The effects of strawberries on insulin sensitivity and cholesterol offer promising directions for scientific study, according to Britt Burton-Freeman, director of the Center for Nutrition Research at Chicago-based Illinois Institute of Technology.
“We are recruiting people in the clinic who have lost sensitivity to insulin, which usually means they’re on the way to diabetes,” said Burton-Freeman, who is also an associate research nutritionist at the University of California-Davis.
“We’re looking at whether strawberries can help improve the cell’s ability to recognize insulin and be able to take up glucose.”
Without that sensitivity, the pancreas keeps producing insulin until it wears down and diabetes sets in.
The research uses powders supplied by the California Strawberry Commission and mixed into drinks. The tests are blind, so some participants get a placebo.
A bit further down the road could be new cholesterol research.
“There’s some data out of UC-Davis by Susan Zunino that suggests with higher amounts of strawberries an obese subject could lower cholesterol,” Burton-Freeman said.
“Another group at the University of Oklahoma showed decreases in LDL cholesterol. We have hints and now we need to test that hypothesis directly.”
A research proposal is being prepared to submit to the California Department of Food and Agriculture’s specialty crop block grant program.
Burton-Freeman was one of five researchers scheduled to gather March 13 in the California Strawberry Commission’s seventh annual strawberry nutrition research meeting.
The others were Arpita Basu, Oklahoma State University; Zhaoping Li, University of California-Los Angeles Center for Human Nutrition; Howard Sesso, Harvard Medical School; and Barbara Shukitt-Hale, U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University.
Besides offering the commission updates on research it’s funded, the annual meetings offer a venue for collaboration and project planning.
Heart-health and brain-aging research was this year’s focus.
“The common thread is that if we look at processes that underlie disease, it’s the oxidative stress and inflammation in body and brain,” Burton-Freeman said.
Inflammation’s role in heart disease has been heavily investigated in the past decade.
“Strawberries seem to have an impact on oxidized LDL and reducing inflammation,” she said.
“If you’re having a pretty hearty lunch but you eat strawberries with that, it helps mitigate unfavorable responses.”
Shukitt-Hale is exploring whether strawberries can help offset aging’s toll on cognitive and motor functions.
Several years ago, a study showed rats eating a 2% strawberry diet had better memory and motor functions than those that didn’t.
“The next step is, ‘Does it help humans?’” Shukitt-Hale said.
In the next few months, her facility will try to answer that with a study of 40 people ages 55-70. A special treadmill will measure variations in their step. Older people tend to vary more. Half will have strawberries in their diet.
“From there we would do a bigger study if we got good results,” Shukitt-Hale said.
“The commission is a full funder.”