High carbohydrate intake has been associated with higher risk of total mortality

Cardiovascular disease is a global epidemic with 80% of the burden of disease in low-income and middle-income countries. Diet is one of the most important modifiable risk factors for cardiovascular disease and other chronic diseases.

The Prospective Urban Rural Epidemiology (PURE) study is a large, epidemiological cohort study of individuals aged 35-70 years (enrolled between 1 Jan 2003 and 31 March 2013) in 18 countries (Argentina, Bangladesh, Brazil, Canada, Chile, China, Colombia, India, Iran, Malaysia, occupied Palestinian territory, Pakistan, Poland, South Africa, Sweden, Turkey, United Arab Emirates, and Zimbabwe) with a median follow-up of 7.4 years (interquartile range (IQR) 5.3-9.3). Dietary intake of 135,335 individuals was recorded using validated food frequency questionnaires.

During follow-up, 5,796 deaths and 4,784 major cardiovascular disease events were documented. Higher carbohydrate intake was associated with an increased risk of total mortality (highest [quintile 5] vs lowest quintile [quintile 1] category, hazard ratio (HR) 1.28 [95% confidence interval (CI) 1.12-1.46], ptrend=0.0001) but not with the risk of cardiovascular disease or cardiovascular disease mortality. Intake of total fat and each type of fat was associated with lower risk of total mortality (quintile 5 vs quintile 1, total fat: HR 0.77 [95% CI 0Β·67-0.87], ptrend<0.0001; saturated fat, HR 0.86 [0.76-0.99], ptrend=0.0088; monounsaturated fat: HR 0.81 [0.71-0.92], ptrend<0.0001; and polyunsaturated fat: HR 0.80 [0.71-0.89], ptrend<0.0001). Higher saturated fat intake was associated with lower risk of stroke (quintile 5 vs quintile 1, HR 0.79 [95% CI 0.64-0.98], ptrend=0.0498).

In this large prospective cohort study from 18 countries in five continents, a high carbohydrate intake (more than about 60% of energy) was associated with an adverse impact on total mortality and non-cardiovascular disease mortality. By contrast, higher fat intake was associated with lower risk of total mortality, non-cardiovascular disease mortality, and stroke. Furthermore, higher intakes of individual types of fat were associated with lower total mortality, non-cardiovascular disease mortality, and stroke risk. An inverse association was found between monounsaturated fatty acid intake and total mortality.

In conclusion, high carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke. Global dietary guidelines should be reconsidered in light of these findings.

 

Dehghan M et al. Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study. Lancet. 2017 Nov 4;390(10107):2050-2062.

https://www.ncbi.nlm.nih.gov/pubmed/28864332