Fish are the best source of omega-3 fatty acids and research shows that the oily compounds, which reduce
inflammation, may help protect against Alzheimer’s disease.
Alzheimer’s disease is a progressive and fatal disease. So far, there is no known cure for Alzheimer’s. According to the Alzheimer’s Association, about 5.5 million Americans are living with the disease. Now, it is the fifth leading cause of death among elderly population.
For the study, researchers in the US studied 1,219 people aged 65 and older who did not have dementia. Each participant was asked questions about their daily diet and had their blood tested for beta-amyloid levels.
Beta amyloid is a small piece of a larger protein called amyloid precursor protein (APP). An accumulation of beta-amyloid in the brain is one of the key hallmarks of Alzheimer’s disease.
The results showed that those who consistently consume fish high in omega-3 fatty acids had lower beta-amyloid levels in their blood compared with those eating less fish. It was found that consuming one gram of omega-3 each day lowered the blood levels of beta-amyloids by between 20% and 30%. This amounts are equal to eating half a filet of salmon per week.
The protein levels in the blood are believed to be the main component of the sticky, insoluble plaques that infest the brains of Alzheimer’s patients.
“Although it is not easy to measure the levels of beta-amyloid deposits in the brain in this type of research, it is relatively easy to measure the levels of beta-amyloid in the blood, which, to a certain degree, related to the level in the brain”, said Lead researcher Dr Nikolaos Scarmeas, of Columbia University Medical Center in New York, as reported on dailymail.
“Determining through further research whether omega-3 fatty acids or other nutrients associate with spinal fluid or brain beta-amyloid levels, or levels of other Alzheimer’s disease-related proteins, can increase our faith on the beneficial effects of a part of our diet in preventing Alzheimer’s.”
Researchers also looked at other nutrients, including saturated fatty acids, omega-6 fatty acids, mono-unsaturated fatty acid, vitamins E, C, B12 & D, folate and beta-carotene. However, besides omega-3 fatty acids, none of them were associated with different blood levels of beta-amyloid.
The link between omega-3 and beta-amyloid and blood remained the same after adjusting for various potential influences, including possession of a version of the APOE which is known to increase Alzheimer’s risk.
Fish that are rich in omega-3 fatty acids include salmon, mackerel and herring. In addition to fish, omega 3 fatty acids can also be found in nuts and some vegetables such as Brussels sprouts, kale, spinach, and vegetable oils.