KLF14 is a gene thought to act like a “Master Switch” for controlling other genes in body fat. The MuTHER study is a large multi-national collaboration and used fat biopsies from under the skin or subcutaneous fat samples from 800 female twin subjects and confirmed that KLF14 was controlling distant gene expression levels in other genes found in the fat tissue with 600 samples from a separate group of people. KLF14 controls traits that in turn affect metabolic syndrome, obesity and type 2 diabetes. This finding may help understand the causes of obesity and its related diseases and how
Functional MRI (fMRI) is rather like using Google Earth. It helps us to delve deeper into our understanding of how certain triggers activate centers in the brain associated with cravings and addictive behaviors. A recent study from Yale University published in Archives of General Psychiatry finds that women who completed a questionnaire that identifies substance dependence behaviors around food also responded to seeing and tasting a glass of chocolate milk shake. The reward centers were triggered by this cue just like cocaine in a drug addict. Maybe this is why it is so hard for people to diet – there are just too many cues around in our environment. Further studies will look at how much of this is learned rather than genetic. For most people it is probably a combination of both genes and environment.
Stress of many types appears to be linked to obesity apparently due to its link with inflammation. Researchers at Ohio State University have identified another source of obesity related stress as polluted air. Mice exposed to particulate air polution (seven times higher than typical ambient air in Columbus, OH) gained weight whether they were on a normal diet or a high fat diet. A study investigating the link of polluted air early in life with overweight and obesity looked at mice over a period matching childhood in humans. The mice also developed insulin resistance and had higher levels of a marker of inflammation TNF-alpha. Pollution may act as a trigger for obesity like other stressors. If so, this may be yet another reason why moving to urban areas is associated with weight gain.
Source: Arterioscler Thromb Vasc Biol, Dec 2010; 30: 2518 – 2527
Two new studies published in Nature Genetics http://www.nature.com/ng/index.html move us closer to identifying gene variants that increase risk of obesity. 18 previously undescribed regions included and confirmation of 14 other regions associated with BMI (Obesity is a BMI of 30 or greater). Unfortunately this doesn’t predict obesity any better than a good family health history. It isn’t the genes that are causing the current epidemic of obesity but how we are adapting to our current environment (fast food 24/7 and much less physical activity).