37 strawberries a day to keep the doctor at bay?
An apple a day may well keep the doctor away, but according to a recent American study, strawberries could also help to keep that very same doctor at bay.
Eating lots of delicious little red strawberries on a daily basis could prevent or delay the development of some illnesses such as diabetes, some types of cancer (particularly cancer of the prostate) and also Alzheimer’s.
Fisetin: the strawberry’s secret weapon
Behind all these health benefits lies fisetin, an antioxidant, or flavonol, which can be found in high concentrations in strawberries as well as other fruit and vegetables. A scientific research team at the Salk Institute’s Cellular Neurobiology Laboratory have already completed work on fisetin (notably showing its neuroprotective effects). In a study published in the review PloS ONE, fisetin was shown to have certain positive effects on diabetes. In order to prove this, researchers fed Akita mice (the best model for studying type 1 and type 2 diabetes) on a diet rich in fisetin.
The researchers were able to establish that there was a clear improvement in symptoms linked to diabetes in these fisetin fed mice: the process of hypertrophy in the kidneys, a characteristic of diabetes, was reversed and the level of protein in urine (also a good indicator of diabetes) literally fell like a stone. In addition to all this, the anxious behaviour in diabetic mice also showed signs of improvement.
The researchers also feel that these studies have produced evidence of molecular mechanisms that support these effects: fisetin could activate an enzyme, glycosylase -1, responsible for the suppression of the toxic precursors to glycation (a process which enables sugars in the blood and brain to fix onto proteins). This enzyme could equally act on similar processes (inflammatory activity) taking place in certain types of cancer.
Getting your 37 strawberries a day
This all means that many hopes are pinned on fisetin. A little dampener however: in order to reproduce these benefits in humans, you would need to eat 37 strawberries a day… assuming that fisetin is actually metabolised at the same rate in humans as it is in mice.
According to Pamela Maher, given that such a strawberry-rich dietary regime could be difficult to maintain (!), fisetin-based supplements, or supplements that mime the same effect, could be more appropriate. "Polyphenolics like fisetin and those in blueberry extracts are found in fruits and vegetables and are related to each other chemically," she says. "There is increasing evidence that they all work in multiple diseases. Hopefully some combination of these compounds will eventually get to the clinic."
"Flavonoids could represent 2-fisted assault on diabetes and nervous system disorders," Press release, Salk Institute, June 2011
"Fisetin Lowers Methylglyoxal Dependent Protein Glycation and Limits the Complications of Diabetes," Maher P, Dargusch R, Ehren JL, Okada S, Sharma K, et al. (2011). PLoS ONE 6(6): e21226
Copyright © 2011 Doctissimo
Get more on this subject…