Female hearts are smaller than males: Before puberty, male and female hearts are about the same size. Yet, by adulthood, the female heart is 26% smaller compared to a males. In 2020, studies from Queen Mary University UK (1), and at Stanford University USA (2), independently found distinct differences between men’s and women’s hearts, indicating that a woman’s heart “is more than just a scaled-down version of the male heart”.
It’s not just the size: The male cardiac muscle exhibits a coarser microscopic texture compared to the finer grain of female heart muscle. Additionally, men’s hearts have a larger surface area, even when adjusted for body size. From a functional perspective, the adult female heart has a higher resting heart rate. This is attributed to the smaller size of the female heart, which pumps less blood with each beat, requiring a faster rate to sustain proper circulation. As such, there is a need for further research to understand the female vs males hearts better.
Cardiovascular disease (CVD): The disparities between adult female and male hearts also influence the types of heart disease observed in each gender. While CVD is a leading cause of death in women, its onset occurs 7-10 years later in women compared to men. This delayed onset is believed to be partially attributed to the various protective effects of the female hormone, estrogen, on the heart and blood vessels. Estrogen plays a role in regulating blood cholesterol levels, thereby reducing the risk of arterial fat accumulation. The build-up of fat in artery walls, particularly in coronary arteries supplying the heart, is a contributing risk factor for CVD. However, with the onset of menopause, estrogen levels decrease, leading to a progressive reduction in its protective cardiovascular effects.
Differences in heart disease: The misconception that estrogen provides complete protection has led to the myth that women are largely immune to developing CVD, resulting in the underestimation of heart disease risk in women. In a 2020 study conducted at the University of Bergen Norway (3), it was emphasised that, “Men and women possess distinct biological differences, leading to varying manifestations of identical heart diseases.” Specifically, it was noted that more women succumb to heart failure than men. In 50% of women diagnosed with heart failure, the underlying cause is often linked to untreated high blood pressure, which progressively harms the heart. The remaining 50% of heart failure cases in women result from experiencing a heart attack. Yet, unlike men, women are more prone to heart attacks that aren’t attributable to coronary artery blockages. There is currently no successful treatment for the particular type of heart failure most frequently observed in women.
According to a 2010 publication from the Netherlands (4), it was concluded that the underestimation of heart disease risks in women due to misconceptions about female ‘protection’ leads to less aggressive treatments, reduced representation in clinical trials, and underscores the need for heightened self-awareness and identification of unique cardiovascular risk factors for effective prevention and treatment strategies. Similarly, the Stanford publication, stated there is a need for “sex-specific diagnostic criteria that will allow us to diagnose cardiac disease in women equally as early, robustly and reliably as in men”.
Diet and heart disease is different in men and women: In a study published by Deakin University Australia (5) in January 2024, it was found that dietary risk factors for heart disease varied between men and women, with diets high in red meat intake for women and low in wholegrain consumption for men were the key factors in diet-related CVD burden. These findings highlight gender-specific approaches are needed for heart health.
What’s next: A better understanding of the differences between female and male hearts will not only raise the degree of self-awareness in women, but also lead to the identification of the cardiovascular risk factors that are specific to women (6). This understanding should facilitate advancements in both the prevention and treatment of heart disease in women.
This article was written together with my colleague, Dr Jim Kiatos MBBS, medical doctor, lecturer, naturopath.
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