A new study suggests that the loss of estrogen after menopause may trigger harmful inflammation throughout the body and increase the risk of heart disease by disrupting the liver and immune system.
The research, carried out by scientists at the University of Texas at Arlington, helps explain a medical mystery that researchers have been trying to solve for decades.
Women generally have lower rates of heart disease than men before menopause, but their risk rises significantly afterward.
The findings were published in the journal Scientific Reports and may eventually help scientists develop safer treatments for women after menopause.
Heart disease is the leading cause of death worldwide, and women face a major increase in risk later in life. Researchers have long suspected estrogen plays a protective role, but exactly how the hormone protects the body remained uncertain.
The new study focused on how estrogen affects metabolism, cholesterol control, inflammation, and liver health.
The liver is one of the body’s most important organs. It helps regulate cholesterol, stores energy, processes nutrients, removes harmful substances, and supports metabolism. Problems in the liver can affect many parts of the body, including the heart and blood vessels.
Researchers discovered that low estrogen levels interfere with important liver functions and trigger inflammatory changes that may contribute to cardiovascular disease.
The study was led by Professor Subhrangsu S. Mandal and Professor Linda Perrotti. Their team found that estrogen helps maintain balance in both the immune system and metabolism. When estrogen disappears after menopause, this balance may be lost.
One of the key discoveries involved an enzyme called IDO1, short for indoleamine 2,3-dioxygenase-1.
IDO1 is already studied in cancer immunotherapy because it affects how immune cells use nutrients and respond to inflammation. The new study found that estrogen deficiency increases IDO1 levels inside the liver.
This appears to create problems with cholesterol handling. According to Professor Mandal, immune cells become less effective at removing cholesterol when IDO1 activity rises. This may increase the buildup of unhealthy cholesterol linked to clogged arteries and heart disease.
The researchers also observed signs of inflammation throughout the body, not only in the liver. Blood markers showed that estrogen loss may trigger a widespread inflammatory state.
This is important because chronic inflammation is increasingly recognized as a major driver of many diseases. Scientists now believe inflammation contributes to heart disease, diabetes, obesity, arthritis, dementia, and autoimmune conditions.
The findings suggest menopause-related hormone loss may affect several body systems at once.
Hormonal imbalance has already been linked to many health problems including osteoporosis, fatty liver disease, weight gain, infertility, endometriosis, and polycystic ovary syndrome.
The study also found encouraging signs that restoring estrogen reversed many of the harmful changes seen in the liver and immune system. This suggests that estrogen-related pathways may become important targets for future medicines.
Still, researchers warned that hormone replacement therapy is not a simple answer. Although estrogen therapy can improve cardiovascular and liver function, it may also increase the risk of cancers such as breast cancer and ovarian cancer.
Because of these risks, scientists are searching for safer alternatives.
Instead of directly replacing hormones, future drugs may target inflammatory pathways such as IDO1. Researchers hope this could eventually provide some of estrogen’s protective effects without the dangers linked to hormone therapy.
Professor Mandal said scientists may eventually develop pill-based medications that work more like common medicines rather than expensive antibody-based therapies used in some modern treatments.
The research highlights the growing understanding that menopause is not only a reproductive transition. Hormonal changes can influence immunity, metabolism, cholesterol balance, and inflammation across the entire body.
The study findings appear important because they provide a biological explanation for the rise in heart disease risk after menopause. The work also connects the immune system and liver health to cardiovascular disease in women in a new way.
However, researchers caution that more studies are needed before new treatments can be developed. Scientists must still determine exactly how safe and effective future therapies targeting pathways like IDO1 would be.
Even so, the findings provide a promising direction for future research and may eventually help millions of women reduce their risk of heart disease after menopause.
If you care about heart health, please read studies about how eating eggs can help reduce heart disease risk, and herbal supplements could harm your heart rhythm.
For more health information, please see recent studies that olive oil may help you live longer, and vitamin D could help lower the risk of autoimmune diseases.
Source: University of Texas at Arlington.
