Women's heart disease risk can rise sharply after menopause, a new study finds. Here's what to know.

Women’s heart health may decline precipitously after going through menopause, a new study suggests. On average, men are more likely to have a heart attack at a younger age. The average age of a first heart attack for men is 65, according to Harvard Health. But, after the midlife change, women’s risk profile quickly catches up to men’s, according to the new research, presented at an American College of Cardiology conference.

Women’s arteries hardened at twice the speed of men’s during the study. The likely culprit, researchers reason, is estrogen, the female hormone that has protective effects for heart health — until it declines during menopause. Scientists have long known about this benefit of estrogen, but many women remain unaware, experts say.

What does this new research mean for women? Here’s what you need to know about estrogen, menopause and heart health.

What did the new study find?

Researchers at Harbor-UCLA Medical Center in Torrance, Calif., looked at a metric of heart health called a coronary artery calcium (CAC) score in 579 postmenopausal women and compared their scores to the scores of as many men with similar risk profiles, including age, race and other health conditions. Everyone included in the study was taking statins to help control their cholesterol.

A CAC score measures how much calcium has built up in the arteries in and around the heart as plaques harden These plaques are a waxy mixture of fat and cholesterol that can build up and calcify, clogging the arteries and blocking oxygen-rich blood from traveling efficiently to the heart. A CAC score of zero means that no calcium plaque was detected, signaling a low risk of heart attack or heart disease. The higher the CAC score, the more plaque is blocking someone’s arteries, putting them at risk for heart attack and heart disease.

Everyone included in the study received two CAC scans at least a year apart. Women’s risk scores rose twice as steeply as men’s on average, suggesting that after menopause, heart health declines dramatically. Any edge in heart health women have over men is soon eroded.

What does menopause have to do with heart health?

The likely link between heart health and menopause — aside from age — is estrogen. (It’s worth noting that men have estrogen too, just at much lower levels than women.)

The sex hormone’s primary responsibility is female sexual development, but it plays many secondary roles throughout the human body. For example, estrogen does some very beneficial housekeeping throughout the cardiovascular system. It helps to keep blood vessels relaxed and open, reducing high blood pressure risks. It binds to and sweeps up cholesterol and plaques from the arteries, keeping them from hardening and narrowing those passageways. Estrogen is similarly sticky to free radicals, harmful stray molecules caused by oxidative stress. The hormone helps clear these away too, reducing inflammation.

When a woman goes through menopause, the ovaries’ production of estrogen slows down dramatically and she loses the hormone’s protective effects. And, during menopause, as “estrogen starts to wean off — it’s like a dimmer, not a light switch — we see an increase in adipose [fat] tissue, weight [gain], the metabolism falls and it affects sleep,” Dr. Melissa Tracy, a cardiologist at Rush University Medical Center, tells Yahoo Life. All of these changes increase women’s risks of heart disease.

How to protect your postmenopausal heart health

A healthy lifestyle is the best protection, says Tracy. This includes “exercising, watching your diet by eating less saturated fats and more whole foods and taking care of your mental health and sleep by practicing mindfulness to help in dealing with stress,” she says.

It’s also important to note that while a woman’s naturally occurring estrogen has protective effects for the cardiovascular system, synthetic estrogen used in hormone replacement therapy (HRT) to treat menopause symptoms, like hot flashes, does not. In fact, for some people, HRT raises risks of other cardiovascular problems, such as blood clots. It’s also not recommended for those with a history of breast or uterine cancer, liver disease or heart attacks. It’s unclear why synthetic estrogen doesn’t have the same cardiovascular benefits as the hormone that’s produced by the ovaries.

The authors of the new study suggested that more postmenopausal women might want to consider a CAC heart scan to determine their risks, based on the results of their study. Tracy also emphasized the importance of taking statins if your health care provider recommends them. Statins — like those taken by the people enrolled in the new study — are drugs that help to lower levels of “bad” cholesterol, which leads to the harmful artery plaques measured by the CAC score.

Statins, which are underutilized, may be especially important for women because postmenopausal women have more “soft plaque” than men, Tracy says. This is because women’s bad cholesterol levels increase after menopause.

The soft plaques she’s referring to are unstable globs of fat and cholesterol, free-floating through the blood system. While calcification is what leads to harder, narrower arteries — and, in turn, heart attack risks — it’s really the amount of free-floating plaques that indicate someone’s total risks, because they will eventually harden into calcification. After starting a statin, “the coronary calcium score increases,” Tracy says, because those soft plaques calm down and find their final places in the blood vessels. But statins block the liver from making more cholesterol, and help the organ remove more existing cholesterol from our blood. Less cholesterol in the blood means fewer soft plaques, which in turn means less calcification and lower heart disease risks overall, even if you see an uptick in calcification right after starting a statin.

“We know that statins help to improve cardiovascular mortality and morbidity. The question is, is it enough in a woman?” says Tracy, who wonders if higher doses of statins or additional treatments might be more beneficial. “Do we need to be treating postmenopausal women more aggressively?”