Alzheimer's disease is a neurodegenerative disease and a leading cause of dementia. It is the sixth most common cause of death in the United States, causing approximately 74,600 deaths in 2007, according to the Centers for Disease Control and Prevention. While many factors play a role in the development of Alzheimer's disease, including genetics and exposure to toxins, some nutritional deficiencies might increase your risk of the disease.
Omega-3 Fatty Acids
Deficiencies in one type of omega-3 fatty acid have been linked with an increased risk of Alzheimer's disease. There are several types of omega-3 fatty acids: ALA, a fat found in several plant oils, as well as DHA and EPA, which your body can synthesize from ALA. Low levels of DHA in your body correlate with an increased risk of developing Alzheimer's disease, according to the Linus Pauling Institute at Oregon State University. In addition, deficiency in DHA can increase your risk of developing other forms of dementia, as well as lead to decline in cognitive function.
Roles of DHA
Of all the omega-3 fatty acid types, your brain contains mostly DHA fatty acids. Though the range of functions of DHA in the brain have not yet been fully elucidated, the fatty acids appear to contribute to brain cell membranes. These membranes contain proteins that allow your brain cells to communicate and function, allowing for the cognitive functioning that is lost in Alzheimer's. In addition, DHA helps prevent oxidative damage -- molecular damage that contributes to Alzheimer's -- according to a study published in "Nutrition and Health" in 2006. Together, consuming adequate omega-3 fatty acids might help protect your brain and prevent the damage that leads to Alzheimer's disease.
Recommended Intake and Sources of Omega-3s
To maintain adequate DHA levels, men should consume 1.6 g of ALA omega-3 fatty acids, while women require 1.1 g, according to the Linus Pauling Institute. Sources of ALA include flax seeds or walnuts, as well as oils extracted from the flax or walnut kernels. Consuming fish, like salmon, also provides a source of DHA, which can contribute to your overall omega-3 fatty acid intake. If you suffer from an omega-3 fatty acid deficiency, talk to a medical professional about the benefits of additional omega-3 supplementation.
Considerations
While omega-3 fatty acid deficiencies can increase some risk factors of Alzheimer's disease, a deficiency in omega-3 fatty acids alone may not prove sufficient to cause the disease. Alzheimer's typically develops due to a range of factors -- some forms of the disease are inherited, while others may develop due to exposure to environmental toxins. As a result, consuming adequate DHA does not guarantee that you will not develop Alzheimer's, and conversely, a deficiency in DHA does not necessarily guarantee you will develop the disease. If you're concerned about your risk of developing Alzheimer's, discuss your concerns with your doctor to determine how best to address the possibility of developing the disease.
References
- Centers for Disease Control and Prevention: FASTSTATS - Alzheimer's Disease
- Linus Pauling Institute; Essential Fatty Acids; Dr. Jane Higdon; December 2005
- "Nutrition and Health;" Docosahexaenoic acid protects from amyloid and dendritic pathology in an Alzheimer's disease mouse model; Cole et al.; 2006
