Twin Studies Show that Cancer Has Stronger Link To Environmental Factors than Genetics

Twin Studies Show that Cancer Has Stronger Link
To Environmental Factors than Genetics

Scientists have long debated the role that genes play in human health. With the Human Genome Project recently completed, many people are looking to genetics to cure diseases.

However, a recent study by epidemiologist Paul Lichtenstein at Sweden's Karolinska Institute, suggests that focusing on genetics as a cure for cancer may not be our best course of action.

The study, which examined 44,788 pairs of twins, reveals that the likelihood of developing cancer has far more to do with exposure to pollutants in the environment than genetics.

Dr. Lichtenstein's results reveal that environmental factors are linked to twice as many cancers as genetic factors. In fact, only three types of cancer show a significant genetic correlation.

Even prostate cancer, which carries the strongest genetic link, is only controlled 42% by genetic factors and 58% by environmental factors.

The other types of cancer showing a genetic link, breast and colorectal cancer, have less than a 35% link to genetics in the study.

The study, which was published in the July 13, 2000 edition of the New England Journal of Medicine (Vol. 343, No. 2), confirms what many physicians, scientists and public health advocates have known for years.

For example, past studies have shown that people living in rural Asia have historically had a very low occurrence of breast and colon cancers.

However, upon moving to the U.S., where these types of cancer are very common, their cancer rates increase dramatically.

This knowledge of the environmental link to cancer has left many questioning US policies on cancer prevention.

For more information or a copy of this study, contact Beyond Pesticides/National Coalition Against the Misuse of Pesticides.