Q. I prefer to eat my vegetables cooked instead of raw. Should I take enzyme supplements to prevent enzyme deficiencies?

A. Enzymes are the body's chemical enablers. They help spark chemical reactions in our body cells, allowing our bodies to perform everyday functions. They're involved in such things as digesting food, fighting infections, breathing and movement.

Luckily, in most cases, nature has equipped our bodies to make all the enzymes we need. We don't need to get them from a bottle.

While it is true that enzyme-deficiency diseases exist, they're uncommon. Some supplement marketers claim we are all deficient in enzymes needed for health.

Let's look at the facts.

Some alternative health practitioners believe our diets are deficient in enzymes because we eat cooked and processed foods. They advise eating raw fruits and vegetables to get "active enzymes." This idea is ludicrous.

Although fruits and vegetables offer many health benefits, this is not usually related to the enzymes in them. Fruits and vegetables contain only a small amount of enzymes. This is because enzymes are proteins, and fruits and vegetables don't have much protein.

Secondly, enzymes in foods are not "active." It doesn't matter whether or not they are cooked. Upon entering the stomach, food enzymes are broken down and digested. These food enzymes never reach the cells inside the body. This means they don't influence body functions.

This doesn't mean you need enzyme supplements. Supplements suffer the same fate as enzymes in foods. They're digested before they ever reach their target organs.

The exception to the "enzymes are digested" rule is digestive enzymes that work in the stomach and intestines before being broken down. For example, a supplement of the enzyme lactase can benefit those with lactose intolerance when consumed with dairy products.

Two conditions where the body is unable to secrete enough digestive enzymes on its own are cystic fibrosis and pancreatitis. In these instances a physician will prescribe the appropriate enzymes at pharmaceutical doses. Pharmaceutical-grade enzymes are more powerful than over-the-counter products. They're also specially coated to withstand the high acidity of the stomach and dissolve in the small intestine where they aid in digestion.

In healthy individuals, enzyme supplements such as proteases, lipases, amylases, bromelin and papain will not improve digestion. Claims that enzyme supplements will eliminate toxins, boost immunity, ease the pain of rheumatoid arthritis, prevent aging and help fight cancer are untrue. Don't waste your money on enzyme supplements.

Amy Tousman is a registered dietitian and certified diabetes educator. Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; islandlife@honoluluadvertiser.com; or fax 535-8170. This column is not intended to provide medical advice.