Strawberries show promise in disease prevention, say researchers
cardiovascular disease (CVD), certain types of cancer and
age-related decline in cognitive function have delivered promising
preliminary data, according to the California Strawberry
Commission.
Strawberries are recognized as a source of important nutrients including vitamin C, folate, potassium, flavonoids, quercetin, kaempferol and ellagic acid.
By funding three separate studies into the possible links between strawberry consuption and disease, the commission hopes to form a basis for further trials and encourage Americans to consumer strawberries regularly as part of a healthy diet, rather than as an occasional "healthy indulgence".
"Several lines of preliminary evidence have suggested that strawberries may have a role in cardiovascular disease prevention, due to their rich nutrient content and corresponding antioxidant potential," said Dr Howard Sesso of the Harvard School of Public Health.
He is analyzing dietary, lifestyle, clinical, and blood data from 28,000 women enrolled in the Women's Health Study, which includes a specific question on strawberry consumption, in order to assess any link between consumption of the fruit and CVD and determine the amount of strawberries that must be consumed to realize the benefits.
"Because of the size of our study population, we hope to be able to detect even a modest association with the risk of CVD, comparing high to low categories of strawberry intake," said Sesso, whose study is due for completion in the spring of this year.
Meanwhile, researchers at the Ohio State University Research Foundation are carrying out what it believed to be the first study to specifically test freeze-dried strawberries' ability to inhibit prostate cancer.
"This project will test the hypothesis that supplementing the diet with freeze-dried strawberries will decrease the incidence and severity of prostate cancer in a laboratory animal model," said principal investigator Dr Russell Klein.
Cell culture studies have already indicated that the flavonoid quercin may inhibit growth of human breast cancer and prostate cancer cells.
Klein and his team are seeking to build on this knowledge by measuring the levels of protective compounds in the prostate tissue after strawberry consumption to see whether the beneficial nutrients are reaching the area, testing the effects of strawberries on prostate cancer biomarkers, such as markers of cell proliferation, and evaluating whether strawberry consumption has any impact on the incidence and/or severity of the disease.
Positive results could provide the impetus for clinical trials in prostate cancer patients, says Klein, and have implications for other hormone-related cancers.
The third California Strawberry Commission-funded study is taking place at the USDA's Human Nutrition Research Center at Tufts University and builds on an earlier pilot study which showed a decrease in age-related cognitive function decline in rats that were fed strawberry extract over a long period of time.
Now researchers are looking at the effects of strawberry supplementation in three areas: behavioral aging; repair and regeneration of nerve cells in aging; and resistance to oxidative stress in aging.
Whatever the conclusions of these three studies, the Commission is anticipating further research by funding the University of California, Los Angeles to develop a standardized strawberry extract, which will enable a direct comparison between studies and allow scientists at different laboratories to replicate each other's work.
California produces 88 percent of the strawberries consumed in the United States and the industry generates annual revenue of $1.1 billion for the state.
Ninety-four percent of households do consume strawberries, according to the California Strawberry Commission. A spokesperson told NutraIngredients-USA.com that sponsoring research is part of an effort to "give people more reasons to eat strawberries, as they are now available almost all year round".
The organization, which represents more than 600 strawberry growers, suppliers and shippers, has just launched a $1 million nationwide advertising campaign, which aims to make consumers aware of the berry's nutritional benefits, dubbed the 'Red Edge'.
