Almost every day, we read about the results of a new "scientific study" in the papers. Most of the studies that make it to the headlines are in the field of medical science. Anyone who follows these news stories knows that they contradict each other very often. One day we read that some drug reduces the risk of some disease and some time later we read that another study has found that the same drug increases the risk of the same disease. Which study should we believe? Or the new study may say that the risk of some other disease will increase if we take that drug. If a drug decreases the risk of one disease and increases the risk of another disease, should we take that drug or not? If we believe in the accuracy of these scientific studies, we face such dilemmas constantly. But are these studies accurate? Are they causing us consumers to waste our money?
A recent article "Lies, Damn Lies and Medical Science" in Atlantic magazine focuses on this issue. More exactly, it focuses on Dr. John Ioannidis who is one of the world's foremost experts on the credibility of medical research. Ioannidis and his team have shown repeatedly that much of published medical research which most doctors follow when they prescribe antibiotics or blood-pressure medication, or when they advise us to consume more fiber or less meat, or when they recommend surgery for heart disease or back pain is misleading, exaggerated, and often flat-out wrong. According to Ioannidis, 90% of published medical studies is flawed. Surprisingly, his work has been widely accepted by the medical community and it has been published in the top medical journals. But even though people accept his conclusions, medical research continues to be dogged by serious methodological problems and conflicts of interest and Ioannides is not optimistic that the situation will change for the better in the foreseeable future.
Research studies done with care and objectivity should stand the test of time. But an astonishingly large percentage of medical research is refuted by later findings. Here are some glaring examples. Recent studies have shown that mammograms, colonoscopies and prostate specific antigen (PSA) tests are not very useful for detecting cancer thus contradicting earlier studies. Recent studies have also shown that widely prescribed antidepressants are useless for most cases of depression thus disproving earlier studies. Again, recent studies have shown that staying out of the sun entirely can actually increase cancer risks, drinking lots of water during intense exercise is potentially fatal, taking fish oil, exercising, and doing puzzles do not really help prevent Alzheimer's disease, taking daily doses of aspirin does not really prevent heart attacks, as long claimed. Studies have come to opposite conclusions on whether using cell phones can cause brain cancer, whether vitamin E prevents heart attacks, and whether sleeping more than eight hours a night is healthful or dangerous.
There are many reasons for these contradictions - measurement errors, wrong analysis, bias of the researcher and some times even fraud. We think of the scientific process as being objective and rigorous, but in reality, "At every step in the process, there is room to distort results, a way to make a stronger claim or to select what is going to be concluded. There is an intellectual conflict of interest that pressures researchers to find whatever it is that is most likely to get them funded", according to Dr. Ioannides. Even when a particular research idea is proved wrong beyond a doubt, if there are thousands of scientists who have invested their careers in it, it will not disappear easily.
Research on nutrition is another subject which gets a lot of media attention. But unfortunately, different studies on nutrition come to different conclusions. How should we choose among these contradictory nutritional findings? Dr. Ioannidis suggests a simple approach: ignore them all. The variables are so many that any apparent connection between a food and its effects are in fact merely flukes, not real health effects.
Drug studies are even less reliable than nutritional studies because they have the added corruptive force of financial conflict of interest. Countless drugs which had been found to be safe and effective in large trials have now been removed from the market as unsafe or ineffective, or both.
For the information of consumers, here are some medicines, procedures and changes in diet commonly prescribed by doctors, but which have been contradicted by recent studies. So the consumers should be cautious when these medicines and procedures are recommended, often at a huge cost.
1. Angioplasties are highly recommended for heart attack victims. But after a trial covering 2,166 patients in 27 countries over a period of five years, the National Institutes of Health of America (a group of 27 federal Institutes and Centres in the USA) have announced that late angioplasty after heart attack offers no advantage over standard drug therapy.
2. Recent studies have shown that antibiotics should be taken for much shorter periods than is usually prescribed by doctors.
3. Despite innumerable new cancer drugs and new cancer treatments, cancer survival rate has not increased in the last 55 years. So most cancer drugs and treatments are useless. The slogan "Cancer can be cured" is misleading. Except for some forms of cancer (childhood cancers and testicular cancer), there is no cure once the cancer has spread.
4. Surgery is recommended as a cure for cancer, especially cancerous tumours. But studies have shown that surgery can promote migration of cancer cells to other parts of the body and actually worsen the patient's condition.
5. Following several recent studies, the American Cancer Society, which has always been a staunch defender of cancer screening, has finally admitted that the benefits of detecting many cancers by cancer screening, especially breast and prostate, have been exaggerated and that screening may lead to treatment when there is no need for treatment at all.
6. Recent studies have shown no correlation between saturated oils (such as coconut oil) and heart disease. Other studies have shown that in selected populations, the incidence of heart disease (and diabetes) increased after the consumption of traditional oils such as coconut oil decreased and the consumption of the so called good oils (e.g. sunflower oil and safflower oil) increased.
7. Recent studies have shown that taking daily aspirin to prevent heart attacks could do more harm than good.
C.V.Nagaraj, Mysore Grahakara Parishat