Carbohydrate-rich food causes fatty liver disease

25 September, 2007

Diets rich in carbohydrates not only lead to obesity but also may help spread a potentially deadly liver disease called fatty liver.

Fatty liver is a condition that can lead to liver failure and even death, which is becoming more common in developed countries.

A new study suggests that the disease might be linked to high-glycaemic foods – carbohydrates that are digested quickly and release their energy rapidly into the blood stream.

The study has been published in the September 2007 issue of the journal Obesity.

High-glycaemic foods include white rice, white bread, most prepared breakfast cereals, and concentrated sugar. Foods with a low-glycaemic index, such as most vegetables, fruits, beans, and unprocessed grains, raise blood sugar more slowly.

Scientists compared the effect of both kinds of food on mice, which were either fed on a high or low-glycaemic form of cornstarch. Each diet had equal amounts of total calories, fat, protein, and carbohydrate.

After six months, the mice weighed the same. But while mice on the low-glycaemic diet were lean, those on the high-glycaemic diet had twice the normal amount of fat in their bodies, blood, and livers.

Energy-giving sugar released by high-glycaemic food enhances the production of the hormone insulin, which tells the body to make and store fat. The message is strongest in the liver, where insulin concentrations can be many times higher than in the rest of the body.

The experiments conducted in mice suggest that raised insulin levels caused by eating high-glycaemic foods can lead to a build-up of fat in the liver which might be severe enough to cause harm.

The ‘fatty liver’ condition usually produces no symptoms, but it increases the risk of inflammation which can lead to hepatitis, liver failure, and even death.

Dr David Ludwig, director of the Optimal Weight for Life program at the Children’s Hospital in Boston, the United States, who led the research, said fatty liver was becoming more common in America, especially among children. Many of these children will be at risk of full-blown liver disease in later life.

Dr Ludwig described the condition as a “silent but dangerous epidemic,” adding, “just as Type 2 diabetes exploded into our consciousness in the 1990s, so we think fatty liver will in the coming decade. Our experiment creates a very strong argument that a high-glycaemic index diet causes, and a low-glycaemic index diet prevents, fatty liver in humans.”