Alzheimer’s Disease: Genetics or Lifestyle?

Wednesday, July 27, 2011

Are our genes our destiny? Several publications have recently concluded that, no, our genes are not always the culprit in the progression of disease. According to the publications, nutritional status and diet appear to play a very large role in the development of neurodegenerative diseases, especially Alzheimer’s disease. A four-week dietary intervention study conducted in Seattle, WA was published in the June issue of the Archives of Neurology. The researchers discovered that healthy individuals who consumed a diet that was both low in saturated fat and full of foods that have a low glycemic index had significant decreases in the levels of Beta-amyloid 42 in their cerebrospinal fluid. Beta-amyloid 42 is used clinically as a biomarker for Alzheimer’s disease risk and cerebrospinal fluid (CSF) is the fluid that nourishes the brain and spinal cord. It is especially shocking that the results were scientifically significant after only four weeks of intervention. The study provided every bite of food consumed by the study participants. The unhealthy diet, which was high in saturated fat and simple carbohydrates, specifically contained 45% fat (25% saturated fat), 35-40% carbohydrates and 15-20% protein. The healthy diet, with a low glycemic index and low saturated fat levels, contained 25% fat (less than 7% saturated fat), 55-60% carbohydrates and 15-20% protein. 24 participants stuck to the high fat diet while 25 were put on the low fat diet. The authors noted that the high fat diet moved beta-amyloid 42 levels “in a direction that may characterize a presymptomatic stage of Alzheimer’s disease before plaque deposition.” They also noted that the low fat diet had “striking effects” and significantly lowered the beta-amyloid 42 levels in the CSF of those participants who consumed the low fat diet.

Also, in a review that was just published in March, investigators conclude that “HHcy [(hyperhomocysteinemia or high homocysteine levels)] has been established as a risk factor and a risk marker for neurodegenerative diseases. Hcy [(homocysteine)] is a surrogate marker for B vitamin deficiency, and in addition it also appears to be able to predict the occurrence and progression of dementia.... HHcy is among the most promising environmental risk factors for dementia which can be lowered easily by vitamin B therapy.” As mentioned by the authors, high homocysteine levels can be caused by low levels of important nutrients, particularly B vitamins. Homocysteine is naturally formed from the amino acid methionine when a methyl group is lost from the methionine during normal metabolism. B vitamins are necessary to re-methylate the homocysteine back to the very safe amino acid methionine. If there is a deficiency in B vitamins, due to either dietary inadequacy or malabsorption, homocysteine levels will increase since the vitamin B-dependent methyl donors are unable to convert the toxic homocysteine back into methionine. These high homocysteine levels are a risk factor for neurodegeneration. The authors of this study also clearly state that “genetic factors do not explain or predict the majority of cases” of Alzheimer’s disease which means that environmental factors most likely play the key role in its development. Now that researchers are slowly uncovering the (seemingly) direct correlation between nutritional status and neurodegenerative diseases such as Alzheimer’s disease, there is yet another compelling reason to incorporate a low-fat, low-sugar whole foods diet full of valuable nutrients into your daily lifestyle. Oh and, if your grandfather has Alzheimer’s disease it doesn't mean that you will too!!! Eat your veggies.

References

Arch Neurol. 2011; 68:743-752.

Clin Chem Lab Med 2011;49(3):435-441.

Laura Firetag ND Student Bastyr University

Labels: Alzheimers, b vitamins, genes, research

posted by Innate Response at

7:05 AM

1 Comments :

Jim said...: This really is not a great study in my opinion. Personally I think the fact that the "unhealthy" diet group consumed high glycemic carbohydrates with the saturated fat (typically simple carbohydrates with saturated fat equals refined, packaged quasi-foods) has more to do with the findings than the saturated fat. A much better study would be a quality low carbohydrate high fat diet verses a low fat high carbohydrate diet.; July 27, 2011 at 12:14 PM

Alzheimer’s Disease: Genetics or Lifestyle?

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