According to "Archives of Neurology," in 2000 there were 4.5 million people with Alzheimer's disease, or AD, in the United States. As America's population ages, the prevalence of this common form of dementia is expected to triple by 2050. Without new discoveries to prevent this condition, AD will present a growing burden on individuals, families and society. Nutritional approaches may play a role in reducing the incidence of AD.
Inflammation and the Aging Brain
The exact cause of AD is unknown. The accumulation of abnormal proteins and tangled nerve bundles within the brains of affected individuals are hallmarks of the disease, but no one knows why these changes occur. A 2010 review in "Nutrition Reviews" discusses the role of oxidative damage and inflammation in aging brains and suggests that high-fat diets and other lifestyle factors contribute to chronic brain injury and mental decline.
Omega-3 Fatty Acids in Fish Oil
Research has shown that the consumption of coldwater fish, such as mackerel, sardines, salmon and trout, reduces a person's risk for heart disease, and it may help to prevent or ameliorate other chronic diseases as well. The oil from these types of fish contains long-chain omega-3 fatty acids, which are a special class of polyunsaturated fatty acids. The two omega-3 fatty acids that have been attributed with most of fish oil's benefits are eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA.
Omega-3 Fatty Acids Fight Inflammation
Fish oil's EPA and DHA have been shown to reduce symptoms in people who suffer from inflammatory disorders such as rheumatoid arthritis. It was assumed that this was due to a passive reduction in the levels of inflammatory chemicals in damaged tissues. However, a 2009 "British Journal of Pharmacology" review describes recently identified molecules, called resolvins and protectins, which play an active role in reversing inflammation. These novel molecules are derived from omega-3 fatty acids found in fish oils.
Fish Oil May Slow Alzheimer's
The Western diet has been implicated in the development and progression of many chronic diseases, including Type 2 diabetes, high blood pressure and coronary heart disease. Although its cause remains undefined, and genetic factors probably play a role in its genesis, AD may be another lifestyle-related disorder. Researchers in the Departments of Medicine and Neurology at the University of California, Los Angeles, believe that omega-3 fatty acids, specifically DHA, help to protect the human brain from AD. The DHA reduces production of abnormal proteins and decreases the inflammatory changes that are characteristic of AD.
Considerations
Fish oil exhibits intriguing properties that may prove useful in the prevention or treatment of a variety of chronic disorders. Not enough evidence is yet available to recommend the use of fish oil for treating or preventing Alzheimer's disease. However, the American Heart Association recommends the consumption of 500 mg of EPA and DHA daily to help reduce the risk for heart disease, and this lifestyle change could also be beneficial for other conditions. If you think fish oil would be helpful for you, talk with your physician.
References
- "Archives of Neurology"; Alzheimer Disease in the US Population; Liesi E. Hebert, et al.; August 2003
- PubMed.gov: Dietary Fatty Acids and the Aging Brain
- PubMed.gov: Resolvins and Protectins: Mediating Solutions to Inflammation
- PubMed.gov: DHA May Prevent Age-related Dementia
- PubMed.gov: Omega-6 and Omega-3 Fatty Acids: Partners in Prevention
