Anthocyanins in Strawberries Improve Insulin Resistance

A new study in Molecular Nutrition & Food Research found that anthocyanin-rich strawberries may improve insulin sensitivity.

Insulin resistance (IR) is a hallmark of metabolic syndrome and a risk factor for heart disease and type 2 diabetes. Typically, after a meal, the pancreas produces an appropriate amount of insulin to usher glucose from the bloodstream into the cells. People with IR have built up a tolerance to insulin, so the pancreas must churn out extra insulin to coax blood sugar into the cells. Over time, this process can lead to type 2 diabetes.

Researchers observed the effect of anthocyanins on the postprandial insulin response of 21 obese adults with insulin resistance. Subjects were served a typical ‘Western-style’ meal high in carbohydrates and fat plus a beverage that contained freeze-dried whole strawberry powder. The beverages were controlled for fiber, and the amount of strawberry powder ranged from 0 grams to 40 grams (equivalent to 3 cups of fresh strawberries). When subjects drank the most concentrated beverage, they didn’t produce as much insulin as when they drank the least concentrated versions. In other words, they didn’t need as much insulin to metabolize their meal after drinking the anthocyanin-rich strawberry shake.

While the exact mechanisms are unclear, strawberry anthocyanins may alter insulin signaling at a cellular level.

These results add to the collective evidence that consuming strawberries may help improve insulin action, says study author Britt Burton-Freeman, Ph.D.

Eunyoung Park, et al. A dose-response evaluation of freeze-dried strawberries independent of fiber content on metabolic indices in abdominally obese individuals with insulin-resistance in a randomized, single-blinded, diet-controlled crossover trial. Molecular Nutrition & Food Research, February 2016.