Alan Tichenal and Joannie Dobbs

Health Options


Wednesday, October 3, 2001

Enzyme hype gives some
people a headache

CLAIMS ABOUND that raw food enzymes are essential for good health. Some proponents go so far as to recommend a totally uncooked diet.

Without a doubt, many studies have shown that eating more fruits and vegetables is a factor in enhancing long-term health.

Of course, fruits and vegetables are great sources of a variety of important nutrients, along with dietary fiber and various other beneficial compounds often called phytochemicals. Also, fresh fruits and vegetables have the added benefit that they contain no added sugars or salt.

But what about the enzymes? The claims for their supposed benefit are based more on belief than science.

This column is based on scientific evidence as much as possible. Not belief. There is little or no evidence that the benefits of raw fruits and vegetables are related to the enzymes in them.

Raw fruits and vegetables contain very small amounts of enzymes. And since enzymes are all proteins, the vast majority will be destroyed by normal stomach acid and the digestive enzymes produced in the stomach and small intestines. Consequently, the enzymes in fresh fruits and vegetables have no measurable effect on the digestion of food and it is highly unlikely that any significant amount of the intact enzymes are absorbed into the body.

These facts have not prevented people from making all kinds of wild and magical claims about the supposed benefits of food enzymes. Many enzymes have found their way into dietary supplements. The claims made for their benefits can be humorous to anyone who understands how enzymes really work.

One product uses some real twisted logic, claiming that an enzyme called lipase promotes weight loss. Any graduate of Nutrition 101 knows that lipase is an enzyme that assists in the digestion of fats. Consequently, if the lipase survived the trip through the stomach and carried out its normal function, the body would actually obtain more fat from the diet.

The same product line suggests that another enzyme called amylase also promotes weight loss. Amylase digests starch, so if the amylase in the supplement really worked, a person would obtain more calories from starch.

Another "wacky" enzyme found in some dietary supplements is cellulase. This enzyme, unlike lipase and amylase, is not produced by the human body. It is produced by microorganisms in the rumen of cows and the intestinal tract of termites. As the name of this enzyme hints, cellulase breaks down (digests) cellulose, a major component of dietary fiber.

Termites can eat wood because cellulase breaks down cellulose into the sugar glucose. Thus, if cellulase supplements "worked," a person would convert much of their dietary fiber into sugar. Obviously, this would result in a diet lower in fiber and higher in sugar. Few Americans need that.

Despite all the scams, some enzyme products really do what they claim. For example, the products Lactaid and Beano are both legitimate enzyme products. Lactaid is a concentrated source of the enzyme lactase, which helps with the digestion of milk sugar, beneficial to those with lactose intolerance. Beano contains enzymes that help to reduce the gassiness of beans by digesting some of the carbohydrates known to produce gas. These products work because some of the enzymes survives digestion long enough to have the intended effect.

Many enzyme products are based on very confused rationale and the minor amounts of enzymes in raw food are unlikely to affect body function.

Save your money!

Health Events

Joannie Dobbs, Ph.D., C.N.S., is a food and nutrition consultant
and owner of Exploring New Concepts, a nutritional consulting firm.
She is also responsible for the nutritional analyses
indicated by an asterisk in this section.

Alan Titchenal, Ph.D., C.N.S., is a sports nutritionist in the
Department of Human Nutrition, Food and Animal Science,
University of Hawaii-Manoa.

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