Exposure to toxic metals in middle-aged women may lead to having fewer eggs in the ovaries as they approach menopause, according to a new study.
Diminished ovarian reserve, also called low egg count, is when women have fewer eggs than others their age. The condition may cause fertility issues and is also linked to health problems such as hot flashes and weak bones.
A new study published in The Journal of Clinical Endocrinology & Metabolism suggests that middle-aged women exposed to heavy metals have lower levels of Anti-Müllerian hormone (AMH), roughly indicating how many eggs are left in a woman's ovaries.
The researchers studied 549 middle-aged women who were transitioning to menopause and had heavy metals, including arsenic, cadmium, mercury, or lead, in their urine samples.
Women with higher levels of metal in their urine were more likely to have lower AMH levels.
"We need to study the younger population as well to fully understand the role of chemicals in diminished ovarian reserve and infertility," Sung Kyun Park, Sc.D., M.P.H., Associate Professor of Epidemiology and Environmental Health Sciences, School of Public Health, the University of Michigan and a study author, said in a statement.
Heavy metals such as arsenic, cadmium, and mercury are considered endocrine-disrupting chemicals (EDCs), meaning that they mimic, block, or interfere with hormones in the body's endocrine system.
EDCs are found in the environment, such as air, soil, and water, as well as foods, personal care, and manufactured products. They have been associated with numerous health problems, including alterations in fertility, endometriosis, early puberty, certain cancers, diabetes, and obesity, among others.
Protecting yourself against EDCs
Although endocrine-disrupting chemicals come from many different sources, there is something an individual can do to limit their exposure. The Endocrine Society recommends taking the following measures:
- Check the air quality in your area. Avoid outdoor exercise when pollution levels are high and near high-traffic areas.
- Read labels and avoid personal care products containing phthalates and fragrances.
- Wash your hands often, especially before preparing and eating food.
- Avoid hand-me-down plastic toys for children and use infant formula bottles and toys labeled "BPA-Free."
- Thoroughly wash fruits and vegetables before consuming them.
- Reduce consumption of canned and processed foods.
- Use glass, porcelain, or stainless-steel containers. Avoid plastic containers designated #3, #6, and #7.
- Consider using a water filter.
- If possible, purchase organic produce, meat, and dairy products.
Causes of diminishing ovarian reserve
Exposure to heavy metals is not the only cause of low ovarian reserve. While aging is one of the most significant contributors, women may have fewer eggs due to genetics or after undergoing certain medical treatments, including:
- Genetic disorders that affect the X chromosome.
- Cancer treatment, such as radiation or chemotherapy.
- Surgery on the ovaries.
- Losing one or both of the ovaries.
- Autoimmune conditions, such as lupus, rheumatoid arthritis, or type 1 diabetes.
While more research is needed on the link between heavy metals and low egg count, reducing exposure to endocrine-disrupting chemicals is crucial to prevent other conditions.
- Newswise. Women exposed to toxic metals may experience earlier aging of their ovaries.
- Endocrine Society. Endocrine-disrupting chemicals.
- Endocrine Society. Endocrine-disrupting chemicals (EDCs).
- Cleveland Clinic. Diminished ovarian reserve.