Tufts University researchers have found that low carb diets may adversely affect cognitive skills, including memory and reaction time.

The small study, published in the journal Appetite (February 2009, volume 52, issue 1, pages 96-103) compared 10 women on a balanced low-calorie diet with 9 women on an Atkins-type diet with a limit of 20g of carbs daily. The women were tested for a variety of cognitive skills before starting the diets, after 48 hours on the diets, at the end of a week, and at two and three weeks after the re-introduction of carbohydrates. The low carb dieters had slower reaction times in all tests and their memory performance decreased gradually throughout the period – though short-term attention improved.

To function, the adult brain depends on glucose, normally derived from at least 130g of carbohydrates daily. The study’s authors said the results showed a clear “difference in cognitive performance as a function of diet.”

This study is not an invitation to pig out on cookies and cakes, but rather a reminder that a moderate amount of good-quality whole grains can play a key role in everyone’s diet. (Cynthia)