Monday, September 17, 2012


Modern medicine has given us many beliefs that we all take for granted.  In fact, I believe that we do such a good job of taking them for granted that we come to absorb them as unquestionable facts, when we should be requesting facts to make sure they are true.  Not only does medicine help us incorporate many assumptions as facts, but it shoves them at us.  What kind of assumptions?  Well, it's unhealthy to be fat.  It's good to exercise.  It's bad to smoke (this one they may have done a good job of proving).  It's unhealthy to overweight.  Salt is bad for you.  Dietary fat is bad for you.  Trans-fats are bad for you. Dietary calcium is important to prevent bone fractures.  Vitamin D levels need to be above a certain level or you should supplement your diet with exogenous/dietary Vitamin D.  It's good to take a multivitamin.  Organic food is healthier.  Pasta is fattening (from my childhood).  Pasta is part of a low-fat, healthy diet (from my teenage years).  Pasta is fattening because it's high in carbohydrates and has little nutritional value (from my carbs-are-bad adulthood). 

Do we believe most of these things?  I think most people do and I'm the skeptic.  I generally keep quiet about my skepticism because it's a game where you don't know the answer until you're dead, and if I die a young death, I don't want to give anyone the satisfactions of saying, but of course, she wouldn't take her Vitamin D, her calcium supplements, and she salted everything.  She got what she deserved.  

So with that thought, I figured I would steer you to an article in the New York Times, "In Obesity Paradox, Thinner May mean Sicker." The article starts by talking about how among people with diabetes, those who are overweight fare better than those who are not, and the same is true for people with some other illnesses.  This is not the fashionable thing to say, we all believe (myself included) that if you have risk factors, then losing weight helps you to be healthier. 

 Harriet Brown writes:

In 2005, an epidemiologist, Katherine Flegal, analyzed data from the National Health and Nutrition Examination Survey and found that the biggest risks of death were associated with being at either end of the spectrum — underweight or severely obese. The lowest mortality risks were among those in the overweight category (B.M.I.s of 25 to 30), while moderate obesity (30 to 35) offered no more risk than being in the normal-weight category.
Whatever the explanation for the obesity paradox turns out to be, most experts agree that the data cast an uncertain light on the role of body fat. “Maintaining fitness is good and maintaining low weight is good,” Dr. Lavie said. “But if you had to go off one, it looks like it’s more important to maintain your fitness than your leanness. Fitness looks a little bit more protective.”
That is a message that may take a long time to reach your family physician, however. “Paradigm shifts take time,” Ms. Bacon said. “They also take courage. Not many people are willing to challenge the weight conventions. They’re just too culturally embedded, and the risk of going against convention is too high.”

Now let me just point out that the fact that heavier people may fare better with diabetes does not necessarily mean that a thinner person with diabetes who gains weight will do better, or that any given overweight person with diabetes might not do better if he loses weight (we all know people who control their diabetes with lifestyle changes and no medications).   It may mean that gaining weight helps, or it may be that there is something intrinsically different about thin vs. heavy people with diabetes. 

In 2007, a study of 11,000 Canadians over more than a decade found that those who were overweight had the lowest chance of dying from any cause.  

As time goes by, we get fatter, and we also live longer.  What health assumptions do you make that might be hard to forgo? 


Simple Citizen said...

Reducing salt intake could actually kill us faster. One of those fun studies that refutes everything we thought we knew.

Anonymous said...

This is like saying it's no big deal to smoke because there are nonsmokers who get lung cancer, too. Chances of getting lung cancer is still higher among smokers.

i know a lot more people with type 2 dm who are overweight/obese than are of thin/normal bmi. i'm much more concerned with the increased risk of getting the things that can shorten life span like type 2 dm, stroke, heart disease than i am in comparing a thin person who against the odds got a disease that is found more often in people who are overweight/obese. What matters to me is the increased risk of getting these health problems in the first place.

That's why i'm about to have to go off my psych meds, because it's increasing my weight and along with that comes those increased risks of getting all those other lovely problems.

Anonymous said...

I think you are reading that article the wrong way. ONCE YOU GET A CHRONIC DISEASE, your chance of living longer is increased by being obese (but in most cases not morbidly obese). However, again and again we see that obesity is a risk factor for chronic diseases that shorten a person's life span. In the world of oncology, obesity is being linked to an increased risk of developing cancer and having a cancer recurrence (in the world of breast and gynecologic cancers it is often attributed to increased levels of endogenous hormones produced by peripheral fatty tissue buy insulin like growth factor and it's relatives probably play a roll). Yes, you can find some studies that show that the obese may live longer with cancer.....but I don't want to get the damn cancer in the first place. Can people be obese and healthy? Yes.

I also see people saying that exercise isn't good for you. I think those studies need to be looked at as well. To exercise 30 minutes 4-5 times a week and sit on your duff for the other 23.5 to 24 hours a day isn't going to be good. It's about moving all day long, or that's what I think.

Dinah said...

So Simple Citizen does not believe that salt is bad for you. I missed those lectures in medical school -- I came away thinking that if you have CHF, salt can kill you, but that if you were healthy, you have kidneys to excrete excess salt.

Anon: I think smoking is one of the few things where the evidence is clear that it's bad for you. And smoking, unlike body weight, begins as a decision: if you never try it, you won't get addicted.

Anon: The article implied that the Canadian study was for all comers (not just those with chronic illness). Hard to believe that the obese are healthier (as opposed to perhaps those who are a little overweight, where you might sell me) but the point of this is to encourage people to question our observations.

Exercise is a complicated thing: it's good for somethings and bad for others. If you injure yourself, live in pain, require surgery and physical therapy, pain medications -- we have somehow created a society where we believe that these people are "healthy" even though their hobbies are leading to bad consequences (injuries among the athletic are very common).

The studies on weight, exercise, etc, look at correlation, not cause and effect. And they never look at age: so increased weight may increase risk for HTN, DM, cardiac disease, stroke, and they may be the leading causes of death, but they are also conditions that are very prevalent among older people and you have to die of something.

I'm pretty convinced that the data are good for the following:
smoking is bad for your health for a number of reasons.
Wearing a seatbelt decreases overall risk of death in a car accident.
IV drug abuse is not good for you.
Heavy drinking is bad for your health, but I'm not sure how heavy.

If they decide that it's healthier to be obese, I still would not opt to make myself obese because: 1) I don't think weight is completely optional and it would require me to ingest an uncomfortable number of calories to become and maintain a BWI of 30 or above. 2) I would look bad.

Simple Citizen said...

When I was in med-school they said the same thing.

But studies from 2011 and more recent show that HEALTHY people can benefit from reducing salt intake.

For those who already have high blood pressure or even heart failure - reducing salt intake led to increased mortality.

I thought it was applicable since your article discusses the same thing. What we thought made sense or seems intuitive can be completely wrong.

It's like the question: What is the treatment for catatonia? Sedatives (IV Ativan)

It seems backwords - but the research proves it over and over again.