Researchers from Tufts University performed a three week study were they took nine women and placed them on a very low carbohydrate diet. They took another 10 women and placed them on a low fat, low calorie diet that is recommended by the American Dietetic Association.  These researches wanted to find out how diet and cognitive performance would be related. They tested for mood, memory and attention span. The tests were performed 72 hours before beginning their assigned diet, at 48 hrs after starting the diet, then again at week 1, 2 and 3 during the diet.

The amount of carbohydrates that the low carb group were able to eat the first week were ZERO and then the second week they were able to add 5-8gm of carbs per day. Then the third week they were able to eat 10-16gm of carbs per day.

Memory impairments occurred in the low carb group when the available glycogen would be at their lowest. But during this time the low carb group had less confusion, and response was quicker during vigilance tasks then the low fat group. Memory improved in the low carb group after reintroducing carbohydrates in the diet.

The brain can run on two fuels – glucose and ketones. When you limit your carbohydrate intake you switch the fuel that the body/brain can run on. Instead of running on glucose it will run on ketones. The body releases ketones on a low carb diet when it starts burning body fat as fuel.

This study shows us a few things. It was a very short study so it would only show us the how the body reacts during the process of change from burning glucose to burning ketones.  It is an unfair to claim that low carb is bad for the memory when it is the changing of the fuels that is shown in this study. The participant ate a NO CARB diet. That is very different from low carb diet. Even during Atkins strictest induction phase the carb limit is 20gm, which is still higher then what the study participants ate. Memory improved when carbs where added to the diet. So even when you are eating 16grams of carbohydrates your memory is ok! That just shows how little carbohydrate our brains need to use for fuel. At 16 gms carbs the primary fuel would be ketones not glucose.

There are many forms of low carb diets – going strictly no carb by eating meat and eggs (this is more restrictive than Atkins), to Atkins induction (20 gm. carbs per day), all the way to eating up to 100 gm. carbs a day.

For low carb fat loss maintenance most people stay within the 35-100 gm. of carbs per day.

This study is not representative or a normal low carb dieter!

The real culprit for memory loss may be high blood sugar which is caused by eating carbs and sweets!

This study was published in December issue of Annals of Neurology and was performed by researchers at Columbia University Medical Center. Their recommendation is to increase exercise to regulate blood glucose levels.

“By improving glucose metabolism, physical exercise also reduces blood glucose. It is therefore possible that the cognitive enhancing effects of physical exercise are mediated, at least in part, by the beneficial effect of lower glucose on the dentate gyrus. Whether with physical exercise, diet or through the development of potential pharmacological interventions, our research suggests that improving glucose metabolism could be a clinically viable approach for improving the cognitive slide that occurs in many of us as we age,” concluded Dr. Small.

Dr. Scott Small is the associate professor of neurology at Columbia University Medical Center and lead researcher of the study.

The dentate gyrus is an area of the brain within the hippocampus. This is the part of the brain that we use for memory.

Eating a healthy low carb diet and exercise can protect you from memory loss related to aging.

To your health and wellness,

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