Exercise and a healthy Mediterranean-style diet may protect against Alzheimer’s disease

Previously I have written about the health benefits of following a Mediterranean diet and I was very interested to read a study (1) that has just been published in the Journal of the American Medical Association which found that eating a Mediterranean-style diet is associated with a reduced risk for Alzheimer’s disease.  The study also found that physical activity was associated with a reduced risk for Alzheimer’s disease (independent of diet).  Adhering to a Mediterranean diet and having a good level of physical activity further reduced the risk of developing this disease.



This research adds to a growing body of evidence which suggests that lifestyle can have a significant impact on health, which certainly seems very logical to me!


A traditional Mediterranean diet is abundant in vegetables, fruits, nuts, legumes/beans, fish (especially oily fish), healthy fats and wholegrains.  It is generally low in processed foods, dairy products, red meats, and saturated fats.  In the past research has been conducted on Mediterranean diet and Alzheimer’s disease as well as physical activity and risk for Alzheimer’s.  This is the first study (1) to investigate the combined effects of diet and physical activity on risk for Alzheimer’s disease.



The authors of the study(1) used data from 1880 elderly residents, who had an average age of 77, living in New York.  None of the participants had Alzheimer’s disease or dementia at the start of the study which ran from 1992 to 2006.  At the start of the study diet and level of physical activity were assessed and scored.  Physical activity was scored as vigorous (e.g. jogging), moderate (e.g. hiking or cycling) and light (e.g. golfing or gardenting).  For diet the participants were given a score from 0-9 depending on how close to a Mediterranean diet their diet was.  These scores were then grouped into low, middle or high adherence to a Mediterranean diet.  Over the course of the study, about every 18 months, participants underwent neurological and neuropsychological tests.


*  A total of 282 cases of Alzheimer’s disease were diagnosed over the course of the study.
*  The most physically active participants had a 33% reduced risk of developing Alzheimer’s disease when compared to participants who were the least physically active
*  Those who most closely followed a Meditteranean diet have a 40% reduction in the risk for Alzheimer’s compared to participants who adhered the least.
*  Those who had the highest level of physical activity and whose diet was closest to the Mediterranean diet had a 60% reduced risk of developing Alzheimer’s when compared to those who did not exercise and did not follow a Mediterranean-style diet.


It was also noted that even a low level of physical activity did seem to have a protective effect which is important since it suggests that making even small changes can be beneficial.


Dr Susanne Sorensen, head of research, at the Alzheimer’s Society said in a Press Release (2) about the study:


‘Dementia is one of people’s biggest fears in later life but very few people realise that there are things they can do to reduce their risk of developing this devastating condition. This study adds to the growing body of evidence that a healthy diet and regular exercise can reduce the chance of developing dementia.


‘A Mediterranean diet full of green leafy vegetables, oily fish, nuts and low in saturated fats is an incredibly healthy approach to eating and may reduce your risk of developing dementia. This study suggests combining this diet with regular exercise is one of the best ways to cut your chances of developing dementia.’


‘With one million people set to develop dementia in the next 10 years, it is essential that we act now to defeat it.’


 


The study was not a clinical trial, it was an observational study and cannot prove the link between following a Mediterranean diet and being physically active and the risk for Alzheimer’s disease.  However, it does point toward a strong association and provides us with indications of the importance of following a healthy eating regimen an including exercise into our lifestyles.  There are many components in the Mediterranean diet which may be protecting the brain including omega 3 fatty acids from oily fish and numerous antioxidant vitamins and flavonoids (bioactive plant chemicals) from vegetables and fruits.  As well as minerals.  No doubt all these components act together synergistically to reduce overall risk of Alzheimer’s and help to keep our brain healthy and functioning efficiently.  The key message seems to be to follow a healthy diet and lifestyle. 


For those of you who do not eat oil fish regularly (at least twice per week) you may want to consider taking a daily fish oil supplement in order to provide omega 3 fatty acids to the body (a supplement to provide around 250-350mg of EPA and 250-350mg DHA), for vegetarians and vegans flaxseed oil can provide the shorter chain omega 3 fatty acid, alpha linolenic acid, (a supplement providing 1000mg alpha-linolenic acid daily can be considered).  Vegetarian EPA and DHA supplements produced from algae are also becoming increasingly available.  In addition to the omega 3 fats, if you feel your diet consistently falls short of vegetables and fruits you may wish to consider taking a food-state multi-vitamin and mineral supplement which tends to provide bioflavonoids in addition to the nutrients.


(1)Scarmeas N et al.  2009.   Physical Activity, Diet, and Risk of Alzheimer Disease.  JAMA. 2009;302(6):627-637.
(2) Press Release: Alzheimer’s Society comment on Mediterranean-type diet reducing Alzheimer’s risk
http://www.alzheimers.org.uk/site/scripts/press_article.php?articleID=386
Written by Ani Kowal

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