For over 2,000 years, reishi mushrooms have kept people spry and healthy well into their golden years. Or at least, that’s what people have been saying. According to some herbalists, red reishi mushrooms can cure many of the issues we associate with aging, such as high blood pressure, arthritis, and liver problems.

Before you go and buy your weight in mushrooms, there are a few things to consider about their safety and efficacy.

The Red Shrooms

You can find reishi mushrooms growing on decaying tree stumps across East Asia and North America. They come in six colors, but it’s the red variety that’s linked to alternative medicine.

As with most herbal remedies, there isn’t much scientific research to back up the claims. However, along with their purported ability to help fight symptoms of old age, the mushrooms are famous for their antioxidant properties.

Antioxidants fight the oxidation process that causes cells to die, and are currently being studied for their potential to kill cancer growths. While the body of evidence is growing, the trials are scarce and the link hasn't been conclusively proven. What we do know for sure is that eating reishi mushrooms doesn't interfere with Western cancer treatments. If you're currently battling cancer, you might ask your doctor about incorporating them into your treatment plan.

Too Bitter for Cooking

In alternative and traditional Chinese medicine, reishi mushrooms are usually dried and powdered to make teas. You can eat them fresh or cooked, as well, but dietitian Lori Zanini says they’re probably too bitter to be enjoyable. “There has not been any research that can confirm that eating reishi mushrooms raw vs. cooked would provide better outcomes,” she adds.

While some herbalists prescribe reishi mushroom supplements to help with high blood pressure, we don't have a clinical trial to prove that it’s an effective treatment. Reishi mushrooms can cause blood thinning, however, so you should avoid it if you're taking any medication for your blood pressure, anticoagulants, or antiplatelets.

“Reishi mushrooms might lower blood pressure, and it's unclear if high doses of reishi mushrooms slows blood clotting,” says Zanini. However, if you’re otherwise healthy, she says most doctors will clear you for 1.5 grams taken with meals. If you're concerned about your blood pressure or clotting, talk with your doctor before adding them to your existing diet.

There's a lot of research still to be done on reishi mushrooms and their ability to help you live a long, healthy life, but if this supplement sounds like something that might improve your overall well-being, talk to your doctor about integrating a supplement into your diet and exercise routine.