Importance Although emphasis has recently been placed on the importance of high-protein diets to overall health, a comprehensive analysis of long-term cause-specific mortality in association with the intake of plant protein and animal protein has not been reported. Objective To examine the associations between overall mortality and cause-specific mortality and plant protein intake. Design, Setting, and Participants This prospective cohort study analyzed data from 416 104 men and women in the US National Institutes of Health–AARP Diet and Health Study from 1995 to 2011. Data were analyzed from October 2018 through April 2020. Exposures Validated baseline food frequency questionnaire dietary information, including intake of plant protein and animal protein. Main Outcomes and Measures Hazard ratios and 16-year absolute risk differences for overall mortality and cause-specific mortality. Results The final analytic cohort included 237 036 men (57%) and 179 068 women. Their overall median (SD) ages were 62.2 (5.4) years for men and 62.0 (5.4) years for women. Based on 6 009 748 person-years of observation, 77 614 deaths (18.7%; 49 297 men and 28 317 women) were analyzed. Adjusting for several important clinical and other risk factors, greater dietary plant protein intake was associated with reduced overall mortality in both sexes (hazard ratio per 1 SD was 0.95 [95% CI, 0.94-0.97] for men and 0.95 [95% CI, 0.93-0.96] for women; adjusted absolute risk difference per 1 SD was −0.36% [95% CI, −0.48% to −0.25%] for men and −0.33% [95% CI, −0.48% to −0.21%] for women; hazard ratio per 10 g/1000 kcal was 0.88 [95% CI, 0.84-0.91] for men and 0.86 [95% CI, 0.82-0.90] for women; adjusted absolute risk difference per 10 g/1000 kcal was −0.95% [95% CI, −1.3% to −0.68%] for men and −0.86% [95% CI, −1.3% to −0.55%] for women; allP < .001). The association between plant protein intake and overall mortality was similar across the subgroups of smoking status, diabetes, fruit consumption, vitamin supplement use, and self-reported health status. Replacement of 3% energy from animal protein with plant protein was inversely associated with overall mortality (risk decreased 10% in both men and women) and cardiovascular disease mortality (11% lower risk in men and 12% lower risk in women). In particular, the lower overall mortality was attributable primarily to substitution of plant protein for egg protein (24% lower risk in men and 21% lower risk in women) and red meat protein (13% lower risk in men and 15% lower risk in women). Conclusions and Relevance In this large prospective cohort, higher plant protein intake was associated with small reductions in risk of overall and cardiovascular disease mortality. Our findings provide evidence that dietary modification in choice of protein sources may influence health and longevity.

Rationale:: Although the health effects of beta carotene have been studied extensively, a systematic examination of serum concentrations and long-term mortality, including cardiovascular disease mortality, has not been reported. Objective:: Explore whether serum beta carotene is associated with overall and cause-specific mortality and to elucidate the strength and dose-response of the association. Methods and Results:: We conducted a prospective serological analysis of 29 103 men in the ATBC study (Alpha-Tocopherol, Beta-Carotene Cancer Prevention). During 31 years of follow-up, 23 796 deaths occurred, including deaths because of cardiovascular disease (9869), cancer (7692), respiratory disease (2161), diabetes mellitus (119), injuries and accidents (1255), and other causes (2700). Serum beta carotene was assayed using high-performance liquid chromatography. Adjusting for major risk factors measured, men with higher serum beta carotene had significantly lower all-cause mortality (hazard ratios=0.81, 0.71, 0.69, and 0.64 for quintile 2 (Q2)-Q5 versus Q1, respectively; P _trend <0.0001). Serum beta carotene was significantly associated with risk of death from cardiovascular disease, heart disease, stroke, cancer, respiratory disease, diabetes mellitus, injuries and accidents, and other causes (Q5 versus Q1, hazard ratio=0.21–0.73, all P _trend <0.0001). The all-cause mortality association was not materially impacted by adjustment for fruit and vegetable consumption (albeit, estimated with some measurement error) and was generally similar across subgroups of smoking intensity, alcohol consumption, trial supplementation, and duration of follow-up, but was significantly modified by age, years of smoking, and body mass index, with stronger inverse associations among men who were younger, smoked fewer years, and had a lower body mass index (all P _interaction ≤0.0025). Conclusions:: This study provides evidence that higher beta carotene biochemical status is associated with lower overall, cardiovascular disease, heart disease, stroke, cancer, and other causes of mortality. The dose-response associations over a 30-year period were not attenuated by adjustment for other important risk factors and support greater fruit and vegetable consumption as a means to increase beta carotene status and promote longevity.

Background: Two recent metabolomic analyses found serum lipid, energy, and other metabolites related to aggressive prostate cancer risk up to 20 years prior to diagnosis. Methods: We conducted a serum metabolomic investigation of prostate cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial that included annual serum total prostate-specific antigen measurement and digital rectal examination. This nested study included 380 cases diagnosed post-screening and 380 controls individually matched to cases on age, race, study centre, and blood-collection date (median time to diagnosis, 10 years (range 4.4–17 years)). Sera were analysed on a high-resolution accurate mass platform of ultrahigh-performance liquid and gas chromatography/mass spectroscopy that identified 695 known metabolites. Logistic regression conditioned on the matching factors estimated odds ratios (OR) and 95% confidence intervals of risk associated with an 80th percentile increase in the log-metabolite signal. Results: Twenty-seven metabolites were associated with prostate cancer at P<0.05. Pyroglutamine, gamma-glutamylphenylalanine, phenylpyruvate, N-acetylcitrulline, and stearoylcarnitine showed the strongest metabolite-risk signals (ORs=0.53, 0.51, 0.46, 0.58, and 1.74, respectively; 0.001⩽P⩽0.006). Findings were similar for aggressive disease (peptide chemical class, P=0.03). None of the P-values were below the threshold of Bonferroni correction, however. Conclusions: A unique metabolomic profile associated with post-screening prostate cancer is identified that differs from that in a previously studied, unscreened population.

Background: Despite substantial research highlighting the importance of exogenous dietary cholesterol intake and endogenous serum cholesterol level in human health, a thorough evaluation of the associations is lacking. Our study objective was to examine overall and cause-specific mortality in relation to dietary and serum cholesterol, as well as egg consumption, and conduct an updated meta-regression analysis of cohort studies. Methods: We conducted a prospective analysis of 27 078 men in the ATBC Study (Alpha-Tocopherol, Beta-Carotene Cancer Prevention). Multivariable-controlled cause-specific Cox proportional hazards regression models were used to calculate hazard ratios and 31-year absolute mortality risk differences. A systematic review and meta-analysis of cohort studies was also performed (PROSPERO [URL: https://www.crd.york.ac.uk/prospero/ ; Unique identifier: CRD42021272756]). Results: Based on 482 316 person-years of follow-up, we identified 22 035 deaths, including 9110 deaths from cardiovascular disease (CVD). Greater dietary cholesterol and egg consumption were associated with increased risk of overall and CVD-related mortality. Hazard ratios for each additional 300 mg cholesterol intake per day were 1.10 and 1.13 for overall and CVD-related mortality, respectively; for each additional 50-g egg consumed daily, hazard ratios were 1.06 and 1.09, respectively, for overall and CVD-related mortality (all P values<0.0001). After multivariable adjustment, higher serum total cholesterol concentrations were associated with increased risk of CVD-related mortality (hazard ratios per 1 SD increment, 1.14; P <0.0001). The observed associations were generally similar across cohort subgroups. The updated meta-analysis of cohort studies on the basis of 49 risk estimates, 3 601 401 participants, and 255 479 events showed consumption of 1 additional 50-g egg daily was associated with significantly increased CVD risk (pooled relative risk, 1.04 [95% CI, 1.00–1.08]; I ² =80.1%). In the subgroup analysis of geographic regions ( P _interaction =0.02), an increase of 50-g egg consumed daily was associated with a higher risk of CVD in US cohorts (pooled relative risk, 1.08 [95% CI, 1.02–1.14]) and appeared related to a higher CVD risk in European cohorts with borderline significance (pooled relative risk, 1.05), but was not associated with CVD risk in Asian cohorts. Conclusions: In this prospective cohort study and updated meta-analysis, greater dietary cholesterol and egg consumption were associated with increased risk of overall and CVD-related mortality. Our findings support restricted consumption of dietary cholesterol as a means to improve long-term health and longevity.

Rationale:: Although there has been a long-standing interest in the human health effects of vitamin E, a comprehensive analysis of the association between circulating vitamin E and long-term mortality has not been conducted. Objective:: Determine whether serum α-tocopherol (the predominant form of vitamin E) is related to long-term overall and cause-specific mortality and elucidate the dose-response relationships with better quantification of the associations. Methods and Results:: We conducted a biochemical analysis of 29 092 participants in the ATBC Study (Alpha-Tocopherol, Beta-Carotene Cancer Prevention) that originally tested vitamin E and β-carotene supplementation. Serum α-tocopherol was measured at baseline using high-performance liquid chromatography, and during a 30-year follow-up we identified 23 787 deaths, including deaths from cardiovascular disease (9867), cancer (7687), respiratory disease (2161), diabetes mellitus (119), injuries and accidents (1255), and other causes (2698). After adjusting for major risk factors, we found that men with higher serum α-tocopherol had significantly lower all-cause mortality (hazard ratios=0.83, 0.79, 0.75, and 0.78 for quintile 2 (Q2)–Q5 versus Q1, respectively; P _trend <0.0001), and significantly decreased mortality from cardiovascular disease, heart disease, stroke, cancer, respiratory disease, and other causes, with risk reductions from 17% to 47% for the highest versus lowest quintile. The α-tocopherol association with overall mortality was similar across subgroups of smoking intensity, years of smoking, alcohol consumption, trial supplementation, and duration of follow-up. The association was, however, significantly modified by baseline age and body mass index, with stronger inverse associations for younger men and men with a lower body mass index ( P _interaction ≤0.006). Conclusions:: In this long-term prospective cohort study, higher baseline serum α-tocopherol biochemical status was associated with lower risk of overall mortality and mortality from all major causes. Our data support the long-term health benefits of higher serum α-tocopherol for overall and chronic disease mortality and should be replicated in other more diverse populations.

Impaired metabolism may play an important role in the pathogenesis of lethal prostate cancer, yet there is a paucity of evidence regarding the association. We conducted a large prospective serum metabolomic analysis of lethal prostate cancer in 523 cases and 523 matched controls nested within the Alpha‐Tocopherol, Beta‐Carotene Cancer Prevention (ATBC) Study. Median time from baseline fasting serum collection to prostate cancer death was 18 years (maximum 30 years). We identified 860 known biochemicals through an ultrahigh‐performance LC–MS/MS platform. Conditional logistic regression models estimated odds ratios (OR) and 95% confidence intervals of risk associated with 1‐standard deviation (s.d.) increases in log‐metabolite signals. We identified 34 metabolites associated with lethal prostate cancer with a false discovery rate (FDR) < 0.15. Notably, higher serum thioproline, and thioproline combined with two other cysteine‐related amino acids and redox metabolites, cystine and cysteine, were associated with reduced risk (1‐s.d. OR = 0.75 and 0.71, respectively; p ≤ 8.2 × 10⁻⁵). By contrast, the dipeptide leucylglycine (OR = 1.36, p = 8.2 × 10⁻⁵), and three gamma‐glutamyl amino acids (OR = 1.28–1.30, p ≤ 4.6 × 10⁻⁴) were associated with increased risk of lethal prostate cancer. Cases with metastatic disease at diagnosis (n = 179) showed elevated risk for several lipids, including especially the ketone body 3‐hydroxybutyrate (BHBA), acyl carnitines, and dicarboxylic fatty acids (1.37 ≤ OR ≤ 1.49, FDR < 0.15). These findings provide a prospective metabolomic profile of lethal prostate cancer characterized by altered biochemicals in the redox, dipeptide, pyrimidine, and gamma‐glutamyl amino acid pathways, whereas ketone bodies and fatty acids were associated specifically with metastatic disease.