According to a study funded by the National Institutes of Health and the Health Resources and Services Administration, children born to women with high blood lead levels are more likely to be overweight or obese than those born to mothers with low blood lead levels. The research was carried out by Xiaobin Wang, M.D., of the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, and colleagues. It appears in JAMA Network Open.
Lead is one of the endocrine disrupting chemicals that has been linked to hypothalamic-pituitary-adrenal axis function, thyroid hormones, and bone metabolism. It could also be linked to obesity. In animal studies, lead exposure was associated with a trend of increased wean bodyweight and even low-level human equivalent gestational lead exposure produces late-onset obesity.
Women with high lead levels had a lower risk of their children being obese or overweight if they got enough folate 24 to 72 hours after giving birth. The U.S. Preventive Services Task Force recommends that all women of reproductive age consume 400 micrograms of folic acid each day to help prevent neural tube defects, a class of birth defects affecting the brain and spine.
Researchers examined data from the Boston Birth Cohort, a large observational study aimed at determining the causes of preterm birth. Blood samples from mothers were tested for lead exposure 24 to 72 hours after giving birth. Throughout childhood, children’s weight was measured on a regular basis. Children born to mothers with high lead levels were more than four times more likely to be overweight or obese than children born to mothers with low lead levels at the age of 8.1 years.
Women with high lead levels had a lower risk of their children being obese or overweight if they got enough folate 24 to 72 hours after giving birth. The U.S. Preventive Services Task Force recommends that all women of reproductive age consume 400 micrograms of folic acid (the synthetic form of folate) each day to help prevent neural tube defects, a class of birth defects affecting the brain and spine.
Women in the study had previously completed a questionnaire indicating whether they had taken a folic acid supplement during their second and third trimesters of pregnancy. If the authors’ findings are confirmed, testing pregnant women for lead exposure and then providing folic acid to those with high levels may reduce their children’s risk of being overweight or obese.
The Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute of Environmental Health Sciences provided funding for this study.
Lead is highly toxic and carcinogenic to humans4, particularly causing nervous system damage and brain disorders. Leaded gasoline was the primary source of human lead exposure for decades5. Although leaded gasoline was banned in China in 2000, the lead-acid battery industry in China could become another major source of blood lead. In terms of production and consumption, China’s lead-acid battery industry is the world’s largest, accounting for more than 67% of total lead production in the country.
Lead exposure during pregnancy may also be harmful to both the mother and the baby. The Centers for Disease Control and Prevention in the United States provides information on how pregnant women can reduce their lead exposure.
