Exercising the Body (Not Just the Brain) May Reduce Risk of Dementia
Doctors have long recommended regular exercise to keep the heart healthy. Now researchers are adding exercise to long-term lifestyle choices that may also protect the brain against cognitive decline.
People who exercise in middle age, according to a new study, are far less likely to develop Alzheimer's and other types of dementia. “This is the first study to show this long-term relation between physical activity and dementia later in life,” said its lead author, Miia Kivipelto, M.D., Ph.D., of the Aging Research Center at the Karolinska Institute in Sweden. “We found that people who were active during midlife had a much lower risk for dementia, especially Alzheimer's disease.”
Specifically, middle-aged people who exercised at least twice a week had a 50 percent lower chance of developing dementia and a 60 percent lower chance of developing Alzheimer's than their sedentary peers.
Just as startling a discovery, exercise was found most beneficial for those genetically predisposed to dementia. “It seems physical activity had an even more pronounced beneficial effect among those with the susceptibility gene ApoE4, an important risk factor for Alzheimer's disease and dementia,” Dr. Kivipelto said.
The study, which monitored 1,499 participants age 65 and older for three decades leading to its fall publication in the journal Lancet Neurology, confirms benefits suggested by smaller studies in animals and humans. And previous studies have found that people with cardiovascular risk factors were more likely to develop Alzheimer's.
While the Swedish study found no link between degree of reduced risk and amount of exercise (mostly walking and biking strenuous enough to cause sweating and strained breathing), it raises the possibility that cardiovascular fitness may be as important as mental gymnastics in delaying cognitive decline. “If an individual adopts an active lifestyle by midlife,” Dr. Kivipelto said, “this may increase the probability of enjoying both physically and cognitively vital years later in life.”
Seafood for Thought
Science keeps catching up with what grandmothers have been preaching for ages: fish really is “brain food.”
Following up on research that has shown eating fish to lower the risk for Alzheimer's, another study adds to the growing evidence that a seafood-rich diet helps keep the mind sharp. People 65 and older who ate fish at least once a week fared better on tests of memory and thinking over six years than peers who didn't eat it, according to the 3,718-participant study published in December's Archives of Neurology.
Eating fish once a week slowed the annual rate of cognitive decline by 10 percent; eating it at least twice a week slowed the decline by 13 percent. Among all the fish eaters, age-related mental decline was delayed by the equivalent of three to four years.
Though previous studies have credit-ed fish that are rich in omega-3 fatty acids with protecting against cognitive decline (as well as preventing heart disease), this one failed to find such a brain link. Researchers speculate that the omega-3 fatty acids in such oily fish as salmon and tuna help keep the mind sharp by providing the main nutrients of cell membranes in the brain.
Diet and Exercise Reduce Weight and Pain in Patients with Prediabetes
In 2002, a large federally funded study was terminated early because it found unequivocal evidence that diet and exercise were more beneficial in preventing diabetes than drug therapy for high-risk patients. That prompted J. Robinson Singleton, M.D., associate professor of neurology at the University of Utah, to offer a program of diet and exercise to his own patients with peripheral neuropathy and glucose impairment.
His resulting study shows that diet and exercise not only slows the progression of peripheral neuropathy in prediabetic patients, but also relieves neuropathic pain.
In his original six-month study of 25 patients, those who lost weight on structured diet and exercise programs were rewarded with an improvement in pain. And those who didn't lose weight reported more pain, according to the study presented at the American Academy of Neurology's 2005 Annual Meeting.
The researchers have updated their ongoing study to include 60 patients on programs designed to lower weight by 5 percent and increase moderate exercise to two and a half hours a week. The latest findings, reported last fall at the American Neurological Association's Annual Meeting, confirm the prediabetes link between that health regimen and relief of neuropathic pain.
This builds on earlier findings that many patients diagnosed with peripheral neuropathy suffer from glucose impairment — that is, blood glucose levels that are higher than normal but not high enough for a diagnosis of diabetes. Most people with glucose impairment, also called prediabetes, have higher risk for the common type of diabetes that generally develops in obese adults. Hence the study's focus on weight reduction to relieve the neuropathic pain that is common in peripheral neuropathy.
“Researchers still don't know why diet and exercise relieves pain,” said Dr. Singleton. “It's possible it simply represents an improvement in the patients' mood, improving depression and making pain better. But regardless of why diet and exercise helps neuropathic pain, it's clear it does.”
SPINAL CORD INJURY
Robotic Treadmill Helps Patients with Partial Paralysis Retrain the Brain
The patient pictured at left, who was paralyzed in an accident, is shown training on a robotic treadmill designed for brain rehabilitation therapy at the University of Texas Southwestern Medical Center in Dallas.
Researchers there have found that people who suffered partial paralysis from spinal cord injury show increased activity in the part of the brain responsible for muscle movement and motor learning after 12 weeks of training on the robotic treadmill. They call their study the first to show that locomotor training can promote activation in the parts of the brain involved in walking for patients with spinal cord injuries.
On the treadmill, robotic devices control the patient's limb movements while a harness supports his weight. During training, he watches his progress on a real-time computer monitor. By providing sensory information to the spinal cord and brain, the device signals the body to step again.
Two of the four patients using the robotic treadmill dramatically improved their ability to walk with canes, according to the study published in December's issue of the journal Neurorehabilitation and Neural Repair. And, not coincidentally, these were the two patients whose brain scans showed the most substantial activation in the cerebellum, the part of the brain that coordinates movement.
Dick Clark's Welcome-Back Party
One year after a stroke kept Dick Clark from hosting his own annual New Year's Eve TV show, his return to ring in 2006 overshadowed even the dropping of the Times Square crystal ball itself.
“I had to teach myself how to walk and talk all over again,” he told the ABC audience, his speech somewhat slurred. “It was a long, hard fight. My speech is not perfect, but I'm getting there.”
In his first appearance since his December 2004 stroke, the 76-year-old legend called his 33rd New Year's telecast “just the happiest time in all of my life.”