Frequent consumption of potato chips,
tortilla chips or other savory snack foods made with the fat substitute
olestra is associated with a significant reduction in serum cholesterol levels
and dietary fat intake, according to researchers at the Fred Hutchinson Cancer
Research Center in Seattle.
The heaviest consumers of olestra -- those who reported eating one to two
servings of chips per week for a year -- experienced a decrease in total serum
cholesterol of more than 10 percent. These findings appear in
the "Archives of Internal Medicine," a publication of the American Medical
"This drop in serum cholesterol associated with olestra use is comparable
to that achieved with a high-fiber diet or conventional cholesterol-lowering
drugs," says Ruth E. Patterson, Ph.D., R.D., an associate member of the
Hutchinson Center's Public Health Sciences Division and the report's lead
While intriguing, the researchers caution that their results are
preliminary, based on first-year data from several hundred participants in an
ongoing nationwide study to monitor use patterns and nutritional effects of
olestra consumption in the general population. Once the four-year study is
complete next year, some 12,000 Americans will have participated at four
clinical sites around the country.
The researchers also caution that while eating olestra may have a
biological, cholesterol-lowering effect, it also may be an indication of a
healthier lifestyle; people who eat olestra simply may be less likely to eat a
lot of artery-clogging foods.
Despite these caveats, however, Patterson and colleagues think their
findings warrant further study.
"For dietary fat and serum cholesterol, the effect was big enough to
overcome the small sample size in terms of statistical significance,&uqot; she
says. "In addition, the dietary data in this study corresponded to changes in
cholesterol and weight."
The researchers measured diet, weight and serum-cholesterol levels in
335 adults in Indianapolis, the first test market for the fat imposter.
Participants were screened with blood tests and dietary questionnaires before
olestra was released into the market and again a year later, after
olestra-containing foods were widely available.
While heavy olestra intake was associated with lowering LDL, or so-called
"bad," cholesterol, it had no effect on HDL, or "good," cholesterol, Patterson
Mean dietary fat intake also fell among heavy olestra consumers, from
35 percent daily calories from fat at the beginning of the study, before
olestra hit the market, to 32 percent a year later. (Nutrition experts
recommend that consumers get 30 percent or less of their daily calories from
fat.) Among the heaviest consumers of olestra, there also was a significant
decrease in saturated-fat intake. In non-consumers, fat intake overall
increased slightly. The effect on weight was less dramatic. Heavy consumers of
olestra lost about a pound, while weight remained stable among non-consumers.
While statistically significant, these effects cannot be explained
entirely by eating olestra, Patterson cautions, since even the heaviest
consumers ate a relatively small amount of the fat substitute. Instead, the
researchers attribute the decrease in fat intake, weight and serum cholesterol
to a combination of factors, biological and behavioral.
"While there are some plausible biologic reasons for these changes, such
as the possibility that olestra sequesters dietary cholesterol in the gut
before it has a chance to get to the bloodstream, olestra consumption is
probably also an indicator of a healthier lifestyle in general," Patterson
says. "Instead of being a marker for bad behavior, we've found it's a marker
of good behavior; people who eat olestra tend to exercise more, eat better and
be more health-conscious."
This observation is supported by an earlier report by Patterson and
colleagues, based on data from the same study population that found people who
eat olestra-based snacks strongly believe in a connection between diet and
health. For example, olestra consumers are significantly more likely to
believe in the importance of eating a low-fat diet and to think about health
when selecting foods as compared with those who don't eat the fat substitute.
These health beliefs in turn influence behavior such as diet and exercise.
Olestra manufacturer Procter & Gamble Co. commissioned the study, called
the Olestra Post-Marketing Surveillance Study, or OPMSS, to meet FDA
requirements for post-marketing surveillance of the fat substitute, also known
by the brand name Olean.
The overall objective of the study is to find out how many people eat
olestra, how much they consume, and whether blood levels of vitamins and
carotenoids are affected by the amount of olestra eaten.
The assessment of olestra's impact on cholesterol, fat intake and weight,
a spin-off of the larger project, was motivated by Patterson's scientific
"When the FDA mandated surveillance of olestra's nutritional impact, we
saw that as an opportunity to address, from a public-health standpoint,
additional scientific questions, to see what happens when one of these
specially manufactured nonfat products becomes available in the marketplace,"
says Patterson, co-principal investigator of OPMSS. "This is the first study
to specifically examine the effects of new fat-modified foods in the U.S. food
Olestra, a synthetic fat substitute made from sucrose and fatty acids, in
1996 gained federal approval for use in savory snacks, in 1997 was test
marketed at selected sites and in 1998 became available in stores nationwide.
Unlike regular fat, which contains 9 calories per gram, olestra provides
zero calories because it is indigestible; its unique molecular structure
prevents bodily absorption. While many fat-modified foods are calorically
dense, those made with olestra are substantially lower in calories than their
While there's been concern that olestra may interfere with the metabolism
of fat-soluble vitamins and carotenoids, preliminary data have shown no
statistically significant evidence that it affects serum levels of carotenoids
or vitamins A, D and E, regardless of the amount consumed, according to
Mark Thornquist, Ph.D., principal investigator of OPMSS.
"With the data to date, we can rule out large nutritional effects of
olestra, but we will need data from the full study to determine whether
olestra has modest effects," says Thornquist, an associate member of the
Hutchinson Center's Public Health Sciences Division.
"This is early in the game," Patterson echoes. "When the study is over in
2001, we'll be able to draw some firm conclusions."
In the meantime, she urges people who eat olestra to do so sensibly.
"Just because we are seeing some positive things associated with
consumption of olestra-containing savory snacks doesn't make them a
high-quality food," Patterson says. "But there's no question that high
cholesterol and obesity are problems in America. Our preliminary research
suggests olestra can be a useful weight-management tool if it's used in
moderation and is not used as a substitute for fruits, vegetables and other
low-fat, high-fiber, whole foods."