Everyday addictions: DNA and brain changes may sabotage New Year | St. Louis Public Radio

Everyday addictions: DNA and brain changes may sabotage New Year

Jan 3, 2011

This article first appeared in the St. Louis Beacon, Jan. 3, 2011 - If you're having trouble keeping your New Year's resolutions, it may be your mother's fault. Or your grandfather's. Or even your great-great grandmother's.

It's not a blame game. It's a relatively new science called epigenetics that may help explain why you blew your diet, sneaked a cigarette or fell off the wagon a short time after vowing to stop on Jan. 1.

The chief tenets in this nascent field are fairly simple: Consuming addictive substances creates changes in the brain that make bad habits hard to break -- no matter how much willpower you think you have. And if this process occurs before you have children, it's possible that your offspring may inherit an addiction to alcohol, food, nicotine or other substances.

"The data that seem to be emerging are that addiction changes the way genes are permanently expressed," said Theodore Cicero, professor of psychiatry at Washington University School of Medicine.

The Addicts Among Us

The word "addict," with all its moral implications, conjures up images of dirty, slumped-over, needle-marked figures lying in an alley. But addiction often wears a suit and tie or heels and hose. It's in your office, your home, your family. It may be you.

Do you have a hangover every weekend --- despite your best intentions to cut back? Can't have cookies in the house without inhaling them? Back to a pack-a-day habit after just one cigarette?

The American Medical Association proclaimed substance abuse a disease in 1966. But what constitutes a substance? Most of us know about cocaine, heroin, pain killers, cigarettes and even alcohol and their relationships to the release of feel-good brain chemicals like dopamine.

Last month, food attached itself more firmly to the list when a Yale brain scientist presented his findings at the annual meeting of the Society for Neuroscience. According to the study, sweet and fatty foods -- which are usually high-calorie -- affect the same pleasure pathways in the brain as other addictive substances. Salty foods may have a comparable effect.

A drug addict's urge to use cocaine is likely "engaging similar circuits that the motivation to eat is in a hungry person," according to the Yale researchers. Over time, the addiction changes brain circuitry that controls eating behaviors, making relapse more likely.

"It's much easier to become addicted a second or third time around. It's as if there is some sort of memory," Cicero said.

Overeating and alcoholism are linked in ways that are not completely understood. A Washington University study, also published last month, that focused on the decade between 1992 and 2002 showed that people, especially women, were at increased risk for obesity if they had alcohol issues in their family background.

"We looked particularly at family history of alcoholism as a marker of risk," said study author Richard Grucza in a press release. "And we found that in 2001 and 2002, women with that history were 49 percent more likely to be obese than those without a family history of alcoholism."

Genetics Compounded By Behaviors

Scientists and the public have long known that basic genetics plays an important role in addiction. Carol Wilton of Maplewood understands that the alcoholism she's kept at bay for 18 years is in her DNA.

"My mother had it, her mother had it, and hers before that," Wilton said.

New genetic research suggests that not just a handful but many different genes are at play, according to Washington University psychiatrist Laura Bierut. Even before tasting their first brownie or taking their first drink, people who are predisposed to addiction have brains that are different -- not better or worse, just different -- from the brains of those who are not.

"It's the same as the way we respond differently to antibiotics or medications for heart disease or other types of medicines," Bierut said.

The debut of epigenetics just takes the process one step further --- into future generations. While scientists thought until recently that inherited characteristics were immutable, new evidence has maneuvered into the mainstream the idea that genes and what turns them on and off can be altered by our behaviors and surroundings.

"The possibility that your environment influences the manner in which your genes express themselves met with a lot of resistance in the early 1990s," Cicero said. "If someone was exposed to toxins or a solider was exposed to poisonous gas, we thought, 'Well, that may make the soldier sick, but it won't have any effect on subsequent offspring.'"

And now? New findings about the impact of behavior and surroundings on the expression of heritable characteristics are refuting what was previously considered a simple either-or equation.

"We typically tried to draw the conclusion that some influences are environmental and some are genetic, but that's probably too simplistic," Cicero said.

The prospect is a nod to Darwin's theory of evolution, according to Cicero. "Darwin's theory suggests that only those adapted to their surroundings are likely to survive," he said. "Some of this could be the result of environmental influences on gene expression."

But the new science of epigenetics matters in ways that reach far beyond evolutionary arguments, as the knowledge is critical to medical advances.

"At this point our treatment for alcohol and all addictions is modest at best," Bierut said. "The more we understand these illnesses, the better we'll be able to target treatments and understand prevention.

Nancy Fowler Larson, a freelance writer in St. Louis, will be joining the Beacon staff later this month.