PARIS, France - Eating more flavanols, antioxidants found in many vegetables, fruits, tea, and wine, may slow your rate of memory loss, a new study finds.
The cognitive score of people in the study who ate the most flavanols declined 0.4 units per decade more slowly than those who ate the fewest flavanols. The results held even after adjusting for other factors that can affect memory, such as age, sex, and smoking, according to the study recently published in Neurology, the medical journal of the American Academy of Neurology.
"It's exciting that our study shows making specific diet choices may lead to a slower rate of cognitive decline", said study author Dr. Thomas Holland, an instructor in the department of internal medicine at Rush University Medical Center in Chicago, in a statement.
"Something as simple as eating more fruits and vegetables and drinking more tea is an easy way for people to take an active role in maintaining their brain health".
Flavanols are cytoprotective, meaning they protect cells, including neurons, so it's plausible there could be a direct impact on cognition, said Dr. David Katz, a specialist in preventive and lifestyle medicine and nutrition who was not involved in the study.
"But they are also a maker of higher intake of fruits and vegetables - which is good for the brain because it is good for every vital organ, and the organism as a whole", Katz said.
"They may also be a maker of better overall diet quality or even greater health consciousness. People who are more health conscious may do things to preserve their cognition, or maybe being more health conscious is a by-product of better cognition".
A Huge Family Of Phytochemicals
Plants contain over 5,000 flavonoid compounds, which play roles in producing cell growth, fighting environmental stress, and attracting insects for pollination.
Flavanols, a type of flavonoid, have been shown in animal and some human studies to reduce inflammation, a major trigger for chronic disease, and are rich sources of antioxidants. Antioxidants combat free radicals, "highly unstable molecules that are naturally formed when you exercise and when your body converts food into energy", according to the National Center for Complementary and Integrative Health, part of the National Institutes of Health.
One of the most common flavanols, quercetin, has shown promise in reducing the onset of colorectal cancer and other cancers, according to studies. Onions contain the highest levels - lower levels can be found in broccoli, blueberries, cauliflower, curly kale, leeks, spinach, and strawberries.
Another common flavanol, kaempferol, appears to inhibit the growth of cancer cells while preserving and protecting normal cells. Good sources of kaempferol are onions, asparagus, and berries, but the richest plant sources are spinach, kale, and other green leafy vegetables, as well as herbs such as chives, dill, and tarragon.
A third major player is a myricetin, which has been studied in rodents for blood sugar control and the reduction of tau, a protein that causes the hallmark tangles of Alzheimer's and other dementia. Spinach and strawberries contain high levels of myricetin, but honey, black currants, grapes, and other fruits, vegetables, nuts, and tea are also good sources.
The last group of flavonols, isorhamnetin, may protect against cardiovascular and neurovascular disease in addition to anti-tumor and anti-inflammatory benefits. Good sources of isorhamnetin are pears, olive oil, wine, and tomato sauce.
