Watermelon juice may protect blood vessels from sugar spikes

After we eat certain foods, the amount of sugar in our blood rises.

These spikes can damage blood vessels due to a reduction in the take up of a protective substance called nitric oxide. However, a study published in the Journal of Nutrition suggests drinking watermelon juice could help counteract these negative effects.

Healthy adults (6 men and 11 women) in their early 20s took part in the randomised, double-blind crossover trial. They were asked to consume 500ml of watermelon juice or a placebo drink every day for two weeks. At the end of this time, they were given an oral glucose tolerance test (OGTT) and measurements were made of their blood vessel dilation, smaller blood vessel function, and any tissue damage.

The results showed that consuming watermelon juice daily for two weeks improved blood vessel dilation and some measures of small blood vessel function.

After consumption of a glucose drink (as part of the OGTT), positive effects were seen for blood vessel dilation, blood flow to small vessels, and oxygen delivery to tissues in those consuming the watermelon juice group compared with the placebo group.

The study results suggest that watermelon juice may protect blood vessels (and oxygen delivery to muscles) from blood sugar spikes after meals. Watermelon juice contains the amino acid citrulline, which is converted into arginine to make nitric oxide. The authors suggested that the increase in nitric oxide production, as well as the antioxidant effect of other bioactive compounds in watermelon juice, may play a role in supporting blood vessel function.

Reference

Vincellette et al. Supplemental Watermelon Juice Attenuates Acute Hyperglycemia-Induced Macro-and Microvascular Dysfunction in Healthy Adults. The Journal of Nutrition. (2021). https://doi.org/10.1093/jn/nxab279