Results from a 2017 study reveal important links between carbohydrates, fat and mortality. Researchers examined food frequency questionnaires from 135,335 subjects from 18 countries across five continents enrolled in the Prospective Urban Rural Epidemiology (PURE) study, an epidemiological cohort study. Findings revealed that higher intake of carbohydrates was associated with an increased risk of mortality, while total fat and individual types of fat were linked to lower total mortality. Subjects with the highest carb intake (77% of calories) had a 28% increased mortality risk than those who ate the least (45% of calories). Alternately, those with the highest fat intake (35% of calories) had a 23% lower risk of mortality compared with those who consumed the least (10% of calories). More specifically, polyunsaturated fat was linked to a 20% reduced risk of death, monounsaturated fat 19% and saturated fat 14%. Total carbohydrates and total fat and types of fat were not associated with cardiovascular disease, myocardial infarction or cardiovascular disease mortality.
Specific types of dietary fat have different associations with total and cause-specific mortality, according to a 2016 study.
Subjects were women and men from the Nurses’ Health Study (n = 83,349) and Health Professionals Follow-up Study (n = 42,884) who were free of cardiovascular disease (CVD), cancer, and types 1 and 2 diabetes at study entry. Dietary intake was measured every two to four years using food frequency questionnaires. Study analyses provide strong evidence that using polyunsaturated (PUFA) and monounsaturated fat (MUFA) as the replacement nutrients for saturated fats (SFAs) can confer substantial health benefits, while replacing SFAs with carbohydrates has little impact on CVD mortality (but may depend partly on the quality of the carbohydrates). When looking at different types of fat, analyses showed that replacement of 5% of calories from SFAs with PUFAs and MUFAs would result in an estimated reduced total mortality by 27% and 13%, respectively.