Japanese plums may help prevent hypertension, cardiovascular disease

The Japanese plum (Prunus mume) is also known as the Japanese apricot and is traditionally called “ume” in Japan.

It is sometimes processed into an infused juice concentrate called bainiku-ekisu for use in juice beverages or wine.

Dr. Satoru Eguchi, professor in the Cardiovascular Research Center at the Sol Sherry Thrombosis Research Center and Center for Metabolic Disease Research at the Lewis Katz School of Medicine at Temple University and senior author of this study, said this research was driven by the need for alternative therapies than medications for hypertension.

“Current treatments are insufficient to normalize the risk of cardiovascular disease death and incidences such as myocardial infarction or stroke even (if) they normalize blood pressure,” he explained to Medical News Today. “Hypertension patients have a higher risk for cardiovascular disease regardless of the treatment or normalization of blood pressure by drugs compared with normal blood pressure subjects.”

According to researchers, previous experiments conducted in smooth muscle cells of blood vessels showed bainiku-ekisu helped hinder growth-promoting signals caused by angiotensin II. Angiotensin II is a circulatory hormone known to play a role in the development of hypertension.

“Angiotensin II is a major hormone (regulating) blood pressure and contributes to the development of hypertension in humans,” Dr. Eguchi said. “Our prior paper showed that it attenuated angiotensin II signaling and function in cultured vascular cells. All other fruit extracts were negative to alter angiotensin effects in these cells. However, our findings were limited in vitro. Thus we hypothesized that it may reduce blood pressure and associated vascular problems of hypertension in vivo.”

For this study, Dr. Eguchi and his team used a mouse model to test their theories about the ume juice concentrate, bainiku-ekisu.

Mice were given an infusion of angiotensin II to induce hypertension. Afterward, the mice were given either water containing bainiku-ekisu or just plain water.

Upon analysis, researchers found mice that received the bainiku-ekisu infused water did not develop hypertension.

Additionally, the bainiku-ekisu helped protect their vasculature from the negative effects of angiotensin II. For example, mice who received the juice concentrate had minimal enlargement of their aorta, while those given plain water had pronounced enlargement, known as aortic hypertrophy.

The scientists also noticed the bainiku-ekisu helped decrease the number of immune cells, which would normally trigger an inflammatory process associated with hypertension.

And researchers observed bainiku-ekisu helped prevent the cellular switch from aerobic metabolism to glycolysis normally seen in hypertension. This helps protect the body from oxidative stress that would cause inflammation, vascular stiffness, and potentially the development of more severe cardiovascular disease.

“Our animal experiments suggest that bainiku-ekisu may reduce blood pressure in patients with hypertension,” Dr. Eguchi explained. “It is safe to combine with current therapy. It may also help to reduce (the) drug amount needed to maintain normal blood pressure.”

“Moreover, taking bainiku-ekisu may prevent you (developing) complications associated with hypertension such as heart attack and stroke,” he added.

The Japanese plum grows on a tree that, like cherry trees, blooms in the spring with plum blossoms, giving way to celebratory events in Japan.

The Japanese plum trees grow well in mild to subtropical temperatures. Although it has been in China and Japan for thousands of years, the Japanese plum has made its way to other areas of the world, including certain parts of the United States.

Although the Japanese plum may look and smell quite a bit like a Western plum or apricot, they have a more acidic and tart taste.

Besides being processed into the infused juice concentrate, bainiku-ekisu, the Japanese plum is often used to make umeboshi, where the plum is highly salted and pickled and used as a condiment in traditional Japanese cuisine.

This is not the first time the Japanese plum has been studied for its potential health benefits. Previous research shows ume may help improve digestive issues in people with gastroesophageal reflux disease (GERD)-related symptoms.

Other studies have found that ume has antioxidant and anti-inflammatory properties and can be potentially helpful against allergic disease and obesity.

And research in 2017 found daily ingestion of ume extract helped improve diastolic blood pressure in people with grade I hypertension.

Medical News Today also spoke with Dr. Rigved Tadwalkar, a board certified cardiologist at Providence Saint John’s Health Center in Santa Monica, CA, about the new research.

“What’s interesting is that even though this is a mouse model, the fact that this substance — bainiku-ekisu — was able to attenuate hypertension and protect against vascular remodeling is really quite positive,” he commented.

However, Dr. Tadwalkar did urge caution as more still needs to be learned about using ume and bainiku-ekisu as potential treatments.

“This is somewhat novel and mouse models don’t always reflect the complex pathophysiology of human cardiovascular disease,” he explained. “So obviously we would need to see something in humans to determine the safety, efficacy, and dosing in terms of managing this.”

“It does provide a potential avenue for these alternative therapies in cardiovascular disease management,” Dr. Tadwalkar added. “So overall, it’s promising, but obviously, there’s just a little bit of caution that I approach the topic with.”

And Dr. Tadwalkar agreed it is important to look for alternative therapies for treating cardiovascular diseases.

“Today’s patient is looking for a range of options and they want to have a specific treatment plan that’s tailored to their needs and circumstances,” he continued. “This provides a bit more of a personalized approach. And it can encompass these holistic approaches that people like — lifestyle modifications, dietary changes, and the whole category of natural remedies.”

“I think it allows patients to feel more empowered because they can take a bit more of an active role in their own care,” Dr. Tadwalkar added. “In my experience, I find that oftentimes (patients are) even more likely to be interested in traditional pharmacotherapy when they can take on a complementary approach that fosters use of alternative therapies.”