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The East African : April 28th 2014
28 The EastAfrican OUTLOOK APRIL 26 - MAY 2, 2014 S CI E N C E duce the overall incidence of cancer by more than 20 per cent. After reviewing more than 4,000 studies, the authors were persuaded that green vegetables helped ward off lung and stomach cancer. Colon and thyroid cancer could perhaps be avoided with broccoli, cabbage and Brussels sprouts. Onions, tomatoes, garlic, carrots and citrus fruits all seemed to play important roles. In 2007, a major follow-up all but reversed these findings. While some kinds of produce may have subtle benefits, the authors concluded, “in no case now is the evidence of protection judged to be convincing.” Reason for the change The reason for the change was Inside the Linear Accelerator Radiotherapy Unit at Kenyatta National Hospital, Nairobi. Picture: File Avoiding cancer: An apple a day and other myths Unless a pe≥son is se≥iously malnou≥ished, the influence of specific foods is ve≥y weak By GEORGE JOHNSON Special Correspondent A trip to almost any bookstore or a cruise around the Internet can leave the impression that avoiding cancer is mostly a matter of watching what you eat. One source after another pro- motes the protective powers of “superfoods,” rich in antioxidants and other phytochemicals, or advises readers to emulate the diets of Chinese peasants or Paleolithic cave dwellers. But there is a yawning divide be- tween this nutritional folklore and science. Over the past two decades, the connection between the foods we eat and the cellular anarchy called cancer has been unravelling string by string. Early April, at the annual meet- ing of the American Association for Cancer Research, a huge event that drew more than 18,500 researchers and other professionals, the latest results about diet and cancer were relegated to a single poster session and a few scattered presentations. There were new hints that coffee may lower the risk of some cancers and more about the possible benefits of vitamin D. Beyond that there was not much to say. Sounded almost rueful Walter C. Willett, a Harvard epi- demiologist who has spent many years studying cancer and nutri- tion, sounded almost rueful as he gave a status report. Whatever is true for other diseas- es, when it comes to cancer there was little evidence that fruits and vegetables are protective or that fatty foods are bad. About all that can be said with any assurance is that controlling obesity is important, as it also is for heart disease, Type 2 diabetes, hypertension, stroke and other threats to life. Avoiding an excess of alcohol has clear benefits. But unless a person is seriously malnourished, the influence of specific foods is so weak that the signal is easily swamped by noise. The situation seemed very differ- ent in 1997, when the World Cancer Research Fund and the American Institute for Cancer Research published a report, thick as a phone book, concluding that diets loaded with fruits and vegetables could re- more thorough epidemiology. The earlier studies tended to be “retrospective,” relying on people to remember dietary details from the distant past. These results were often upended by “prospective” protocols, in which the health of large populations was followed in real time. The hypothesis that fatty foods are a direct cause of cancer has also been crumbling, along with the case for eating more fibre. The idea that red meat causes colon cancer is shrouded in ambiguity. Two meta-analyses published in 2011 reached conflicting conclusions — one finding a small effect and the other no clear link at all. If ham- Participants at a recent diet and cancer event 8,500 burger s are carcinogen-- ic, the effect appears to be mild. One study suggests that a 50-yearold man eating a hefty amount of red meat — about a sixth of a kilogramme a day — raises his chance of getting colorectal cancer to 1.71 per cent during the next decade, from 1.28 per cent. Spread over a population of millions, that would have an effect. New York Times News Service Study links wa≥ on mala≥ia to ≥eduction in HIV cases By CHRISTABEL LIGAMI Special Correspondent MALARIA PREVENTION and treatment in pregnant HIV-positive women may enhance the effectiveness of HIV prevention in mother-tochild transmission (MTCT) programmes, a new study shows. The study, conductedoin more than 2,000 Tanzanian women, calls for universal access to insecticide-treated bed nets and “large-scale dissemination of information regarding the possible malaria-associated higher risk of HIV MTCT.” Malaria and HIV together account for four million deaths yearly, according to the World Health Organisation, and most malaria deaths occur in tropical Africa. Both pregnant women and young children run a particularly high risk of Plasmodium falciparum — a malaria-causing parasite infection in malaria-endemic areas. The researchers assessed fever symptoms and clinical diagnoses of malaria in pregnancy in 2,368 pregnant HIV-positive women and their infants in Dar es Salaam. Follow-up lasted from before delivery to six months after delivery. Women and infants received antiretroviral prophylaxis at study entry was 22.2 weeks. During follow-up, 16.6 per cent of mothers had at least one clinical malaria-in-pregnancy diagnosis, 15.9 per cent had fever and 8.7 per cent had both. Among HIV-exposed infants, 11 per cent became infected with HIV through the first six weeks of life, a rate comparable to that seen in other malaria-endemic areas. Vertical transmission Each malaria-in-pregnancy episode raised chances of vertical HIV transmission by 29 per cent by the age of six weeks. Malaria and HIV are among the two most im- portant global health problems of our time. According to WHO, there is a growing body A child in a cot protected by a mosquito net. Picture: File to prevent vertical HIV transmission, and after July, 2,005 women were evaluated for combination antiretroviral therapy. Mean gestational age of knowledge on the interactions between HIV/ Aids and malaria. The consequences of such interactions are particularly serious for reproductive health. Co-infected pregnant women are at very high risk of anaemia and malarial infection of the placenta. As a result, a considerable proportion of children born to women with HIV and malaria infection have low birth weight and are more likely to die during infancy. A man smokes marijuana. Pic: File Tanzania assures elderly of free health care Tanzania’s National Health Insurance Fund (NHIF) has pledged to help elderly people obtain free health care as stipulated in the law. The acting NHIF executive director, Hamisi Mdee, said that the elderly need to be attended to effectively when they fall sick. Tanzanian government policy stipulates that old people are entitled to free medical services. The country’s Social Security Regulatory Authority (SSRA) is currently looking at how the elderly can be helped to benefit from the health scheme. Researchers to ‘improve food crop breeding’ Global policymakers meeting at the second Global Conference on Biofortification held in Kigali earlier this month committed themselves to making biofortified nutritious foods more widely available to improve nutrition and health for millions of people around the world. These foods include staples such as beans, sweet potato, cassava, maize, pearl millet, rice and wheat, which people rely on for sustenance. In support of this goal, the Consultative Group on International Agricultural Research (CGIAR) announced that its research centres would start improving mineral and vitamin content across all conventional breeding programmes for food crops. BRIEFS Ugandan MPs table Aids Bill, court controversy Ugandan MPs have tabled a report for debate on HIV/Aids with a provision compelling men to undergo mandatory HIV/Aids testing alongside their pregnant partners. The HIV/Aids Prevention and Control Bill 2010 is intended to protect the rights of people to life and to place an obligation on each other to be responsible. However, some stakeholders have opposed the provision, saying it doesn’t provide for informed consent, thereby making testing mandatory. Marijuana use ‘changes size, shape of the brain’ The size and shape of two brain regions involved in emotion and motivation may differ in young adults who smoke marijuana at least once a week, according to a new study published in the Journal of Neuroscience. The findings suggest that recreational marijuana use may lead to brain changes even if it is lightly or moderately used. Previous studies also show that repeated exposure to the drug causes structural changes in brain regions involved with these functions.
April 21st 2014
May 5th 2014