Genetic research has been called a mixed blessing, but these days there is nothing mixed about it. The announcement of the long and comprehensive studies of the prevalence of the BRCA1 and BRCA2 genes in Ashkenazi Jewish women has produced some important information for all of us. (You can find the article in the Washington Post [ed: Remember that the Post is only free for two weeks, so if you are checking after 8 November, there may be a fee to see the entire article]. Science Magazine, a fee-based web site and print publication, carried the original article.)

The short version is this: women who have inherited mutated versions of these genes are at a high risk of getting breast cancer and/or ovarian cancer. About one in forty Ashkenazi Jewish women carry this gene, and stand a better than fifty-fifty chance of developing breast cancer by age 60. The lifetime risk for ovarian cancer is 54%, compared with 2% of the general population. These statistics are independent of family history.

While the news is alarming, it is not dismal. Testing is available to identify the mutated genes, and preventative actions can dramatically reduce the incidence of these cancers. That brings me to the new mitzvah.

Piku’ach nefesh, preserving life, is certainly one of the most well known of our commandments. This new mitzvah is in a subset of piku’ach nefesh: active prevention of avoidable illness. Every person of Ashkenazi background must be tested for the presence of BRCA1 and BRCA2. Women and girls must do so for their own health. Men and boys, unaffected by the gene, can nonetheless pass it along to their offspring. Once the test results are known, you should follow the recommendations of your physician.

The study revealed that the emergence of the cancers can be forestalled by two kinds of preventative actions when a woman is in her teens and twenties. The first is regular exercise and a healthy diet, with special attention to avoiding obesity. Though the link between them and prevention is unclear, it seems nonetheless effective. If you have a loved one – including yourself – in those age groups, it is a mitzvah to insist on those healthy choices.

The second preventative action will certainly be more controversial. Pregnancy earlier in life seems to have a positive effect on these conditions as well. It has become the standard among Jews to postpone marriage and childbearing into the late twenties and thirties. While no one should rush into marriage for its own sake, young women (and men) should be encouraged to place family life as a priority earlier rather than later.

This column is a summary of a summary. You should read more and ask your health care professionals for more information as well. But we all know too many people who have struggled with these cancers. Many of them have overcome its aggressiveness, but not without a price. Some of them – too many – have lost the battle they didn’t even know they had to fight. Choose life for yourselves and for our daughters. Get tested. Get healthy.