The Romans called them Jupiter’s royal acorn. Some experts say they’re the oldest tree food known to man, with evidence of their consumption dating back 7,000 years. In ancient Persia, they were reserved for royalty.

We introduce you to the hearty walnut. It’s not just any nut.

Scientists are increasingly looking to the walnut for its possible health benefits. Now, a study out of Spain suggests they might offer cardiovascular benefits when consumed daily.

More than 600 healthy, older adults were separated into two groups that either added 30 to 60 grams of walnuts a day to their diet or that did not eat them at all. The study lasted two years. Scientist found the walnut diet led to a reduction of six out of 10 inflammatory markers in the blood, an overall drop of 11.5%.

Those markers are associated with a reduced risk of cardiovascular disease.

While the investigation focused on older adults, researchers say daily consumption of walnuts might benefit people of all ages.

The findings aren’t entirely surprising. Previous research has pointed to the possibility that walnuts contribute to vascular health and might even help lower cholesterol.

Chronic inflammation can cause severe problems to the human body, particularly the heart. And it is thought to be a major player in the buildup of arterial plaque, also known as hardening of the arteries.

The thinking is that walnuts contain essential nutrients that aid the body that could boost their anti-inflammatory effect.

Scientists caution that further study is needed in a more diverse population of subjects. But Jupiter’s royal acorn shows promise as a healthy addition to your diet.