In mice, low-carb pregnancy diet helps pups

Cutting carbohydrates in pregnancy may help babies' livers, protecting them from later diseases such as diabetes, according to preliminary studies conducted in mice.

A group of investigators based in the UK found that mice fed a diet low in carbohydrates and high in unsaturated fats during pregnancy tended to have pups with lower triglyceride levels in the liver. Having too much triglyceride in the liver can cause a condition called fatty liver, which is linked to diabetes and other health problems.

Moreover, young mice whose mothers ate low-carb fare while pregnant had higher levels of proteins that oxidize fatty acids, a process that helps reduce the amount of fat circulating in the blood. Too much blood fat can increase the risk of cardiovascular disease, diabetes and other ills.

Despite the apparent benefits of a low-carb pregnancy diet in mice, lead author Dr. Junlong Zhang warned Reuters Health that "it is too early to recommend a low-carb diet to pregnant women simply based on the results observed from our study."

The researcher, who is based at the University of Southampton, said the investigators are studying whether it is safe for women to follow a low-carbohydrate diet during pregnancy.

Research suggests that a mother's diet in pregnancy can have long-lasting effects on her children. Given the recent popularity of low-carbohydrate diets, the researchers decided to investigate how these diets might impact a developing fetus.

Zhang and colleagues fed pregnant mice a standard diet or a low-carb diet, in which approximately 17 percent of calories came from carbohydrates, 27 percent from protein, and 53 percent from fat.

The investigators found that female mice whose mothers received the low-carb diet had half the concentration of liver triglycerides seen in other mice, and significantly more proteins that oxidize fatty acids.

Male mice also appeared to have lower liver triglycerides if their mothers ate low-carb foods during pregnancy, but the evidence was not strong enough to determine whether the trend was due to chance, the authors report in the American Journal of Physiology - Regulatory, Integrative, and Comparative Physiology.

Zhang explained that mice that had mothers on low-carb diets during pregnancy likely changed their physiology in response to their mothers' diet. When pregnant mice eat low-carb, high-fat foods, he said, "their babies may adapt to the type of diet before birth."

Consequently, "these babies were able to cope with a greater amount of fat, and lower amount of carbs even after they were born and grew up," Zhang said.

SOURCE: American Journal of Physiology - Regulatory, Integrative, and Comparative Physiology, January 2005.