WATERVILLE, Maine — Lack of exercise and overeating aren’t the only factors contributing to an alarming rate of obesity in the country, said a group of doctors at a Colby College conference Friday.

“Chemicals, Obesity and Diabetes: How Science Leads Us to Action,” was the subject of a daylong forum in the Diamond Building.

Doctors and researchers from around the country spoke about how chemicals people come in contact with in their daily lives have an adverse effect on their health, mostly in the name of convenience.

Bruce Blumberg of the Department of Developmental and Cell Biology at the University of California-Irvine was the keynote speaker. He focused much of his 45-minute speech on obesogens, which he said are chemical compounds that disrupt the metabolism of lipids in the body, resulting in obesity.

Obesogens include chemicals such as tributyltin, bisphenol A (BPA) and diethylhexyl phthalate (DEHP).

Blumberg stated that 34 percent of the U.S. population is clinically obese, double the worldwide average. He added that 68 percent are overweight, but by 2020, that number is expected to jump to 86 percent.

Today, obesity accounts for 8 percent of health care costs, he said, amounting to $75 billion.

Blumberg said that in the years since World War II, many chemicals have been added to our foods and daily lives.

How those chemicals are determined to be safe is a topic of debate for Blumberg.

“They start at the toxic dose that kills all the animals. Then they take it down, down, down until they find the dose that kills only half. Then they take it down, down, down until they find the dose that there’s no effect and then they stop,” he said. “Toxicologists … say there’s no effect [because] they never looked, to be perfectly honest. They’ll stand here, pound on the table, jump up and down and say, ‘There’s no effect below this dose,’ but they didn’t look.
[But] the people who do look find effects very often.”

Blumberg identified BPA as one of many chemicals to be avoided.

“I would encourage, especially parents of young children, insofar as they’re financially able, to reduce their exposure to all sorts of such chemicals,” said Blumberg. “That’s not because it’s proven without a doubt the chemicals are bad, but I can say without the slightest shred of a doubt that there’s no benefit whatsoever. So if there’s no benefit and some risk, you should probably reduce exposure as much as you’re able. Eat organic as much as you can. In doing so, you not only help your own health, but you support small farmers, which is a good thing.

“I would avoid, and I do avoid, the use of plastic as much as possible — particularly for food storage and beverage storage,” added Blumberg. “Whether we’ll ever get the legislatures, the EPA or Congress to ban them is another matter. But we can take our own steps to minimize exposure.”

Chemicals have the most effect on the youngest population, speakers at the conference said.

“There may be effects on puberty from the chemicals that we’ve been discussing today.
There’s good evidence to that,” said Micheal Dedekian of the National Institute of Environmental Health Sciences. “The age of the first period in adolescent girls is changing a bit.”

Elizabeth Hatch, associate professor of epidemiology at the School of Public Health at Boston University, talked about the links between early childhood patterns and obesity.

She said babies who grew faster were five times more likely to have a higher body mass index than average and slow-growing babies. She added that the risk of obesity is 50 percent higher among the offspring of women who smoked during pregnancy.