You may already be aware that many health experts recommend people consume flavonoid-rich foods and drinks, such as dark chocolate, red wine and tea. Flavonoids are thought to be a key indgredient for maintaining heart health.

Now, Australian scientists have found some preliminary evidence that nutritional supplements containing flavonoids may improve the functioning of the lining of blood vessels, NutraIngredients.com reports.

Published in the American Journal of Clinical Nutrition, the study looked at the effect of oral supplements of two pure dietary flavonoids on nitric oxide in men. Nitric oxide was used because its measure is an indication of cardiovascular health.

In addition to concluding that flavonoids provided beneficial effects to blood vessels, the researchers found evidence that the antioxidants were being successfully absorbed by the body.

The next steps include “some longer-term follow-up studies where we intend to measure vascular function and blood pressure,” lead researcher Professor Kevin Croft told the news provider.

Foods that contain high levels of flavonoids include red beans, cranberries, blackberries, onions, garlic and basil.