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Common Gene Variant Drives Weight Gain
One in two people have a gene variation that drives overeating; healthy lifestyles blunt the effects
5/29/2014By Craig Weatherby
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Image More than one-third of American adults aged 65 and over are obese.

Excessive weight promote heart disease, high blood pressure, diabetes, gallstones, breathing problems, and certain cancers.

Overweight results from a blend of diet, activity, genetics, stress, personal metabolism – how your body changes food and oxygen into energy – and more.

Recent research has found that almost one in two people – 45 percent – have a variation in a gene called FTO that’s linked to a 20 percent increase in the risk for obesity.

And about 16 percent of the American population have two copies of the FTO gene, which makes them 67 percent more likely to become obese.

(Carriers of FTO gene variants also have smaller frontal lobes in the brain, less verbal fluency, and an increased risk for incident Alzheimer’s disease.)

The link between the FTO gene variation and risk for obesity is strongest in Caucasians, moderate in Asians, and is not seen in African-Americans.

Exercise seems to counter the effects of the FTO variants ... see “Genes are not destiny: Lifestyle can help overcome heritage”, below.

A genetic test for FTO variants is not yet commercially available.

Some researchers think that if people knew they had a “bad” FTO gene variant, this would motivate them to exercise and watch their diets.

But others fear that such knowledge would make carriers of the weight-promoting FTO variants feel helpless and demotivate them from efforts to follow a healthy lifestyle.

Obesity gene undermines impulse control
Recent research has convincingly linked certain variations of the FTO gene to obesity, but the reasons for that link have been unclear.

The new analysis involved 692 people participating in the Baltimore Longitudinal Study of Aging (BLSA) – including 69 people who agreed to annual PET brain scans (Chuang YF et al. 2014). 

Most of the participants were upper-middle class white people and all were free of chronic diseases at the outset of the study.

BLSA researchers periodically measured the participants’ body mass index (BMI), asked about their eating patterns, and gave them cognition (thinking/memory) tests, and personality tests designed to determine their impulsiveness and self-discipline.

As in the general population, 45 percent of the percent of the people in the study had one or two copies of the FTO variant.

The results linked the presence if the FTO gene to several key trends and characteristics:
  • Greater gains in BMI and weight.
  • Greater tendency to favor fatty foods other calorie-dense fare.
  • Reduced function in a brain region (medial prefrontal cortex) that controls impulsivity and responses to the taste and texture of food.
In other words, the new study confirmed that having the gene leads to greater weight gain over time, probably because it cripples impulse control and leaves people less able to resist fatty, calorie-dense foods.

As lead author Madhav Thambisetty, M.D., said, “There may be a common biological factor underlying both the risk for obesity during aging as well as obesity-related behavior like your ability to resist impulse eating.” (HD 2014)

If future studies confirm these results, it will mean that people with the FTO gene need to fight their inherited weakness by taking extra steps to maintain a healthy weight.

Genes are not destiny: Lifestyle can help overcome heritage
Fortunately, other research shows that having these genetic traits does not doom people to obesity.

Previous studies show that people can overcome the risk of having the FTO gene through regular, vigorous, long-term exercise (Andreasen CH et al. 2008; Rampersaud E et al. 2008).

Although it is not the most accurate measure, the easiest way to find out whether you may be overweight or obese is to calculate your body mass index (BMI).

BMI is also a good gauge of your risk for diseases associated with excess body fat. You can use the online BMI calculator at the National Heart, Lung, and Blood Institute website to determine your BMI.


Sources
  • Andreasen CH, Stender-Petersen KL, Mogensen MS, et al. Low physical activity accentuates the effect of the FTO rs9939609 polymorphism on body fat accumulation. Diabetes. 2008;57:95–101.
  • Benedict C, Jacobsson JA, Rönnemaa E, Sällman-Almén M, Brooks S, Schultes B, Fredriksson R, Lannfelt L, Kilander L, Schiöth HB (June 2011). The fat mass and obesity gene is linked to reduced verbal fluency in overweight and obese elderly men. Neurobiol. Aging 32 (6): 1159.e1–5. 
  • Cecil JE, Tavendale R, Watt P, Hetherington MM, Palmer CN. An obesity-associated FTO gene variant and increased energy intake in children. N Engl J Med. 2008 Dec 11;359(24):2558-66. doi: 10.1056/NEJMoa0803839.
  • Chuang YF, Tanaka T, Beason-Held LL, An Y, Terracciano A, Sutin AR, Kraut M, Singleton AB, Resnick SM, Thambisetty M. FTO genotype and aging: pleiotropic longitudinal effects on adiposity, brain function, impulsivity and diet. Mol Psychiatry. 2014 May 27. doi: 10.1038/mp.2014.49. [Epub ahead of print]
  • Ho AJ, Stein JL, Hua X, Lee S, Hibar DP, Leow AD, Dinov ID, Toga AW, Saykin AJ, Shen L, Foroud T, Pankratz N, Huentelman MJ, Craig DW, Gerber JD, Allen AN, Corneveaux JJ, Stephan DA, DeCarli CS, DeChairo BM, Potkin SG, Jack CR, Weiner MW, Raji CA, Lopez OL, Becker JT, Carmichael OT, Thompson PM (May 2010). A commonly carried allele of the obesity-related FTO gene is associated with reduced brain volume in the healthy elderly. Proc. Natl. Acad. Sci. U.S.A. 107 (18): 8404–9.
  • Keller L, Xu W, Wang HX, Winblad B, Fratiglioni L, Graff C (2011). The obesity related gene, FTO, interacts with APOE, and is associated with Alzheimer's disease risk: a prospective cohort study. J. Alzheimers Dis. 23 (3): 461–9.
  • Kivimäki M, Jokela M, Hamer M, Geddes J, Ebmeier K, Kumari M, Singh-Manoux A, Hingorani A, Batty GD. Examining overweight and obesity as risk factors for common mental disorders using fat mass and obesity-associated (FTO) genotype-instrumented analysis: The Whitehall II Study, 1985-2004. Am J Epidemiol. 2011 Feb 15;173(4):421-9. doi: 10.1093/aje/kwq444. Epub 2011 Jan 19.
  • Rampersaud E, Mitchell BD, Pollin TI, et al. Physical activity and the association of common FTO gene variants with body mass index and obesity. Arch Intern Med. 2008;168:1791–7.
  • Rankinen T, Rice T, Teran-Garcia M, Rao DC, Bouchard C. FTO genotype is associated with exercise training-induced changes in body composition. Obesity (Silver Spring). 2010 Feb;18(2):322-6. doi: 10.1038/oby.2009.205. Epub 2009 Jun 18.
  • Tanofsky-Kraff M, Han JC, Anandalingam K, Shomaker LB, Columbo KM, Wolkoff LE, Kozlosky M, Elliott C, Ranzenhofer LM, Roza CA, Yanovski SZ, Yanovski JA. The FTO gene rs9939609 obesity-risk allele and loss of control over eating. Am J Clin Nutr. 2009 Dec;90(6):1483-8. doi: 10.3945/ajcn.2009.28439. Epub 2009 Oct 14.
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