Low-carb diets 'are unsafe and should be avoided'

By Ana Sandoiu

Fact checked by Jasmin Collier

A large study concludes that a low intake of carbs raises the risk of premature mortality, as well as mortality from several chronic illnesses. Therefore, scientists urge dieters to avoid low-carb diets.

Recent estimates have suggested that as many as 45 million people in the United States go on a diet each year.

Also, U.S. individuals reportedly spend around $33 billion on weight loss products annually.

The two thirds of the population that are either overweight or obese have a plethora of diets to choose from. From low-fat to high-fat, keto diets and intermittent fasting, the fads are numerous — but what are their consequences for our health?

A new study focuses on low-carb diets and explores the health risks that are associated with them. Carbohydrates are a major source of energy for most living organisms, so how does a diet low in these molecules impact health?

The new research does not offer a causal answer to this question, but it does examine the links between low-carb diets and the risk of premature mortality, as well as mortality from specific chronic diseases.

The new study was presented at the European Society of Cardiology Congress, held in Munich, Germany, by Prof. Maciej Banach, of the Medical University of Lodz in Poland.

Studying low-carb diets and death risk

Prof. Lodz and his colleagues examined the links between low-carb diets and the risk of death from any cause among 24,825 individuals who had participated in the National Health and Nutrition Examination Survey in 1999–2010.

Also, the researchers examined the associations between a low carb intake and the risk of death from coronary heart disease, cerebrovascular disease — which includes stroke — and cancer.

On average, the study participants were 47.6 years old, and their carb intake was calculated as a percentage. Then, based on these percentages, the participants were divided into fourths. Prof. Banach and colleagues followed the participants for an average period of 6.4 years.

The participants were also classified as obese and non-obese, according to their body mass index (BMI).

In the second part of the study, the team examined the same associations in a large meta-analysis of prospective studies that summed up almost 450,000 participants who were followed for an average period of 15.6 years.

Why 'low-carb diets should be avoided'

Overall, the analysis using data from the survey found that those who consumed the least amount of carbs were 32 percent more likely to die prematurely from any cause. This was in comparison with participants who ate the most carbs.

Also, low carb consumers were 51 percent more likely to die from coronary heart disease, 50 percent more likely to die from cerebrovascular disease, and 35 percent more likely to die of cancer. The associations were strongest among older, non-obese people.

These results were replicated in the meta-analysis, which found that the overall risk of death from any cause was 15 percent higher in people who consumed the least amount of carbs, the risk of cardiovascular death was 13 percent higher, and that of dying of cancer was 8 percent higher.

"[Low-carb] diets should be avoided," concludes Prof. Banach, who also ventures some possible causal explanations for the links found.

He says, "The reduced intake of fiber and fruits and increased intake of animal protein, cholesterol, and saturated fat with these diets may play a role. Differences in minerals, vitamins, and phytochemicals might also be involved."

"Low-carbohydrate diets might be useful in the short-term to lose weight, lower blood pressure, and improve blood glucose control, but our study suggests that in the long-term they are linked with an increased risk of death from any cause, and deaths due to cardiovascular disease, cerebrovascular disease, and cancer."

"The findings suggest that low-carbohydrate diets are unsafe and should not be recommended."

Prof. Maciej Banach



Hello Anna,

Are you able to able to post a link directly to the study referenced here? Thank you for the summary of the study findings, but I would like to review the study conditions and who the sponsor of the study is before I can accept any percentage of a study summary as fact. I went to the link included, but that only lead me to the main website. Not to question the quality of European Society of Cardiology content in itself, but summary reviews of any publication need to be scrutinized closely; 'fact checkers' are a dubious mechanism at best. Even the American Heart Association has had many regretable recomendations and misinformation over the years, so studies made available through otherwise creditable institutions are not to be trusted by default, especialy by summary propaganda blurbs that dont even give a direct reference to the study data itself. Without that, one must by default assume an unscrupulous corperate motivation (study sponsor) when a missing link to the actuall study means this was likely written for lemmings.

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