Archive for January, 2011

Risk for alcoholism linked to risk for obesity

Addiction researchers at Washington University School of Medicine in St. Louis have found that a risk for alcoholism also may put individuals at risk for obesity.

The researchers noted that the association between a family history of alcoholism and obesity risk has become more pronounced in recent years. Both men and women with such a family history were more likely to be obese in 2002 than members of that same high-risk group had been in 1992.

“In addiction research, we often look at what we call cross-heritability, which addresses the question of whether the predisposition to one condition also might contribute to other conditions,” says first author Richard A. Grucza, PhD. “For example, alcoholism and drug abuse are cross-heritable. This new study demonstrates a cross-heritability between alcoholism and obesity, but it also says — and this is very important — that some of the risks must be a function of the environment. The environment is what changed between the 1990s and the 2000s. It wasn’t people’s genes.”

Obesity Rates Have Doubled

Obesity in the United States has doubled in recent decades from 15 percent of the population in the late 1970s to 33 percent in 2004. Obese people – those with a body mass index (BMI) of 30 or more – have an elevated risk for high blood pressure, diabetes, heart disease, stroke and certain cancers.

Reporting in the Archives of General Psychiatry, Grucza and his team say individuals with a family history of alcoholism, particularly women, have an elevated obesity risk. In addition, that risk seems to be growing. He speculates that may result from changes in the food we eat and the availability of more foods that interact with the same brain areas as addictive drugs.

“Much of what we eat nowadays contains more calories than the food we ate in the 1970s and 1980s, but it also contains the sorts of calories — particularly a combination of sugar, salt and fat — that appeal to what are commonly called the reward centers in the brain,” says Grucza, an assistant professor of psychiatry. “Alcohol and drugs affect those same parts of the brain, and our thinking was that because the same brain structures are being stimulated, overconsumption of those foods might be greater in people with a predisposition to addiction.”

Grucza hypothesized that as Americans consumed more high-calorie, hyper-palatable foods, those with a genetic risk for addiction would face an elevated risk because of the effects of those foods on the reward centers in the brain. His team analyzed data from two large alcoholism surveys from the last two decades.

Family History of Alcoholism

The National Longitudinal Alcohol Epidemiologic Survey was conducted in 1991 and 1992. The National Epidemiologic Survey on Alcohol and Related Conditions was conducted in 2001 and 2002. Almost 80,000 people took part in the two surveys.

“We looked particularly at family history of alcoholism as a marker of risk,” Grucza explains. “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. We also noticed a relationship in men, but it was not as striking in men as in women.”

Grucza says a possible explanation for obesity in those with a family history of alcoholism is that some individuals may substitute one addiction for another. After seeing a close relative deal with alcohol problems, a person may shy away from drinking, but high-calorie, hyper-palatable foods also can stimulate the reward centers in their brains and give them effects similar to what they might experience from alcohol.

“Ironically, people with alcoholism tend not to be obese,” Grucza says. “They tend to be malnourished, or at least under-nourished because many replace their food intake with alcohol. One might think that the excess calories associated with alcohol consumption could, in theory, contribute to obesity, but that’s not what we saw in these individuals.”

Change in the Food Environment

Grucza says other variables, from smoking, to alcohol intake, to demographic factors like age and education levels don’t seem to explain the association between alcoholism risk and obesity.

“It really does appear to be a change in the environment,” he says. “I would speculate, although I can’t really prove this, that a change in the food environment brought this association about. There is a whole slew of literature out there suggesting these hyper-palatable foods appeal to people with addictive tendencies, and I would guess that’s what we’re seeing in our study.”

The results, he says, suggest there should be more cross-talk between alcohol and addiction researchers and those who study obesity. He says there may be some people for whom treating one of those disorders also might aid the other.

January 11th, 2011  in Alcoholism No Comments »

Vaccine blocks cocaine high in mice

Researchers have produced a lasting anti-cocaine immunity in mice by giving them a safe vaccine that combines bits of the common cold virus with a particle that mimics cocaine.

In their study, published in the online edition of Molecular Therapy and funded by the National Institute on Drug Abuse, the researchers say this novel strategy might be the first to offer cocaine addicts a fairly simple way to break and reverse their habit, and it might also be useful in treating other addictions, such as to nicotine, heroin and other opiates.

Fighting Cocaine Addiction

“Our very dramatic data shows that we can protect mice against the effects of cocaine, and we think this approach could be very promising in fighting addiction in humans,” says the study’s lead investigator, Dr. Ronald G. Crystal, chairman and professor of genetic medicine at Weill Cornell Medical College.

He says the antibody immune response produced in lab mice by the vaccine binds to, and sequesters, cocaine molecules before the drug reached the brains of these animals — and prevents any cocaine-related hyperactivity. The vaccine effect lasted for at least 13 weeks, the longest time point evaluated.

“While other attempts at producing immunity against cocaine have been tried, this is the first that will likely not require multiple, expensive infusions, and that can move quickly into human trials,” Dr. Crystal says. “There is currently no FDA-approved vaccine for any drug addiction.”

“An approach that works is desperately needed for cocaine addiction, which is an intransigent problem worldwide,” he adds. “There are no therapies now.”

The novelty of this possible treatment is that it hooks a chemical that is very similar in structure to cocaine, onto components of the adenovirus, a common cold virus. In this way, the human immune system is alerted to an infectious agent (the virus) but also learns to “see” the cocaine as an intruder as well, Dr. Crystal says. Once the structure of the new intruder is recognized, natural immunity builds to cocaine particles, so any time cocaine is snorted or used in any way, antibodies to the substance are quickly produced and the cocaine molecules are engulfed by the antibodies and prevented from reaching the brain.

Engineering a New Response

“The human immune system doesn’t naturally tag cocaine as something to be destroyed — just like all small-molecule drugs are not eliminated by antibodies,” he says. “We have engineered this response so that it is against the cocaine mimic.”

In this study, a team of researchers — scientists from Weill Cornell Medical College, Cornell University in Ithaca, and the Scripps Research Institute in La Jolla, Calif. — ripped apart an adenovirus, retrieving only the components that elicit an immune response and discarding those that produce sickness. They then hooked the cocaine analog on to these proteins to make the vaccine. “We used the cocaine analog because it is a little more stable than cocaine, and it also elicits better immunity,” Dr. Crystal says.

The researchers then injected billions of these viral concoctions into “garden variety” laboratory mice (mice that are not genetically engineered). They found a strong immune response was generated against the vaccine, and that these antibodies, when put in test tubes, gobbled up cocaine.

Vaccine for Addicts

They then tested the vaccine’s effect on behavior, and found that mice that received the vaccine before cocaine were much less hyperactive while on the drug than mice that were not vaccinated. The effect was even seen in mice that received large, repetitive doses of cocaine. Proportionally, the cocaine doses reflected amounts that humans might use.

The vaccine needs to be tested in humans, of course, says Dr. Crystal, but he predicts that if it works, it will function best in people who are already addicted to cocaine and who are trying to stop using the drug. “The vaccine may help them kick the habit because if they use cocaine, an immune response will destroy the drug before it reaches the brain’s pleasure center.”

January 6th, 2011  in Illegal Drugs No Comments »