Strawberries can help attenuate the progression of cardiovascular disease in high-risk adolescents, according to a new study published in the British Journal of Nutrition.
Cardiovascular disease lays down its roots in adolescent vasculature, eventually leading to the heart attacks and strokes seen in adults. Overweight and obese teenagers are at an increased risk and may already show signs of low-grade inflammation and blood vessel dysfunction.
Since diets rich in polyphenols can help reduce the risk of cardiovascular disease in adults, researchers set out to determine if they have a similar effect in adolescents. Strawberries are an especially good source of polyphenols, which have been shown to improve lipid profiles, insulin sensitivity, and inflammation.
In this study, 25 healthy, male adolescents between ages 14-18 participated in a randomized, controlled, double-blind crossover study. Researchers looked at both the acute and short-term effects of consuming freeze-dried strawberry powder (FDSP) on vascular function.
Participants consumed either 50 grams of FDSP or a calorically equivalent placebo powder in a strawberry-flavored shake. They drank the shake every day for one week, took a week off, and then used the other powder for a week. Plasma measurements were taken an hour after consumption and then again a week later. Fifty grams of FDSP is equivalent to 500 grams or three servings of fresh strawberries.
After one week, the FDSP group showed a significant increase in plasma nitrate/nitrite levels versus the control group, indicating a reduction in inflammation and blood vessel dysfunction.
The researchers hypothesize that a synergistic effect is responsible for these positive results. While strawberries contain powerful polyphenolic compounds, they’re also a naturally rich source of dietary nitrates, which may help dilate blood vessels and reduce dysfunction.
Dragana Djurica, et al. Effects of a dietary strawberry powder on parameters of vascular health in adolescent males. [link: http://dx.doi.org/10.1017/S0007114516002348] British Journal of Nutrition, June 2016.