It’s baffling why some persons, even nonagenarians, possess minds that are supple and young and why multitudes of others living an extremely long life carry the distressing baggage of pronounced mental decline. As countless people would attain incredible longevity in the decades ahead the answers to such conundrums will take on even more pressing importance.
Searching for answers over the past few years, researchers have learned a good deal about what transpires to the human brain as it grows older, how we might possibly influence those changes and even how we might restore the brain to health after it has been diseased or damaged. One thing we are aware of aging of the brain is that it gets shrunk, from the high of billions (some say trillions) of brain cells in our teens and in the early twenties we lose cells at the rate of at least 1000 feet day. Thus, by the time we attain the age of 80, we have irretrievably lost around 10 percent of the brain’s three-pound weight.
The dwindling in the size of the brain is clearly seen on autopsy or through a brain scan. “People have actually counted and tracked the number of cells lost,” says Stephen N Peroutka, a specialist in Parkinson’s disease and an assistant professor of neurology at Stanford University (USA). What had been discovered is that some parts of the brain lose more cells than others in the substantia nigra, the portion of the brain that controls movements and is involved in Parkinson’s disease.
We commence with six lakh cells, according to Peroutka. By the age of 80, a majority of people are down to only one lakh. In some cases, the numbers dip even lower, and this sometimes happens to younger people – persons in their forties. Such a drastic and alarming falling-off of substantia nigra cells culminate in Parkinson’s with its characteristic disabling symptoms of body rigidity, stooped posture and shuffling gait.
Just about every 80-year-old displays some mild, fleeting Parkinson’s like symptoms, just as most exhibit some of the forgetfulness associated with Alzheimer’s disease. But, for the majority, impairments are hardly a problem. An immense number of people retain enough cells well into their 80s for relatively normal functions. Still, there are millions of diagnosed Alzheimer’s and Parkinson’s patients, and some researchers consider this the tip of the iceberg. Thus it is these two ailments that are most associated with deteriorating brain, and against which the greatest research has been directed.
Fortunately for those unfortunate patients of Parkinson’s, some remarkable breakthroughs both in science and strategy have brought new hope.
The standard medication for these patients, levodopa (L-dopa), lessens some symptoms but does nothing to change the ruthless trajectory of this dreadful ailment. In 1989, however, an in-depth study in the USA confirmed that a new drug, deprenyl, can actually slow the pace of Parkinson’s.
Surgeons in Sweden and Mexico had also pioneered an operation in which the cells are removed from the patient’s adrenal gland and transplanted it into the brain. There they transform into nerve cells and produce dopamine, the chemical that is manufactured in substantia nigra and is depleted because of cell loss in Parkinson’s disease.
The distressing symptoms of Alzheimer’s disease are the familiar loss of memory, especially for recent events, as well as disorientation, confusion and dementia. The smaller brain is observed in autopsy. As we get older memory loss is something we all fear intensely. But a promising drug treatment may prevent the brain changes behind such lapses well before their start. With age the brain’s ability to metabolise its prime energiser, glucose, declines. It dips below 50 per cent of the healthy young adult levels, senile dementia (marked by forgetfulness and confusion) culminates. But as per studies by William Meier-Ruge, professor of pathology at the University Medical School in Switzerland, brain energy reserves can be pumped back to keep one sharp. He found that the drug hydergine increased the uptake of brain glucose by 25 to 30 per cent in old rats. Though clinical studies have yet to be carried out, he believes the drug will accomplish the same for humans.
There are some basic low-tech steps people can take to keep a clear head through a long life. The first is to avoid poisoning the brain. Alcohol is a known and confirmed destroyer of brain cells, the forgetfulness and dementia are principal ravages caused. Other drugs cause their own damages. Cocaine is known to interfere with the vital blood chemical dopamine that’s involved with emotions and involuntary movements. Some researchers firmly believe that protracted use of marijuana will cause brain damage. Ironically, one of the breakthroughs in brain research occurred because of the accidental discovery that a synthetic heroin produced the symptoms of Parkinson’s disease, allowing scientists to reproduce the disease in animals and study its effects.
Promoting brain health
Keeping weight and blood pressure down promotes brain health, too. Hypertension is a major cause of stroke, whose devastation of the brain kills or disables millions of persons annually. In almost all cases, hypertension can be controlled by drugs. Controlling weight helps to control BP as well. In a sense, what you eat goes to your head because a host of dietary-deficiency diseases attack the nervous system. Nerve and muscle degeneration is a sign of beriberi, caused by lack of vitamin B1; memory loss results from pernicious anaemia caused by lack of vitamin B12. Both vitamins are found in liver and other organ meats, B1 in grains and cereals, green vegetables and nuts. There may also be a brain-health reason to eat organic foods. One theory suggests that the case of Parkinson’s may be modern chemicals since the disease was not recorded until after the industrial revolution.
Studies have clearly demonstrated that workouts appear to boost levels of dopamine, a brain chemical whose depletion leads to Parkinson’s.
Warren W Spirduso, professor of kinesiology at the University of Texas, found that exercise increased the levels of dopamine in the brains of rats that worked out.