Strawberry powder and blood vessel function in overweight teenage boys
What it found
In overweight teenage boys, a week of daily strawberry powder raised certain blood markers linked to better blood vessel function.
The benefit was seen only in those whose nitrate levels went up.
What they found
Studies in people
Blood vessel response
One hour after drinking the strawberry shake, nitrate and nitrite levels in the blood rose sharply compared with the control shake. This happened both on the first day and after a full week of daily use.
Vessel function in responders
After one week, the boys whose fasting nitrate levels rose on the strawberry powder also showed better small blood vessel function. Boys whose nitrate levels did not rise saw no change in vessel function.
Blood pressure unchanged
Neither the strawberry powder nor the control powder changed blood pressure over the week or in the hour after drinking the shake.
Blood fats mostly similar
Over the study period, LDL cholesterol fell slightly and HDL rose slightly in both groups, so these changes were not tied to the strawberry powder. Total cholesterol rose a small amount one hour after the strawberry shake compared with the control.
Platelet stickiness
A marker of sticky platelets dropped after one week, but it dropped just as much with the control powder as with the strawberry powder. The authors suggest something shared by both powders may have caused this.
What the authors conclude
- They say strawberries may offer blood vessel benefits to heavier teenage boys, especially for those whose nitrate levels rise after eating them.
- They note that the short one-week testing period might have been too brief to see changes in blood fats or other measures.
- They call for future trials to look at longer feeding periods and stricter ways to check whether participants actually finished their drinks.
How it was done
Earlier work showed freeze-dried strawberry powder improved heart and blood vessel markers in adults at risk of heart disease. Scientists did not know if the same would happen in heavier teenagers, who can already show early signs of blood vessel problems.
Twenty-five overweight or obese boys aged 14 to 18 drank a shake made with 50 g of freeze-dried strawberry powder or a matching control powder every day for one week. After a one-week break they switched to the other powder for another week. Researchers checked their blood vessels, blood fats and platelet activity before and after each week, and again one hour after drinking the shake.
What it can’t tell you
- The trial lasted only one week per powder, so it cannot show what happens when teenagers eat strawberries over months or years.
- Only boys took part, so the results may not apply to girls.
- Most participants did not return their empty packets, so scientists cannot be fully sure everyone drank all of the powder.
Who paid
- Authors work at
- University of California, USA
The paper
- Title
- Effects of a dietary strawberry powder on parameters of vascular health in adolescent males
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Djurica D, Holt RR, Ren J, Shindel AW, Hackman RM, Keen CL (2016). Effects of a dietary strawberry powder on parameters of vascular health in adolescent males. The British journal of nutrition. doi:10.1017/S0007114516002348Free full textPubMed 27464461DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error