Belly fat in middle age shrinks brain later in life--study

The middle aged people who carry a lot of weight around their waist are at increased risk of developing Alzheimer's or another form of dementia, a progressive decline in cognitive function, suggests a preliminary US study.

Pot belly and dementia linked
The new study led by an Indian origin scientist Sudha Seshadri, an associate professor of neurology at the Boston University School of Medicine, has linked belly fat in middle age to smaller brain volume, a factor linked with dementia, according to BBC report.

In their study, Dr. Seshadri and her colleagues from Boston University School of Medicine found that those who carried a lot of weight around their middle had smaller brains than those with the lowest amount of waistline fat.

Overall, the researchers found that increasing levels of BMI, waist circumference, waist-hip ratio, and subcutaneous and visceral adipose tissue were associated with lower total brain volume, regardless of vascular risk factors.

Study details
For their study, the research team looked at 730 people, with an average age of 60 years, 70 percent of whom were women.

The researchers measured abdominal obesity of all the study participants, and compared them to brain volume on CT scans.

They looked at the potential associations of study subjects’ body mass index--a measurement of whether someone's height and weight are proportional-- waist circumference, waist-to-hip ratio, and the CT measure of abdominal fat with their total brain volume, According to a WebMD report.

The report further says that CT measured both deep belly fat, also known as visceral fat, and subcutaneous fat--the fat that lies right below the skin.

Findings
Overall, the researchers found that increasing levels of BMI, waist circumference, waist-hip ratio, and subcutaneous and visceral adipose tissue were associated with lower total brain volume, regardless of vascular risk factors.

“Our results confirm the inverse association of increasing BMI (Body Mass Index) with lower brain volumes in older adults and with younger, middle-aged adults and extends the findings to a much larger study sample,” said Dr. Seshadri.

Abdominal fat most dangerous
Particularly, the research team found that those who had larger stomachs during their 30s were significantly more likely to have smaller brains by the time they reached their 50s.

“More importantly our data suggests a stronger connection between central obesity, particularly the visceral fat component of abdominal obesity, and risk of dementia and Alzheimer’s disease,” she added.

The researchers hope their findings, published in online in Annals of Neurology, could lead to promising prevention strategies in the future.

"Our findings, while preliminary, provide greater understanding of the mechanisms underlying the link between obesity and dementia," Dr. Seshadri said. "Further studies will add to our knowledge and offer important methods of prevention."

About AD and dementia
Alzheimer's disease (AD), which causes senility and can lead to death, is a neurodegenerative disorder characterized by the development of unusual clumps of proteins called amyloid plaques and nerve cell tangles that hinder messages being processed by the brain. AD that destroys patients' memories and capacity for speech affects an estimated 5.3 million Americans.

Alzheimer's affects almost half of all patients with dementia. The most striking early symptom of Alzheimer’s is loss of short term memory. As the disorder progresses, cognitive injury extends to the domains of language (aphasia), skilled movements (apraxia), recognition (agnosia), and those functions (such as decision-making and planning) closely related to the frontal and temporal lobes of the brain.

Researchers have been trying to formulate various methods to prevent dementia, which can stem from Alzheimer's disease or other causes and is common among the elderly. But the various medications available do not promise a full cure. Although they help in ameliorating memory, but effectual treatment can be seen only in a handful of patients.

According to statistics, there are about 24 million people with dementia worldwide, and it has been projected that by 2040, the number of people suffering from AD will increase to 81 million.

Globally, there are about 60 percent people in the developing countries affected by Alzheimer’s and by 2040, this proportion will rise to 71 percent.