05/01/2025
Canadian Health Network (...) Medical literature has shown that late menopause is associated with longer life expectancy or a lower risk of dementia.
Several studies have also shown that the risk of heart attack or stroke increases after menstruation stops, but that among women menopausal after the age of 55, this risk is 20% lower than among those menopausal between the ages of 45 and 54.
It was already known that the estrogen produced by the menstrual cycle protects cardiovascular function. Researchers at the University of Colorado, Boulder, have now identified another mechanism behind the cardiovascular benefits of late menopause. In an article published in Circulation Research, a journal of the American Heart Association, explained that late menopause has the ability to slow the aging of blood vessels.
Scientists assessed the vascular health of 92 post-menopausal women by studying their endothelial function. To do this, they measured brachial artery flow-mediated dilation, which indicates whether this artery of the arm dilates properly when blood flow increases. They also analyzed the mitochondria of the cells that line arteries and blood vessels.
Key findings
All menopausal women had poorer endothelial function than premenopausal women.
This deterioration in endothelial function is due to reduced production of nitric oxide, a gas produced by the endothelium that promotes blood vessel dilation, prevents arterial stiffness and slows the development of atherosclerotic plaques.
Endothelial cell mitochondria also become dysfunctional with age, generating more cytotoxic free radicals.
Among women who had undergone late menopause (after the age of 55), endothelial function was 24% lower than that of non-menopausal women, compared with 51% for women who had undergone menopause around the age of 50.
These differences persisted five years and more after menopause, with endothelial function in late menopausal women being 44% more efficient than in women menopausal around age 50.
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Inherent protection
The article also mentions that blood circulation is more efficient in late menopausal women due to “more favourable” levels of 15 lipid or fat metabolites present in the blood.
“Our data suggest that women who complete menopause at a later age have a kind of natural inherent protection against vascular dysfunction that can arise from oxidative stress over time,” said lead author Matthew Rossman, assistant professor in the department of integrative physiology at the University of Colorado, in a statement.
His team will continue their research to determine exactly what leads to this protection of endothelial function. They suspect that enhanced mitochondrial activity and certain lipids circulating in the blood are involved. Scientists also plan to explore how early menopause might impact heart health, and whether dietary supplements aimed at neutralizing free radicals inside blood vessels could reduce the risk of heart disease in women most at risk.
In a previous study, Rossman provided preliminary evidence that MitoQ—an antioxidant that targets the mitochondria of endothelial cells—significantly counteracts blood vessel aging within a few weeks in both men and women. A large-scale clinical trial is now underway to confirm this evidence, says the University of Colorado press release.
