Global study shows carbohydrate intake associated with higher risk of mortality

High carbohydrate intake is associated with a higher risk of mortality, and high fat intake with a lower risk, according to a new study published in The Lancet Diabetes & Endocrinology.

The study looked at diet and mortality in 135,335 individuals between 35 and 70 years old in 18 countries over an average of more than seven years. Diet information depended on self-reported food questionnaires, and the international team of scientists controlled factors including age, sex, smoking, physical activity, and body mass index.

Compared with people who ate the lowest 20 percent of carbohydrates, those who ate the highest 20 percent had a 28 percent increased risk of death. However, high carbohydrate intake was not associated with cardiovascular death, according to the study.

People with the highest 20 percent in total fat intake (an average of 35.3 percent of calories from fat) had about a 23 percent reduced risk of death compared with the lowest 20 percent (an average of 10.6 percent of calories from fat).

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.

The relationship between macronutrients and cardiovascular disease and mortality is controversial. Most available data are from European and North American populations where nutrition excess is more likely, so their applicability to other populations was unclear. This lack of data is what originally drove researchers to conduct this study, which was formally released at the European Society of Cardiology meeting earlier this month.

Researchers called for global dietary guidelines to be reconsidered in light of these findings.