A gene linked to obesity may also cause Alzheimer’s disease, according to a new study.
Obesity causes brains to shrink – increasing the risk of Alzheimer’s disease later in life, researchers say
Researchers at the University of California, Los Angeles, found the same gene — allele, from the fat mass and obesity associated gene, the FTO gene, which increases risk of gaining weight — is also linked to brain shrinkage.
The researchers generated three-dimensional “maps” of brain volume differences in 206 healthy elderly subjects using magnetic resonance imaging from 58 sites in the United States.
The study, published in the journal Proceedings of the National Academy of Sciences, found consistently less brain tissue — up to less than 12 percent of some parts of the brain — in those with the FTO allele compared with non-carriers of the variant.
In addition, the study said the differences of brain volume could not be directly attributed to other obesity-related factors such as cholesterol levels, diabetes or high blood pressure.
“If you have the bad FTO gene, your weight affects your brain adversely in terms of tissue loss,” Thompson said in a statement. “If you don’t carry FTO, higher body weight doesn’t translate into brain deficits.”
A Spokesperson for the Alzheimer’s Society said: “We’ve known for some time that there’s a link between obesity in mid life and the development of Alzheimer’s disease. However this study suggests that healthy people who carry a specific DNA sequence associated with obesity could be at a greater risk of developing dementia.
“This is a relatively small study but the findings support the need for more research. One million people will develop dementia in the next 10 years but dementia research is desperately under-funded, however with the right investment, it can be defeated
The American Institute for Cancer Research (AICR) has released figures showing approximately 100,000 cases of cancer each year in the United States can be attributed to excess body fat.
The AICR estimates the following percentages of cancers are linked to being overweight or obese:
49% of endometrial cancers (approximately 20,700 cases per year)
35% of esophageal cancers (approximately 5,800 cases per year)
28% of pancreatic cancers (approximately 11,900 cases per year)
24% of kidney cancers (approximately 13,900 cases per year)
21% of gallbladder cancers (approximately 2,000 cases per year)
17% of breast cancers (approximately 33,000 cases per year)
9% of colorectal cancers (approximately 13,200 cases per year)
The researchers found a definite link between excess body fat and cancers of the endometrium, esophagus, pancreas, kidney, breast (post-menopausal) and colorectal. The link between excess body fat and gallbladder cancer is felt to be probable at this time.
“We now know that carrying excess body fat plays a central role in many of the most common cancers,” said Laurence Kolonel, MD, PhD, Deputy Director of the Cancer Research Center of Hawaii and AICR/WCRF expert panel member “And it’s clearer than ever that obesity’s impact is felt before, during and after cancer – it increases risk, makes treatment more difficult and shortens survival.”
The connection between being overweight and cancer may be due to the fact excess body fat increases the production of estrogen, a hormone many cancers require for growth, as well as other hormones and body chemicals that help prevent or control cancer formation. Studies also show being overweight reduces the effectiveness of the immune system.
The American Institute for Cancer Research and the World Cancer Research Fund released the report Policy and Action for Cancer Prevention, which estimated the percentage of cancers attributable to poor diet, lack of exercise and excess body weight, earlier in 2009. The new estimates, released on November 5, 2009, were calculated using information from that report and the latest US cancer incidence data provided by the American Cancer Society.