Study in The Lancet Public Health shows both high and low carbohydrate increases mortality risk
Low-carb diets that replace carbohydrates with proteins and fats from plant sources are associated with lower risk of mortality compared to those that replace carbohydrates with proteins and fat from animal sources.
Eating carbohydrates in moderation seems to be optimal for health and longevity, suggests new research published in The Lancet Public Health journal.
The observational study of more than 15,400 people from the Atherosclerosis Risk in Communities Study (ARIC) in the USA found that diets both low (< 40% energy) and high (>70% energy) in carbohydrates were linked with an increase in mortality. Moderate (50-55% of energy) carbohydrate consumers on the other hand had the lowest risk of mortality.
“animal-based low carbohydrate diets, might be associated with shorter overall life span”
The primary findings, confirmed in a meta-analysis of studies on carbohydrate intake including more than 432,000 people from over 20 countries, also suggest that not all low-carbohydrate diets appear equal. Eating more animal-based proteins and fats from foods like beef, lamb, pork, chicken and cheese instead of carbohydrate was associated with a greater risk of mortality. Alternatively, eating more plant-based proteins and fats from foods such as vegetables, legumes, and nuts was linked to lower mortality.
“We need to look really carefully at what are the healthy compounds in diets that provide protection”, says Dr Sara Seidelmann, Clinical and Research Fellow in Cardiovascular Medicine from Brigham and Women’s Hospital, Boston, USA who led the research.
She added: “Low-carb diets that replace carbohydrates with protein or fat are gaining widespread popularity as a health and weight loss strategy. However, our data suggests that animal-based low carbohydrate diets, which are prevalent in North America and Europe, might be associated with shorter overall life span and should be discouraged. Instead, if one chooses to follow a low carbohydrate diet, then exchanging carbohydrates for more plant-based fats and proteins might actually promote healthy ageing in the long term.”
Previous randomised trials have shown low carbohydrate diets are beneficial for short-term weight loss and improve cardiometabolic risk. However, the long-term impact of carbohydrate restriction on mortality is controversial with prospective research so far producing conflicting results. What’s more, earlier studies have not addressed the source or quality of proteins and fats consumed in low-carb diets.
