For the study, researchers looked at the blood levels of DHA and dementia rates for almost 900 men and women who were involved in the Framingham Heart Study. The participants had an average age of 76 at the beginning of the study were followed for nine years.
While none of the participants had dementia at the beginning of the study, 99 ultimately developed some form of it, with 71 being diagnosed with Alzheimer’s disease. Alzheimer’s disease is known to cause about 70 percent of dementia cases in the elderly. However, those men and women who had the highest blood levels of DHA throughout the study, had a 47 percent lower risk of developing dementia and a 39 percent lower risk of developing Alzheimer’s disease than those who had lower DHA levels.
Moreover, those with the lowest risk of dementia reported eating an average of three servings of fish a week.
The researchers suggest, therefore, that increased fish intake can help to prevent age-related dementia, but are unsure if supplements of DHA will work just as well.
“In the future, it will also be important to determine whether combined dietary supplementation with DHA can decrease further mental deterioration in patients with established dementia,” the authors write.
