Navigation Links
Low-carb diets can affect dieters' cognition skills
Date:12/11/2008

MEDFORD/SOMERVILLE, Mass. -- A new study from the psychology department at Tufts University shows that when dieters eliminate carbohydrates from their meals, they performed more poorly on memory-based tasks than when they reduce calories, but maintain carbohydrates. When carbohydrates were reintroduced, cognition skills returned to normal.

"This study demonstrates that the food you eat can have an immediate impact on cognitive behavior," explains Holly A. Taylor, professor of psychology at Tufts and corresponding author of the study. "The popular low-carb, no-carb diets have the strongest potential for negative impact on thinking and cognition."

Taylor collaborated with Professor Robin Kanarek, former undergraduate Kara Watts and research associate Kristen D'Anci. The study, "Low-carbohydrate weight-loss diets. Effects on cognition and mood," appears in the February 2009 edition of the journal "Appetite."

While the brain uses glucose as its primary fuel, it has no way of storing it. Rather, the body breaks down carbohydrates into glucose, which is carried to the brain through the blood stream and used immediately by nerve cells for energy. Reduced carbohydrate intake should thus reduce the brain's source of energy. Therefore, researchers hypothesized that diets low in carbohydrates would affect cognitive skills.

Study participants included 19 women ages 22 to 55 who were allowed to select the diet plan they preferred -- either a low-carbohydrate diet or a low-calorie, macronutrient balanced diet recommended by the American Dietetic Association. Nine women chose a low-carbohydrate diet and 10 selected the low-calorie diet.

"Although the study had a modest sample size, the results showed a clear difference in cognitive performance as a function of diet," says Taylor.

The 19 dieters completed five testing sessions that assessed cognitive skills, including attention, long-term and short-term memory, and visual attention, and spatial memory. The first session was held before participants began their diets, the next two sessions occurred during the first week of the diet, which corresponded to the week when low-carb dieters eliminated carbohydrates. The final two sessions occurred in week two and week three of the diets, after carbohydrates had been reintroduced for those on the low-carb diet.

"The data suggest that after a week of severe carbohydrate restriction, memory performance, particularly on difficult tasks, is impaired," Taylor explains.

Low-carb dieters showed a gradual decrease on the memory-related tasks compared with the low-calorie dieters. Reaction time for those on the low-carb diet was slower and their visuospatial memory was not as good as those on the low-calorie diet. However, low-carb dieters actually responded better than low-calorie dieters during the attention vigilance task. Researchers note that past studies have shown that diets high in protein or fat can improve a person's attention in the short-term, which is consistent with the results in this study.

Participants were also asked about their hunger levels and mood during each session. The hunger-rating did not vary between participants on a low-carb diet and those on a low-calorie diet. The only mood difference between dieters was confusion, which was higher for low-calorie dieters during the middle of the study.

"Although this study only tracked dieting participants for three weeks, the data suggest that diets can affect more than just weight," says Taylor. "The brain needs glucose for energy and diets low in carbohydrates can be detrimental to learning, memory and thinking."


'/>"/>

Contact: Suzanne Miller
suzanne_c.miller@tufts.edu
617-627-4703
Tufts University
Source:Eurekalert

Related biology news :

1. New study shows low-fat diets more likely to reduce risk of heart disease than low-carb diets
2. Eliminating soda from school diets does not affect overall consumption
3. U of M finds teens who eat breakfast daily eat healthier diets than those who skip breakfast
4. Sea otter study reveals striking variability in diets and feeding strategies
5. Food can affect a cell in the same way hormones do
6. Eating eggs when pregnant affects breast cancer in offspring
7. Previous abortions and exercise: Do they affect pregnancy?
8. SNPs affect folate metabolism in study of Puerto-Rican adults
9. Seasonal affective disorder may be linked to genetic mutation, study suggests
10. UC Riverside scientist to explore how vegetation affects urban heat islands
11. Decline in Alaskan sea otters affects bald eagles diet
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2017)... , May 16, 2017  Veratad Technologies, LLC ( ... online age and identity verification solutions, announced today they ... Conference 2017, May 15 thru May 17, 2017, in ... and International Trade Center. Identity impacts ... and in today,s quickly evolving digital world, defining identity ...
(Date:4/18/2017)... April 18, 2017  Socionext Inc., a global expert in SoC-based ... edge server, the M820, which features the company,s hybrid codec technology. ... by Tera Probe, Inc., will be showcased during the upcoming Medtec ... show at the Las Vegas Convention Center ... Click here ...
(Date:4/11/2017)... -- Research and Markets has announced the addition of ... offering. ... market to grow at a CAGR of 30.37% during the period ... has been prepared based on an in-depth market analysis with inputs ... growth prospects over the coming years. The report also includes a ...
Breaking Biology News(10 mins):
(Date:8/15/2017)... NC (PRWEB) , ... August 15, 2017 , ... ... 2017, celebrating 10 years of successes helping medical technology companies and inventors develop and ... to a renowned full-service national engineering firm with a portfolio of clients in the ...
(Date:8/15/2017)... ... 15, 2017 , ... The Conference Forum and The Trout ... a series of upcoming panels and events. The partnership culminates with the 4th ... in New York City. , “With our experience in producing the Immuno-Oncology 360° NYC ...
(Date:8/14/2017)... ... 14, 2017 , ... The Conference Forum has confirmed the one-day ... on September 6, 2017 at the Marriott Copley Place in Boston, MA. , Returning ... and Regulatory Strategy, Pfizer Innovative Research Lab, Pfizer, who leads 19 industry speakers in ...
(Date:8/10/2017)... , ... August 09, 2017 , ... ... help the agriculture industry reach its ideal customers with the right message. Their ... , “As a Midwest company, we realize how crucial the agriculture industry is,” ...
Breaking Biology Technology: