Folic acid supplements may be an inexpensive way to help seniors cope with heat waves. Penn State researchers have found folic acid increases skin blood flow by enhance blood vessel dilation— reducing the risk for heat-related stroke and heart attack.

"We know that when older adults are exposed to heat, their bodies are not able to increase skin blood flow to the same extent that young subjects do, and as a consequence, older adults are at a greater risk for cardiovascular events, such as heart attack and stroke, during environmental heat waves," said Anna Stanhewicz, a Penn State researcher.

One reason this is so: Aged blood vessels cannot produce enough nitric oxide to compensate for the heat.

"When young, healthy people are exposed to heat, their bodies increase blood flow to the skin and this increased flow, combined with sweating, helps to cool the body down," Stanhewicz said.

In two studies of seniors who were exposed to increased temperatures, the researchers found folic acid triggers a change in the body that leads to increased nitric oxide production, helping them cope.

"The bottom line is that folic acid supplementation increased nitric oxide production in older blood vessels," Stanhewicz said. "In the past, studies conducted in our lab showed that we can increase nitric oxide production, and then consequently reflex skin blood flow, in older adults by giving them an expensive pharmaceutical. So in this study, we wanted to test that again, but with an inexpensive treatment that might work the same way."

She added that researchers hope to investigate whether folic acid can also improve vessel function in people with clinical cardiovascular disease.

The study, published online in the journal Clinical Science., was funded by the National Institutes of Health.