Excerpts

Introduction "Is that a fact?" "They say that . . ." "I heard that . . ." Just listen in on some conversations around the water cooler and it won't be long before one of these phrases rings out. After all, this is the Communication Age. We are connected through cellphones, radio, TV, and of course the web. We talk, we tweet, we link, we text, we Facebook. We are informed. But in many cases, unfortunately, also misinformed. We suffer from information overload. Just Google a subject and within a second you can be flooded with a million references. It is therefore more important than ever to be able to analyze those references and be able to separate sense from nonsense. And that's where learning comes in. Information has to be scrutinized in the light of what is already known. But learning must be coupled with critical thinking. Confucius said it very well: "Learning without thought is labor lost; thought without learning is perilous." The University of Google is well stocked with information, but its students are left to flounder when it comes to determining whether that information is reliable. Accounts of miraculous cancer cures, the rants of anti-vaccine activists, the exploits of fake psychics and the claims of various alternative healers may sound very seductive but stand to lose their luster in the light of scientific education. It would, however, be incorrect to suggest that education is the vaccine against folly. The annals of history are replete with examples of educated people who have succumbed to nonsense. Sir Arthur Conan Doyle, a physician by training, believed in fairies and in communicating with the dead. Curiously, he was the creator of Sherlock Holmes who was a logician extraordinaire and eschewed such silliness. Indeed it was Holmes who reminded us that "It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories instead of theories to suit facts." These days, those of us who follow Holmes' dictum and put evidence-based science on a pedestal, often get criticized for challenging claims we consider to be unscientific. "They laughed at Galileo," the promoters of such claims say, "and at Columbus, and at the Wright Brothers." But, as Carl Sagan pointed out, the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They also laughed at Bozo the Clown. Our best bet to differentiate the Bozos from the prospective Galileos is to push for more science education at all levels with a strong emphasis on the importance of critical thinking. Furthermore, it should be realized that when it comes to separating sense from nonsense, mental prowess is not enough. Benjamin Franklin was right on when he opined that "genius without education is like silver in a mine." Indeed, the value is there, but the silver is not of much use until you extract it. But how do you go about this extraction? How do we know who is right and who is wrong? How do I know what I claim to know? Actually, that is a question I had to contemplate recently when a student innocently asked me, "And how do you know that?" I had just finished a lecture on toxicology in which I had described the problem of cyanide poisoning by cassava, a tuber similar to the potato. However, with some varieties of cassava, a staple in some parts of Africa, there's an issue. If not properly processed, it can harbor a lethal amount of cyanide. (This is not the case with the cassava grown in the Caribbean.) But soaking the peeled tuber in water for several days releases enzymes that degrade the cyanide-storage compound linamarin, causing the toxic cyanide to be dissipated into the air as hydrogen cyanide. Unfortunately cases of acute cyanide poisoning have occurred when famine conditions forced a shortening of the soaking time. Since even proper processing doesn't remove all the cyanide, chronic low-level exposure can lead to goiter or even "konzo," a type of paralysis. I've described the cyanide connection in lectures numerous times but never before had I been asked a question about how I had acquired this knowledge. It did start me thinking. Indeed, I've never been to Africa, have never even seen a live cassava plant. I've never carried out any testing of cassava for cyanide. Truth be told, I wouldn't even know how to go about it, although I think with a little digging I could figure it out. I do have a vague recollection of once eating fried cassava somewhere in the Caribbean, but that's as close as I've come to experimenting with the tuber. So, in fact, how do I know about its chemistry? It all comes down to reading various accounts of cassava poisoning in toxicology and chemistry texts. And how do the authors of these texts know what they are writing about? Chances are they haven't had any closer cassava encounters than I have had. But they have read the peer-reviewed literature on the topic, have digested the facts and have managed to piece together the story. They would have read papers in a medical journal about how the symptoms of "konzo" were traced to cyanide poisoning and about how a link to cassava was discovered. Then in a chemical publication they would have learned that the actual culprit, linamarin, was present in unprocessed cassava but not in the soaked version. Finally, a paper likely in a biochemistry journal would have revealed the action of enzymes on linamarin. Basically, then, what we call scientific knowledge is gained through a distillation of the relevant peer-reviewed literature. And that literature is the altar at which scientists worship. But as with religion, there is faith involved. Faith that the peer-reviewed literature can be trusted. That faith, however, cannot be blind. It should be tempered with a dose of skepticism. Problems may eventually crop up even with research that was properly carried out. A side effect of a medication that affects a fraction of a percent of patients will not be detected in trials, but will become obvious when millions take the drug. So peer-review isn't the end-all. But remember what Churchill said about democracy? "It is the worst form of government except all the others that have been tried." Ditto for the peer-review process. Peer review, however, is the final stage in a scientific investigation that usually begins with a "gee, that's funny" comment after making some observation. And that observation may happen in a serendipitous fashion. But as Louis Pasteur would go on to say, "Chance favors the prepared mind." Fishy Claims for Fish Oil Supplements It's a pretty common scenario. An observational study suggests that some food or beverage is associated with some aspect of health. A hypothesis is forged about the effect being due some particular component. The component is isolated and tested in cell cultures or in animals with some intriguing results. A few small-scale human studies follow and generate optimism. Supplement manufacturers gear up and begin to flood the market with pills containing the supposed active ingredient. Their ads are supported by references to cherry-picked data, their hype couched with many a "may." Personal testimonials of benefit pour in and profits mount. The results of randomized, controlled double-blind trials (RCTs) begin to emerge with contradictory results. Marketers highlight the positive results and dismiss contradictory research as "flawed." Sales continue to increase with various producers claiming that their product is superior to that of competitors. As controversy mounts, researchers undertake "meta analyses" that pool data from the best available studies. Results suggest that the initial optimism cannot be supported but there is a call for more studies. (Isn't there always?) Sales begin to slump as manufacturers and their industry associations scramble to punch holes in the meta analysis and issue press releases that emphasize the studies with positive findings. Regulatory agencies walk a fine line, having to take into account business interests, freedom of choice arguments and public health. Consumers are left bewildered, not knowing whom to believe or trust. In recent years we have seen such scenarios unfold with vitamin E, calcium, beta-carotene, ginkgo biloba and now, omega-3 fats. The omega-3 saga can be traced back to the early 1970s when Danish researchers discovered a surprisingly low incidence of heart disease in Inuit tribes despite a diet dominated by fatty fish. Could this be due to the specific type of fat found in fish, they wondered? After all, the molecular structure of these fats differed from the fats found in meat and most vegetables. Perhaps these "polyunsaturated fats" which feature a double bond on the third carbon from the end of the molecule, the so-called "omega carbon," had some special cardioprotective property. This was a reasonable guess, given that other populations around the world that consumed a fish-rich diet, such as the Japanese, were also known to have a low incidence of heart disease. Laboratory studies soon revealed that the omega-3 fats have anti-inflammatory properties and can also reduce the clotting tendency of blood. Both of these observations mesh with theories of reduced cardiac risk. There were also implications of reduced blood pressure and a slowing of the progression of arteriosclerosis. Then came evidence of a lowered incidence of abnormal heart rhythms in fish consumers and a decrease in triglycerides in their blood, both established risk factors for heart disease. By the 1980s supplement manufacturers had begun to capitalize on the tantalizing studies and were filling capsules with various mixtures of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the two dominant fatty acids in fish oils. Recommended dosages were no more than educated guesses. The U.S. Food and Drug Administration essentially endorsed the supplements, allowing labels to state that "supportive but not conclusive research shows that consumption of EPA and DHA may reduce the risk of coronary heart disease." Furthermore, FDA approved a high-dose prescription mixture of EPA/DHA derived from fish oil for the treatment of high levels of triglycerides. Before long claims of protection against heart disease were joined by a plethora of others. Omega-3 fats were said to reduce the risk of cancers of the colon, breast and prostate as well as that of macular degeneration and gum disease. They were also said to be useful in the treatment of depression and anxiety. There were claims of a slowing of cognitive decline in the elderly and improvement in attention deficit hyperactivity disorder (ADHD) in children. Moms consuming fish oils supposedly gave birth to children with higher IQs. Even pets benefited from fish oil supplements, sporting shinier coats. As the twentieth century came to an end, we were swimming in a sea of claims about the wonders of omega-3 fats. We were hooked on fish oil. And then the double-blind studies started to appear and the scales began to fall from our eyes. Suddenly we were confronted with headlines like: "Fish oil disappoints versus cancer," "Fish oil won't fix abnormal heart rhythms," and "Omega-3s of No Added Benefit to Heart Attack Patients." The highly respected journal Circulation featured a study demonstrating that among heart attack survivors, 1,000 mg of purified omega-3 oils a day for one year was no better than olive oil at preventing sudden cardiac arrest, death, heart attack, stroke, or the need for bypass surgery or angioplasty. The British Medical Journal published a study that found survivors of a heart attack or ischemic (clot-caused) stroke, or those with unstable angina (chest pain at rest), taking 600 milligrams of omega-3s a day for almost five years to be no better off than with a placebo at reducing nonfatal heart attacks, strokes, or deaths from cardiovascular disease. Still, business was going along swimmingly for the fish oil supplement industry until the publication of a recent meta analysis in the Journal of the American Medical Association that pooled the results of twenty high quality randomized trials involving 68,000 people and found that supplementation with omega-3 fats did not reduce the risks of all-cause mortality, cardiac death, sudden death, heart attack or stroke. The researchers conclude that their findings "do not justify the use of omega-3 as a structured intervention in everyday clinical practice or guidelines supporting dietary omega-3 fat administration. Needless to say the industry responded claiming the analysis was flawed since many of the studies were on people who were already ill and therefore might not apply to people who were taking supplements just to maintain health. Furthermore, most studies, they claim, didn't control for the amount of fish people were already eating. If they already were consuming a fair amount, the supplements would not be expected to have an effect. Given the size and number of the trials embodied in the meta analysis, these seem to be weak counter-arguments. The analysis did, however, provide some comfort for people taking omega-3 supplements in that no harmful effects were noted. It turns out, as it almost always does, that eating the whole food is better than gulping the fishy claims made on behalf of some supplement. But unfortunately people are tantalized by simple solutions to complex problems and are far too ready to swallow such claims hook, line and sinker. Excerpted from Is That a Fact?: Frauds, Quacks, and the Real Science of Everyday Life by Joe Schwarcz All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.