Higher circulating concentrations of select vitamins and minerals appeared to stave off the risk of developing high blood pressure about 20 years later in middle age, according to new research. The findings were presented at the American Heart Association’s Epidemiology and Prevention Lifestyle and Cardiometabolic Health scientific sessions.

According to the study authors, the study is the first to explore the associations of pregnancy metal levels with women’s midlife blood pressure and hypertension risk. The manuscript for the research was published in Hypertension.

Manganese, selenium, magnesium, and copper are associated with antioxidant and inflammatory properties, and may help protect against cardiovascular disease, the American Heart Association reports. High levels of manganese was associated with a lower risk of preeclampsia (high blood pressure during pregnancy). However, it wasn’t known how supplementing with essential metals during pregnancy might impact outcomes later in life. Meanwhile, heavy metal exposure is emerging as a potential cardiovascular risk factor.

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“People are constantly exposed to heavy metals and trace elements, and much research has shown that exposure to those metals and elements may have an impact on cardiovascular health, especially hypertension,” said Mingyu Zhang, PhD, MHS, lead author of the present study and epidemiologist and instructor in medicine at Beth Israel Deaconess Medical Center and Harvard Medical School. “In our study, we wanted to examine how levels of essential metals and elements during pregnancy may affect blood pressure and hypertension risk in midlife.”

The researchers analyzed data from the ongoing Project Viva, which began tracking health outcomes of women and their children in 1999. Nearly 500 women enrolled in the study between 1999 and 2002. Researchers measured concentrations of non-essential metals (arsenic, barium, cadmium, cesium, mercury, and lead), essential minerals (copper, magnesium, manganese, selenium, and zinc), folate, and vitamin B12 in blood samples during study enrollment.

Researchers conducted a midlife study visit after nearly 20 years of follow-up, when the participants were at a median age of 51.2 years. Blood pressure was measured to assess potential associations with individual metals, and participants were characterized as having high blood pressure if their readings were greater than 130/80 mm Hg or if they confirmed taking anti-hypertensive medication. The potential collective effects of all 11 metals and two micronutrients on blood pressure were analyzed. The study found that as copper and manganese levels doubled in blood during pregnancy, the risk of high blood pressure in midlife was 25% and 20% lower, respectively. As blood levels of vitamin B12 doubled during pregnancy, women had reduced average systolic (-3.64 mm Hg) and diastolic (-2.53 mm Hg) blood pressure nearly two decades later. About 95% of participants had B12 levels in the normal range. Blood levels of a mixture of copper, manganese, selenium, and zinc were also associated with lower blood pressure in a dose-dependent relationship.