Secrets of Longevity

Monday, June 06, 2005
RELATED TAGS: WOMEN’S HEALTH, CANCER

Later moms, longer lives
Waiting to have children may add years to a woman’s life, says Jenni Pettay of the University of Turku in Finland. The evolutionary biologist analyzed 5,000 birth records from four generations of 17th- and 18th-century Finns and found that women who waited the longest before having their first child were statistically more likely to live longer. The delay in childbirth seems to be inherited: Late mothers’ daughters also tended to become late mothers themselves. (Late was defined as after 30.)

Previous research has suggested that women who delay having children live longer. But none of these studies was able to determine if the longevity was due to cultural factors, such as a higher socioeconomic class or better living conditions. Pettay got around those issues by studying women from a homogeneous population who did not have access to contraception or advanced medical care.

Still, Pettay says, it’s culture, not genes, that explains why Westerners delay parenthood: “In modern society there tends to be a low number of offspring per couple, so natural selection isn’t at work. But this study does suggest there may be benefits to later motherhood that evolved to counteract the decrease in total fertility years, such as living longer to provide care to grandchildren.”
Jocelyn Selim

How olive oil helps fight breast cancer
For decades, epidemiologists have collected evidence showing that a Mediterranean diet rich in olive oil offers protection against breast cancer. But they never understood why. Javier Menendez of the Northwestern University School of Medicine recently figured out how it works.

Olive oil is a rich mixture of fatty acids, chiefly oleic acid. When Menendez bathed human breast cancer cells with purified oleic acid, the cells cut production of a cancer-causing gene, HER2, by nearly 50 percent. The fatty acid also increased the effectiveness of Herceptin, a drug made from antibodies that latch onto HER2 proteins and trigger the death of cancer cells.

The HER2 gene is overactive in more than one-fifth of all breast cancers and operates in a host of other tumors that may prove vulnerable to oleic acid. So far, Menendez and his colleagues have discovered the fatty acid cuts the expression of the gene in ovarian, stomach, and colon cancer cell lines. “It will probably turn out to be a universal effect,” he says.

The researchers also found that other dietary fatty acids, like the omega-3 fatty acids in fish, can block HER2. It may mean there is an “ultimate molecular mechanism” by which fatty acids in food prevent cancer. Menendez suspects the compounds help the malevolent cells survive and grow, “but when you are getting fatty acids from the diet, the cancer cells’ fatty-acid factory gets blocked.”

Prevention comes in relatively small doses: Olive-oil researchers and health experts recommended 40 to 50 grams of olive oil a day (four to six tablespoons) to help stave off cancers and reduce the risk of heart disease. “You can get that very easily in a salad,” Menendez says. More of the oil might be necessary to help beat existing breast tumors and other cancers, he says, although just how much is not yet known.
Kathy A. Svitil

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