Pesticiden en andere chemische stoffen kunnen overgewicht veroorzaken.*
Volgens een Amerikaanse studie onder leiding van de wetenschapper Fredrick vom Saal van de universiteit van Missouri-Columbia kunnen chemische stoffen in alledaagse kunststoffen en pesticiden de aanleiding zijn voor overgewicht. Tegenwoordig zijn er wel 55.000 verschillende chemische stoffen waarvan er ruim duizend (waaronder bisphenol-A) het hormoonsysteem kunnen beïnvloeden. Uit de studie blijkt dat deze stoffen het functioneren van de genen van een foetus kunnen veranderen en daardoor een verandering teweeg brengen in het metabolisme waardoor een aanleg tot overgewicht ontstaat. Later in het leven zullen deze mensen hun levensstijl flink moeten aanpassen om geen overgewicht te krijgen.
Everyday
plastics and pesticides may influence obesity
Obesity
is generally discussed in terms of caloric intake (how much a person eats) and
energy output (how much a person exercises).
However,
according to a University of Missouri-Columbia scientist, environmental
chemicals found in everyday plastics and pesticides also may influence obesity.
Frederick vom Saal, professor of biological sciences in MU's College of Arts and
Science, has found that when fetuses are exposed to these chemicals, the way
their genes function may be altered to make them more prone to obesity and
disease.
"Certain
environmental substances called endocrine-disrupting chemicals can change the
functioning of a fetus's genes, altering a baby's metabolic system and
predisposing him or her to obesity. This individual could eat the same thing and
exercise the same amount as someone with a normal metabolic system, but he or
she would become obese, while the other person remained thin. This is a serious
problem because obesity puts people at risk for other problems, including cancer,
diabetes, cardiovascular disease and hypertension," vom Saal said.
Using
lab mice, vom Saal has studied the effects of endocrine-disrupting chemicals,
including bisphenol-A, which recently made news in San Francisco, where
controversy has ensued over an ordinance that seeks to ban its use in children's
products. In vom Saal's recent study, which he will present at the 2007 Annual
Meeting of the American Association for the Advancement of Science (AAAS), he
found that endocrine-disrupting chemicals cause mice to be born at very low
birth weights and then gain abnormally large amounts of weight in a short period
of time, more than doubling their body weight in just seven days. Vom Saal
followed the mice as they got older and found that these mice were obese
throughout their lives. He said studies of low-birth-weight children have shown
a similar overcompensation after birth, resulting in lifelong obesity.
"The
babies are born with a low body weight and a metabolic system that's been
programmed for starvation. This is called a 'thrifty phenotype,' a system
designed to maximize the use of all food taken into the body. The problem comes
when the baby isn't born into a world of starvation, but into a world of fast
food restaurants and fatty foods," vom Saal said.
More
research must be done to determine which chemicals cause this effect. According
to vom Saal, there are approximately 55,000 manmade chemicals in the world, and
1,000 of those might fall into the category of endocrine disrupting. These
chemicals are found in common products, from plastic bottles and containers to
pesticides and electronics.
"You
inherit genes, but how those genes develop during your very early life also
plays an important role in your propensity for obesity and disease. People who
have abnormal metabolic systems have to live extremely different lifestyles in
order to not be obese because their systems are malfunctioning," vom Saal
said. "We need to figure out what we can do to understand and prevent this."
"Perinatal Programming of Obesity: Interaction of Nutrition and Environmental Exposures" is the title of vom Saal's AAAS presentation. Also presenting with vom Saal at the AAAS symposium are Reth Newbold of the National Institute of Environmental Health Sciences, Bruce Blumberg of the University of California-Irvine, George Corcoran of Wayne State University and James O'Callaghan of the National Institute for Occupational Safety and Health. (April 2007) (Opm. De stof bisphenol-A is een product dat gebruikt wordt bij de productie van plastics waaronder bijv. flessen voor babyvoeding!! Al langer is bekend dat door migratie ook bisphenol van de (plastic)verpakking in de voeding terecht komen. Ouders let dus op koop alleen flessen voor uw baby die absoluut vrij zijn van bisphenol-a.)