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Alcohol message must be carefully worded
THE LANCET
SCIENCE AND MEDICINE
Alcohol message must be carefully worded
T
he much-publicised benefits of light-to-moderate alcohol consumption in later life may have been overestimated. Public-health experts, epidemiologists, cardiologists, and sociologists attending a Novartis Foundation Symposium on Alcohol and Cardiovascular Disease (London, UK; Oct 7–9) heard that the J-shaped alcohol consumption/ coronary-heart-disease risk curve could be the result of inappropriate questionnaires, misleading classifications, and poor analysis. The most consistent finding in the vast alcohol and health literature is that non-drinkers (ex-drinkers and life-long teetotallers) have higher overall morbidity and mortality rates than light-to-moderate drinkers. But having seen little evidence that such drinkers owe their health to alcohol, researchers are beginning to wonder whether drinking habits are in fact a reflection of other, more powerful, risk factors such as social class, education, and general ill-health. “The degree of protection [against
heart attacks] has almost certainly been exaggerated by comparison with inappropriate control groups”, said Gerry Shaper (Royal Free Hospital, London, UK). His work on the British Regional Heart Study and his detailed analysis of six other large surveys has revealed two factors that make nondrinkers a biased baseline group. First, there is a strong downward drift from heavy or moderate drinking towards non-drinking as people age, which is associated with declining health; and second, non-drinkers (like heavy drinkers) are usually working class and in poorer health than regular light drinkers who are the healthiest, wealthiest, and fittest group of all. Michael Gaziano (Harvard Medical School, Boston, MA, USA), who works on alcohol’s ability to increase serum high-density
Xenotransplantation prospects thwarted
R
esearch published this week has damaged the prospects for transplantation of pig organs into human beings. The research shows that multiple copies of viruses that can infect human cells are present in all pig tissues—implying that it may never be possible to breed pigs from which virus-free organs could be harvested. The potentially infectious agents, C-type retroviruses related to HIV-1 and HTLV-1, are transmitted through the germline, and proviral DNA is present in all pig cells. It was shown earlier this year that the retroviruses could infect human tissue, but it was hoped that would be possible to breed the viruses out of the pigs. In the new research (Nature 1997; 389: 681–82), scientists at the National Institute for Medical Research and the Institute of Cancer Research (London, UK) report that between 10 and 20 copies each of two viral variants are present in the germline of all pigs.
1148
It is difficult or impossible to remove these viruses by breeding, says team leader Jonathan Stoye. Inevitably, they will be present and transcribed in the pig organs. Noone knows whether these retroviruses, or others as yet undiscovered, will have any ill effects in people— they do not seem to harm their pig hosts. But, similar viruses isolated from mice have caused thymic leukaemia in macaques, says Stoye. George Griffin (St George’s Hospital Medical School, London, UK), an infectious diseases specialist with a close interest in xenotransplantation, comments: “Potentially, these findings are bad news. They will make clinical trials more distant rather than closer, but they do not mean that xenotransplantation will never happen.” Primate experiments are now crucial, he continues. “We must know what these viruses will do in an immunosuppressed recipient.”
lipoprotein values remains enthusiastic. “Alcohol is not as important as smoking, hypertension, and high cholesterol, but neither is this a trivial association. Even if [the association] is less than anticipated, it could have real implications for society as a whole.” But Gaziano was quick to point out that the balance of risks and benefits make for a dangerous publichealth message. “Global recommendations like ‘1–3 drinks a day are good for you’ are meaningless. The message should be: heavy drinking is bad for you; light drinking seems to be safe; and the potential risks and benefits for each individual mandate that you talk to your physician about it. The most important thing is that we do not increase heavy drinking.” Sara Abdulla
News in brief Why garlic is good for you Since ancient times, garlic has been used as a medicine for many ailments. Israeli scientists now report that an active agent in garlic, allicin, inhibits the cysteine proteinases that are important in Entamoeba histolytica virulence (Antimicrob Agents Chemother 1997; 41: 2286–88). Treatment for Crohn’s disease In a 12-week double-blind, placebocontrolled trial, 33% of patients given a single infusion of cA2, a monoclonal antibody specific for tumour necrosis factor-␣, went into remission, compared with only 4% of patients in the placebo group (N Engl J Med 1997; 337: 1029–35). Selenium deficiency and HIV-1 Selenium deficiency may be an independent predictor of poor survival for people infected with HIV-1 (J Acquir Immune Defic Syndr Hum Retrovirol 1997; 13: 1325–32). The authors of the report call for clinical trials to assess whether selenium supplementation would affect HIV-1-disease progression.
Peter Mitchell
Vol 350 • October 18, 1997
SCIENCE AND MEDICINE
Alcohol message must be carefully worded
T
he much-publicised benefits of light-to-moderate alcohol consumption in later life may have been overestimated. Public-health experts, epidemiologists, cardiologists, and sociologists attending a Novartis Foundation Symposium on Alcohol and Cardiovascular Disease (London, UK; Oct 7–9) heard that the J-shaped alcohol consumption/ coronary-heart-disease risk curve could be the result of inappropriate questionnaires, misleading classifications, and poor analysis. The most consistent finding in the vast alcohol and health literature is that non-drinkers (ex-drinkers and life-long teetotallers) have higher overall morbidity and mortality rates than light-to-moderate drinkers. But having seen little evidence that such drinkers owe their health to alcohol, researchers are beginning to wonder whether drinking habits are in fact a reflection of other, more powerful, risk factors such as social class, education, and general ill-health. “The degree of protection [against
heart attacks] has almost certainly been exaggerated by comparison with inappropriate control groups”, said Gerry Shaper (Royal Free Hospital, London, UK). His work on the British Regional Heart Study and his detailed analysis of six other large surveys has revealed two factors that make nondrinkers a biased baseline group. First, there is a strong downward drift from heavy or moderate drinking towards non-drinking as people age, which is associated with declining health; and second, non-drinkers (like heavy drinkers) are usually working class and in poorer health than regular light drinkers who are the healthiest, wealthiest, and fittest group of all. Michael Gaziano (Harvard Medical School, Boston, MA, USA), who works on alcohol’s ability to increase serum high-density
Xenotransplantation prospects thwarted
R
esearch published this week has damaged the prospects for transplantation of pig organs into human beings. The research shows that multiple copies of viruses that can infect human cells are present in all pig tissues—implying that it may never be possible to breed pigs from which virus-free organs could be harvested. The potentially infectious agents, C-type retroviruses related to HIV-1 and HTLV-1, are transmitted through the germline, and proviral DNA is present in all pig cells. It was shown earlier this year that the retroviruses could infect human tissue, but it was hoped that would be possible to breed the viruses out of the pigs. In the new research (Nature 1997; 389: 681–82), scientists at the National Institute for Medical Research and the Institute of Cancer Research (London, UK) report that between 10 and 20 copies each of two viral variants are present in the germline of all pigs.
1148
It is difficult or impossible to remove these viruses by breeding, says team leader Jonathan Stoye. Inevitably, they will be present and transcribed in the pig organs. Noone knows whether these retroviruses, or others as yet undiscovered, will have any ill effects in people— they do not seem to harm their pig hosts. But, similar viruses isolated from mice have caused thymic leukaemia in macaques, says Stoye. George Griffin (St George’s Hospital Medical School, London, UK), an infectious diseases specialist with a close interest in xenotransplantation, comments: “Potentially, these findings are bad news. They will make clinical trials more distant rather than closer, but they do not mean that xenotransplantation will never happen.” Primate experiments are now crucial, he continues. “We must know what these viruses will do in an immunosuppressed recipient.”
lipoprotein values remains enthusiastic. “Alcohol is not as important as smoking, hypertension, and high cholesterol, but neither is this a trivial association. Even if [the association] is less than anticipated, it could have real implications for society as a whole.” But Gaziano was quick to point out that the balance of risks and benefits make for a dangerous publichealth message. “Global recommendations like ‘1–3 drinks a day are good for you’ are meaningless. The message should be: heavy drinking is bad for you; light drinking seems to be safe; and the potential risks and benefits for each individual mandate that you talk to your physician about it. The most important thing is that we do not increase heavy drinking.” Sara Abdulla
News in brief Why garlic is good for you Since ancient times, garlic has been used as a medicine for many ailments. Israeli scientists now report that an active agent in garlic, allicin, inhibits the cysteine proteinases that are important in Entamoeba histolytica virulence (Antimicrob Agents Chemother 1997; 41: 2286–88). Treatment for Crohn’s disease In a 12-week double-blind, placebocontrolled trial, 33% of patients given a single infusion of cA2, a monoclonal antibody specific for tumour necrosis factor-␣, went into remission, compared with only 4% of patients in the placebo group (N Engl J Med 1997; 337: 1029–35). Selenium deficiency and HIV-1 Selenium deficiency may be an independent predictor of poor survival for people infected with HIV-1 (J Acquir Immune Defic Syndr Hum Retrovirol 1997; 13: 1325–32). The authors of the report call for clinical trials to assess whether selenium supplementation would affect HIV-1-disease progression.
Peter Mitchell
Vol 350 • October 18, 1997