For over a decade, obesity has been called an “epidemic”, both in the popular and scientific literature. Traditionally, the term “epidemic” is associated with a highly contagious disease that carries with it a significant risk of mortality. A comprehensive review of observational studies (1) suggested that obesity did not fit this definition, despite the use of the term in a widely disseminated report by the World Health Organization in 2002.
Regardless of the etymological fine points, the worldwide prevalence of obesity and its associated health risks are clear. These risks include type 2 diabetes, hypertension, several cancers, gall bladder disease, coronary artery disease and stroke (2). Yet, the debate over obesity and options for reducing its risks has become increasingly polarized. As a result, some health researchers are advocating a “health at every size” (HAES) approach to address the social, cultural and lifestyle implications of obesity (2).
Forty-some years ago fat was just fat. And it was regarded with disdain, to say the least.
An entire industry existed to help get rid of fat, using what was then the latest mass media technology, television. If you wanted to get rid of fat you could exercise with Jack LaLanne as he worked out on television. We exercised in elementary school PE class to a vinyl recording of “Chicken Fat”. You could strap into a device that employed shaking to get rid of the fat from your “hips”, or eat a piece of chocolate fudge with a hot beverage before meals to curb your appetite.
Fat was not our friend. We knew long before the current diabetes epidemic that being overweight was not good for our health.
Fast forward to the 21st century, where we’ve learned that some forms of fat are actually good for you–important in metabolism, growth and immunity. The variety of types of mammalian fat include brown adipose tissue, beige adipose tissue and white adipose tissue, and it’s possible to convert one to the other under certain conditions. For details on these types of adipose tissue, read this article —after you finish this blog. Continue reading “A Surprising New Role for Body Fat?”
A basic tenet of immunology is that antibodies produced by B cells are very important and specific immunoprotective agents, released in response to infection.
However, antibodies do not supply immediate protection. The invading organism needs to get into the host, meet up with T cells and then B cells, in order for antibody production to occur. If the host has seen this particular pathogen previously, the antibody response occurs somewhat more quickly, but we’re still talking about days. If the invading organism is a bacterium, it can multiply and double in numbers in just hours. Thus an infection could potentially gain a foothold in a body prior to an antibody response.
Fortunately we have a more rapid, first line of defense to invading pathogens, a cellular response. In the case of a puncture or skin wound, epithelial cells, mast cells and leukocytes are activated quickly in response to pathogens. Neutrophils and monocytes also aid the cellular response.
Estimates of obesity in the U.S. range from 30% (Centers for Disease Control data) to 70% (persons selling online and television audience-focused weight-loss programs). We are a nation of fat or fat-obsessed persons, and rightfully so. CDC data shows that the cost of obesity, in 2008 dollars, was estimated at $147 billion. That amount of money would buy a lot of french fries or cheesecake or __ (name your poison).
We all help pay those high-dollar amounts in terms of rising healthcare costs, thus there is considerable interest in finding ways to not only avoid, but also to combat obesity.
In recent years researchers working to understand body fat biology have produced exciting information on differences in types of fat. For instance, we now understand that in addition to white adipose tissue, animals and humans also have brown and beige adipose tissue. White adipose tissue or WAT is commonly found in humans and mice subcutaneously and in visceral fat. Brown adipose tissue or BAT, and beige adipose, is less common, and in humans and mice, is found in deeper cervical, supraclavical and paraspinal areas.