RESEARCH DESIGN AND METHODS: The Prospective Urban Rural Epidemiology (PURE) study enrolled 143,567 adults aged 35-70 years from 4 high-income countries (HIC), 12 middle-income countries (MIC), and 5 low-income countries (LIC). The mean follow-up was 9.0 ± 3.0 years.

RESULTS: Among those with diabetes, CVD rates (LIC 10.3, MIC 9.2, HIC 8.3 per 1,000 person-years, P < 0.001), all-cause mortality (LIC 13.8, MIC 7.2, HIC 4.2 per 1,000 person-years, P < 0.001), and CV mortality (LIC 5.7, MIC 2.2, HIC 1.0 per 1,000 person-years, P < 0.001) were considerably higher in LIC compared with MIC and HIC. Within LIC, mortality was higher in those in the lowest tertile of wealth index (low 14.7%, middle 10.8%, and high 6.5%). In contrast to HIC and MIC, the increased CV mortality in those with diabetes in LIC remained unchanged even after adjustment for behavioral risk factors and treatments (hazard ratio [95% CI] 1.89 [1.58-2.27] to 1.78 [1.36-2.34]).

DESIGN: Population-based prospective observational study.

SETTING: Urban and rural communities in 20 high income, middle income and low income.

PARTICIPANTS: 119 894 community-dwelling middle-aged adults.

MAIN OUTCOME MEASURES: Associations of social isolation with mortality, cardiovascular death, non-cardiovascular death and incident diseases.

RESULTS: Social isolation was more common in middle-income and high-income countries compared with low-income countries, in urban areas than rural areas, in older individuals and among women, those with less education and the unemployed. It was more frequent among smokers and those with a poorer diet. Social isolation was associated with greater risk of mortality (HR of 1.26, 95% CI: 1.17 to 1.36), incident stroke (HR: 1.23, 95% CI: 1.07 to 1.40), cardiovascular disease (HR: 1.15, 95% CI: 1.05 to 1.25) and pneumonia (HR: 1.22, 95% CI: 1.09 to 1.37), but not cancer. The associations between social isolation and mortality were observed in populations in high-income, middle-income and low-income countries (HR (95% CI): 1.69 (1.32 to 2.17), 1.27 (1.15 to 1.40) and 1.47 (1.25 to 1.73), respectively, interaction p=0.02). The HR associated with social isolation was greater in men than women and in younger than older individuals. Mediation analyses for the association between social isolation and mortality showed that unhealthy behaviours and comorbidities may account for about one-fifth of the association.

METHODS: The Prospective Urban-Rural Epidemiology study is a large, longitudinal population study done in 21 countries of varying incomes and sociocultural settings. We enrolled an unbiased sample of households, which were eligible if at least one household member was aged 35-70 years. Height was measured in a standardized manner, without shoes, to the nearest 0.1 cm. During a median follow-up of 10.1 years (interquartile range 8.3-12.0), we assessed the risk of all-cause mortality, major cardiovascular events and cancer.

RESULTS: A total of 154 610 participants, enrolled since January 2003, with known height and vital status, were included in this analysis. Follow-up event data until March 2021 were used; 11 487 (7.4%) participants died, whereas 9291 (6.0%) participants had a major cardiovascular event and 5873 (3.8%) participants had a new diagnosis of cancer. After adjustment, taller individuals had lower hazards of all-cause mortality [hazard ratio (HR) per 10-cm increase in height 0.93, 95% confidence interval (CI) 0.90-0.96] and major cardiovascular events (HR 0.97, 95% CI 0.94-1.00), whereas the hazard of cancer was higher in taller participants (HR 1.23, 95% CI 1.18-1.28). The interaction p-values between height and country-income level for all three outcomes were <0.001, suggesting that the association with height varied by country-income level for these outcomes. In low-income countries, height was inversely associated with all-cause mortality (HR 0.88, 95% CI 0.84-0.92) and major cardiovascular events (HR 0.87, 95% CI 0.82-0.93). There was no association of height with these outcomes in middle- and high-income countries. The respective HRs for cancer in low-, middle- and high-income countries were 1.14 (95% CI 0.99-1.32), 1.12 (95% CI 1.04-1.22) and 1.20 (95% CI 1.14-1.26).

METHODS AND RESULTS: A healthy diet score was developed in 147 642 people from the general population, from 21 countries in the PURE study, and the consistency of the associations of the score with events was examined in five large independent studies from 70 countries. The healthy diet score was developed based on six foods each of which has been associated with a significantly lower risk of mortality [i.e. fruit, vegetables, nuts, legumes, fish, and dairy (mainly whole-fat); range of scores, 0-6]. The main outcome measures were all-cause mortality and major cardiovascular events [cardiovascular disease (CVD)]. During a median follow-up of 9.3 years in PURE, compared with a diet score of ≤1 points, a diet score of ≥5 points was associated with a lower risk of mortality [hazard ratio (HR) 0.70; 95% confidence interval (CI) 0.63-0.77)], CVD (HR 0.82; 0.75-0.91), myocardial infarction (HR 0.86; 0.75-0.99), and stroke (HR 0.81; 0.71-0.93). In three independent studies in vascular patients, similar results were found, with a higher diet score being associated with lower mortality (HR 0.73; 0.66-0.81), CVD (HR 0.79; 0.72-0.87), myocardial infarction (HR 0.85; 0.71-0.99), and a non-statistically significant lower risk of stroke (HR 0.87; 0.73-1.03). Additionally, in two case-control studies, a higher diet score was associated with lower first myocardial infarction [odds ratio (OR) 0.72; 0.65-0.80] and stroke (OR 0.57; 0.50-0.65). A higher diet score was associated with a significantly lower risk of death or CVD in regions with lower than with higher gross national incomes (P for heterogeneity <0.0001). The PURE score showed slightly stronger associations with death or CVD than several other common diet scores (P < 0.001 for each comparison).

METHODS: We assessed fruit and vegetable consumption using data from country-specific, validated semi-quantitative food frequency questionnaires in the Prospective Urban Rural Epidemiology (PURE) study, which enrolled participants from communities in 18 countries between Jan 1, 2003, and Dec 31, 2013. We documented household income data from participants in these communities; we also recorded the diversity and non-sale prices of fruits and vegetables from grocery stores and market places between Jan 1, 2009, and Dec 31, 2013. We determined the cost of fruits and vegetables relative to income per household member. Linear random effects models, adjusting for the clustering of households within communities, were used to assess mean fruit and vegetable intake by their relative cost.

FINDINGS: Of 143 305 participants who reported plausible energy intake in the food frequency questionnaire, mean fruit and vegetable intake was 3·76 servings (95% CI 3·66-3·86) per day. Mean daily consumption was 2·14 servings (1·93-2·36) in low-income countries (LICs), 3·17 servings (2·99-3·35) in lower-middle-income countries (LMICs), 4·31 servings (4·09-4·53) in upper-middle-income countries (UMICs), and 5·42 servings (5·13-5·71) in high-income countries (HICs). In 130 402 participants who had household income data available, the cost of two servings of fruits and three servings of vegetables per day per individual accounted for 51·97% (95% CI 46·06-57·88) of household income in LICs, 18·10% (14·53-21·68) in LMICs, 15·87% (11·51-20·23) in UMICs, and 1·85% (-3·90 to 7·59) in HICs (ptrend=0·0001). In all regions, a higher percentage of income to meet the guidelines was required in rural areas than in urban areas (p<0·0001 for each pairwise comparison). Fruit and vegetable consumption among individuals decreased as the relative cost increased (ptrend=0·00040).

INTERPRETATION: The consumption of fruit and vegetables is low worldwide, particularly in LICs, and this is associated with low affordability. Policies worldwide should enhance the availability and affordability of fruits and vegetables.