Calling all pasta lovers: Low carb diets could actually shorten your lifespan

Calling all pasta lovers: Low carb diets could actually shorten your lifespan

In a study of nearly 15,500 people over the course of 25 years, researchers found that participants whose diets included 50 to 55 percent carbohydrates had the lowest risk of death.

"When carbohydrate intake is reduced in the diet, there are benefits when this is replaced with plant-origin fat and protein food sources but not when replaced with animal-origin sources such as meats".

According to the BBC, researchers estimated that people in the moderate carb group were on average expected to live for another 33 years from the age of 50.

"Low-carb diets that replace carbohydrates with protein or fat are gaining widespread popularity as a health and weight loss strategy", said study leader Dr Sara Seidelmann, Clinical and Research Fellow in Cardiovascular Medicine from Brigham and Women's Hospital, Boston. Another important finding was that switching meat for plant-based protein led to healthier outcomes, in people with low-carb diets.

For the study, which was published in Lancet Public Health, researchers followed 15,428 adults aged 45-64 over two decades from 1987.

Low-carb diets that replace carbohydrates with protein or fat are becoming increasingly popular. Eating moderate levels between that range offered the best options for a healthy lifespan.

"These data also provide further evidence that animal-based low carbohydrate diets should be discouraged".

"Yet supporters of the cult of Low Carb High Fat eating will no doubt disagree with this newest research".

Diets where you either get less than 40% of your energy from carbs or more than 70% of your energy or calories from carbs was associated with the greatest risk of death.

The results were also combined with seven other studies on carbohydrate intake among people in North American, European and Asian countries, which revealed similar trends in life expectancy.

The questionnaires relied upon people remembering what they ate, and it is this information that scientists used to estimate the proportion of calories they received from carbohydrates, fats and protein.

Food plans which replace carbs with protein and fat, such as the Ketogenic or Atkins diets, have gained popularity, and endorsed by celebrities such as Gwyneth Paltrow and Kim Kardashian. "Too much and too little carbohydrate can be harmful but what counts most is the type of fat, protein, and carbohydrate", says Walter Willett, Professor of Epidemiology and Nutrition at Harvard T.H. Chan School of Public Health and co-author of the study.

They found that eating more beef, lamb, pork, chicken and cheese in place of carbs was linked with a slightly increased risk of death.

Prof Nita Forouhi, from the MRC Epidemiology Unit, University of Cambridge, added: "This finding is spot on in line with the Public Health England dietary guidelines in the United Kingdom".

As a caveat, there are some limitations to this study.

The findings show observational associations rather than cause-and-effect and what people ate was based on self-reported data, which might not be accurate. However, they speculate that having a low-carb diet over the long-term featuring a greater amount of animal fats and proteins and a lower intake of whole-grains, fruits and vegetables could "stimulate inflammatory pathways, biological ageing, and oxidative stress".