Heart disease doesn’t suddenly appear in middle age—it starts building quietly years earlier. And according to a new study, that buildup begins much sooner for men than for women.

Research published in the Journal of the American Heart Association has found that men begin showing a higher risk of cardiovascular disease far earlier in adulthood than previously thought. In fact, by the age of 50.5 years, 5% of men have already developed cardiovascular disease. Women don’t reach the same level until about seven years later, at 57.5 years.

What’s even more striking is that the gap between men and women starts opening up as early as age 35. And this difference remains even after accounting for other factors, including lifestyle habits and the protective effects of female sex hormones.

For researchers, this was an eye-opening finding—and one with serious implications for how early heart health screening should begin, especially for men.

For years, scientists have known that men tend to develop coronary heart disease roughly a decade earlier than women. But most of that research focused narrowly on heart attacks. Much less was known about how sex differences play out in other cardiovascular conditions like heart failure and stroke.

The new study set out to look at the bigger picture. Researchers also wanted to understand whether changing lifestyle patterns—such as similar smoking rates and rising diabetes and blood pressure in both sexes—might be narrowing the heart disease gap. As it turns out, the gap is still very much there.

To explore this, scientists analyzed long-term data from the CARDIA (Coronary Artery Risk Development in Young Adults) study. The study followed 5,112 participants who were between 18 and 30 years old when they enrolled and tracked their health for more than 30 years. This made it an ideal group for understanding how heart disease develops from young adulthood onward.

Over the course of the study, men were consistently more likely than women to develop cardiovascular disease, coronary heart disease, and heart failure. Stroke was the one exception, with similar rates seen in both sexes.

Men reached a 5% incidence of cardiovascular disease seven years earlier than women, and they also reached a 2% incidence of coronary heart disease about a decade sooner. For stroke and heart failure, however, men and women reached similar risk levels at roughly the same ages.

The most important takeaway came from when these differences began. Researchers found that men’s cardiovascular risk starts accelerating around age 35. Before the early 30s, risk levels between men and women look fairly similar. After that, men begin to accumulate risk much faster—well before most routine heart screenings are even considered.

“This divergence happens long before people think they need to worry about heart disease,” said Dr. Raj Dasgupta, chief medical advisor for Sleepopolis, who was not involved in the study. Cardiovascular disease, he explained, develops silently over decades, which makes early prevention especially important.

Because of this, the authors argue that the fourth decade of life—your 30s—should be seen as a critical window for prevention. They suggest more intensive screening and earlier detection of hidden or “subclinical” heart disease in men to help prevent problems later on.

Experts stress that prevention isn’t complicated, but it does require consistency. Dr. Peter Kowey, a professor of medicine and clinical pharmacology at Thomas Jefferson University, says heart-healthy habits should be non-negotiable for adults of all ages. Regular exercise, a balanced diet, avoiding smoking, managing stress, and moderating alcohol intake can go a long way toward protecting the heart.

Diet, in particular, plays a major role. Both Kowey and Dasgupta point to the rise of ultra-processed foods as a growing threat to heart health. These foods are often cheap and convenient, but they’re strongly linked to obesity, high cholesterol, and heart disease.

Instead, experts recommend focusing on vegetables, fruits, whole grains, legumes, lean proteins, and healthy fats, while cutting back on sugary drinks, excess salt, and processed meats. Diets like the Mediterranean and DASH diets continue to have the strongest evidence when it comes to protecting heart health.

Despite recent social media trends promoting saturated fats like butter and tallow, experts remain firm that high saturated fat intake raises LDL cholesterol—a key risk factor for heart disease. A balanced diet, they emphasize, doesn’t mean eliminating meat or dairy, but it does mean making plant-based foods a central part of daily meals.

The message from the study is clear: heart disease risk in men starts rising earlier than most people realize. Waiting until middle age to focus on prevention may be too late. Building heart-healthy habits—and paying attention to early screening—can make a meaningful difference long before symptoms ever appear.