Blueberries To Prevent Alzheimer's?
I understand that eating blueberries may ward off Alzheimer’s disease. This seems too good to be true. Has it been proven? If so, how often should you eat blueberries?
Andrew Weil, M.D. |July 26, 2016
Some intriguing evidence suggests that blueberries might help protect against Alzheimer’s disease, but much more research is needed to confirm the findings. A team of investigators from the University of Cincinnati Academic Health Centers looked at the effect of consuming blueberries (in the form of freeze-dried powder) in a group of 47 adults aged 68 and older diagnosed with mild cognitive impairment. The researchers gave the seniors in the study group either freeze-dried blueberry powder equivalent to a cup of blueberries or a placebo powder once a day for 16 weeks.
Results showed an improvement in cognitive performance and brain function in those who received the blueberry powder compared to those who were given the placebo. Study leader Robert Krikorian, Ph.D., said those in the blueberry group “demonstrated improved memory and improved access to words and concepts.” In addition, functional magnetic resonance imaging (fMRI) showed increased brain activity in the participants who consumed the blueberry powder.
In a second study, Dr. Krikorian’s team divided 94 seniors aged 62 to 80 into four groups. The participants had complained about declining memory although they hadn’t been tested to demonstrate brain changes associated with cognitive problems. The groups received either blueberry powder, fish oil, fish oil plus blueberry powder or a placebo powder. Results showed that cognition – but not memory – improved a bit in those who consumed either the blueberry powder or the fish oil separately. Here, fMRI results were not as striking as they were in participants in the first study who received blueberry powder, possibly because participants in the second study had less severe problems than those in the first.
Preliminary human research and some animal studies have suggested that blueberries may improve cognition, possibly due to the effects of anthocyanins, antioxidant pigments responsible for the berries’ health benefits. Dr. Krikorian presented the results of his team’s studies at a meeting of the American Chemical Society in March 2016. He acknowledged funding for the studies from the U.S. Highbush Blueberry Council, the National Institute on Aging, and Wild Blueberries of North America.
I’m a big fan of all berries, including blueberries. They’re delicious and pack a powerful antioxidant punch: a half-cup of blueberries is equivalent to the antioxidant power of five servings of peas, carrots, apples, squash or broccoli. Blueberries are also a good source of fiber – a half-cup serving gives you almost three grams.
In addition to any cognitive protection blueberries may afford, some evidence suggests that the anthocyanins they contain may help prevent cancer, protect against urinary tract infections and protect the brain from stroke damage. Animal studies have suggested that consuming blueberries may reduce the risk of heart disease by protecting blood vessels in the heart from oxidative stress and inflammation. I’m optimistic that further research will show that these compounds have an important role to play in preventing cancer, diabetes, and cardiovascular and neurological diseases. I recommend regularly adding blueberries, and other berries, to your diet. I eat them frequently (and always buy organically grown varieties).
Andrew Weil, M.D.
Robert Krikorian et al, “Blueberries, the well-known ‘super fruit,’ could help fight Alzheimer’s.” Paper presented at American Chemical Society National Meeting and Exposition, March 13, 2016, San Diego, CA.