Last month I wrote about a book on evolutionary medicine that I could not recommend. Now I’ve found one I can recommend. Marlene Zuk, an evolutionary biologist at the University of California, Riverside, has written a delightful book entitled Riddled with Life: Friendly Worms, Ladybug Sex, and the Parasites That Make Us Who We Are. She describes how our parasites and diseases co-evolved with us: as we developed better defenses, they developed better weapons. “We do not choose to have them, but our lives are unimaginable without them, and for better or worse, they have made us who we are.” Parasites have altered our bodies in ways that science fiction filmmakers could never have imagined. She even suggests that we can thank parasites for the fact that we reproduce sexually rather than asexually.
She advocates an evolutionary medicine that “places diseases and defects in an evolutionary framework to make sense of the apparent mismatch between the way our bodies often work and the way we would like them to.” Evolution did not design our bodies for health, but to maximize reproduction.
“Just because our species evolved in a different environment does not mean …that following the ways of the past is automatically going to free us from the illnesses of modern life.” She incisively debunks the myth of the Paleolithic diet and points out that if we wanted to copy our hunter-gatherer ancestors we would have no way of deciding which ones to copy – the ones from 10,000 years ago or the ones from 100,000 years ago; the Inuits or the Kalahari Bushmen. She also points out that evolution explains why humans vary and why one diet won’t suit everyone. (more…)
Alcoholics Anonymous is the most widely used treatment for alcoholism. It is mandated by the courts, accepted by mainstream medicine, and required by insurance companies. AA is generally assumed to be the most effective treatment for alcoholism, or at least “an” effective treatment. That assumption is wrong.
We hear about a few success stories, but not about the many failures. AA’s own statistics show that after 6 months, 93% of new attendees have left the program. The research on AA is handily summarized in a Wikipedia article. A recent Cochrane systematic review found no evidence that AA or other 12 step programs are effective.
In The Skeptic’s Dictionary, Bob Carroll comments:
Neither A.A. nor many other SATs [Substance Abuse Treatments] are based on science, nor do they seem interested in doing any scientific studies which might test whether the treatment they give is effective. (more…)
There is no question that patients on insulin benefit from home monitoring. They need to adjust their insulin dose based on their blood glucose readings to avoid ketoacidosis or insulin shock. But what about patients with non-insulin dependent diabetes, those who are being treated with diet and lifestyle changes or oral medication? Do they benefit from home monitoring? Does it improve their blood glucose levels? Does it make them feel more in control of their disease?
This has been an area of considerable controversy. Various studies have given conflicting results. Those studies have been criticized for various flaws: some were retrospective, non-randomized, not designed to rule out confounding factors, high drop-out rate, subjects already had well-controlled diabetes, etc. A systematic review showed no benefit from monitoring. So a new prospective, randomized, controlled, community based study was designed to help resolve the conflict. (more…)
Three recent news items about chiropractic have particularly irritated me.
(1) U.S. Army Brigadier General Becky Halstead (Retired) Speaks Out for Chiropractic Care
(2) Chiropractic Helps Child with Brain Disorder
(3) Swine Flu Chiropractor’s Handout
(1) General Halstead has become a spokesperson for The Foundation for Chiropractic Progress, a nonprofit organization dedicated to increasing public awareness of chiropractic. Her quoted comments boil down to
- I like the personal attention and caring I get from my chiropractor.
- Chiropractic advice about healthy lifestyle is essential
- Chiropractic care prevents more serious health concerns
- Chiropractic is essential for assisting in recovery from minor injuries.
- Chiropractors don’t mask the problem with drugs and all their side effects.
- Chiropractors are holistic and involve the patient in her own care.
- “Listening appears to be a major tool.”
This is nothing but opinion based on personal experience and scientific ignorance. She offers no evidence that chiropractic theory is true, that chiropractic adjustments are effective, or that a chiropractor has any advantage over a science-based medical doctor who also spends time listening to patients, is interested in the whole patient, advises about healthy lifestyle, and avoids unnecessary use of drugs. Caring clinicians can be found in chiropractic, in homeopathy, in every kind of quackery, and in scientific medicine, with the advantage that the scientific clinician can also provide effective evidence-based treatments. (more…)
I read this Reuters Health article on MedlinePlus, and then I read the study the article referred to (The impact of acupuncture on in vitro fertilization) and now my head hurts. The study found that acupuncture was not effective in increasing the pregnancy rate (PR) during in vitro fertilization (IVF). As quoted on MedlinePlus, the lead author, Alice Domar, seems to blame her patients (the presumably poor quality of their embryos) rather than acupuncture for the lack of success, and then she recommends using acupuncture even if it doesn’t work. That was bad enough, but “poor quality embryos” is a hypothesis that was actually tested and rejected in the study itself. Has Domar forgotten?
The headline of the MedlinePlus article says “acupuncture doesn’t boost IVF success for all” – suggesting that it boosts success for some? Then the first sentence says the study suggested that acupuncture doesn’t work, period. But wait…
The lead researcher says acupuncture may not have worked in her study because, unlike past research, her investigation wasn’t limited to women who had good quality embryos available for transfer. “I’m wondering if my sample was just not a good sample, in that most of the patients in my study were probably not the best-prognosis patients,”
Domar and her team say the most likely explanation for the lack of an acupuncture effect in their study was the fact that they included many women who didn’t have good quality embryos available for transfer. While acupuncture may help a woman become pregnant after the transfer of a healthy embryo, the researcher noted in an interview, it can’t repair an embryo with chromosomal defects or other abnormalities.
Hold the boat!! In the Discussion section of the paper itself, Domar et al point out that previous research has included mostly patients with good quality embryos. They ask if perhaps acupuncture only works for good quality embryos? They test that hypothesis by separately analyzing the subjects in this study who had good quality embryos. There was no increase in PR with acupuncture in this sub-group; the results were the same as for the entire sample. (more…)
We criticize alternative medicine for not being evidence-based, and they criticize conventional medicine in turn, saying that much of what conventional medicine does is not based on evidence either. Sometimes that criticism is justified. I have run across a conventional practice that I suspect began because it sounded like a good idea, but that never was adequately tested and is not carefully thought out for individual patients.
I recently had a bone marrow aspiration. The written instructions said not to eat or drink for 6 hours before the procedure, to bring someone to drive me home, and to expect an IV. I suspected from these instructions that they were planning to use IV sedation, and I was right.
I questioned the need for sedation. I am prejudiced about bone marrow aspirations. I observed several and did one myself during my internship. When I had finished, the patient asked me when I was going to start. We did the procedure at the patient’s bedside in a multi-bed ward with no sedation, only local anesthesia. So my prejudice was that the procedure was no big deal and was not terribly painful.
I can imagine that some patients may be terrified by the idea of a needle going into their bone and may want to be sedated and not remember the experience. But I was not anxious about it, and I saw no need for the fentanyl and Versed they wanted to give me. I figured it would only prolong my time in the hospital, produce amnesia, expose me to a small risk of adverse effects, and leave me groggy; so I asked to opt out. They readily agreed – although they did keep asking me if I was really sure I didn’t want it. They would not have offered the option of no sedation if I had not known to ask. (more…)
I have been asked to review a pre-publication proof of a book that will be published in May 2009: Evolution Rx: A Physician’s Guide to Harnessing Our Innate Capacity for Health and Healing by William Meller, MD. It offers “a primal yet radical new view of why we act and feel the way we do, why we get sick and how we heal. This new perspective, known as evolutionary medicine, looks at how our Stone Age ancestors lived, loved, got sick and got well over millions of years, which leads to guidelines for living longer healthier and happier lives today.”
He says we are the way we are because that’s what it took to adapt and survive throughout our evolutionary history. To some extent, that’s true, but that’s not the whole story. Sometimes we are the way we are because of an accident of evolutionary history that had no bearing on survival. Sometimes we are the way we are because a useless trait was linked to a useful one and came along for the ride – what Stephen Jay Gould referred to as “spandrels.”
The problem with evolutionary explanations is that we can never know for sure if they are true. We may be inventing “Just So Stories” like Rudyard Kipling’s “How the Camel Got His Hump.” Our explanation may seem perfectly reasonable but we may not have all the information and there may be a better explanation that simply doesn’t occur to us. (more…)
You’ve all heard the dramatic testimonials in the media: “I had a PSA test and they found my prostate cancer early enough to treat it. The test saved my life. You should get tested too.” The subject of screening tests is one that confuses the public. On the surface, it would seem that if you can screen everyone and find abnormalities before they become symptomatic, only good would result. That’s not true. Screening tests do harm as well as good, and we need to carefully consider the trade-offs.
About half of American men over the age of 50 have had a PSA (prostate-specific antigen) screening test for prostate cancer. Recommendations for screening vary. The US Preventive Services Taskforce (USPSTF) says there is insufficient evidence to recommend screening. The American Urological Association and the American Cancer Society recommend screening. Urologists practice what they preach: 95% of male urologists over the age of 50 have been screened. But other groups like the American Academy of Family Physicians recommend discussing the pros and cons of screening with patients and letting them make an informed choice.
Two recent studies published simultaneously in The New England Journal of Medicine have added to the controversy. One concluded that screening does not reduce deaths from prostate cancer; the other concluded that it reduces deaths by 20%. (more…)
Three kids on the same block were diagnosed with leukemia last year. That couldn’t happen just by chance, could it? There MUST be something in the environment that caused it (power lines, the chemical plant down the street, asbestos in their school, iPods, Twinkies?). Quick, let’s measure everything we can think of and compare exposures to other blocks and find an explanation.
That may be the common reaction, and it may seem plausible to the general public, but it’s not good science.
I have just read a book that does a great job of elucidating the pitfalls of epidemiologic studies, the problematic interface between science and emotion-laden public concerns, and the way environmental hazards have been hyped far beyond the evidence. Hyping Health Risks: Environmental Hazards in Daily Life and the Science of Epidemiology by Geoffrey C. Kabat.
He covers the uses, strengths and limitations of epidemiology, discusses the pros and cons of different study designs, and explains how to judge whether an association is causal.
In the 1950s, 558,000 people were in mental institutions in the U.S. Many were there against their will and were being warehoused or treated badly. Deinstitutionalization was intended to restore their civil rights and improve their lot. Did it? By 2006, there were only 40,000 people in institutions. What happened to the other 518,000?
Some of them are living in the community with supportive family members, taking their medications, and contributing to society. Some of them have been ghettoized in halfway houses or group homes in crime-ridden and run-down neighborhoods. Some of them are homeless, living on the streets and eating out of garbage cans. Some of them are in jail. Some of them have killed family members or have killed multiple people in “rampage” murders provoked by their psychotic delusions.
Accurate numbers are difficult to obtain. By some estimates, as many as 30-50% of the homeless (and even more of the hard-core homeless) and as many as 40-50% of the jail population are mentally ill. There are more mentally ill people in jails than in hospitals. The mentally ill are more likely to be victims of violence and rape and are more likely to be shot by the police in “justifiable homicide” incidents.
Mentally ill people who are adequately treated are no more violent than the non-mentally ill, but a disproportionate number of murders are committed by the mentally ill. The risk of violence increases with past history of violence, substance abuse, anosognosia with medication noncompliance, antisocial personality disorder, paranoid symptoms, and male sex. (more…)