Researchers Question Pro-Caffeine Conclusion of Parkinson’s Report
A study about a connection between coffee drinking and Parkinson’s disease drew lots of media attention last week, but some researchers are questioning the interpretation of the results.
A team of researchers from the U.S. Department of Veterans Affairs reported that drinking lots of coffee is associated with a lower risk of Parkinson’s disease. The findings, reported Wednesday in the Journal of the American Medical Assn., came from analyzing data from the Honolulu Heart Study, an ongoing examination of more than 8,000 Japanese American men with an average age of 53.
The researchers, headed by Dr. G. Webster Ross of the Honolulu VA Medical Center, reported that men who drank the most coffee--at least 28 ounces a day--were only about 20% as likely to develop Parkinson’s disease as those who drank none at all (https://jama.ama-assn.org). Webster and his colleagues speculated that caffeine in the coffee somehow protects against Parkinson’s or delays its onset.
But some researchers question that interpretation. Previous studies have also shown that smoking many cigarettes daily is associated with a lowered risk of Parkinson’s disease. Others have shown the same effect for a high intake of alcohol. So are we to believe that nicotine, caffeine and alcohol all protect against this debilitating disease?
An alternate interpretation, offered earlier this month by Dutch researchers, is that the chemistry of the brain itself is at the root of the observations. Addictive behaviors are caused, most researchers now believe, by high levels of a brain chemical called dopamine--the effects of a so-called novelty-seeking gene.
Those same high levels of dopamine also seem to protect against Parkinson’s, Dr. Patricia Willems-Giesbergen and her colleagues at the Erasmus Medical Center in Rotterdam said at a meeting of the American Academy of Neurology. So the link to coffee, alcohol and nicotine, these researchers contend, is not one of cause and effect. The same brain chemistry that reduces the risk of Parkinson’s also makes that person more likely to pursue addictive behaviors, such as smoking and drinking alcohol and coffee.
Ross and his colleagues discussed this possibility in their paper. But that point was mostly lost in last week’s media hullabaloo over caffeine and Parkinson’s.
Team Warns Against Antibiotics for E. Coli
Antibiotics should not be used to treat children infected with an especially virulent strain of Escherichia coli because the drugs can make the children worse instead of better, according to researchers at the University of Washington Medical School in Seattle. The research is scheduled to be published in the June 29 New England Journal of Medicine, but the journal posted the paper on its Web site (https://www.nejm.org) Wednesday because of its public health importance.
The bug is E. coli 0157:H7. Contamination of undercooked hamburgers by the strain at Jack in the Box restaurants in four Western states in 1993 caused the deaths of four children and led to illness in more than 600 others. The E. coli strain was also responsible for a 1997 recall of 25 million pounds of hamburger meat destined for Burger King outlets, and it was the culprit in a number of other food poisoning incidents.
Although antibiotics are not effective against the microorganism, many physicians prescribe them for food poisoning--often before the strain is identified. Even worse, the antibiotics can provoke the bacterium to release a toxin that causes hemolytic-uremic syndrome. That disorder is marked by destruction of red blood cells and kidney damage.
The Washington team studied 71 children infected by the bacterium, nine of whom received antibiotics. Five of the nine who received antibiotics developed the syndrome, compared with five of the 62 who received only palliative treatment. All of the children eventually recovered.
Viagra Doesn’t Work on Women, Study Says
Viagra may be a boon to men with impotence, but it does not improve women’s sexual response, according to the first major study of its kind. Earlier small studies had hinted that the drug could increase arousal in women, but that proved not to be the case, Dr. Rosemary Basson of the Vancouver Hospital and Health Science Centre in Canada reported Monday at a San Francisco meeting of the American College of Obstetrics and Gynecology.
The multinational trial studied 577 women who had at least a six-month history of problems with sexual arousal. They were divided into four groups. Three groups each took a different dosage of Viagra one hour before sex; the fourth received a placebo. After 12 weeks, Basson said, the groups receiving Viagra performed no better than those receiving placebo. The study was funded by Pfizer, which manufactures Viagra.
Newer Arthritis Drugs Tested Against NSAIDs
Two large studies have confirmed smaller studies showing that the new arthritis drugs Celebrex and Vioxx are substantially less likely to cause ulcers and gastrointestinal bleeding than non-steroidal anti-inflammatory drugs, commonly known as NSAIDs. NSAIDs include aspirin, ibuprofen, diclofenac and naproxen.
Each study involved about 8,000 arthritis patients. Some patients in each study received conventional treatment with NSAIDs; the rest received either Vioxx or Celebrex. Both studies showed that patients receiving NSAIDs were at least twice as likely to suffer ulcers, bleeding and other adverse effects as those taking the newer drugs. The studies, released last week at the Digestive Diseases Week meeting in San Diego, were funded by Pfizer Inc., which manufactures Celebrex, and by Merck & Co., which sells Vioxx.
Concussions’ Effects on Athletes Observed
Athletes who return to action shortly after being knocked unconscious are risking serious injury to the brain, according to UCLA researchers. Athletes’ brains are already exhibiting subpar performance as a result of the first blow, and a second one soon afterward could cause severe damage, a team led by Dr. Marvin Bergsneider reported in Monday’s issue of the Journal of Neurotrauma.
Bergsneider’s team performed PET scans on 42 patients to analyze how their brains were using energy in the aftermath of a concussion. In the scans, radioactively labeled sugar molecules are injected into the bloodstream, and researchers can watch them being taken up by cells--a measure of how actively the cells are functioning.
The team could find no difference in energy use between those who had just suffered a concussion and people who were in comas and severely brain-injured. Earlier animal studies have shown that such low sugar use by brain cells renders them much more susceptible to damage from trauma.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
