Background Diet is an important risk factor for cancer that is amenable to intervention. Estimating the cancer burden associated with diet informs evidence-based priorities for nutrition policies to reduce cancer burden in the United States. Methods Using a comparative risk assessment model that incorporated nationally representative data on dietary intake, national cancer incidence, and estimated associations of diet with cancer risk from meta-analyses of prospective cohort studies, we estimated the annual number and proportion of new cancer cases attributable to suboptimal intakes of seven dietary factors among US adults ages 20 years or older, and by population subgroups. Results An estimated 80 110 (95% uncertainty interval [UI] = 76 316 to 83 657) new cancer cases were attributable to suboptimal diet, accounting for 5.2% (95% UI = 5.0% to 5.5%) of all new cancer cases in 2015. Of these, 67 488 (95% UI = 63 583 to 70 978) and 4.4% (95% UI = 4.2% to 4.6%) were attributable to direct associations and 12 589 (95% UI = 12 156 to 13 038) and 0.82% (95% UI = 0.79% to 0.85%) to obesity-mediated associations. By cancer type, colorectal cancer had the highest number and proportion of diet-related cases (n = 52 225, 38.3%). By diet, low consumption of whole grains (n = 27 763, 1.8%) and dairy products (n = 17 692, 1.2%) and high intake of processed meats (n = 14 524, 1.0%) contributed to the highest burden. Men, middle-aged (45–64 years) and racial/ethnic minorities (non-Hispanic blacks, Hispanics, and others) had the highest proportion of diet-associated cancer burden than other age, sex, and race/ethnicity groups. Conclusions More than 80 000 new cancer cases are estimated to be associated with suboptimal diet among US adults in 2015, with middle-aged men and racial/ethnic minorities experiencing the largest proportion of diet-associated cancer burden in the United States.

Key Points Question What are the changes in the rural-urban distribution of the primary care workforce in the US from 2009 to 2017? Findings In this cross-sectional study of 3143 US counties (1167 urban and 1976 rural) using county-level data, the density of primary care clinicians increased significantly in both rural and urban counties from 2009 to 2017. The increase in primary care clinician density was more pronounced in urban counties compared with rural counties. Meaning In this study, the density of primary care clinicians increased overall, yet rural-urban disparities in the primary care workforce are increasing in the US.

Background Sugar-sweetened beverage (SSB) consumption contributes to obesity, a risk factor for 13 cancers. While SSB taxes can reduce intake, the health and economic impact on reducing cancer burdens in the United States (US) are unknown, especially among low-income Americans with higher SSB intake and obesity-related cancer burdens. Methods We used the Dietary Cancer Outcome Model (DiCOM), a probabilistic cohort state-transition model, to project health gains and economic benefits of a penny-per-ounce national SSB tax on reducing obesity-associated cancers among US adults age 20+ years by income. Results A national SSB tax was estimated to prevent 22,075 (95% uncertainty interval [UI] = 16,040 to 28,577) new cancers cases and 13,524 (95% UI = 9,841 to 17,681) cancer deaths among US adults over a lifetime. The policy was estimated to cost $1.70 (95% UI = $1.50 to $1.95) billion for government implementation and $1.70 (95% UI = $1.48 to $1.96) billion for industry compliance, while saving $2.28 (95% UI = $1.67 to $2.98) billion cancer-related healthcare costs. The SSB tax was highly cost-effective from both a government affordability perspective (incremental cost-effectiveness ratio [ICER] = $1,486, 95% UI = -$3,516 to $9,265 per quality-adjusted life year [QALY]) and a societal perspective (ICER = $13,220, 95% UI = $3,453 to $28,120 per QALY). Approximately 4,800 more cancer cases and 3,100 more cancer deaths would be prevented, and $0.34 billion more healthcare cost savings would be generated among low-income (federal poverty-to-income ratio [FPIR] ≤1.85) than higher-income individuals (FPIR >1.85). Conclusions A penny-per-ounce national SSB tax is cost-effective for cancer prevention in the US, with the largest health gains and economic benefits among lower-income Americans.

Background Epidemiological studies suggest that higher fruits and vegetables (F&V) consumption correlates with reduced risk of hepatic steatosis, yet evidence for causality and the underlying mechanisms is lacking. Objectives We aimed to determine the causal relation between F&V consumption and improved metabolic disorders in mice fed high-fat (HF) (Experiment-1) or normal-fat (Experiment-2) diets and its underlying mechanisms. Methods Six-week-old male C57BL/6J mice were randomly grouped and fed diets supplemented at 0%–15% (wt:wt) with a freeze-dried powder composed of 24 commonly consumed F&V (human equivalent of 0–9 servings/d) for 20 wk. In Experiment-1, mice were fed an HF (45% kcal fat) diet with 0% (HF0), 5%, 10%, or 15% (HF15) F&V or a matched low-fat control diet (10% kcal fat). In Experiment-2, mice were fed an AIN-93 diet (basal) (B, 16% kcal fat) with 0% (B0), 5%, 10%, or 15% (B15) F&V supplementation. Body weight and composition, food intake, hepatic steatosis, inflammation, ceramide levels, sphingomyelinase activity, and gut microbiota were assessed. Results In Experiment-1, mice fed the HF15 diet had lower weight gain (17.9%), hepatic steatosis (48.4%), adipose tissue inflammation, blood (24.6%) and liver (33.9%) ceramide concentrations, and sphingomyelinase activity (38.8%) than HF0 mice (P < 0.05 for all). In Experiment-2, mice fed the B15 diet had no significant changes in weight gain but showed less hepatic steatosis (28.5%), blood and adipose tissue inflammation, and lower blood (30.0%) ceramide concentrations than B0 mice (P < 0.05 for all). These F&V effects were associated with favorable microbiota changes. Conclusions These findings represent the first evidence for a causal role of high F&V intake in mitigating hepatic steatosis in mice. These beneficial effects may be mediated through changes in ceramide and/or gut microbiota, and suggest that higher than currently recommended servings of F&V may be needed to achieve maximum health benefits.