It is estimated that 5% of people living in Sub-Saharan Africa are infected with HIV – that’s 22.5 million people. Infection rates vary wildly from country to country, with Swaziland having the highest rate at 25.9%. Gambia is below average, at 2% or 18 thousand people, but still has a serious HIV problem, and now finds themselves at the center of the HIV controversy in Africa.
This epidemic has been magnified by unfortunate realities on the ground. Africa has an insufficient public health and medical infrastructure to deal with the massive challenge such an epidemic presents. This has led the World Health Organization to contemplate partnering with local traditional healers, to make them into an extension of the effort to bring modern medical treatment to the HIV-infected in Africa. This desperate strategy is fraught with problems, not the least of which is that most traditional healers have had no prior contact with science-based medicine.
Former South African president Thabo Mbeki seriously set back his country’s HIV efforts by embracing crank HIV denial. Coupled with his denialism was efforts by Health Minister Manto Tshabalala-Msimang to use traditional medicines to treat HIV/AIDS. This combination resulted in restrictions on the distribution of anti-retoviral drugs in South Africa that is estimated to have cost hundreds of thousands of lives.
A recent survey about patient attitudes and desires with regard to health care demonstrate that respect for scientific evidence is still the dominant factor in preferring treatments. (Full study) This is good news, although the numbers could be better.
Researchers asked subjects what factors were important in determining which treatments they would prefer, the scientific evidence, the experience of the clinician, or their own personal preferences. Not surprisingly, most subjects wanted it all, agreeing that all three are important. Scientific evidence, however, scored the highest with 71% rating it as very important (and over 90% as important or very important). Clinical expertise had 61% strongly supported and personal preference, 57%.
Further, patients wanted their doctors to talk to them about the evidence. The phrase they felt had the most impact on their decision to accept a treatment was, “What is proven to work best.”
All of this matches my personal experience as a clinician. At least for the self-selective population of patients who seek out a university physician, patients tend to find recommendations based upon published evidence compelling, and greatly appreciate when I take the time to tell them about the evidence, even if it goes against their initial interests.
Sometimes science works the way it’s supposed to. Scientists make hypotheses, test them by gathering preliminary evidence, and then argue about the inevitable conflicting results. Eventually better and better evidence is gathered until a consensus is achieved. Actually, I think that is how science usually works, it’s just that most questions in science are narrow and technical and don’t command media or public attention. Those that do tend to be the more enduring controversies or where a particular special interest (ideological, social, corporate, etc,) is involved.
In medicine scientific controversies may take on a life of their own, or become manufactured controversies (manufactroversies) that endure long past any genuine scientific debate. Such false controversies are often driven by patient groups who feel they are not being treated fairly or honestly, or by practitioners who do not want to give up on their favorite (lucrative) modality. This leads to a disconnect between the scientific controversy and the public controversy – a frequent theme on SBM.
I am happy to report that one such controversy has taken a turn for the good – a recent study has provided fairly definitive evidence that chronic fatigue syndrome (CFS) is not associated with either the XMRV or the pMLV viruses. The study was a consensus trial with both sides in the controversy collaborating to address all the criticisms of the earlier conflicting studies.
The health conscious and trendy public are a bit obsessed with the food they consume. This can be a good thing, to the extent that it results in a more healthful diet, but unfortunately those interested in improving their diet must wade through a great deal of misinformation before getting to accurate and helpful information.
For example, I recently gave a lecture (ironically on health information) at Google (you can view the entire talk here). Google is a progressive company that tries to help their employees stay healthy. They provide many snack stations and helpfully divide snacks into red, yellow, and green shelves. Employees can freely choose whatever snacks they want, but they are gently encouraged to choose from the more healthful green shelf and avoid the unhealthy red shelf. I noticed that beverages sweetened with sugar cane were placed on the green shelf, while those sweetened with artificial sweeteners like aspartame or Splenda were slumming on the red shelf. It was ironic to see such a high-tech company falling for the naturalistic fallacy.
Sugar cane sweetened sodas are becoming fashionable, mainly to avoid high fructose corn syrup (HFCS), which many claim is associated with obesity and increased cardiovascular risk. Jim Laidler did an excellent job reviewing this controversy two years ago on SBM. To me this represents a general tendency to try to understand a complex question by oversimplifying, specifically by avoiding perceived “villains.” It may seem overwhelming to grapple with all the complex information involved in basic dietary health choices, like which beverages are best. Following simple rules, such as avoiding single ingredients that are perceived to be “bad,” therefore has an appeal. I also think this is part of the appeal of the naturalistic fallacy, a simple litmus test to what is good vs bad.
A recent meta-analysis of acupuncture studies for chronic pain by Vickers et al is getting a great deal of press. The authors’ conclusions are:
Acupuncture is effective for the treatment of chronic pain and is therefore a reasonable referral option. Significant differences between true and sham acupuncture indicate that acupuncture is more than a placebo. However, these differences are relatively modest, suggesting that factors in addition to the specific effects of needling are important contributors to the therapeutic effects of acupuncture.
News reports generally reflect this conclusion – acupuncture works, but mostly (although not entirely) through placebo effect, but that’s OK.
I took a close look at the study and find that the authors display considerable pro-acupuncture bias in their analysis and discussion. They clearly want acupuncture to work. That aside, the data are simply not compelling, and the authors, in my opinion, grossly overcall the results, which are compatible with the conclusion that there are no specific effects to acupuncture beyond placebo.
A recent review of 240 studies has concluded that:
The published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods. Consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.
Organic produce has become increasingly popular in recent years. There are several reasons that consumers might prefer organic produce, including the belief that organic farming is better for the environment and more sustainable. I am going to focus in this article about the health effects of organic produce. Environmental claims for organic farming are complex and controversial – I will just say that such claims largely fall prey to the naturalistic and false dichotomy fallacies. In my opinion, farming practices should be evaluated on their own merits individually, based on evidence rather than philosophy. Sustainable and environmentally friendly farming are certainly laudable goals and I support farming practices promote them, however they are labeled.
The alleged superiority of organically grown produce is a separate question. In a 2003 survey 68.9% of people who purchase organic food said they did so because they believed it to be healthier (more than any other reason given). However, fifty years of research has so far not produced convincing evidence that there is any health benefit to consuming organic food. Likewise, systematic reviews of nutritional quality of organic produce also reveals no difference from conventional produce.
I love reading quotes by the likes of Karl Popper in the scientific literature. A recent replication of Bem’s infamous psi research, Feeling the Future, gives us this quote:
Popper (1959/2002) defined a scientifically true effect as that “which can be regularly reproduced by anyone who carries out the appropriate experiment in the way prescribed.”
The paper is the latest replication of Daryl Bem’s 2011 series of 9 experiments in which he claimed consistent evidence for a precognitive effect, or the ability of future events to influence the present. The studies were published in The Journal of Personality and Social Psychology, a prestigious psychology journal. All of the studies followed a similar format, reversing the usually direction of standard psychology experiments to determine if future events can affect past performance.
In the 9th study, for example, subjects were given a list of words in sequence on a computer screen. They were then asked to recall as many of the words as possible. Following that they were given two practice sessions with half of the word chosen by the computer at random. The results were then analyzed to see if practicing the words improved the subject’s recall for those words in the past. Bem found that they did, with the largest effect size of any of the 9 studies.
Be careful what you wish for. In the last few decades purveyors of dubious medical treatments and products have been trying to go mainstream, and they have had some unfortunate success. They asked for serious scientific investigation into their claims – and they got it. They asked to be treated like real medicine (but not really, they only want the trappings of legitimacy, not the substance), and when they actually are treated with the standards similar to science-based medicine, they cry foul.
The response of the fake-medicine lobby is not to alter their claims to fit the evidence, or to carry out better studies, or to clean up their act when problems are brought to their attention – but to attack their critics.
Homeopathy is perhaps the best example of this behavior. Homeopathy’s biggest marketing advantage is that most people don’t know what it really is. They think it’s “natural” medicine or herbs. That is why, during homeopathy awareness week, I was happy enough to oblige. I want people to know exactly what homeopathy is – sugar pills. They are placebos on which the equivalent of a magical ritual has been cast. Active ingredients, which themselves are as fanciful as fairy dust, are diluted into non-existence.
The headline of a recent Los Angeles Times article is, “No yolk: eating the whole egg as dangerous as smoking?” The question mark is meant to convey uncertainty or surprise, or perhaps both. The article represents much of what is wrong with science and health reporting by mainstream media.
The news report is based upon an article published in Atherosclerosis – Egg yolk consumption and carotid plaque. The study is highly problematic in ways not explored at all in the LA Times article. The researchers surveyed 1,262 patients seen in a vascular prevention clinic, asking them about their egg consumption, smoking history, and other lifestyle factors. They created a measure known as “egg yolk years” – the number of egg yolks consumed on average per week times the number of years of consumption. They compared this to pack years of smoking – packs per day times number of years, a routine method of reporting smoking history.
“Our findings suggest that regular consumption of egg yolk should be avoided by persons at risk of cardiovascular disease. This hypothesis should be tested in a prospective study with more detailed information about diet, and other possible confounders such as exercise and waist circumference.”
I have nothing against berries. I, in fact, enjoy many kinds of berries in my diet. My favorite fruit, the banana, is actually a berry (botanically speaking). I am disturbed, however, at the extent to which various kinds of berries are being sold as the latest superfood cure-all.
Dr. Oz, for example, has been pushing the lingonberry (a relative of the cranberry and blueberry) as “a new superfruit for longevity.” An attached article on his site states:
“Today, scientists are showing its value in both human and animal studies that are proving to have positive results.”
Curiously, there are no links or references to these studies.
Polyphenols and Antioxidants
We are still in the midst of the “antioxidant craze” – if you read the justification for just about any so-called “superfood” or longevity supplement you are sure to read about antioxidants. I have already covered antioxidants, but briefly: Cell metabolism in part creates oxygen free radicals which are molecules that steal electrons from other molecules, causing a cascade of reactions that can damage proteins and other chemicals in the body. Anti-oxidants are chemicals that can stop free radicals and limit the damage. They therefore decrease “oxidative stress” on cells. So far it sounds like anti-oxidants are therefore a good thing and we should be gobbling up as much as we can. However – free radicals and anti-oxidants exist in cells in a homeostasis. Free radicals are used by the immune system, for example, to fight invading organisms. They are also important signaling molecules, triggering other cell-protective mechanisms.