Low carb diets may increase the risk for bowel cancer

Jun 19 2007

Researchers in the UK are suggesting that low-carbohydrate diets such as the Atkins diet may increase a persons risk of developing bowel cancer.

Scientists from Aberdeen's Rowett Research Institute believe there could be a link between eating less carbohydrate and reducing cancer-fighting bacteria.

In a study where 19 overweight men were placed on three diets containing different levels of carbohydrates the researchers say they discovered a link between consuming carbohydrate and the production of a fatty acid in the gut that protects against colorectal cancer.

The men were given three diets containing different levels of carbohydrate: high, medium and low; those on the high diet consumed 400 grams of carbohydrate daily - the level in an average diet.

On the low diet, the men consumed only 24 grams a day - a normal amount in low-carbohydrate diets and a four-fold drop was seen in the level of the cancer-fighting bacteria.

According to Professor Harry Flint from the Rowett Research Institute, the acid called butyrate, is produced by bacteria and helps kill off cancerous cells and low-carbohydrate regimes could cause a four-fold reduction in such cancer-fighting bacteria.

Although low-carbohydrate diets, such as Atkins have been shown to be effective, many in the medical profession say they are unhealthy especially in the long-term.

The Atkins diet is based on the theory that cutting carbohydrates switches the body's chemistry, turning it from a carbohydrate-burning machine to one that burns fat.

The diets work by reducing the carbohydrate intake in foods such as potatoes and bread and the researchers say the danger is that dieters are tempted to keep the level low.

Professor Flint says in the long run, it is possible that such diets could contribute to colorectal cancer.

Colorectal cancer says Flint is a preventable disease, and there is evidence that poor diet can increase the risk and it was likely the results would be the same in women.

Other experts say beyond the fact that low carb diets help people lose weight quickly compared to other low fat diets, there is little merit in low carbohydrate diets which cut down on fruits and fibre such as in bread.

The Atkins diet has been lauded by many celebrities for helping them to stay slim but it demands a drastic reduction in carbohydrate intake, including foods such as potatoes, fresh dairy products and alcohol; but over a two week period the diet in most cases causes a huge drop in weight.

Carbohydrate levels are then supposed to be slowly increased over the following weeks but Professor Flint says many dieters are tempted to keep the level low, and thus create a greater likelihood of bowel cancer developing.

Other experts say the risk of bowel cancer increases when people eat a lot of animal fat and there was slow moving transit of food through the gut.

Experts recommend eating a healthy, balanced diet that is high in fibre, fruit and vegetables, and low in red and processed meat.