In the past I have criticized evolutionary medicine for its tendency to rely on unverifiable “Just-So Stories,” but a new book has helped me appreciate what the best kind of evolutionary thinking can contribute to our understanding of medicine. Doves, Diplomats, and Diabetes: A Darwinian Interpretation of Type 2 Diabetes and Related Disorders by Milind Watve investigates diabetes from an evolutionary perspective, suggesting how it might have originated, why it persisted, and how it is related to survival advantages. Watve develops well-reasoned hypotheses that can be tested by examining their expected consequences. He believes it is impossible to understand metabolism without understanding behavioral ecology, and he makes a good case.
A reassessment of the evidence concerning Type II diabetes (T2D) reveals a number of paradoxes. Elevated blood glucose is the defining feature of T2D but controlling it doesn’t prevent all the complications of diabetes, and it doesn’t appear that elevated blood sugar could produce all the pathological changes of diabetes. Insulin resistance is believed to be central to a cluster of deadly diseases in humans, but in other animals it has no adverse effects on health and even increases lifespan. Studying diabetes from an evolutionary perspective can shed light on such paradoxes. (more…)
On my recent trip to Nashville for CSICon, I took advantage of the long hours on the plane to read Breakthrough: Elizabeth Hughes, the Discovery of Insulin, and the Making of a Medical Miracle, by Thea Cooper and Arthur Ainsberg. One of our commenters recommended it. I’m not sure who (was it Chris?), but I want to thank you.
It’s the history of insulin told from the perspective of the scientists and of a typical patient, and it touches on a number of issues that we have addressed on SBM. It shows how science works to save lives, in stark contrast to the empty promises of CAM. (more…)
Being fat is bad except when it’s good. It’s called “the obesity paradox.” (No, that isn’t a mis-spelling for “two physicians who treat fat people.”) The adverse health effects of obesity are well established, but there are exceptions. Obesity appears to confer an advantage in certain subgroups with conditions like heart disease and diabetes.
In the News
Casual consumers of some recent media reports might interpret them as an excuse to stop trying to lose excess weight, especially if they are diabetic. Others might think we have been lied to about the dangers of the obesity epidemic. The reality is more complicated. (more…)
A customer strolled up to the counter one night when I was working in a retail pharmacy:
“My doctor says I have prediabetes. I don’t want to take any drugs. Do you have something natural I can use to cut my blood sugar?”
I looked at him in the eye, and pointed at his sizeable midsection. “Sir, if you’re at risk for diabetes, and you don’t want to take medication, the single best thing you can do for yourself is lose some weight.”
He grinned and asked, “Great – what supplement can I take to help me?”
This type of discussion occurs all the time. A patient has been assessed by their physician, and informed that they have a medical problem of some sort. The patient, reluctant to accept the physician’s evaluation, heads to the pharmacy for a second opinion. In some cases, the patient may question the physician’s advice: “All my physician wants to do is prescribe drugs.” Yet there’s a disconnect when it comes to strategies for management. More often than not, non-drug approaches are rejected out-of-hand (probably because the sample I speak with have already made the decision to buy something). And in those that are leery of medical management, there’s often a willingness to consider anything that’s available without a prescription – particularly if it’s perceived as “natural.” Natural products are gentle, safe, and effective, while medicine is thought of as unnatural, harsh, and potentially dangerous. This is the naturalistic fallacy, nothing more. Purveyors of supplements leverage the naturalistic fallacy into the marketing strategy of choice for almost all supplements and “alternative” medicines. And it leads to bad health care decisions. (more…)
A number of buzz-words appear repeatedly in health claims, such as natural, antioxidants, organic, and inflammation. Inflammation has been implicated in a number of chronic diseases, including diabetes, Parkinson’s, rheumatoid arthritis, allergies, atherosclerosis, and even cancer. Inflammation has been demonized, and is usually thought of as a bad thing. But it is not all bad.
In a study in Nature Medicine in September 2011, a research group led by Dr. Umut Ozcan at Children’s Hospital Boston (a teaching hospital affiliated with Harvard Medical School) reported that two proteins activated by inflammation are crucial to maintaining normal blood sugar levels in obese and diabetic mice. This could be the beginning of a new paradigm. Ozcan says:
This finding is completely contrary to the general dogma in the diabetes field that low-grade inflammation in obesity causes insulin resistance and type 2 diabetes. For 20 years, this inflammation has been seen as detrimental, whereas it is actually beneficial.
Increasing levels of these inflammatory signals might actually be therapeutic in diabetes and obesity. On the other hand, they might worsen inflammatory diseases like asthma and rheumatoid arthritis. Ozcan’s findings are intriguing and might eventually lead to new treatments, but there are no clinical applications as yet.
Dr. H. Gilbert Welch has written a new book Over-diagnosed: Making People Sick in the Pursuit of Health, with co-authors Lisa Schwartz and Steven Woloshin. It identifies a serious problem, debunks medical misconceptions and contains words of wisdom.
We are healthier, but we are increasingly being told we are sick. We are labeled with diagnoses that may not mean anything to our health. People used to go to the doctor when they were sick, and diagnoses were based on symptoms. Today diagnoses are increasingly made on the basis of detected abnormalities in people who have no symptoms and might never have developed them. Overdiagnosis constitutes one of the biggest problems in modern medicine. Welch explains why and calls for a new paradigm to correct the problem. (more…)
Red meat consumption has been linked to diabetes, cardiovascular disease, and several types of cancer (breast, colorectal, stomach, bladder, prostate, and lymphoma). There are plausible mechanisms: meat is a source of carcinogens, iron that may increase oxidative damage, and saturated fat. But correlation and plausibility are not enough to establish causation. Is red meat really dangerous? If so, how great is the risk? A couple of recent studies have tried to shed light on these questions, but they have raised more questions than they have answered.
A Systematic Review and Meta-Analysis
A new study in Circulation, “Red and Processed Meat Consumption and Risk of Incident Coronary Heart Disease, Stroke, and Diabetes Mellitus. A Systematic Review and Meta-Analysis,” by Micha, Wallace and Mozaffarian, is a systematic review of the literature. It analyzed 17 prospective cohort studies and 3 case-control studies, with a total of 1.2 million subjects. As far as I can judge, it appears to be a well-done systematic review with excellent methodology and multiple precautions. They even looked for things like publication bias (which they did not find).
They found that the consumption of processed meats, but not red meats, is associated with a higher incidence of coronary heart disease and diabetes. (Processed meats include bacon, sausage, ham, hot dogs, salami, luncheon meat and other cured meats.) The increased risk per 50 gram serving of processed meats per day was 42% for heart disease and 19% for diabetes. Unprocessed red meats were not associated with CHD and were associated with a nonsignificant trend towards higher risk of diabetes. They found no association with stroke, but this was based only on 3 studies.
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…)
In this space we’ve read about the efforts of “alternative” practitioners such as naturopaths to gain the moniker “primary care provider”. I’ve been wondering a bit about this. I’m a primary care physician. Specialists in internal medicine, pediatrics, and family medicine provide the bulk of primary care in the U.S. They attend a 4-year medical school, complete a 3-4 year residency, take their specialty board, and then work as experts in the screening, prevention, diagnosis, and treatment of common diseases.
So, what I’d like to do is give you a typical scenario from an internal medicine or family medicine practice. It’s a simple one, one you might see on Step II of the USMLE boards or on a shelf exam for an internal medicine rotation. I’d like to offer alternative practioners, especially naturopaths, an opportunity to show how they would approach the clinical scenario so that we can see what kind of primary care they provide.
Yes, every patient and every situation is different, but there are some general ways to approach health and disease based on the evidence.