NAGOYA — Pregnant women who frequently eat ready-made bento lunches and frozen foods have more than double the chances of having a stillborn baby, according to results of analysis by a Japanese research team.
Based on the data of 94,062 pregnant women obtained from the Japan Environment and Children’s Study (JECS) by the Ministry of the Environment, the research team led by Nagoya City University obstetrics and gynecology professor Mayumi Sugiura and specially appointed professor of nutrition Hazuki Tamada looked at the relationship between pregnancy results and eating ready-made meals sold in bento lunchboxes, retort pouches, frozen foods, instant foods and canned foods.
At the time of the analysis, statistical processing was performed to remove the influence of factors such as age and physique, smoking and drinking history, and the mother’s income that were found to be related to pregnancy results in the JECS. The JECS was conducted on about 100,000 pregnant women and their children from January 2011 to March 2014 to investigate the impact of environmental hazards such as chemical substances.
The team’s analysis found a link between stillbirths and the frequency of having bento lunches and frozen foods. Pregnant women who consumed a “medium amount” (once or twice a week) of ready-made lunches had double the chances of having a stillborn baby than those who ate a “small amount” (less than once a week), while women who consumed a “large amount” (at least three to seven times a week) had 2.6 times the risk. For frozen foods, stillbirth chances for women who ate medium to large amounts were 2.2 times higher than those who only consumed a small amount.
Professor Sugiura said, “There is a previous study suggesting that bisphenol A, which dissolves out of polycarbonate used for food containers when microwaved, affects pregnancy results. Ready-made bento lunchboxes and frozen foods are often heated in the microwave, and the chemicals that leach out may be the cause of stillbirths. Further research is needed.”
A small amount of bisphenol A remains in polycarbonate containers, and the health ministry has established elution test standards for these and other receptacles. However, since there are multiple research reports suggesting that even extremely small amounts of bisphenol A impact living organisms, the ministry requested the Cabinet Office’s Food Safety Commission of Japan to evaluate their health implications in 2008. It is still awaiting a reply.
Of the 94,062 people surveyed in the JECS, 0.9% women had stillbirths, 4.8% preterm births, 7% babies small for gestational age — referring to a baby smaller than usual for the number of weeks of pregnancy — and 8.1% babies with low birth weights.
The research results were published in the international scientific journal Nutrients dated Feb. 20.
(Japanese original by Motoyori Arakawa, Nagoya News Center)