHD risk.
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Studies have found beneficial effects of plant-based diets on weight. However, not all plant foods are necessarily beneficial.
The aim of this study was to examine associations of changes in intake ...of 3 variations of plant-based diet indices (overall, healthful, and unhealthful) with weight change over 4-y intervals spanning >20 y.
Data from 3 ongoing prospective observational cohort studies in the United States were used, namely the Nurses’ Health Study (NHS), NHS2, and the Health Professionals Follow-up Study (HPFS), with 126,982 adult men and women. Self-reported diet data were collected every 4 y, and self-reported weight data were used to compute weight change every 4 y over >20 y of follow-up.
On average, participants gained a mean of 0.90 kg (HPFS) to 1.98 kg (NHS2) over 4-y intervals. Different types of plant-based diet indices were associated with different amounts of weight gain. After adjusting for several potential confounders, including concomitant changes in other lifestyle factors, a 1-SD increase in intake of an overall plant-based diet index was associated with 0.04 kg less weight gain over 4-y periods (95% CI: 0.05, 0.02 kg; P < 0.001). A 1-SD increase in intake of a healthful version of a plant-based diet index (emphasizing whole grains, fruits/vegetables, nuts/legumes, vegetable oils, tea/coffee) was associated with 0.68 kg less weight gain over 4-y periods (95% CI: 0.69, 0.66 kg; P < 0.001). Conversely, a 1-SD increase in an unhealthful version of a plant-based diet index (emphasizing refined grains, potato/fries, sweets, sweetened drinks/juices) was associated with 0.36 kg more weight gain (95% CI: 0.34, 0.37 kg, P < 0.001).
Plant-based diets, especially when rich in healthier plant foods, are associated with less weight gain over 4-y intervals. This supports current recommendations to increase intake of healthy plant foods, and reducing intake of less-healthy plant foods and animal foods, for improved health outcomes.
The article discusses the growing use of plant-based meat alternatives (PBMAs) as a replacement to meat-rich diets in order to help promote a healthy and sustainable diet. However, some of the policy ...and technological changes that are necessary to make this system possible are highlighted.
BACKGROUND:Whether consumption of sugar-sweetened beverages (SSBs) or artificially sweetened beverages (ASBs) is associated with risk of mortality is of public health interest.
METHODS:We examined ...associations between consumption of SSBs and ASBs with risk of total and cause-specific mortality among 37 716 men from the Health Professional’s Follow-up study (from 1986 to 2014) and 80 647 women from the Nurses’ Health study (from 1980 to 2014) who were free from chronic diseases at baseline. Cox proportional hazards regression was used to estimate hazard ratios and 95% confidence intervals.
RESULTS:We documented 36 436 deaths (7896 cardiovascular disease CVD and 12 380 cancer deaths) during 3 415 564 person-years of follow-up. After adjusting for major diet and lifestyle factors, consumption of SSBs was associated with a higher risk of total mortality; pooled hazard ratios (95% confidence intervals) across categories (<1/mo, 1–4/mo, 2–6/week, 1-<2/d, and ≥2/d) were 1.00 (reference), 1.01 (0.98, 1.04), 1.06 (1.03, 1.09), 1.14 (1.09, 1.19), and 1.21 (1.13, 1.28; P trend <0.0001). The association was observed for CVD mortality (hazard ratio comparing extreme categories was 1.31 95% confidence interval, 1.15, 1.50, P trend <0.0001) and cancer mortality (1.16 1.04, 1.29, P trend =0.0004). ASBs were associated with total and CVD mortality in the highest intake category only; pooled hazard ratios (95% confidence interval) across categories were 1.00 (reference), 0.96 (0.93, 0.99), 0.97 (0.95, 1.00), 0.98 (0.94, 1.03), and 1.04 (1.02, 1.12; P trend = 0.01) for total mortality and 1.00 (reference), 0.93 (0.87, 1.00), 0.95 (0.89, 1.00), 1.02 (0.94, 1.12), and 1.13 (1.02, 1.25; P trend = 0.02) for CVD mortality. In cohort-specific analysis, ASBs were associated with mortality in NHS (Nurses’ Health Study) but not in HPFS (Health Professionals Follow-up Study) (P interaction, 0.01). ASBs were not associated with cancer mortality in either cohort.
CONCLUSIONS:Consumption of SSBs was positively associated with mortality primarily through CVD mortality and showed a graded association with dose. The positive association between high intake levels of ASBs and total and CVD mortality observed among women requires further confirmation.