Olestra: The new fat substitute. Is it harmful? Does it cause diarrhea? Does it cause cancer? What about fat soluble vitamins and carotenoids? Which foods will it be found in? Will there be a chance that I could eat Olestra and not know it, say in a fast-food restaurant?
These and other questions fueled a lively discussion among the pharmacy students in the biotechnology course that I teach at the Kansas University School of Pharmacy. Since these students will become a major part of your health care community very soon, it was important to interrupt the scheduled class discussion of recombinant DNA to clear up some of the myths about Olestra.
As a member of the FDA's Advisory Panel to the Center for Food Safety and Applied Nutrition, I took part in the government hearings on Olestra and was part of the panel that recommended approval. After reading many pages of text, listening to four days of testimony and questioning the FDA scientists, and scientists from Procter & Gamble, here is what I learned, including the good and the not so good.
As the result of the FDA ruling, Olestra can only be used in what are called "savory snacks." This means only snacks without a sweet taste like potato chips, corn chips, some crackers and other items in this group. Olestra will not be used in cookies, cakes, candy or other sweet desserts, and Olestra will not be used to cook your french fries in the local Burger Doodle restaurant.
How much fat is in Olestra? Olestra is made by linking fats to a sugar molecule in a manner that does not occur in nature. As a result, Olestra is not absorbed into the bloodstream from the gut and does not appear in the blood or urine after eating. Olestra is not digested by the normal bacteria that grow in our gut and is not broken down in the test tube by enzymes known to digest normal fats and sugars. Because of this, it can taste like fat and feel like fat in your mouth but there is no available fat in the product.
My students applauded when they learned they could eat fat without actually eating fat. Most people who taste it can't tell the difference from items prepared from normal fat. A small percentage of people can detect a difference in the taste and mouth feel.
The most frequently heard incorrect statement is that Olestra causes diarrhea. We listened to testimony about intestinal function and examined data from scientific studies for four days. I learned much more than I ever wanted to know about diarrhea.
The medical definition of diarrhea includes electrolyte loss and water loss from the body. Olestra causes severe cramps in some people, but does not cause diarrhea. The result is actually a loose, unformed stool, but it is not a health hazard as is prolonged clinical diarrhea. In many people, this loose stool may not be desirable, but in certain situations it may actually be beneficial. One panel member proposed that some of her patients who are senior citizens might find Olestra an easy and pleasant way to regularity. In a few people, the cramps can occur at low doses and anyone who wishes to try this product should begin slowly and learn how much the body can tolerate.
Another not so pleasant effect of Olestra is called "anal leakage." In many people, the Olestra seems to sail right through the gut without stopping and a small amount will exit at the appropriate place whether you want it to or not. The result is soiled underwear. Opponents of Olestra suggested that young children could suffer psychological damage from this if they were teased while changing clothes in gym class. We heard testimony from one of the few people who react at small doses. This person was forced to pull to the side of the road for several minutes because the pain made driving impossible. Most people do not experience this unless they consume very high amounts. The best thing is to test your response at home.
Next, the question of fat soluble vitamins. It is true that Olestra will soak up fat soluble vitamins. The FDA has required that Procter & Gamble fortify Olestra-containing products with vitamins A, D, E and K to prevent loss from the body.
Members of the large group of carotenoids are also fat-soluble and one, beta-carotene, is used by the body to make vitamin A. Since vitamin A will be added to Olestra, there was no reason to request addition of beta-carotene.
We heard testimony from experts in the field of carotenoids who were not able to state that there is any essential use for the other carotenoids in the body.
So we had no reason to ask that any carotenoids be added to the products. To its credit, Procter & Gamble testified that as soon as some data appears that any specific carotenoid is necessary, they will add that carotenoid to the products. Some committee members objected very strongly to the possibility that our ability to take up carotenoids might be impaired. There are many more members to the carotenoid family than have been tested, and some panel members felt that not enough is known about these to allow Olestra to be used.
Another drawback to the fat-soluble vitamin question was raised by some nutrition experts on the committee. Teen-agers may be a population that is especially at risk to vitamin deficiency since many do not eat balanced diets and can exist for days on snack foods. Exclusive diet of Olestra-containing products might be difficult to prevent in some of these individuals.
I have seen some reports that Olestra might cause cancer. We examined scientific evidence, and asked very direct questions about the cancer issue. We were told that Olestra cannot enter the cells lining of the gut and cannot enter the bloodstream from the gut. We were told that Olestra does not have any effect on cells growing in the test tube. Cancer is caused by alterations in the genes inside the cells and if the information we received is accurate, there is no way for Olestra to cause cancer.
One of the toxicologists on the panel raised an interesting question. Since Olestra is not digestible and not absorbable, it will pass through the gut and end up in the toilet and eventually in the sewers. His question was about the great amount of non-digestible oil in the water supply.
While he was asking his question, I calculated that if each citizen of Kansas City ate one small bag of Olestra potato chips per week, we could have a two-inch oil slick on the Missouri River within a very short time. I visualized people water skiing very fast, nobody drowning since we would all float and using Styrofoam shoes to walk across the river. While I was visualizing myself getting rich with the Styrofoam shoe concession, we learned it would not happen. It turns out that the Environmental Protection Agency had already been consulted and normal bacteria and fungi in the environment are able to break down Olestra.
In the final analysis, we on the panel were asked to consider all the evidence and testimony and determine whether, based on the evidence presented, there was a "reasonable certainty of no harm" to the citizens of the United States if Olestra were approved as suggested. Based mostly on the carotenoid question, a few of the panelists could not agree with the 'no harm' statement and spoke in favor of disapproval. Most of the panel advised approval for the following reasons:
- After considerable effort, we could find no evidence that Olestra would cause any long-term effects.
- Every question except the one about carotenoids was answered to the satisfaction of the panel, and no evidence was presented that carotenoids are necessary.
- Since all the symptoms stop if you stop eating Olestra, no permanent harm is done to the body.
- The customer will vote at the cash register and the product will fail if the effects are unpleasant enough.
Did any members of the panel try it? The answer is no, we were not given the chance. We assumed that this was because of the possibility that one of us might be in the small group who react strongly at low doses and this was too big a chance for the company to take. Will it try it? Because of my weight and my high cholesterol and triglyceride levels, the answer is a resounding "probably," but in the privacy of my own home, and at very small doses to start with.