(Reuters Health) – Feeding baby food with infant girls that contain soy can set them up for more painful menstrual periods as young women, a new study suggests.
The study, which contained information on more than 1,500 African-American women, strengthens the findings in previous studies that mainly include white women.
"We found that feeding soy in childhood was associated with different indicators of severe menstrual pain in women of childbearing age," said Kristen Upson, a postdoctoral fellow in the epidemiology department at the National Institute of Environmental Health Sciences (NIEHS). in Research Triangle Park, North Carolina.
"This included a 40 percent increased risk of ever using hormonal contraception for menstrual pain and a 50 percent increased risk of moderate to severe menstrual discomfort with most menstrual periods during adulthood," notes Upson.
The researchers analyzed data from 1553 African-American women living in Detroit and who participated in a larger NIEHS study on health effects on the environment. The women were all 23-35 years old when they enrolled in that study, which was designed to look at risk factors for the development of benign uterine tumors called fibroids. All were free from fibroids at the beginning of the larger study.
At the beginning of the study, women were asked to fill in an early-stage study by e-mail and return them by post with questions for their mothers about exposure to young children. If the mothers were not available, the women were asked to ask a family member or a close friend of the mother.
The questions were asked to women whether they had received soya as a baby (yes or no), how long they had been given soy (less than a month, one to three months, four to six months), and whether the soy was introduced during the first two months after they were born (yes or no).
Overall, the researchers found that women who were once given soy as babies, aged 18-22 years, had a 50 percent higher chance than those who did not get soy to experience moderate or severe cramps during most periods when they did not use hormonal contraception.
Women who received soya as a baby were also 40 percent more likely to ever use hormonal contraception to relieve menstrual pain, reports the research team in Human Reproduction.
Although the results do not explain why the soy formula can be linked to painful cramps during menstruation, Upson has some theories. "The relationship between soy feeding during childhood and menstrual pain in adulthood can be biologically plausible, since in the first months after birth the reproductive system of a baby continues to develop and the feeding of a baby mainly consists of breast milk and / or food, "said in an e-mail.
"This can lead to significant exposure to the components in the formula, including phytoestrogens (plant compounds that are similar in structure to estrogen) in the soy preparation during a critical development window."
There is some evidence of what can happen to animal models, Upson said. "Data from animal studies have shown that genistein, one of the phytoestrogens in the soy preparation, given after birth, has effects on the development of the reproductive system that continues in adulthood, including the parts of the reproductive system involved. are in menstrual pain. "
Although the new study will not help women who are already experiencing cramps, Upson hopes that it will prevent another generation of women from developing the same problem.
"Given the common menstrual pain and the impact this can have on women's lives, our findings point to the need for a better understanding of exposures, even those that occur earlier in life, which can reduce a woman's risk of menstrual pain. to increase." she said. "This information can be used to make prevention efforts to improve the health of women in the future."
SOURCE: bit.ly/2AXXFzk Human Reproduction, online November 9, 2018.