Saturday, July 29, 2017

Strawberries Might Reduce the Mental Effects of Aging

This article originally appeared on Yahoo!

You’ve probably heard that certain foods, such as salmon and avocado, are considered good for your brain health. But scientists have found there’s a surprising new food to add to that list: strawberries.

That’s the takeaway from research published in the Journals of Gerontology Series A, which found that a natural compound in strawberries reduces mental defects and inflammation associated with aging in mice. The compound, which is called fisetin, is an antioxidant that researchers say has the potential to help treat age-related mental decline and conditions like Alzheimer’s disease or stroke.

For their research, scientists from the Salk Institute for Biological Studies fed 3-month-old mice that were aging prematurely either a daily dose of fisetin with their food for seven months or food with no fisetin. Both groups of mice were put through various activity and memory tests during the study. Scientists also studied the levels of certain proteins in the mice that were related to brain function, as well as responses to stress and bodily inflammation.

By the time they were 10 months old, mice that were not treated with fisetin struggled with the cognitive tests, and also had elevated markers of stress and inflammation. Brain cells that typically are anti-inflammatory were also inflamed. But the 10-month-old mice that were treated with fisetin had similar behavior, mental ability, and inflammatory markers to 3-month-old mice that were aging prematurely but were otherwise untreated.

It’s worth pointing out that this is a mouse study, and the researchers can’t yet say that the results would be the same in humans. But the findings are promising.

Fisetin in particular might help prevent cognitive decline because it reduces brain inflammation, maintains the levels of the important omega-3 fatty acid DHA in the brain, and reduces the loss of proteins involved in the connections between nerve cells, study co-author Pamela Maher, a senior staff scientist in Salk’s Cellular Neurobiology Laboratory, tells Yahoo Beauty.

Maher notes that most people are probably not getting enough fisetin in their regular diet to make an impact. For example, a 154-pound person would have to eat 37 large strawberries a day to get close to the dose researchers gave to the mice in the study. However, she adds, “it might not hurt” to eat more strawberries in any amount, especially given that berries have been linked with other health benefits like boosting bone health and contributing to healthy hair and nails.

While strawberries might help on some level, Clifford Segil, a neurologist at Providence Saint John’s Health Center in Santa Monica, Calif., tells Yahoo Beauty that it’s a good idea to take classes if you want to stay mentally sharp. That could mean taking a cooking class or signing up for something more academic at your local community college. As you get older, making a point to get out and do new things is crucial, he says. Maher also recommends following a Mediterranean-style diet, exercising regularly, and keeping yourself mentally stimulated. And adding a few strawberries to the mix won’t hurt either.

David's Commentary


These studies are always great because they continue to show the benefits of fruits and other plant-based foods, and also sheds light on how the various molecules in these foods achieve those benefits. However, there's a big gap in mouse studies vs human studies, so any time claims are made such as those made in this article, it's always wise to take it with a grain of salt. Often we see very positive results in rodent models, but more often than not the results do not translate when tried in humans. Sometimes they do of course, but most often not. A great example is that of resveratrol, a compound found in grapes and red wine that was considered a super-molecule and was shown to extend the life of rodents. However, these results have not been replicated in humans.

In the case of fisetin, it may have to do with the dose...I like that the authors acknowledge that consuming large quantity of strawberries everyday would be necessary to possibly achieve the benefits they are claiming. They note that a 154-pound (70 kg) person would have to eat 37 large strawberries (~670 grams, about 18 grams per strawberry) to get close to the dose used in the study.

However, I performed my own math based on the numbers in the study and came to a very different answer. The mice were given a diet supplemented with fisetin at a dose of 25 mg/kg/day. The amount of fisetin in strawberries is 0.160 mg per gram of strawberry. So here's the math for a 70 kg person:

25 mg/kg/day x 70 kg person = 1,750 mg fisetin per day
1,750 mg fisetin / 0.16 mg per gram strawberry = ~11,000 grams strawberry = 11 kg strawberry

Based on my calculations, you would need to eat closer to 600 large strawberries per day to achieve the amount of fisetin used in the study.

Nevertheless, the title of the article is true, emphasis on "Might." It definitely can't hurt to eat strawberries, whether that's to try to reduce the mental effects of aging, or just to be healthy overall. But if you are suffering from the mental effects of aging, I would not expect strawberry consumption to have much of an impact.



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