Omega-3 fatty acids may not benefit thinking skills, say scientists who looked at how the cognitive abilities of older women declined over nearly seven years.
The scientists looked at 2,157 women ages 65 to 80 who were taking part in the Women's Health Initiative trials studying hormone therapy. The women took annual tests of their memory and thinking skills in seven areas, including visual memory, fine motor speed and spatial ability. Blood tests measured the levels of omega-3s in the women's blood.
There was no difference in how fast their cognitive skills declined based on whether they had high or low levels of omega-3s, the scientists reported.
Omega-3 fatty acids are found in nuts and in fish such as salmon. There was speculation that omega-3s could help slow cognitive decline.
But the lead researcher said people should not change their diets based on this study.
"Researchers continue to study the relationship between omega-3s and the health of the heart, blood vessels and brain. We know that fish and nuts can be healthy alternatives to red meat and full-fat dairy products," Eric Ammann of the University of Iowa.
Scientists know that the rate of cognitive decline as people age can vary widely from person to person, and so there are efforts underway to try to determine what factors - exercise, diet or social support, for instance - might be modified to slow the decline.