The new medical research indicates that diets which are low and high in carbohydrates were linked with an increase in mortality; however, moderate consumption of carbohydrates as part of a weekly diet shows the lowest risk of mortality. In addition, the research found that low-carb diets which replace carbohydrates with proteins and fats derived from plant sources are associated with lower risk of mortality, when compared to diets that replace carbohydrates with proteins and fat from animal sources.
Carbohydrates are one of three macronutrients (nutrients that form a large part of our diet) found in food; the others are fat and protein. There are three different types of carbohydrates found in food: sugar, starch and fiber.
These findings are a challenge to low-carb diets, such as Atkins, which have become increasingly popular for weight loss. The Atkins diet, also known as the Atkins nutritional approach, is a commercial weight-loss program devised by Robert Atkins. The effectiveness of this dietary regime remains a point of debate between nutritional scientists.
In-depth research
With the study, 15,400 people from the U.S. completed questionnaires relating to the food and drink they consumed, plus information about portion sizes. From this, researchers assessed the proportion of calories each person obtained from carbohydrates, fats, and protein. The researchers tracked each person for around 25 years. These results were pooled, according to The Guardian, with seven other observational studies carried out across the world, involving a total of more than 430,000 people.
The assessment, as the BBC summarizes, indicated that people who obtained 50-55 percent of their energy from carbohydrates (the so-called moderate carb group) had a slightly lower risk of death compared with the low and high-carb groups.
The researchers additionally compared low-carb diets that were rich in animal proteins and fats with diets that contained lots of plant-based protein and fat. This analysis showed that eating more beef, lamb, pork, chicken and cheese in place of carbs was linked with a slightly increased risk of death. However, replacing carbohydrates with more plant-based proteins and fats, such as legumes and nuts, was linked with a reduced risk of mortality.
Vegetable based carbs are best
According to Dr Sara Seidelmann, Clinical and Research Fellow in Cardiovascular Medicine from Brigham and Women’s Hospital, Boston: “Low-carb diets that replace carbohydrates with protein or fat are gaining widespread popularity as a health and weight loss strategy.”
She adds: “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 aging in the long term.”
Research paper
The new research is published in the journal The Lancet Public Health. The research paper is titled “Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis.”
Essential Science
This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week we discussed the work of researchers from University of California San Diego, who managed to turn a powerful and viscous disinfectant into breathable mist for the first time. This development could help with the much-needed fight against hospital-acquired infections.
The week before we learnt how the study of blue crystals in meteorites have shown that our Sun went through the astronomical equivalent of the ‘terrible twos’.
