Low-carb diets affect women’s ability to think straight, a new study has found.
The US study compared two weight loss diets: a low-carbohydrate diet, like the Atkins diet, and a low-calorie diet. They found that on a low-carb diet women’s cognitive ability worsened. When the carbohydrates were re-introduced, the women’s cognitive ability returned.
The study, which is to appear in Appetite journal in February, looked at 19 women, aged 22 to 55. For three weeks, nine women tried a low-carb diet, and the other 10 tried a low-calorie diet recommended by the American Dietetic Association.
The dieters completed five testing sessions that assessed cognitive skills, including attention, spatial memory and long and short-term memory.
The low-carb dieters got gradually worse at the memory-related tasks, compared to the low-calorie dieters. Their reaction times were also slower.
However, the low-carb dieters responded better than their low-calorie counterparts, during the attention task.
'Although this study only tracked dieting participants for three weeks, the data suggest that diets can affect more than just weight,' said Holly A. Taylor, co-author of the study.
'The brain needs glucose for energy and diets low in carbohydrates can be detrimental to learning, memory, and thinking.'
Appetite (2009) 52: 96-103