Dec 16, 2008
No-Carb Diets May Impair Memory
Study Shows Lack Of Brain-Fueling Carbs Could Lead To Poorer Memory
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One week after starting a weight loss diet that severely restricted carbohydrates, participants in the Tufts University study performed significantly worse on memory tests than participants who followed a low calorie, high-carbohydrate diet.
The low-carb dieters' memory-test performances improved in the following weeks after they began eating some carbohydrates.
"The connection between the foods we eat and how we think doesn't really enter into most people's minds," study co-author and cognitive psychologist Holly A. Taylor, PhD tells WebMD. "But this study demonstrates that the foods we eat can have an immediate impact on brain function."
Carbs Are Brain Fuel
The body breaks carbohydrates into glucose, which it uses to fuel brain activity. Proteins break down into glycogen, which can also be used for fuel by the brain, but not as efficiently as glucose.
So it stands to reason that eliminating carbohydrates from the diet might reduce the brain's source of energy and affect brain function. But there has been little research examining this hypothesis in people following low-carb weight loss diets.
The study by Taylor and colleagues included 19 women between the ages of 22 to 55 who were closely followed after beginning a low-carb weight loss plan similar to the Atkins diet or the low-calorie diet recommended by the American Dietetic Association that includes plenty of fruits, vegetables, and whole grains.
Before starting the diets, the women underwent testing designed to measure long- and short-term memory and attention. The tests were repeated one, two, and three weeks after the diet began.
Low-carb dieters ate virtually no carbohydrates during their first week on the diet. In testing conducted after week one, they performed worse on memory-based tasks than the women following the ADA diet.
Reaction times for those on the low-carb diet were slower and their visual-spatial memories were not as good as the low-calorie dieters.
They did perform better than the low-calorie dieters in testing that measured attention and the ability to stay on task, however.
And their performance on the memory tests improved after week one, when limited carbohydrates were reintroduced into their diets.
"Although this study only tracked dieting participants for three weeks, the data suggest that diets can affect more than just weight," Taylor notes in a news release. "The brain needs glucose for energy and diets low in carbohydrates can be detrimental to learning, memory, and thinking."
The study is published in the February 2009 issue of the journal Appetite.
More Study Needed
Australian research scientist Grant D. Brinkworth, PhD, tells WebMD that the findings, while intriguing, do not prove that low-carbohydrate weight loss diets affect memory.
In a study published in 2007, Brinkworth and colleagues performed cognitive function testing on dieters after they had been on either a low-carb or high-carb weight-loss diet for eight weeks.
Both groups lost weight and showed improvements in mood.
The low-carbohydrate dieters showed slight impairments in cognitive processing speed, but no difference was recorded between the two groups in working memory.
Brinkworth says if eliminating carbohydrates from the diet does affect memory, the effect may only be temporary.
"What (Taylor and colleagues) recorded may be an acute, transient effect that may just be the body readjusting to an unfamiliar diet," he says. "We really need studies that examine the long-term impact of these diets on cognition."
Calls to a representative from the private equity firm North Castle Partners, which owns controlling interest in Atkins Nutritional Holdings, were not immediately returned.
By Salynn Boyles
Reviewed by Brunilda Nazario
©2005-2008 WebMD, LLC. All rights reserved.
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The preferred food for the brain are ketones which are a byproduct if burning fat in the absence of carbs (which is utilized as glucose then turned to energy)
3 Things many people do not understand about low carb diets:
1. That the AMA has finally admitted this year that low carb diets are more effective for weight loss and can actually lower hbp and cholesterol levels when done correctly.
2. That "ketogenic diets" or low carb diets have been used effectively since the 1920s to help combat high cholesterol, type II diabetes and high blood pressure
3. That responsible low carb diets include a variety if vegetables and fruits including cabbge, kale, broccoli, all greens, tomatoes,green beans, peppers, squash, sprouts, celery, rhubarb, raspberries, blackberries, canteloupe, blueberries, strawberries, honey dew. The only absolute no no foods are corn, potatoes, rice, and most legumes and of course sugar.
Low carb diets are almost a must to control type II diabetes as the low fat or reduced cal diets still allow for the use of an insulin based pathway instead of a glucagon based pathway.
Part 2: You type 1 Diabetics - Do you keep your carbs low or just add the extra units before eating?
Part 2: You type 1 Diabetics - Do you keep your carbs low or just add the extra units before eating?
Posted by PapaBC at 01:14 AM : Dec 17, 2008
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My husband has been a diabetic since he was 2 (29 years). He now uses the sliding scale which allows him to do the extra units. But not everyone is on a sliding scale. Before he switched the the sliding scale yes he was on a low carb diet.
Part 2: You type 1 Diabetics - Do you keep your carbs low or just add the extra units before eating?
Posted by PapaBC at 01:14 AM : Dec 17, 2008
--------
My husband has been a diabetic since he was 2 (29 years). He now uses the sliding scale which allows him to do the extra units. But not everyone is on a sliding scale. Before he switched the the sliding scale yes he was on a low carb diet.
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Or it could mean your are a blonde.
Low carb diets are almost a must to control type II diabetes as the low fat or reduced cal diets still allow for the use of an insulin based pathway instead of a glucagon based pathway.
Posted by harbinger09 at 12:52 AM : Dec 17, 2008
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UH, green beans are legumes.