New research(1) has just emerged from Baycrest which shows that adults with type 2 diabetes who eat unhealthy, high-fat, meals may experience memory declines immediately afterward, but this may be offset by taking antioxidant vitamin supplements together with the meal.

Baycrest is an academic health sciences centre, affiliated with the University of Toronto, which is internationally-renowned for its research on aging and the conditions associated with ageing such as memory loss, depression and stroke.

The study authors make reference to the fact that there is already a growing body of evidence that links diabetes to cognitive (mental) complications in humans.  Adults with type 2 diabetes seem especially vulnerable to acute memory deficits after eating unhealthy foods.  This latest study suggests that taking high doses of antioxidant vitamins C and E with such meals may help minimize those memory slumps.

One of the study authors, Michael Herman Chui, said “Our bottom line is that consuming unhealthy meals for those with diabetes can temporarily further worsen already underlying memory problems associated with the disease”.

The study was a very small preliminary trial that involved only 16 adults (with an average age of 63) with type 2 diabetes who were not regularly taking antioxidant supplements.  They attended three weekly sessions that involved consuming a different test meal on each visit. One meal consisted of high fat foods (a Danish pastry, cheddar cheese and yogurt with added whipped cream); the second meal consisted of only water; and the third test meal was the same high-fat meal plus vitamin C (1000 mg) and E (800 IU) supplements.

After eating the meal, participants completed a series of tests that measured their recall abilities for words they had heard and paragraph information they had read.  It was found that vitamin supplementation consistently improved recall scores.  Compared to those who consumed only water or the meal with antioxidant vitamins, participants who ate the high fat meal showed significantly more forgetfulness (of words and paragraph information) in immediate and time delay recall tests. 

The study authors emphasize that their findings obviously require further replication in much larger trials. Future studies will also need to look at how the antioxidant vitamins may be working.  Personally, I would also like to see further trials using antioxidant foods, such as fruits and vegetables, in conjunction with meals to test if the same benefits are seen as with supplementation (I have a feeling results would be very positive)!

Type 2 diabetes is associated with persistent, long term oxidative stress, a known major contributor to cognitive (mental) decline and Alzheimer disease. Consuming unhealthy foods can induce this type of stress which is triggered by elevations of free radicals: unstable molecules that can damage body tissue, including brain tissue. These destructive reactions tend to occur over a 1-3 hour period after the ingestion of food.  Fruits and vegetables contain numerous antioxidant nutrients and can minimise oxidative stress, it is important to include such foods as an integral part of all meals.  This study showed that antioxidants could reduce immediate memory deficits caused by unhealthy eating.

Dr. Carol Greenwood, senior author of the study, cautioned that relying on antioxidant vitamins at meal time is not a quick fix. “While our study looked at the pill form of antioxidants, we would ultimately want individuals to consume healthier foods high in antioxidants, like fruits and vegetables” (well said!).

An overall healthy lifestyle is important in maintaining optimal mental health at all ages.  This includes regular exercise, staying mentally active, being socially engaged in a variety of activities as well as adopting a healthy diet rich in fruits, vegetables and healthy fats found in oily fish, nuts and seeds.

(1) Chui MH & Greenwood CE.  2008.  Antioxidant vitamins reduce acute meal-induced memory deficits in adults with type 2 diabetes.  Nutrition Research.  28 (7): 423-494
(2) Baycrest press release

Written by Ani Kowal