The chances of women developing heart disease are much higher after menopause and a healthy lifestyle can help offset this risk. The type of diet, for example, plays a key role, as a new study by Penn State researchers has revealed that daily consumption of beet juice could improve blood vessel function in postmenopausal women, enough to to reduce their risk of heart disease in the future.
Beet juice contains high levels of nitrate, which the body converts into nitric oxide. Nitric oxide helps blood vessels expand, facilitating blood flow through the circulatory system. According to scientists at this Pennsylvania university, nitric oxide’s ability to widen blood vessels is particularly useful during periods of limited blood flow and oxygen supply, such as during a heart attack.
Researchers tested the effects of nitrate-rich beet juice on vascular health in 24 postmenopausal women between 50 and 60 years old. Participants underwent vascular function testing at the Penn State Clinical Research Center and then consumed two 2.3-ounce (68 milliliters) bottles of beet juice as a starting dose, followed by one bottle each morning for a week.
All participants consumed concentrated beet juice, so each serving provided as much nitrate as three large beets. A few weeks later, the participants drank beet juice without nitrate. Neither the researchers nor the participants knew what juice they were consuming at the time of the test.
One day after their last dose, participants returned for testing of their vascular function. The researchers compared the ability of each woman’s blood vessels to expand when they did and did not consume the nitrate-rich beet juice. Results published in Frontiers in Nutrition indicated that daily consumption of beet juice by postmenopausal women could improve blood vessel function enough to reduce the risk of heart disease later in life.
Plants rich in nitrate protect the heart and blood vessels
“After menopause, women no longer produce estrogen, which helps maintain nitric oxide in the body,” explained Jocelyn Delgado Spicuzza, doctor in integrative and biomedical physiology and lead author of the research. “This loss of nitric oxide production contributes to the substantially increased risk of heart disease for postmenopausal women. “Nitrate-rich foods, especially beets, are being investigated as a natural, non-pharmaceutical way to protect the heart and blood vessels.”
This study included women in early stages of postmenopause (one to six years after menopause) and in late stages (six or more years after menopause). Women in the late stage of postmenopause experienced the same benefits as the early stage group.
Delgado Spicuzza mentioned that the research team was especially excited to discover that beet juice improved blood vessel health in women who had gone through menopause years earlier. Some treatments to protect cardiovascular health in postmenopausal women – such as hormone therapy – are only safe during the first few years after menopause. Subsequently, hormone therapy may increase the risk of cancer and stroke.
Nitrate is an approved food additive for some animal products, such as processed meats. However, nitrate additives and preservatives are strictly regulated due to their potential to cause cancer, according to Delgado Spicuzza. In contrast, plants such as beets, spinach and lettuce accumulate nitrate naturally from the soil. These plant sources of nitrate have cardiovascular benefits because the human body can convert plant nitrates into nitric oxide, which it cannot do with nitrate added to meats.
Researchers used an ultrasound sensor to monitor blood flow through the brachial artery – located in the upper arm and supplying blood to the hands – during a stress test in which blood flow to the forearm was restricted. of each participant for five minutes. When the restriction was removed, they again measured how blood flow changed in the brachial artery.
“Nitrate-rich foods, especially beets, are being investigated as a natural, non-pharmaceutical way to protect the heart and blood vessels.”
The results showed that daily consumption of nitrate-rich beet juice improved blood flow compared to nitrate-free beet juice. The researchers noted that this level of improvement in blood vessel function – if it could be maintained throughout the postmenopausal years – could significantly reduce the risk of heart disease. While the long-term benefits of beet juice have not yet been studied, nitrate-rich vegetables have been confirmed to have long-lasting benefits.
“Women may need to consume beet juice daily, or even more frequently, to experience the full potential cardiovascular benefits,” said David Proctor, professor of kinesiology and physiology at Penn State and the study’s other senior author. “However, this research shows that beet juice may be very helpful in protecting blood vessel health in middle-aged women during a period of increased heart disease risk.”
“Some doctors already recommend beet juice to men and women with high blood pressure,” says Delgado Spicuzza. “By providing a safe and effective way to improve blood vessel function, beets could help maintain cardiovascular health in postmenopausal women. Considering that most women are postmenopausal for at least a third of their lives, the potential importance of these results can be understood,” she concludes.
