Supplementing with strawberries

The study, published in the Journal of Nutritional Biochemistry, included 23 healthy people from 24 to 30 years old, who were instructed to eat a strawberry-free diet that was also low in other high-polyphenol foods for 10 days. Polyphenols, plant chemicals that are often strong antioxidants, are found in certain foods such as berries, citrus fruits, chocolate, and green tea. Following that, they ate 500 grams (one pound or 3 to 4 portions) of strawberries per day for 30 days. Finally, they were instructed to eat their usual diet, minus strawberries, for the last 15 days of the trial.

Strawberry eating boosts antioxidants

Blood and urine tests were done after the first 10 days (baseline), after 30 days of adding strawberries to the diet, and after the last 15 days to measure cholesterol and triglyceride levels and check markers of antioxidant activity. These test results showed the following:

• Total cholesterol, LDL cholesterol, and triglyceride levels all dropped during the strawberry-eating phase.
• Vitamin C levels increased and other markers of antioxidant status improved during the strawberry-eating phase.
• All of these levels returned to baseline values after the 15-day usual-eating phase, with one exception: a test measuring red blood cells’ resistance to oxidative damage remained improved, suggesting a long-term benefit from eating strawberries.

“The findings presented here are interesting because they may partly explain the protective role of a diet rich in fruit and vegetables in preventing cardiovascular disease and other chronic diseases mediated by oxidative stress,” the researchers said.

Eating a high-polyphenol diet

Eating strawberries is just one flavourful way to boost health-promoting vitamin C and polyphenol intake. Here are some others:

• Enjoy a cup of cocoa. Cocoa is one of the richest sources of polyphenols, and studies have linked cocoa and dark chocolate consumption with lower blood pressure and lower stroke risk, as well as better blood vessel health.
• Add some herbs and spices. Sweet culinary spices like cloves and cinnamon are rich polyphenol sources. Use them liberally to add flavour to porridge, squash soup, or herbal tea. Other high-polyphenol herbs to consider for your savoury dishes include basil, sage, rosemary, marjoram, and various types of mints.
• Don’t forget the nuts. Specifically, walnuts and pecans are good choices for boosting your polyphenol intake.

(J Nutr Biochem 2014;25:289–94)