Sunday, May 23, 2010

Harvard study links brain blood vessels, elderly falls

A stiffening of the aging brain's blood vessels reduces their ability to respond to changes in blood pressure, increasing the risk of falls by as much as 70 percent, researchers report. Although the change in the arteries is only one of many factors that lead to falls among the elderly, the findings provide a potential target for intervention, said Dr. Joe Verghese, a neurologist at Albert Einstein University College of Medicine who was not involved in the research. Treating high cholesterol, high blood pressure and diabetes, among other factors, can reduce the stiffening.
"Even if it accounts for only 10 percent to 15 percent of all falls, that's still large numbers that you are talking about," he said.
According to the Centers for Disease Control and Prevention, more than a third of adults over the age of 65 fall each year, and 30 percent of those suffer moderate to severe injuries, including hip fractures and traumatic brain injuries. Most elderly who are hospitalized with a hip fracture end up in a nursing home.
A variety of factors have been linked to falls, including diseases, foot problems, overmedication, environmental hazards — and abnormalities in the signaling potential of the brain's white matter, which controls both cognitive and motor functions, have also been linked. The new study was designed to demonstrate at least one mechanism by which these latter abnormalities could occur.
Dr. Farzaneh A. Sorond, a neurologist at Harvard University's Institute for Aging Research, and her colleagues studied 420 people older than the age of 65. The team used ultrasound to measure the flow of blood in the patients' brains while they were at rest and when they were breathing rapidly.
Heavy breathing increases carbon-dioxide levels and normally produces a dilation of the blood vessels, a phenomenon known as vasoreactivity. If blood vessels don't properly dilate under stress, the brain does not get enough oxygen and glucose.
The researchers also studied the patients' gait over a 12-foot course and had them keep a record of their falls. Poor gait is also a factor in falls. About 85 percent of 65-year-olds have a normal gait, but only 18 percent of 80-year-olds do.
The team reported in the journal Neurology that patients in the bottom fifth for vasoreactivity had a slower, worse gait than those in the top fifth and were 70 percent more likely to have suffered a fall during the study period.
"This gives us a window to intervene," Sorond said. "There is a lot of data, for example, that says (cholesterol-lowering) statins improve vasoreactivity. We hope to be funded to study that over the next five years."
The team also plans to do imaging studies to see if the low vasoreactivity is linked to problems with white matter.
The study was funded by the National Institute on Aging and a private donor.

The Bigger Your Belly, The Smaller Your Brain

Belly fat: image via
Belly fat: image via shinyhealth.comResearchers from Boston University School of Medicine and other U.S. medical centers have studied the relationship of various markers of body fat to brain markers for Alzheimer's disease, and their findings are not good for those who have fat around their mid-sections, or 'belly fat.
The researchers sampled 733 participants of the Framingham Study Offspring Cohort with a mean age of 60, who had undergone a variety of measurements: body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), computed tomography (CT)-based measurements of subcutaneous (SAT), and visceral (VAT) adipose tissue, as well as MRI measures of total brain volume (TCBV).   Correlations were made between each of the body fat measurements and TCBV as well as other brain markers seen in aging brains that indicate increased risk for dementia and Alzheimer's disease.
Normal brain (above) with Alzheimer's brain (below): image via
Normal brain (above) with Alzheimer's brain (below): image via An inverse relationship was found between BMI and TCBV (i.e., a higher BMI correlated with lower TCBV), but the strongest inverse relationship occurred between VAT and TCBV (i.e., a higher VAT correlated with TCBV).  This suggests that abdominal fat may be a better indicator for dementia risk than BMI. Those with smaller brain volumes tend to do poorly on tests even before other signs of dementia are apparent.

This study shows that belly fat, which poses greater risk of heart disease, also presents a greater risk for dementia.  But if you're younger than 60, you're not out of the woods.
Dr. Sudha Seshadri, M.D, lead researcher, said "Our results confirm the inverse association of increasing BMI with lower brain volumes in older adults and with younger, middle aged adults..." (italics mine)
"Our findings, while preliminary, provide greater understanding of the mechanisms underlying the link between obesity and dementia," concluded Dr. Seshadri. "Further studies will add to our knowledge and offer important methods of prevention."

10 brain damaging habits to avoid

1. No breakfast
People who do not take breakfast are going to have a lower blood sugar level. This leads to an
insufficient supply of nutrients to the brain causing brain degeneration.
2 . Overeating
It causes hardening of the brain arteries, leading to a decrease in mental power.
3. Smoking
It causes multiple brain shrinkage and may lead to Alzheimer disease.
4. High sugar consumption
Too much sugar will interrupt the absorption of proteins and nutrients causing malnutrition and may interfere with brain development.
5. Air pollution
The brain is the largest oxygen consumer in our body. Inhaling polluted air decreases the supply of oxygen to the brain, bringing about a decrease in brain efficiency.
6 . Sleep deprivation
Sleep allows our brain to rest. Long term deprivation from sleep will accelerate the death of brain cells.
7. Head covered while sleeping
Sleeping with the head covered increases the concentration of carbon dioxide and decreases concentration of oxygen that may lead to brain damaging effects.
8. Working your brain during illness
Working hard or studying with sickness may lead to a decrease in effectiveness of the brain as well as damage the brain.
9. Lacking in stimulating thoughts
Thinking is the best way to train our brain. Lacking in brain stimulation thoughts may cause brain shrinkage.
10. Talking rarely
Intellectual conversations will promote the efficiency of the brain.