Being overweight is not harmless – excess fat is the major factor responsible for insulin resistance and resultant type 2 diabetes, and a risk factor for a plethora of conditions including heart disease, stroke, hypertension, high cholesterol, liver disease, gallbladder disease, respiratory problems, arthritis, and infertility. Obesity is thought to be responsible for over 100,000 new cancer cases each year in the U.S. alone, and both overweight and obesity are associated with a greater risk of death from all causes.
Recent findings in the field of obesity research have given us two more reasons to keep one’s weight in check:
- Excess weight may restrict blood flow to certain areas of the brain, impairing brain function and possibly fueling more overeating.
- Even just a few extra pounds on someone with a “normal” BMI may increase risk of death from heart disease.
Obesity in mid-life is already known to increase the later risk of dementia, suggesting that excess weight has detrimental effects on the brain. The high blood pressure, arterial stiffness, and insulin resistance that come with excess weight could be the factors that harm the brain.
In this particular study, the researchers compared overweight and normal weight subjects (average BMI 28.43 and 21.79, respectively) using an imaging technique that measures blood flow in specific areas of the brain. They focused on the prefrontal cortex, an area of the brain that governs focus, impulse control, and executive function (which includes decision-making, planning, and working toward goals).
In overweight subjects compared to normal subjects, they saw a decrease in blood flow to the brain overall, and also specifically to the prefrontal cortex. Because of the unique functions of the prefrontal cortex in regulating impulse control, they concluded that excess weight has the potential for driving further overeating by reducing blood flow to this area.
Conversely, another recent study has found that losing weight can improve memory. Subjects underwent memory, concentration, and problem solving tests before and 12 weeks after bariatric surgery. Memory performance had improved after 12 weeks. Importantly, the baseline tests also revealed that the obese subjects and cognitive impairment. Of course, bariatric surgery is not a safe way to lose weight, but this study makes the point that the brain begins to work more effectively when excess fat begins to disappear.
Heart disease: Read more at DiseaseProof.com.
Dr. Fuhrman is a New York Times best-selling author, nutritional researcher and board certified family physician specializing in nutritional medicine. His new book Super Immunity, (released September 20, 2011) discusses how to naturally strengthen the immune system against everything from the common cold to cancer Learn more by visiting his informative website at DrFuhrman.com and his blog at DiseaseProof.com, and following Dr. Fuhrman on Facebook and Twitter.
U.S. Centers for Disease Control and Prevention. Overweight and Obesity: Health Consequences. http://www.cdc.gov/obesity/causes/health.html
Fitzpatrick AL, Kuller LH, Lopez OL, et al. Midlife and late-life obesity and the risk of dementia: cardiovascular health study. Arch Neurol. 2009 Mar;66(3):336-42.
Willeumier KC, Taylor DV, Amen DG. Elevated BMI Is associated With Decreased Blood Flow in the Prefrontal Cortex Using SPECT Imaging in Healthy Adults. Obesity (2011) 19, 1095–1097
Gunstad J, Strain G, Devlin MJ, et al. Improved memory function 12 weeks after bariatric surgery. Surg Obes Relat Dis. 2010 Oct 30. [Epub ahead of print]