Longevity

Researchers from the MacArthur Foundation found that identical twins don’t age at the same rate, nor do they die at the same age. The MacArthur team estimated that genes account for less than one-third of the way we age; the rest is lifestyle—except for centenarians. Their extreme longevity does seem to run in families.

Americans born in 1900 were expected to live just 47 years, while today’s babies have a life expectancy nearing 80. The improvement is due to many factors, including better nutrition and prenatal care, more powerful medications, and medical advances in the early detection and treatment of disorders such as cancer, HIV/AIDS and heart disease. Some experts believe the trend will continue. They predict that by midcentury in some developed nations, life expectancy at birth will reach 100.

Turmeric, a chief ingredient in Indian curries, may help prevent or treat a number of diseases, including cancer and arthritis. For 4,000 years, this herb played a role in Indian and Chinese medicine. Now American scientists are studying its active ingredient, curcumin. They report that curcumin is an antioxidant and can reduce inflammation. When it was given to rats specially bred to develop rheumatoid arthritis, many of them remained arthritis-free, and it reduced joint swelling for those that already had the disease. In a study using mice, curcumin helped prevent breast cancer from spreading. In addition, it may offer some protection from other types of cancer and from Alzheimer’s. Scientists have moved on to the next stage and are beginning to test curcumin as a medication for humans. Meanwhile, if you eat lots of curries, will they keep you healthy? It’s possible, but no one knows for sure yet. Stay tuned.

Women still outlive men in almost every country. An American male’s life expectancy at birth is about 75, while females are expected to survive to around 80. Why do women live longer? Some scientists speculate that men may take more risks than women, especially while they’re young. They’re more likely to work in hazardous jobs, to smoke and drink too much and are more inclined to neglect their health. The difference between male and female life expectancies has begun to narrow in recent years, probably because more women now take the risk of smoking and more men currently take better care of themselves.

Investigators for the New England Centenarian Study (NECS) invited 246 children of centenarians to participate in their research. Exceptional longevity appears to be partly hereditary, so the offspring of centenarians likely will live to 100 themselves. The scientists found that these future centenarians were more extraverted and less neurotic than the average person. NECS director Thomas Perls, MD, MPH, suggests that centenarians may be able to handle stress well because they’re less often plagued by negative emotions. And as extraverts, they’re probably good at making friends and looking after themselves—qualities that can contribute to healthy aging.

Scientific studies have repeatedly failed to prove that antioxidant supplements, such as vitamin C or E, can decelerate aging or lengthen life. All the same, there’s good evidence that a balanced diet that includes antioxidants in the form of fruits, vegetables and whole grains can help slow, if not prevent, the onset of some chronic diseases that occur more frequently with age, such as diabetes, heart disease and cancer.

People who move around a lot—whether they play tennis, do housework or just plain fidget—tend to live longer than those who aren’t as active, according to a study done by exercise physiologist Todd M. Manini, PhD, of the National Institute on Aging. Manini recruited 302 healthy adults between 70 and 82 years of age and recorded how much energy each spent per day. Over the next six years, those who had been the least active were much more likely to die. It didn’t seem to matter whether the more active people worked out or did household chores. It was the amount of energy they spent that counted. Manini’s study suggests that almost anything that gets you moving is good for you—and that includes just twiddling your thumbs.

Longevity increased evenly nationwide until the early 1980s, but this has since changed, especially for women. A county-by-county analysis of data on all deaths from 1959 through 2001 revealed that life expectancies have decreased in parts of Appalachia, the Mississippi River Valley, the Deep South, Texas and the southern region of the Midwest. The data shows that smoking, obesity and high blood pressure were partly responsible for shortened life spans. The investigators also point out that the areas where life expectancy declined the most were economically depressed.

In 1984, researchers from Stanford University recruited about 500 runners in their 50s, along with a similar group of nonrunners, for a long-term study. Once a year, the researchers checked with their subjects. On average, the runners developed disabilities 16 years later than the nonrunners and were half as likely to die over a period of about two decades. What’s more, the runners were no more prone to arthritis and knee replacements than their nonrunning peers.

In the United States, the average life expectancy at birth is about 78. According to a 2006 United Nations report, 37 other countries and territories have surpassed that, including most of Europe, Costa Rica, Chile and Cuba. The Japanese can expect to live the longest, to 82, and Swaziland ranks last with a life expectancy of less than 40. Afghanistan comes in just shy of 44 years. Why do Americans live shorter lives than citizens of many other countries? Experts believe that health care isn’t as good in the United States; they also blame factors such as lifestyle and diet.