Low-carbohydrate diets are linked to early death in a study presented on Tuesday at a major heart conference.

Professor Maciej Banach‚ of the Medical University of Lodz in Poland‚ told delegates at the European Society of Cardiology conference: “We found that people who consumed a low carbohydrate diet were at greater risk of premature death.

“Risks were also increased for individual causes of death including coronary heart disease‚ stroke and cancer. These diets should be avoided.”

Scientists including South Africa’s Tim Noakes have become increasingly vocal about the health benefits of low-carb high-fat diets in combating obesity and linked chronic conditions such as cardiovascular disease‚ hypertension‚ type 2 diabetes and cancer.

But the long-term safety of these diets is controversial‚ with previous studies reporting conflicting results of their influence on the risk of cardiovascular disease‚ cancer and death.

Banach’s study looked at the relationship between low-carb diets‚ deaths from all causes‚ and deaths from coronary heart disease‚ cerebrovascular disease (including stroke) and cancer in 24‚825 people who took part in the US National Health and Nutrition Examination Survey between 1999 and 2010.

Compared to participants with the highest carbohydrate consumption‚ those with the lowest intake had a 32% higher risk of all-cause death over an average 6.4-year follow-up.

Risks of death from coronary heart disease‚ cerebrovascular disease and cancer increased by 51%‚ 50%‚ and 35%‚ respectively.

Banach told cardiologists in Munich‚ Germany: “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 researchers also examined the link between all-cause death and low-carb diets for obese and non-obese participants in two age groups (over and under 55) and found the link was strongest in the non-obese older participants.

Speculating on the mechanisms underlying the link between low-carb diets and death‚ Banach said animal protein — specifically red and processed meat — had already been linked with an increased risk of cancer.

“The reduced intake of fibre 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‚” he said.

“The findings suggest that low carbohydrate diets are unsafe and should not be recommended.”