20 March 2009

Better feelings with fewer drinks

Having fewer drinks and having them with friends results in more positive experiences, researchers report in two new studies.

Having fewer drinks and having them with friends results in more positive experiences, researchers report in two new studies.

Experiments in rats suggest that a low or moderate amount of drinking releases "feel-good" brain chemicals called beta-endorphins, but this activity tapers off with heavier drinking, reports HealthDayNews.

"Drinking the low amounts of alcohol is associated with mild euphoria, decreased anxiety and a general feeling of well-being, while drinking high amounts of alcohol is associated with sedative, hypnotic effects and often with increased anxiety," said study author Christina Gianoulakis, a professor of psychiatry and physiology at McGill University and Douglas Mental Health University Institute, in Montreal.

The bottom line
The bottom line: "If after consumption of about two drinks of alcohol an individual does not experience the pleasant effects of alcohol, he or she should stop drinking," Gianoulakis said.

In the study, researchers injected male laboratory rats with saline or alcohol and tracked levels of opioid brain chemicals such as endorphins, enkephalins and dynorphins.

Rodents given low to moderate levels of alcohol showed increased levels of beta-endorphins, which produce a feeling of well-being in humans, while those given higher levels of alcohol did not. The same doses did not alter levels of the two other opioids, enkephalins and dynorphins.

Higher doses of alcohol failed to trigger the same release of beta-endorphins, the team found.

The study results were published online March 19 in the journal Alcoholism: Clinical & Experimental Research and will be available in the journal's June print issue.

Treatment implications
Besides helping to explain the "buzz" that comes with light, social drinking, the research may have implications for the treatment of alcoholism, experts said.

"We're always looking for medications that can be used with the alcoholic to cut back on craving and dependency," noted Dr Marc Galanter, director of the division of alcoholism and drug abuse in the department of psychiatry at New York University School of Medicine in New York City. "That's why this whole neurotransmitter system is one area where we may find useful medications."

While medications that curb alcoholism by acting on brain chemicals are already prescribed today, Gianoulakis speculated that future research may lead to even more targeted therapies.

Better targeting
"Among the current treatments of alcoholism is administration of substances that block the activity of opioid peptides in a non-specific fashion [all opioid peptides in all brain regions]," she explained. "Our findings suggest that a more targeted approach may be developed by blocking the activity of beta-endorphin in the [brain's] ventral tegmental area."

But researchers say additional research is needed to better understand the relationship between alcohol and endorphins and to further develop treatments to treat the disease, beginning with studies involving human beings who actually consume alcohol.

"This is a laboratory study, so it's not easy to extrapolate from this study into specific effects on people in real-life situations," Galanter said. "But it does illustrate how that whole domain is important in research for alcoholism treatment."

Until definitive conclusions are drawn, addiction specialists and physicians continue to advocate that healthy adults consume alcohol in moderation.

"Consumption of high amounts of alcohol not only will fail to increase the release of endorphins and produce a feeling of well-being, but may stimulate other systems in the brain that may lead to the development of anxiety and depression," said Gianoulakis. "My advice to everyone is to drink less alcohol, because more is not necessarily better."

In addition, recent studies have also suggested that as little as one drink a day may increase the risk of developing certain cancers, and this risk is thought to rise with increased alcohol consumption.

The social factor
Meanwhile, Reuters Health reports that having a supportive social network enhances the cardiovascular health benefits of having a few drinks, according to new research from Japan.

The study of Japanese men found that moderate to light alcohol consumption, coupled with high levels of social support, were linked to lower rates of heart disease and stroke.

"But remember," Dr Hiroyasu Iso from Osaka University noted in a statement, "this beneficial effect of social support is confined to light-to-moderate drinking. Heavy drinking is risky irrespective of social support level."

In a report in the journal Alcoholism: Clinical and Experimental Research, the researchers note that light to moderate drinking has been shown to help protect against stroke and heart disease. Being surrounded by lots of family and friends is also known to be good for the heart and may even help people live longer.

Support makes the difference
The new study, Iso and colleagues say, shows that high levels of social support may enhance the heart-healthy effects of light to moderate alcohol consumption.

Iso's team examined drinking patterns, social support and cardiovascular health of 19 356 men in their 40s, 50s and 60s who were enrolled in the Japan Public Health Centre-based Prospective Study. Their alcohol consumption was classified into seven categories: never, past, occasional, 1 to 149, 150 to 299, 300 to 449, or 450 or more grams of alcohol per week.

During an average follow up of more than nine years, 629 strokes and 207 coronary heart diseases were documented in the men.

Confirming past studies, heavier drinking (i.e. 300 grams per week or more) was associated with an increased risk of stroke. This may be explained at least partly by alcohol-induced high blood pressure, the researchers say.

In contrast to heavy drinking, light to moderate drinking - up to 299 grams of alcohol per week - was associated with reduced risks of stroke and heart disease, and the effect was more pronounced in men with high levels of social support, "probably due to avoidance of unhealthy behaviours and enhancement of stress buffering," Iso surmised.

Compared with light to moderate drinkers with high social support, those with low social support had unhealthier lifestyle behaviours; they were more apt to be sedentary and had fewer opportunities for medical checkups. They were also more likely to have high stress levels, no job, and no spouse.

The researchers speculate that low levels of social support may cause mental stress, which is hard on the heart. Mental stress activates components of the body's neuro-endocrine system, "which lead to an increased risk of cardiovascular disease," Iso explained. - (HealthDayNews/Reuters Health, March 2009)

Read more:
A drink a day ups cancer risk
Alcohol ups depression risk

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