Jewish World Review Sept. 12, 2001 / 23 Elul, 5761




Genes may hold secret to long life

By Robert A. Wascher, M.D., F.A.C.S.

http://www.jewishworldreview.com -- THIS current issue of the Proceedings of the National Academy of Science reports on a possible genetic basis for longevity in humans. It has long been known that humans living beyond 100 years of age tend to cluster in families, suggesting a genetic basis for longevity in at least some cases. Siblings of centenarians, or those who live to be at least 100, have four times the likelihood of living into their nineties than the general population.

While the underlying genetic mechanisms are far from clear, these modern day Methuselahs appear to retain generally good health beyond the age of 65, often avoiding the usual age-related causes of death such as heart and vascular disease, stroke, cancer, diabetes, and dementia. In studying 308 volunteers from families with centenarian relatives, the researchers found compelling evidence that a region of chromosome 4 may play a role in the longevity of members of such families. The researchers are currently attempting to identify which gene, or genes, may be involved within the suspected region of this chromosome, in an effort to better understand the genetic basis of human longevity.

To further evaluate their findings, the study's authors are continuing to add new participants who have centenarian family members, or who are centenarians themselves. Interested volunteers can call (866) 548-3100, or log on to the New England Centenarian Study Web site at www.med.harvard.edu/programs/necs.

MEN AND WOMEN: COGNITIVE FUNCTION IN THE ELDERLY
Dutch researchers have recently published the results of a study on the gender-specific patterns of cognitive and memory decline in the elderly (Journal of Neurology, Neurosurgery and Psychiatry). A total of 599 men and women aged 85 and older were studied to assess their cognition ("higher thinking processes") and memory functions. Despite their lower overall level of formal education, the women, as a group, had almost double the cognitive and memory abilities as compared to their elderly male counterparts. The study's conclusion was that older women retain better overall brain function than older men, and that this gender-specific difference is more likely a consequence of biology rather than due to educational differences. One possible explanation is the well-known faster rate of atherosclerosis ("hardening of the arteries") that occurs in men compared with women.

PHYSICAL ACTIVITY, OBESITY AND THE RISK OF PANCREATIC CANCER
It appears that cancer of the pancreas may join a growing list of diseases linked to obesity and sedentary lifestyle, including diabetes, high blood pressure, stroke and cardiovascular disease. Previously, cigarette smoking, and possibly chronic diabetes, were the only risk factors identified for this disease.

The pancreas is an organ that lies behind the stomach, deep within the abdomen. This glandular organ has multiple functions, including the manufacture and release of insulin into the blood, which enables the body to utilize sugar to fuel cellular function. It also discharges substances called enzymes into the small intestine, aiding in the digestion of the fats and proteins that we eat. Because of its location, buried deep inside the abdomen, there are seldom any symptoms of pancreatic cancer in its early and curable stages.

Although the 26,000 annually reported cases of this disease account for less than 3% of cancer diagnoses in the United States, it is the fourth most common cause of cancer death. Less than 5% of patients with pancreatic cancer will survive five years following diagnosis. Pancreatic cancer can occur at any age, but it more commonly affects those in their fifth and sixth decades of life, and afflicts men more often than women.

A prospective study, reported in this week's Journal of the American Medical Association, observed nearly 170,000 men and women over a 20-year period, and has concluded that tall body height and obesity are each associated with a greater risk of developing pancreatic cancer. Among those who were obese, greater physical activity appeared to somewhat reduce the obesity-related increased risk of developing this cancer. Patients who were not overweight, however, did not appear to be at increased risk of developing pancreatic cancer, even if they lived a sedentary lifestyle.

The association between obesity and sedentary lifestyle, on the one hand, and pancreatic cancer, on the other hand, mirror the risk factors associated with the development of diabetes. These findings strengthen the results of previous studies showing an increased risk of pancreatic cancer in patients with diabetes, and even in patients with pre-diabetic elevations of blood sugar levels. In view of the epidemic of obesity and inactivity in this country, the likely correlation between obesity and activity levels with an increased risk of pancreatic cancer gives further "food for thought" about the way we lives our lives. In addition to smoking, overeating a fat-riddled diet, and excessively relying upon effort-saving (exercise-saving…?) modern technology may prove even more harmful than previously thought.

JWR contributor Dr. Robert A. Wascher is a senior research fellow in molecular & surgical oncology at the John Wayne Cancer Institute in Santa Monica, CA. Comment by clicking here.

Up

09/05/01:English milk cows prefer Beethoven and Simon & Garfunkel over Bananarama; new prostate cancer prevention study: looking for a few good men; exercise & diet can help prevent diabetes
08/28/01: Arthritis drugs may be linked with increased risk of heart disease; errors in blood clotting tests can be fatal; infant soy formula not associated with reproductive side effects

© 2001, Dr. Robert A. Wascher