Low-carb diets are mostly built on the belief that they can help people lose weight by eliminating or reducing carbohydrates and replacing them with other foods, particularly those that are rich in protein or fat. While advocates of these diets claim other health benefits, such as a lower rate of heart disease, new research suggests that getting rid of the carbs might not be that healthy after all, as far as life expectancy is concerned.
According to the Washington Post, one of the new papers linking low-carb diets to a higher chance of premature death came from a team of Harvard University and University of Minnesota researchers, who reviewed data from the large-scale Atherosclerosis Risk in Communities study to come up with their findings. The researchers conducted the study because existing trials that had associated carbohydrate reduction to a number of health benefits only covered the short term.
The study, which was published last month in the journal Lancet Public Health, revealed that a person aged 50-years-old whose diet consists of less than 30 percent carbohydrates has a life expectancy of 79.1 years, as opposed to people the same age who eat more than 65 percent carbs, who were found to live an average of 82 years.
The Washington Post noted that the above findings were consistent with those discussed in separate research that was also published in August. According to a news release posted on the European Society of Cardiology website, a team of Medical University of Lodz (Poland) researchers studied data from close to 25,000 people who took part in the U.S. National Health and Examination Survey between 1999 and 2010. The findings revealed that those who consumed the least carbs had a 32 percent higher risk of death than the participants who consumed the most carbs, with the difference rising to 50 percent if only cardiovascular deaths were taken into account.
Although Maciej Banach, lead author of the Medical University of Lodz paper, suggested that low-carb diets have long-term risks that might outweigh the short-term benefits, his team’s analysis reportedly did not consider all of the variables examined by the authors of the Harvard/Minnesota study.
— CBC Health News (@CBCHealth) September 19, 2018
The Washington Post wrote that the authors of the first paper specifically looked at the types of protein and fat people on low-carb diets were consuming in lieu of carbohydrates, and found that people who consumed more animal-based protein and fat from beef, pork, lamb, and chicken had a higher risk of early death than those who swapped carbs with plant-based protein and fat. As such, the first study suggested that the choice of carbohydrate substitutes plays a very important role in determining whether low-carb diets have long-term health benefits or not.
While the U.S. team also observed similar results when they conducted a meta-analysis of seven other studies examining the link between carbohydrate intake and longevity, their paper has its share of limitations. According to the Washington Post, the researchers only asked the participants about their diets at the start of the 25-year study and six years later, which means there’s a chance certain dietary changes might have been overlooked. Furthermore, the study’s observational nature prevents it from establishing any causality between low-carb diets and early death.