Sugar Substitutes:
Americans Opt for Sweetness and
Lite
U.S.
Food and Drug Administration
November - December 1999
by John Henkel
"Sugar in the
morning, sugar in the evening, sugar at suppertime ..."
The lyrics of that old
song go a long way toward describing the cravings of many Americans. A bowl of
sugary breakfast cereal may be followed by a mid-morning donut, a lunch time
soda, ice cream at supper, and, in between, snacks of pudding, pie or pastry.
Not to mention all the goodies that are part of Valentine's Day, Halloween, and
the year-end holiday season. It all adds up to one massive national sweet
tooth.
So much so that the
average American eats the equivalent of 20 teaspoons of sugar a day, according
to figures from the most recent federal Continuing Survey of Food Intakes by
Individuals (1994-1996). Nearly 60 percent of this intake, says the trade group
The Sugar Association, is from corn sweeteners, used heavily in sodas and other
sweetened drinks. Another 40 percent is from sucrose (table sugar), and a small
amount comes from other sweeteners, such as honey and molasses.
There's nothing unusual
about craving sweets, experts say. Humans naturally have an appetite for sugary
things. But in excess, sugary foods can take a toll. Large quantities add up to
surplus calories, which can contribute to weight gain. In order to lose weight,
the total calories from foods, especially those with lots of calories from
sugars as well as fats, must be decreased and physical activity increased. As a
result, many consumers seeking to control their weight have turned to
sugar substitutes as one way to help lower the daily calorie
count without having to give up their favorite foods.
"Anything that can help
people cut back on [excess] calories is good," says Adam Drewnowski, Ph.D.,
director of nutritional science at the University of Washington. He emphasizes
that weight loss is complex and can't be attributed to any one food product.
But existing studies, some of which he has conducted, show that sugar
substitutes can help certain people maintain a weight loss. Because
sugar substitutes, also called artificial sweeteners, are many
times sweeter than sugar, it takes much less of them to create the same
sweetness. The resulting calorie count of the amount used is
negligible.
According to a 1998
survey by the Calorie Control Council, 144 million American adults regularly
consume low-calorie, sugar-free products such as artificially sweetened sodas
and desserts. The Food and Drug Administration has approved four sugar
substitutes --saccharin, aspartame, acesulfame-K, and sucralose--for
use in a variety of foods. At least three other sweeteners are under FDA review
but had not been approved at press time.
Two approved
sugar substitutes, saccharin and aspartame, have been the
subject of ongoing controversy that, in the case of saccharin, dates back more
than 20 years. Questions still linger about whether saccharin may cause cancer
in humans, and though the sweetener is still widely used, it carries a label
that warns of its potential risks.
Aspartame has come
under fire in recent years from individuals who have used the Internet in an
attempt to link the sweetener to brain tumors and other serious disorders. But
FDA stands behind its original approval of aspartame, and subsequent
evaluations have shown that the product is safe. A tiny segment of the
population is sensitive to one of the sweetener's byproducts and should
restrict intake. However, the agency continually monitors safety information on
food ingredients such as aspartame and may take action to protect public health
if it receives credible scientific evidence indicating a safety
problem.
Other organizations
give aspartame and the other approved sugar substitutes a
thumbs up. For example, the American Heart Association endorses their use by
diabetics and those on weight-loss diets. The American Diabetes Association
calls sugar substitutes "free foods" because they make food
taste sweet, but they have essentially no calories and do not raise blood sugar
levels.
More Than a
Century of Use
The granddaddy of all
sugar substitutes is saccharin. Discovered in 1879, it was
used during both world wars to sweeten foods, helping to compensate for sugar
shortages and rationing. It is 300 times sweeter than sugar.
An early attempt to ban
saccharin came in 1911 when a board of federal scientists called the artificial
sweetener "an adulterant" that should not be used in foods. This same board
later decided to limit saccharin just to products "intended for invalids," a
restriction that was lifted after World War I began.
In 1958, Congress
passed the Food Additives Amendment to the Food, Drug, and Cosmetic Act, which
required premarket approval from FDA for food additives developed after 1958.
This requirement did not apply to ingredients "generally recognized as safe,"
or GRAS. Saccharin was considered GRAS, so it remained on the
market.
FDA began reviewing
hundreds of GRAS substances--including saccharin--in the early 1970s to ensure
that the latest scientific information continued to back up their safety.
Studies in 1972 and 1973 of rats fed saccharin raised concerns about the
sweetener's role in causing bladder cancer, but data analysis later suggested
that impurities, not saccharin, may have caused the tumors.
Then in 1977, a
Canadian study that looked specifically at the role of impurities--and of other
suspected tumor causes, such as parasites in test animals--showed convincingly
that saccharin itself was causing bladder cancer in rats. That same year, FDA
proposed to ban saccharin for all uses except as an over-the-counter drug in
the form of a tabletop sweetener. At the time, saccharin was the only available
alternative to sugar.
The FDA proposal
prompted a public outcry, fueled in part by media reports that the test rats
were fed the equivalent of as many as 800 diet sodas a day. Congress responded
by passing the Saccharin Study and Labeling Act, which placed a two-year
moratorium on any ban of the sweetener while additional safety studies were
conducted. The law also required that any foods containing saccharin must carry
a label that reads "Use of this product may be hazardous to your health. This
product contains saccharin which has been determined to cause cancer in
laboratory animals." Congress has extended the moratorium several times, most
recently renewing it until 2002.
Saccharin has remained
on the market and continues to have a fairly large appeal as a tabletop
sweetener, particularly in restaurants, where it is available in single-serving
packets under trade names such as Sweet 'n Low. Because it has a good shelf
life, saccharin is used widely in fountain sodas, and its stability at high
temperatures makes it an option for sweetening baked goods, unlike aspartame,
which degrades when heated. Saccharin also is favored economically because it
can be made inexpensively.
But given saccharin's
continuing tentative status, should consumers use it? "We know for certain that
it causes cancer in animals," says Andrew Laumbach, Ph.D., consumer safety
officer in FDA's Office of Premarket Approval. He acknowledges, however, that
animal studies do not always predict the behavior of a substance in the human
body.
The National Cancer
Institute states in its "Cancer Facts" documents that "epidemiological studies
do not provide clear evidence" of a link to human cancer. Regina Ziegler,
Ph.D., an NCI epidemiologist, says, "Typical intakes of saccharin at normal
levels for adults show no evidence of a public health problem."
The government's
National Toxicology Program has kept saccharin on its roster of "anticipated
carcinogens," though it periodically considers "de-listing" the sweetener based
on available safety evidence.
In the late 1970s FDA
and NCI conducted a population-based study of saccharin's role in causing
bladder cancer in humans and found that "in general," people who used the
sweetener had no greater risk of bladder cancer than the population at large.
However, the study found "suggestive evidence" that heavy saccharin
users--defined as those using six or more servings of the sweetener a day--may
have an increased risk. Laumbach says that for consumers who use saccharin, the
key to a lower risk may be moderation, as is the case with many foods that can
cause problems when eaten in excess. Other health groups, including the
American Medical Association, the American Cancer Society, and the American
Dietetic Association, agree that saccharin use is acceptable.
The Aspartame
Controversy
While questions about
saccharin may persist, the safety of another artificial sweetener, aspartame,
is clear cut, say FDA officials. FDA calls aspartame, sold under trade names
such as NutraSweet and Equal, one of the most thoroughly tested and studied
food additives the agency has ever approved. The agency says the more than 100
toxicological and clinical studies it has reviewed confirm that aspartame is
safe for the general population.
This message would not
necessarily be apparent to consumers surfing the Internet, especially those who
use Web-based search engines to find information about sugar
substitutes or artificial sweeteners. Websites with screaming
headlines and well-written text attempt to link aspartame consumption to
systemic lupus, multiple sclerosis, vision problems, headaches, fatigue, and
even Alzheimer's disease. One report distributed nationally over e-mail systems
claims that aspartame-sweetened soft drinks delivered to military personnel
during the Persian Gulf War may have prompted Gulf War syndrome.
No way, says FDA, along
with many other health organizations such as the American Medical Association.
David Hattan, Ph.D., acting director of FDA's division of health effects
evaluation, says there is no "credible evidence," to support, for example, a
link between aspartame and multiple sclerosis or systemic lupus. Some Internet
reports claim that patients suffering from both conditions went into remission
after discontinuing aspartame use. "Both of these disorders are subject to
spontaneous remissions and exacerbation," says Hattan. "So it is entirely
possible that when patients stopped using aspartame they might also
coincidentally have had remission of their symptoms."
It is true, says
Hattan, that aspartame ingestion results in the production of methanol,
formaldehyde and formate--substances that could be considered toxic at high
doses. But the levels formed are modest, and substances such as methanol are
found in higher amounts in common food products such as citrus juices and
tomatoes.
Other circulating
reports claim that two amino acids in aspartame--phenylalanine and aspartic
acid--can cause neurotoxic effects such as brain damage. "This is true in
certain individuals and in high enough doses," says Hattan. He explains that a
very small group of people who have the rare hereditary disease
phenylketonuria, estimated at 1 in 16,000 people, are sensitive to
phenylalanine. These "phenylketonurics" have to watch their intake of
phenylalanine from other sources as well. People with advanced liver disease
and pregnant women with high levels of phenylalanine in the blood also may have
trouble metabolizing the substance. FDA requires all products containing
aspartame to be labeled for phenylalanine so consumers will be aware of the
substance's presence and can avoid or restrict it.
Aspartic acid also has
the potential to cause brain damage at very high doses. But under normal intake
levels, the brain's mechanism for controlling aspartic acid levels ensures no
adverse effects. It is unlikely that any consumer would eat or drink enough
aspartame to cause brain damage: FDA figures show that most aspartame users
only consume about 4 to 7 percent of the acceptable daily intake the agency has
set for the sweetener.
Still other reports
attempt to link aspartame to seizures and birth defects. Regarding seizures,
Hattan cites animal and human studies showing that the sweetener neither causes
nor enhances the susceptibility of seizures. Aspartame also has been evaluated
for its potential to cause reproductive effects or birth defects. Again,
researchers found no evidence, even in test animals fed the sweetener at doses
much higher than those to which humans would be exposed.
Approved in 1981,
aspartame is 180 times sweeter than sugar. It is used in products such as
beverages, breakfast cereals, desserts, and chewing gum, and also as a tabletop
sweetener. In 1996, a study raised the issue that aspartame consumption may be
related to an increase in brain tumors following FDA's approval of the
sweetener in 1981. But analysis of the National Cancer Institute's database on
cancer incidence showed that cases of brain cancers began increasing in
1973--well before aspartame was approved--and continued to increase through
1985. In recent years, brain tumor frequency has actually decreased slightly.
NCI currently is studying aspartame and other dietary factors as part of a
larger study of adult brain cancer.
Other Sweetener
Choices
FDA also has approved
two other artificial sweeteners, acesulfame potassium and sucralose, both of
which are available in products such as fruit drinks and gelatin
desserts.
Acesulfame Potassium:
First approved in 1988 as a tabletop sweetener, acesulfame potassium, also
called Sunett, is now approved for products such as baked goods, frozen
desserts, candies, and, most recently, beverages. More than 90 studies verify
the sweetener's safety.
About 200 times sweeter
than sugar and calorie free, acesulfame potassium often is combined with other
sweeteners. One major beverage maker mixes acesulfame potassium with aspartame
to sweeten one of its diet sodas. Worldwide, the sweetener is used in more than
4,000 products, according to its manufacturer, Nutrinova. Acesulfame potassium
has excellent shelf life and does not break down when cooked or
baked.
Sucralose: Also known
by its trade name, Splenda, sucralose is 600 times sweeter than sugar. After
reviewing more than 110 animal and human safety studies conducted over 20
years, FDA approved it in 1998 as a tabletop sweetener and for use in products
such as baked goods, nonalcoholic beverages, chewing gum, frozen dairy
desserts, fruit juices, and gelatins. Earlier this year, FDA amended its
regulation to allow sucralose as a general-purpose sweetener for all
foods.
Sucralose tastes like
sugar because it is made from table sugar. But it cannot be digested, so it
adds no calories to food. Because sucralose is so much sweeter than sugar, it
is bulked up with maltodextrin, a starchy powder, so it will measure more like
sugar. It has good shelf life and doesn't degrade when exposed to heat.
Numerous studies have shown that sucralose does not affect blood glucose
levels, making it an option for diabetics.
Sugar Alcohols: Though
not technically considered artificial sweeteners, sugar alcohols are slightly
lower in calories than sugar and do not promote tooth decay or cause a sudden
increase in blood glucose. They include sorbitol, xylitol, lactitol, mannitol,
and maltitol and are used mainly to sweeten sugar-free candies, cookies, and
chewing gums. FDA classifies some of these sweeteners as "generally recognized
as safe" and others as approved food additives.
Other "natural
sweeteners" are available, but these are variations of table sugar and contain
about the same amount of calories. These products include honey, molasses,
evaporated cane juice, rice syrup, barley malt, and fructose.
Another product,
stevia, is derived from a South American shrub. Though it can impart a sweet
taste to foods, it cannot be sold as a sweetener because FDA considers it an
unapproved food additive. "The safety of stevia has been questioned by
published studies," says Martha Peiperl, a consumer safety officer in FDA's
Office of Premarket Approval. "And no one has ever provided FDA with adequate
evidence that the substance is safe." Under provisions of 1994 legislation,
however, stevia can be sold as a "dietary supplement," though it cannot be
promoted as a sweetener.
Three other sugar
sweeteners are currently under FDA review. One of them, cyclamate, was marketed
in the 1960s, but FDA banned it in 1970 after evidence emerged linking it to
bladder cancer. Subsequent studies have failed to verify that link, so FDA is
considering a petition to reapprove cyclamate. The other sweeteners under
review are neotame and alitame.
Though sugar
substitutes have a long history of controversy, the Calorie Control
Council says Americans are continually searching for good-tasting, low-calorie
products as part of a healthy lifestyle. Market surveys show that
calorie-conscious consumers want more low-calorie foods and beverages. And
though artificially sweetened products are not magic foods that will melt
pounds away, they can be, experts say, a helpful part of an overall weight
control program that includes exercise and other dietary factors.
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