Our future genes.

Q: What's so important about genetics?

Spelsberg: Genes control all the physical traits you inherit. They instruct your cells to make proteins that determine everything from the color of your eyes to whether you'll be at risk for--or get--certain diseases.

Today scientists are unlocking the blueprint of genes at their most basic level. The Human Genome Project involves researchers around the world. They hope to identify and interpret (decode) the roughly 100,000 genes that tell the story of human heredity. By locating and adjusting genetic material, they may possibly prevent or alter the course of certain diseases.

Q: What are some potential uses for genetic engineering?

Spelsberg: Scientists hope to insert material to erase or replace "bad" genes, such as those that lead to colon cancer. Or doctors might enhance the capabilities, maybe even the number, of "good" genes. Good genes might strengthen your immune system or keep your blood vessels from clogging.

If you have diabetes, for example, new genetic material might encourage production of insulin. If you have a kidney transplant, genetic material could halt the organ rejection process.

Genetic engineering may make you more receptive to chemotherapy or better able to resist hepatitis or the AIDS virus.

Genetic engineering may enable scientists to correct genetic defects, thereby preventing ailments from being passed on to one's descendants.

Q: How many illnesses may respond to gene therapy?

Spelsberg: Heredity seems to have a leading role in about 4,000 diseases. One example is hemophilia, in which normal blood clotting isn't possible. Originally we thought gene therapy would be most useful in these "classic" genetic diseases.

What's surprising is the genetic tie to conditions that aren't strictly hereditary but that "run" in families--coronary heart disease, colon and breast cancer, Alzheimer's disease, emphysema, multiple sclerosis, and diabetes, even deafness and some forms of male sterility.

In these illnesses genes don't play a cause-and-effect role. But they could make you vulnerable, and then environmental factors could trigger the condition.

For example, you might have a genetic predisposition to lung cancer, but not get the illness unless you smoke.

Now we can fight disease on two fronts. You can follow a healthy lifestyle to avoid environmental triggers. Gene therapy someday may lessen the risk you and your children face of getting a disease, and may play a role in treatment.

Q: How could gene therapy fight cancer?

Spelsberg: Researchers hope to use proteins called growth factors. Some inhibit cell growth. By injecting genes that activate those factors, we could stop cancer cells from growing.

Other factors stimulate the immune system, your body's built-in defense against illness. An injection would give your immune system a boost, greatly enhancing its ability to recognize and attack cancer cells.

Q: If you're injecting genetic products, how is gene therapy different from the vaccines we're all familiar with?

Spelsberg: Since the days of Hippocrates medical research has used a "needle-in-the-haystack" approach. Doctors would make formulations of many plants or, in the modern era, screen perhaps thousands of chemicals, hoping to find a treatment for a given disease. And there's always been the risk that helpful drugs may cause unwanted side effects.

Q: Will gene therapy replace conventional medicine?

Spelsberg: No. Doctors will find ways to combine gene therapy with conventional medicine, depending on an illness and its symptoms.

There are practical limits to gene therapy as we understand it now. For example, it can introduce only natural substances to the body. It can't deliver aspirin or other synthetic chemicals.

And most cells have short life spans--weeks or even days, in some cases. When genetically altered cells die, the helpful alterations are lost too.

Researchers hope to find a long-living "stem cell" that renews many different cells in a given tissue. Altering the "parent" cell could have permanent beneficial effects.

Q: How can genetics help with family planning?

Spelsberg: By providing more accurate counseling. Just a few years ago we could only offer odds that you or your children would develop a certain problem. Now there are tests to confirm a predisposition to Huntington's disease, Tay-Sachs disease, sickle-cell anemia, Down's syndrome, and Duchenne's muscular dystrophy.

But remember that having a genetic defect doesn't guarantee you'll develop a problem.

These tests could help you decide whether to conceive children.

Someday it may be possible to eliminate genetic problems in an unborn child, before an illness emerges and is passed to future family members.

Q: What about ethical concerns?

Spelsberg: Everyone, doctors and the public alike, must come to terms with gene therapy. We have to do so on the basis of incomplete, evolving data.

Researchers can publish facts, but society must decide how to use the information.

Gene therapy has practical concerns. Say you apply for a job, and tests show you carry a gene leading to kidney disease. You might not get the job--or you could be denied insurance.

In this century we've already seen a terrible misuse of science--Adolf Hitler's attempt to breed a "master race."

Now we must ask who decides if a condition is "defective" and how best to respond.

There are no easy answers.

I think the best approach is an informed, lively debate involving people from many points of view--the family; leaders of religion, ethics, and business; government officials; scientists and doctors.

Together we can decide which results we want from this remarkable technology.

In my opinion our Creator gave us this knowledge. And we are expected to use it wisely.

Got a Minute for Your Health?

Nuts for Your Heart

Take your hand out of the cookie jar and grab a few nuts, and you'll be doing your heart a favor.

We've known that nuts are a fine source of unsaturated fats, linolenic acid, dietary fiber, and vitamin E, as well as magnesium, which can help prevent heart arrhythmias.

But we had no idea how important nuts could be for healthy hearts until Dr. Gary Fraser, a cardiologist at Loma Linda University, reported his findings in the July 1993 Archives of Internal Medicine. From a study that included 27,000 participants, he found that people who ate nuts--almonds, walnuts, and peanuts--more than five times a week had a 50 percent lower risk of heart attacks than people who rarely ate nuts.

So treat your heart to a few nuts. But remember, just because a few is good, it doesn't mean a lot is better! Nuts are a high-fat food, and should be substituted for some other fat in the diet, not just added.