Tuesday, October 21, 2008

Here we go again: Does drinking alcohol shrink your brain?

More stupid epidemiology. Brain size and IQ are correlated so what the findings probably show is that dumb people drink more. What is refreshing to note however is that the small size of the differences found is mentioned

What's good for the heart may hurt the brain, according to a new study of the effects of alcohol. People who drink alcohol -- even the moderate amounts that help prevent heart disease -- have a smaller brain volume than those who do not, according to a study in the Archives of Neurology. While a certain amount of brain shrinkage is normal with age, greater amounts in some parts of the brain have been linked to dementia. "Decline in brain volume -- estimated at 2 percent per decade -- is a natural part of aging," says Carol Ann Paul, who conducted the study when she was at the Boston University School of Public Health. She had hoped to find that alcohol might protect against such brain shrinkage.

"However, we did not find the protective effect," says Paul, who is now an instructor in the neuroscience program at Wellesley College. "In fact, any level of alcohol consumption resulted in a decline in brain volume."

In the study, Paul and colleagues looked at 1,839 healthy people with an average age of about 61. The patients underwent magnetic resonance imaging (MRI) of the brain and reported how much they tippled. Overall, the more alcohol consumed, the smaller the brain volume, with abstainers having a higher brain volume than former drinkers, light drinkers (one to seven drinks per week), moderate drinkers (eight to 14 drinks per week), and heavy drinkers (14 or more drinks per week).

Men were more likely to be heavy drinkers than women. But the link between brain volume and alcohol wasn't as strong in men. For men, only those who were heavy drinkers had a smaller brain volume than those who consumed little or no alcohol. In women, even moderate drinkers had a smaller brain volume than abstainers or former drinkers.

It's not clear why even modest amounts of alcohol may shrink the brain, although alcohol is "known to dehydrate tissues, and constant dehydration can have negative effects on any sensitive tissue," says Paul. "We always knew that alcohol at higher dosages results in shrinking of the brain and cognitive deficit," says Dr. Petros Levounis, M.D., director of the Addiction Institute of New York at St. Luke's -- Roosevelt Hospital Center, who was not involved in the study. "What is new with this article is that it shows brain shrinking at lower doses of alcohol."

However, the study did not demonstrate that the smaller brain volume actually impaired memory or mental function, notes James Garbutt, M.D., professor of psychiatry at the University of North Carolina at Chapel Hill. And the differences between brain volumes in drinkers and nondrinkers were quite small -- less than 1.5 percent between abstainers and heavy drinkers. "We're talking very small differences here," says Dr. Garbutt, who was not involved in the study. "We're not seeing 10 to 20 percent shrinkage." However, he says, reduction in brain mass is an interesting finding. "But we have a long way to go to figure out the implications of it."


Just one of glass of wine a day increases women's risk of breast cancer

Findings about alcohol derived from a campaign against it should be treated with a saltmine full of salt

Drinking just one large glass of wine a day increases the chances of developing breast cancer by a fifth, say experts. The amount of alcohol in measures regularly served in wine bars and pubs pushes up the risk of cancer by far more than most women realise, it is claimed. A large glass of wine is the equivalent of three units of alcohol at 12 per cent strength. Drinking two glasses raises the risk by more than a third and it doubles for women who consume nine units or three glasses a day compared with those who do not drink.

However, Government research reveals that four out of five women are ignorant of the breast cancer risk. The findings from the Know Your Limits campaign represent a total of more than four million women who are regularly putting their health in danger.

Doctors believe rising rates of breast cancer are being fuelled by soaring levels of drinking among women, as there has been a steady increase in breast cancer cases in the last ten years when rates should have been falling, or at least reached a plateau, because of mass screening.

Only obesity levels - which are also linked to breast cancer - have shown the same kind of upward trend over the last decade. Around 44,000 British women are diagnosed with breast cancer each year, and it claims 13,000 lives. Previous research suggests that binge drinking - five or more drinks on one occasion - can double the risk of breast cancer.

It is unclear how drinking alcohol promotes breast cancer but it may work by raising levels of the sex hormone oestrogen in the body. Drinking alcohol is one of the few identified risk factors for developing breast cancer, although the biggest risk factor is increasing age. Four out of five breast cancers diagnosed in the UK occur in women over 50.

Dr Sarah Cant, Policy Manager at Breakthrough Breast Cancer, said: 'Drinking moderate or high levels of any type of alcoholic drink has many health consequences, including an increased chance of breast cancer. 'Although many factors might affect our risk of getting breast cancer, limiting how much we drink is one thing we can do to try to reduce that risk.'

Public Health Minister-Dawn Primarolo said: 'It's shocking, even for me, to see the potential risks of drinking over recommended guidelines in black and white. 'One large glass of 12 per cent wine takes a woman to her recommended daily limit in just one drink. 'Knowing the potential health consequences enables women to make choices that can reduce their risk of developing breast cancer.'

A separate survey published by Breakthrough Breast Cancer also shows women wrongly blame their genes for getting cancer. A strong genetic history of breast cancer is to blame in only 5 per cent of all breast cancer cases, but nearly two-thirds of women over the age of 50 believe the disease 'runs in the family'.



This is a 1999 study but bears repeating

Hormone replacement therapy before breast cancer diagnosis significantly reduces the overall death rate compared with never-use among 984 breast cancer patients

By H Jernstrom et al.

Nine hundred and eighty-four breast cancer patients were interviewed regarding exogenous hormonal use. This represents a random sample of breast cancer patients in Southern Sweden referred to the Department of Oncology at Lund for treatment between 1978 and 1997 (excluding 1980 and 1981) with a 100% follow-up. Ever-use of hormone replacement therapy (HRT) prior to diagnosis was significantly associated with a longer overall survival in women with their breast cancer diagnosed at ages 45 and above, relative risk (RR) of dying 0.73 (95% confidence interval (CI) 0.62-0.87; P = 0.0005). Ever use of HRT prior to breast cancer diagnosis was significantly positively associated with overall longer survival after adjustment for T-stage, N-stage, M-stage, year of diagnosis and age at diagnosis, RR of dying 0.78 (95% CI 0.65-0.93; P = 0.006). Hormone replacement therapy use and oestrogen receptor positivity were independently significantly associated with overall longer survival, P = 0.005 and P < 0.0001, respectively, in one model. HRT use and progesterone receptor positivity were also independently significantly associated with longer overall survival, P = 0.003 and P = 0.0003, respectively, in another model. The mode of diagnosis was known in 705 women. Mammography screening was not more common among HRT users compared with never-users, where this information was available. Both mammography screening and HRT use were independently associated with longer survival, P = 0.002 and P = 0.038 respectively.


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