The Key to Keeping Your Brain Fit (Even at 90!)... Use Your Brain

By Ellen Kuwana Neuroscience for Kids Staff Writer July 2, 2002 This April, I had the happy occasion to help celebrate my grandmother's 90th birthday. At her birthday reception, 170 friends and relatives showed up to wish her well. Afterwards, my grandmother secretly told me that she was irked that she could not remember one of the guest's name. I thought, "We all should be so lucky to have that kind of memory at her age!" What is her secret for staying mentally sharp? Some data show that mentally challenging activities may protect people from Alzheimer's disease. My grandmother, who still lives independently in her own home, does keep her mind sharp. She completes the crossword paper every morning, does math without a calculator, stays active socially, writes letters often, and never drinks or smokes. (Maybe we should have given her a glass of champagne on her birthday because research suggests that moderate drinking might help protect the brain's blood vessels.) Regardless of the reasons for her good mental health, my 90-year-old grandmother is in good company: all over the globe, as more people are living longer, relatives are faced with the challenge of how to fit more and more candles onto a birthday cake! Not only are more people living longer, many elderly people are living independently, even into their ninth decade of life. Researchers at the University of California at Irvine, led by neurologist Claudia Kawas, studied 334 people in their 90s who lived at a retirement community in California. The researchers wanted to learn more about how the elderly manage in terms of everyday tasks such as running errands. The majority of the study group (67%) was women. About 66% of the people had some college education and most were above average in terms of socioeconomic status. Only 23% of the sample group needed a daily or live-in caregiver. Most lived alone and more than half reported that they drove a car every day. Many (85%) said that they feared falling and hurting themselves, but less than half (40%) had fallen during the last year. How do these people manage to do so well at this late stage in life? One consistent trait among this group was that almost no one smoked. Only 3% smoked regularly. Many (40%) reported having a daily alcoholic drink. Moderate alcohol consumption has been shown to reduce the risk of heart disease and stroke by raising the level of "good cholesterol" called high-density lipoproteins in the blood system. Moreover, a study of 8,000 people over the age of 55 in the Netherlands concluded that moderate consumption of alcohol reduces the risk of dementia by 50%. The key word here for alcohol consumption is moderate. More than moderate alcohol intake is associated with adverse health effects such as increased risk of heart disease, especially in women. Heavy use of alcohol may result in alcoholism and also damage the liver. What is moderate consumption of alcohol? For older people, "moderate" intake is considered to be one serving per day of alcohol for men and one-half to one serving per day for women. Each person's metabolism is different, however, so some people can process alcohol more efficiently than others. Older people's bodies function differently than younger people's. As people age, their metabolism changes. As we age, body mass, represented by muscle and bone, is lost and more body fat is acquired. Levels of an important stomach enzyme, alcohol dehydrogenase decrease, as does blood flow to the liver, the main organ that processes alcohol. All of these factors mean that elderly people cannot handle alcohol like younger people. A drink has a greater effect on an older person because the alcohol is eliminated from the body more slowly than in a younger person. Furthermore, the elderly tend to take more medications than younger people, and alcohol does not interact well with many medications, including but not limited to: acetaminophen, antidepressants, aspirin, sleep aids, and many pain and anti-inflammatory medications. High alcohol intake contributes to brain damage and dementia. Japanese researchers reported that heavy drinkers had more brain shrinkage as they age. In a study of 1,400 people ranging in age from 30 to 60, the researchers found that by the age of 60, about 60% of the people had shrunken frontal lobes. This figure compares to 8% of people showing brain shrinkage by the age of 40. The researchers estimate that about 30% of this brain shrinkage represents normal, age-related changes, but 10% may be due to heavy drinking. Some of the alcohol-induced damage is reversible if people reduce the amount of alcohol they consume. The data suggest that if you want to live to a ripe old age, do not smoke, drink only in moderation, and consider limiting how many calories you eat each day. Studies in spiders, dogs, and rodents all show that consuming two-thirds of your regular caloric intake results in a longer lifespan. Not only do these animals live longer, they do not develop "diseases of aging" such as arthritis and cancer until later in life than usual. Aging is a hot topic among scientists because the fastest-growing segment of the population is the elderly. Diseases such as Alzheimer's will affect more and more people each year. The race is on to understand more about the aging brain and how to combat the effects of time.