Fat and tuberculosis

Obesity May Have Offered Edge Over TB:

Over the course of human evolution, people with excess stores of fat have been more likely to survive famines, many scientists believe, living on to pass their genes to the next generation.

But these days, obesity is thought to be harmful, leading to chronic inflammation and metabolic disorders that set the stage for heart disease. So what went awry? When did excess fat stop being a protective mechanism that assured survival and instead become a liability?

A provocative new hypothesis suggests that in some people, fat not only stores energy but also revs up the body's immune system. This subgroup may have enjoyed a survival advantage in the 1800s, when people were plagued by a disease that decimated Europe: tuberculosis.

The original paper is here. I'm skeptical, but I'd like people who know more about the history and distribution of tuberculosis to weigh in. My working assumption is that excess fat was helpful in most pre-modern contexts (i.e., female fertility) and obesity wasn't common and simply a modern overshoot.

More like this

This entry is cross posted from the the SITN Flash, a bimonthly publication written and edited by Harvard graduate students. You can find my piece, as well as archives of previous articles written by many graduate students at the Science in the News website. In 1985, the Centers for Disease Control…
Dienekes reports on an abstracts for paper presentations at the ESHG 2009. This was is particularly interesting: European Lactase Persistence Allele is Associated With Increase in Body Mass Index J. A. Kettunen et al. The global prevalence of obesity, usually indexed by body mass index (BMI) cut-…
Genome Wide Association (GWA) Study for Early Onset Extreme Obesity Supports the Role of Fat Mass and Obesity Associated Gene (FTO) Variants. Even if this is true, these correlations between particular alleles and obesity hold for the modern German lifestyle. I guarantee you that population level…
That's right - contrary to what many religiously believe, it is the inability to grow more fat during times of energy surpluss, rather than the excess of fat which appears to directly contribute to the metabolic consequence often associated with obesity. A recent article in the New Scientist…

"Overweight" seems to be the best band for life expectancy, which makes me wonder what evidence can possibly exist to justify the "over" prefix.

By bioIgnoramus (not verified) on 24 Jun 2009 #permalink