|The Problems With Olestra|
Olestra rapidly depletes blood levels of many valuable fat-soluble substances, including carotenoids.
Olestra has an extraordinary avidity for certain fat-soluble substances, far exceeding what one would expect based on the fat substitute's proportion of the diet. Olestra's removal from the body of fat-soluble nutrients is linked directly to the additive's being a non-absorbable lipid-like substance.
In Procter & Gamble's two eight-week clinical studies, the lowest level tested -- 8 gm/day (equivalent to 16 olestra-containing potato chips) — caused dramatic depletion of fat-soluble vitamins within two weeks. Procter & Gamble also measured total serum carotenoids, alpha-carotene, beta-carotene, lutein, and lycopene. Olestra caused significant declines in all carotenoids monitored. Total serum carotenoids declined sharply by the fourteenth day of olestra consumption and was down by 50% to 60% by the end of the studies. A dosage of 32 gm/day of olestra reduced total serum carotenoids by 70% over the eight weeks.
In a recent four-week study conducted in Holland, 3 gm/day (equivalent to just 6 potato chips) of sucrose polyester (the general name for olestra-like chemicals) caused a 20% decline in beta-carotene levels and a 38% decrease in lycopene, another key carotenoid (Am. J. Clin. Nutr. 62:591 (1995)).
Feeding olestra with one or more meals, as was done in the several clinical studies, results in the greatest depletion of carotenoids. While that might seem to be a worst-case scenario, many people would, indeed, consume olestra-containing foods with meals. In fact, Procter & Gamble's petition states that mealtimes constitute the great majority (79%) of the occasions during which consumers eat "savory snacks." Also, since the frequency of consumption of snacks would likely increase if olestra snacks were available, interaction between nourishing foods and olestra at meals would be likely to increase, resulting in lower serum levels of fat-soluble carotenoids and other phytochemicals. There would also be more opportunities for olestra to reduce the absorption of beta-carotene and fat-soluble vitamins that people ingest in dietary supplements and fortified foods.
Olestra's depletion of carotenoids is of great concern, because a growing body of evidence indicates that they may confer important health benefits. The physiological activities of fat-soluble plant nutrients are just now being elucidated. For instance, in a recent case-control study, lutein (along with zeaxanthin) was strongly associated with a lower risk of macular degeneration, the most common cause of blindness in the elderly (J.A.M.A. 272: 1413 (1994)). That observation is buttressed by the fact that lutein and zeaxanthin form the yellow pigment in the macula (the central part of the retina). In three clinical studies, 3 gm/day of sucrose polyester or 8 gm/day of olestra reduced lutein levels by 20% to 40%.
Cancer experts are urging Americans to eat much greater quantities of vegetables and fruits, in part because of their carotenoids and other phytochemicals. Beta-carotene and other carotenoids have reduced cancer incidence in animals exposed to carcinogens. (J. Nutr. 119:123-6 (1989); Am. J. Clin. Nutr. 53(1 Suppl):238#-246S (1991))
In humans, numerous epidemiological studies have linked diets rich in carotenoid-rich fruits and vegetables to lower risks of cancers of the lung, esophagus, pharynx, mouth, stomach, colon, rectum, and bladder. Several studies have found an association between low levels of serum beta-carotene [which could be a marker for other carotenoids) and high rates of stomach and lung cancer. (Am. J. Epidemiol. 135: 115 (1992)]
The Surgeon General's Report on Nutrition and Health, released in 1988 by the Department of Health and Human Services, states:
[E]pidemiological studies provide suggestive evidence that consumption of foods containing carotenoids, including the beta-carotene precursor of vitamin A, protects against development of epithelial cell cancers such as those of the oral cavity, bladder, or lung. These studies have generally shown lower rates of cancer among individuals consuming the highest overall levels of vitamin A, carotenoids, or fruits and vegetables.
The National Research Council stated in its landmark 1989 report, Diet and Health, "[T]here is strong evidence that a low intake of carotenoids, which are present in green and yellow vegetables, contributes to an increased risk of lung cancer." The director of the National Cancer Institute's "5 A Day" program pointed out the plausible biochemical mechanisms for the association between fruits and vegetables and lower cancer risks:
Fruits and vegetables are sources of vitamins and minerals (including vitamins A, C, E, and folate), carotenoids and other antioxidants, fiber, and various phytochemicals. . . . Each of these substances may play a role in reducing risk. More likely, it is a combination of these factors, and others not yet explored, which may confer protections. (J. Heimendinger, program director, The National 5 A Day for Better Health Program, Scientific and Program Design Rationale (Aug. 10, 1994)
In January, 1996, just three weeks before the FDA approved olestra, the federal government (HHS, USDA) published the newest edition of Dietary Guidelines for Americans, the nation's basic nutrition policies. That document urged people to consume carotenoid-rich fruits and vegetables because of their likely role in preventing cancer and other chronic diseases.
While there is not yet conclusive proof that carotenoids reduce cancer risk, to approve a major new additive that would significantly reduce levels of carotenoids (and possibly other fat-soluble phytochemicals) defies logic. It is a remarkable case of governmental ineptitude to have one agency of the Department of Health and Human Services, the National Cancer Institute, encouraging consumers to eat more carotenoid-rich fruits and vegetables, while another agency, the FDA, approves a food additive that depletes the body of potentially beneficial substances in those foods.
Supplementing olestra with selected vitamins will not solve all of olestra's nutrient-depletion problems.
Olestra is highly effective at reducing serum levels of the fat-soluble vitamins A, D, E, and K. Simply supplementing olestra with those vitamins, as Procter & Gamble has proposed, would not completely solve that problem. Consider the 1.5 million patients taking the anticoagulant drug Coumadin (warfarin). Coumadin therapy often employs low doses of the anticoagulant, making the drug's efficacy particularly sensitive to fluctuations in vitamin K levels. Eating snack foods containing olestra and added vitamin K might cause substantial fluctuations in serum vitamin K levels, possibly impairing the efficacy of Coumadin. Furthermore, researchers are now identifying important functions for vitamin K other than those associated with blood clotting, such as bone formation in fetal development and childhood and retention of bone in older women.
No animal or clinical studies have demonstrated that vitamin K-supplemented olestra would be safe for Coumadin users and effective in maintaining physiological functions in addition to blood coagulation.
Doctors will have to warn their patients to avoid olestra (or, more safely, all snack foods of unknown composition).
Olestra causes gastrointestinal disturbances, which are sometimes severe, including diarrhea, fecal urgency, and more frequent and looser bowel movements.
A variety of gastrointestinal symptoms occurred in subjects who consumed on a daily basis the amount of olestra that would be found in less than one ounce of potato chips (about 16 chips), as well as higher doses. For instance:
Gastrointestinal disturbances are not normally life-threatening, but they can be very inconvenient, unpleasant, uncomfortable, and worrisome. Imagine the plight of a school child who must repeatedly request permission to go to the toilet (and consider the teacher's plight, too). Think of the driver of a giant 18-wheeler barreling down the highway at 70 miles per hour when he gets hit with a bout of fecal urgency. Consider a teenager on a first date when he or she is constantly worrying about diarrhea and gas. Or a young woman who has to see a doctor because she worries that her nausea might be caused by a pregnancy, or an elderly person who fears that his diarrhea reflects a serious intestinal problem. Many people will eventually link the olestra snack foods to their gastrointestinal problems, but they may experience much discomfort before they make that link. And as long as olestra snack foods are marketed, new consumers will constantly be experiencing those problems.
Olestra sometimes causes underwear staining associated with "anal leakage."
Olestra sometimes causes underwear staining. That phenomenon may be caused most commonly by greasy, hard-to-wipe-off fecal matter, but occasionally also from anal leakage (leakage of liquid olestra through the anal sphincter).
Procter & Gamble conducted a study that examined the effects of different formulations of olestra. The study used a dose of 34 gm/day, but, unfortunately, it lasted only five days, so it must be considered very preliminary. However, even that study showed that anal leakage occurred at a slightly higher rate in the test groups consuming the types of olestras than in the control group (which, inexplicably, included 2 cases of anal leakage). In addition, anal leakage was reported by one subject in the high-dose group (32 gm/day) of the eight-week dose-response study. Given the small size of the study groups (an average of 20 subjects/group) in the two eight-week studies, this single occurrence adds further evidence that Procter & Gamble has not yet resolved the anal leakage problem in heavy consumers of olestra.
Although underwear staining and anal leakage do not endanger consumers' physical health, those phenomena could cause psychological problems, including feelings of embarrassment and insecurity. Children and teenagers, especially, are likely to be disturbed about having dirty underwear, fearing embarrassment in front of friends and family. Snacking should be a pleasure undiluted with problems like dirty underwear.
Another condition associated with olestra consumption, "oil in toilet," occurred frequently in Procter & Gamble's two eight-week clinical studies. It could be disconcerting and might spur some people to see their doctor.
Data are lacking on the health effects of olestra on potentially vulnerable segments of the population. Key tests were unacceptably brief.
Only poor studies have examined the effect of olestra on gastrointestinal disturbances in children, while no studies at all have focused on gastrointestinal problems and nutrient losses in healthy people over 44 years of age and people with poor nutritional status. For instance, the longest test on children, who would likely be major consumers of olestra-containing snacks, lasted only 7 days and exposed children to an average of only 7 gm/day of olestra, equivalent to two thirds of an ounce of potato chips. People who had poor diets and relatively low levels of carotenoids and who ate olestra regularly might be at special risk.
Furthermore, Procter & Gamble has not conducted human studies to assess the potential long-term health effects of olestra consumption. The results from brief (eight-week) clinical trials suggest possible serious long-term nutrient depletion and gastrointestinal effects for regular consumers of olestra. Eight-week-long studies are inadequate for a product that may be consumed by millions of people at high levels over a lifetime. Long-term tests on various population groups are essential to ascertaining the health effects of olestra. In addition, Procter & Gamble must conduct human studies to demonstrate the effect on serum carotenoid levels of occasional consumption of various amounts of olestra.
Olestra's possible carcinogenicity needs to be better resolved.
Olestra was fed to rats (two studies) and mice (two studies) for two years at levels up to 10% of the animals' diets. Liver foci, which may be precursors of cancer, occurred in both rat studies. In one mouse study there was a statistically significant increase in lung tumors in the two highest-dosage groups; those tumors were not seen in a second study.
The levels of olestra fed to the rats and mice are of the same order of magnitude likely to be consumed by people. Especially since there is little margin of safety between human and animal consumption in these studies, findings of liver lesions in both rat studies and lung tumors in one mouse study are of particular concern. The FDA should appoint a committee of independent cancer experts (who do not consult for industry) to review the animal data and determine whether the liver foci and lung tumors (a) are definitely not a problem, (b) provide clear evidence of risk, or (c) raise questions that must be resolved through further research.
Procter & Gamble's claim that olestra's gastrointestinal effects are similar to those caused by high-fiber diets is not true.
Procter & Gamble has claimed that olestra has gastrointestinal effects that are comparable to those caused by eating larger amounts of dietary fiber. In fact, the gut microflora usually adjust quickly to increased fiber, but do not adjust to olestra. Increasing fiber consumption often results in flatulence and similar effects, but, as the National Research Council has pointed out in Diet and Health, those effects seem to be temporary. Olestra's adverse effects persisted throughout the two eight-week studies and can be eliminated only by ceasing consumption of olestra.
It is not possible to set an Acceptable Daily Intake (ADI) for olestra use in snack foods.
An ADI for food additives is normally set by dividing the highest "no-observed-effect level" (NOEL) by a safety factor. However, Procter & Gamble has not been able to demonstrate a NOEL for olestra. In eight-week clinical studies, important adverse effects, including depletion of fat-soluble carotenoids and vitamins and gastrointestinal disturbances, occurred at 8 gm/day, the lowest olestra consumption level tested. Arguendo, if 8 gm/day were considered the NOEL for olestra, dividing by a minimal safety factor of 10 would yield an ADI of 0.8 gm/day, far below the likely consumption levels for olestra if the pending petition were to be approved. If the 3 gm/day level of sucrose polyester at which other investigators found significant depletion of carotenoids were used as the NOEL, application of the 10-fold safety factor would result in a 0.3 gm/day ADI, even further below the likely daily intake of olestra from savory snacks.
The only NOEL justified to date for olestra is zero and that fact alone should have been sufficient to deny the petition. Of course, one could argue that diarrhea, fecal urgency, and flatulence are merely "unpleasant phenomena" and not "adverse effects," the average consumer would likely concur that those sometimes severe gastrointestinal effects are indeed "adverse effects." Some consumers would undoubtedly associate their adverse effects with consumption of olestra, but many others might not. Furthermore, it is highly inappropriate for the FDA to permit a laxative food additive to be used in foods that would be widely consumed by a large fraction of the population. Likewise, even though the benefits of carotenoids and other non-vitamin phytochemicals are just beginning to be understood, many independent researchers concerned about carotenoids have told the FDA that reduced levels of those dietary substances should be considered an adverse effect.
Any benefits of olestra do not outweigh the risks.
Industry and the public have been excited about olestra because of the possibility that it would help people eat diets lower in fat and saturated fat — and prevent obesity and heart disease. The current petition asks for use of olestra only in potato chips and similar foods. A person who ate an ounce of potato chips only occasionally would receive little calorie-saving from olestra-containing chips. A frequent chip-eater would save more fat, but would also experience a substantial decline in carotenoids and other phytochemicals (along with an increased risk of macular degeneration and possibly cancer and heart disease) and might experience gastrointestinal problems. Poorly nourished people, Coumadin-users, and other subgroups might experience additional problems. On balance, olestra's meager benefits are outweighed by its risks. Of course, people who wanted safe fat-free or lowfat chips can simply choose from the growing variety of such products already on the market.