Which Sweetener Should I Choose?
By: Kenneth Chang
NY Times
Tony Cenicola/The New York Times
White. Pink. Blue. Yellow.
On restaurant tables everywhere, the colors of the sweetener packets instantly identify the contents.
Sugar. Saccharin. Aspartame. Sucralose.
Reaching
for one to pour into a cup of coffee or tea can sometimes feel like
sweetener roulette, with the swirl of confusing, conflicting assertions
about which are safe and which are not.
Alissa Kaplan Michaels, for one, never picks pink. She still associates saccharin with cancer. The Food and Drug Administration sought to ban it in the 1970s, because rats that gorged on the chemical developed bladder cancer.
But Congress imposed a moratorium to delay the ban, and the pink
packets of Sweet’N Low remained on restaurant tables. The F.D.A.
withdrew its ban proposal in 1991, and the warnings were taken off
saccharin in 2000 after research showed that it acts differently in rats
and humans, and no conclusive increase in cancers was observed in
people. Ms. Michaels, a public relations consultant in New York, knows
this.
But, she said, “It’s the cancer in the rats. I can’t get that out of my head.”
Although
many people have nagging worries about artificial sweeteners, they
still use mountains of them — globally, artificial sweeteners are a
$1.5-billion-a-year market — to avoid sugar and calories.
The
scientific world is also a dichotomy of conclusions. For any of the
sweeteners, one can as easily find a study that offers reassuring
analysis of safety as one that enumerates potential alarming effects.
And it is possible that there could be long-term effects in humans that
will become evident only after people have been consuming these
sweeteners for decades.
Thus hearsay, mythology and whim guide the choices of many people.
For Ms. Michaels, childhood impressions trump absolution from the F.D.A.
She
even carries in her purse packets of her sweetener of choice —
sucralose, sold as Splenda — for those occasions when a restaurant has
run out of it and she might otherwise confront a choice between pink and
blue. “I’m a yellow girl,” she said.
Hundreds of millions of
people swallow food and drinks containing artificial sweeteners, and so
far, no widespread calamities of health have swept over them.
The
F.D.A. places the three main artificial sweeteners available today in
the same category: “generally recognized as safe.” The manufacturers
cite multitudes of health studies to back up that assertion.
“Based on conventional food safety
considerations, the scientific community feels that these have been
very adequately tested for any potential toxicities,” said Dr. Gary M. Williams,
a professor of pathology at New York Medical College who has been
involved in safety reviews of artificial sweeteners, some financed by
the manufacturers. “I drink diet soda. I don’t need the calories. My favorite is Fresca, and actually I don’t know what’s in it.”
Part
of Dr. Williams’s confidence about safety is that the artificial
sweeteners are much more intensely sweet than sugar, so people consume
very little of them. Most of the white stuff in the packets is filler,
not sweetener. Safety tests in animals looked at doses that were
hundreds or thousands of times higher.
But critics — particularly
of aspartame, sold as Equal or NutraSweet — say that health problems
like headaches, neurological disorders and cancers are occurring, but
that regulators are ignoring them.
The Center for Science in the Public Interest, a health advocacy group, slaps an “avoid” label on saccharin and aspartame,
but deems sucralose and neotame — a newer, more intense sweetener that
is chemically similar to aspartame — to be safe. The center also warns
against acesulfame potassium, a less common sweetener that is rarely
found in tabletop packets but is combined with other sweeteners in soda
and baked goods for a more sugarlike taste. Dr. Williams’s favorite
soda, Fresca, for example, is sweetened with acesulfame potassium and
aspartame, as are Halls sugar-free cough drops.
For those who turn
to stevia, a sweetener derived from a plant, the center gives it a
“caution,” because cancer studies were conducted in only one species of
lab animals. (“Just because a substance is natural does not mean that it
is safe,” the center’s Web site warns.)
A Google search instantly
turns up worries that many have about the various sweeteners: Does
NutraSweet cause brain cancer? Is Splenda really in the same chemical
family as DDT? What about the studies that suggest that artificial
sweeteners, despite their dearth of calories, cause weight gain?
Dr. Walter Willett,
chairman of the nutrition department at the Harvard School of Public
Health, says people can make rational decisions, taking into account
risks and uncertainty. “The world is almost never black and white, and
we rarely operate with absolute certainty about anything,” he said.
“What is most important is to avoid risks that are large and clear, like
smoking, obesity and regular consumption of full-strength soda.”
Chemical Concerns
Saccharin,
aspartame, sucralose and acesulfame potassium are all molecules that
sidle up to certain proteins on the surface of the tongues, tickling
neurons that then send a signal that exclaims to the brain: “Sweet!”
The concerns arise over what happens to the artificial sweeteners after they are swallowed.
Consider
aspartame. It is essentially two amino acids and a molecular snippet
known as a methyl ester. Certain people — about 1 in 25,000 in the
United States — have a genetic condition that prevents them from
metabolizing one of the amino acids, phenylalanine, and those people are warned away from aspartame.
Many
foods contain the same two amino acids, in higher quantities. “It’s not
like these are totally foreign, unique substances,” Dr. Willett said.
“It doesn’t absolutely prove they’re harmless, but it makes it less
likely that there’s a huge surprise waiting for us.”
Others look
at the same components of aspartame and see poisons. The two amino
acids, while essential for the human diet, cause problems when present
out of balance, they say.
The third part, the methyl ester, turns
into methanol, which is a poison — though fruit juices have higher
concentrations of methanol. Woodrow C. Monte, emeritus professor of
nutrition at the University of Arizona, ascribes a host of ills, including multiple sclerosis, to low-level methanol poisoning.
The
scientific literature contains findings that can alarm or reassure. A
huge study at a cancer research institute in Italy found that rats given
aspartame had higher rates of leukemia and lymphomas. The National
Cancer Institute in Maryland, however, reviewed health data from a half a
million retirees and found no correlation between beverages with
aspartame and these cancers.
Meanwhile, sucralose, as the Splenda
manufacturer, McNeil Nutritionals, notes in its advertising, starts out
as sugar. Chemical reactions excise bits of the sugar molecules and
replace them with chlorine atoms. The chlorine effectively camouflages
the molecules, and most pass through the body undigested. Hence, zero
calories. But some wonder if the chlorine in the sucralose molecules
that are absorbed by the body might cause a problem. Michael F.
Jacobson, the executive director of the Center for Science in the Public
Interest, said the animal testing of sucralose was sufficient for a
“safe” rating.
The durability of sucralose molecules gives rise to
a different concern. Measurable levels of sucralose have been found in
the water supply, raising questions about what happens to various
animals when they consume it.
Weighing the Risks
With the questions about artificial sweeteners, some may even wonder: How bad is sugar, anyway?
White
sugar offers the purest taste of sweetness. It is natural. But its
deleterious health effects are the best established: It can make you
fatter.
Research published last year that analyzed health data on more than 100,000 nurses
in the United States over nearly a quarter-century found a strong
correlation between weight gain and consumption of sugar-sweetened
beverages and desserts. There was no weight gain for those who drank
beverages with artificial sweeteners.
Obesity leads to numerous health problems — diabetes,
heart disease, even cancer. Sugary drinks like soda (fruit juices, too)
particularly contribute to weight gain. Usually, if the diet changes,
hunger signals adjust to ensure proper nutrition. But the human
digestive system seems to overlook liquid calories. Someone who drinks
the 140 calories in a 12-ounce can of Coke will not subconsciously
eliminate 140 calories elsewhere in the diet.
“Liquid calories
seem to be different, and that’s why they’re so problematic,” Dr.
Willett said. “Many foods contribute to weight gain, but it does appear
that sugar-sweetened beverages are the single, by far, most important
problem.” (That reasoning led to Mayor Michael R. Bloomberg’s proposal
to ban the sale of large sugary sodas in New York City while allowing
mega-size diet sodas.)
Dr. Willett said the long-term safety of
the artificial sweeteners remained an open question. “It’s interesting
to keep in mind, if you smoke cigarettes,
the lung cancer risk doesn’t go up for 30 years,” he said. “And that’s a
really powerful carcinogen. A lot of things don’t show up for several
decades.”
He also noted that trans fats,
used since 1900, did not show up on the radar of doctors’ concerns
until the 1990s. “It took us about 90 years to discover it was a big
problem,” Dr. Willett said. “It’s a bit sobering how long that took.”
In
terms of relative risk — the known dangers of sugar and weight gain
versus the uncertainties of artificial sweeteners — “artificially
sweetened beverages are much less bad than the full-sugar beverages,”
Dr. Willett said. Still, diet sodas are less than optimal. “I view them
like a nicotine patch,” he said.
The better solution to protect health: Eat and drink less sweet stuff.
Source: http://well.blogs.nytimes.com/2012/06/11/which-sweetener-should-you-choose/
