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, US 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 Professor Maciej Banach, of the Medical University of Lodz in Poland.

Studying low-carb diets and death risk

Professor 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. Professor 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 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% 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% more likely to die from coronary heart disease, 50% more likely to die from cerebrovascular disease, and 35% 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% higher in people who consumed the least amount of carbs, the risk of cardiovascular death was 13% higher, and that of dying of cancer was 8% higher.

"[Low-carb] diets should be avoided," concludes Professor 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."

–Professor Maciej Banach