Information from newsinhealth.nih.gov
Most of us love sweet foods and drinks. But after that short burst of
sweetness, you may worry about how sweets affect your waistline and your
overall health. Is sugar really bad for us? How about artificial or
low-calorie sweeteners? What have scientists learned about the sweet
things that most of us eat and drink every day?
Our bodies need one type of sugar, called glucose, to survive. “Glucose
is the number one food for the brain, and it’s an extremely important
source of fuel throughout the body,” says Dr. Kristina Rother, an NIH
pediatrician and expert on sweeteners. But there’s no need to add
glucose to your diet, because your body can make the glucose it needs by
breaking down food molecules like carbohydrates, proteins, and fats.
Some sugars are found naturally in foods, such as fruits, vegetables,
and milk. “These are healthful additions to your diet,” says Dr. Andrew
Bremer, a pediatrician and NIH expert on sweeteners. “When you eat an
orange, for instance, you’re getting a lot of nutrients and dietary
fiber along with the natural sugars.”
Although sugar itself isn’t bad, says Rother, “sugar has a bad
reputation that’s mostly deserved because we consume too much of it.
It’s now in just about every food we eat.”
Experts agree that Americans eat and drink way too much sugar, and it’s
contributing to the obesity epidemic. Much of the sugar we eat isn’t
found naturally in food but is added during processing or preparation.
About 15% of the calories in the American adult diet come from added
sugars. That’s about 22 teaspoons of added sugar a day. Sugars are
usually added to make foods and drinks taste better. But such foods can
be high in calories and offer none of the healthful benefits of fruits
and other naturally sweet foods.
Sugar-sweetened beverages like soda, energy drinks, and sports drinks
are the leading source of added sugars in the American diet. Juices
naturally contain a lot of sugar. But sometimes, even more is added to
make them taste sweeter.
“Juices offer some vitamins and other nutrients, but I think those
benefits are greatly offset by the harmful effects of too much sugar,”
says Bremer.
Over time, excess sweeteners can take a toll on your health. “Several
studies have found a direct link between excess sugar consumption and
obesity and cardiovascular problems worldwide,” Bremer says.
Because of these harmful effects, many health organizations recommend
that Americans cut back on added sugars. But added sugars can be hard to
identify. On a list of ingredients, they may be listed as sucrose
(table sugar), corn sweetener, high-fructose corn syrup, fruit-juice
concentrates, nectars, raw sugar, malt syrup, maple syrup, fructose
sweeteners, liquid fructose, honey, molasses, anhydrous dextrose, or
other words ending in “-ose,” the chemical suffix for sugars. If any of
these words are among the first few ingredients on a food label, the
food is likely high in sugar. The total amount of sugar in a food is
listed under “Total Carbohydrate” on the Nutrition Facts label.
Many people try cutting back on calories by switching from
sugar-sweetened to diet foods and drinks that contain low- or no-calorie
sweeteners. These artificial sweeteners—also known as sugar
substitutes—are many times sweeter than table sugar, so smaller amounts
are needed to create the same level of sweetness.
People have debated the safety of artificial sweeteners for decades. To
date, researchers have found no clear evidence that any artificial
sweeteners approved for use in the U.S. cause cancer or other serious
health problems in humans.
But can they help with weight loss? Scientific evidence is mixed. Some
studies suggest that diet drinks can help you drop pounds in the short
term, but weight tends to creep back up over time. Rother and other
NIH-funded researchers are now working to better understand the complex
effects that artificial sweeteners can have on the human body.
Studies of rodents and small numbers of people suggest that artificial
sweeteners can affect the healthful gut microbes that help us digest
food. This in turn can alter the body’s ability to use glucose, which
might then lead to weight gain. But until larger studies are done in
people, the long-term impact of these sweeteners on gut microbes and
weight remains uncertain.
“There’s much controversy about the health effects of artificial
sweeteners and the differences between sugars and sweeteners,” says Dr.
Ivan de Araujo of Yale University. “Some animal studies indicate that
sweeteners can produce physiological effects. But depending on what kind
of measurement is taken, including in humans, the outcomes may be
conflicting.”
De Araujo and others have been studying the effects that sugars and
low-calorie sweeteners might have on the brain. His animal studies found
that sugar and sweeteners tap differently into the brain’s reward
circuitry, with sugars having a more powerful and pleasurable effect.
“The part of the brain that mediates the ‘I can’t stop’ kinds of
behaviors seems to be especially sensitive to sugars and largely
insensitive to artificial sweeteners,” de Araujo says. “Our long-term
goal is really to understand if sugars or caloric sweeteners drive
persistent intake of food. If exposed to too much sugar, does the brain
eventually change in ways that lead to excess consumption? That’s what
we’d like to know.”
Some research suggests that the intensely sweet taste of artificial,
low-calorie sweeteners can lead to a “sweet tooth,” or a preference for
sweet things. This in turn might lead to overeating. But more studies
are needed to confirm the relative effects of caloric vs. non-caloric
sweeteners.
“In the long run, if you want to lose weight, you need to establish a
healthy lifestyle that contains unprocessed foods, moderate calories,
and more exercise,” Rother says.
When kids grow up eating a lot of sweet foods, they tend to develop a
preference for sweets. But if you give them a variety of healthy foods
like fruits and vegetables early in life, they’ll develop a liking for
them too.
“It’s important for parents to expose children to a variety of tastes
early on, but realize that it often takes several attempts to get a
child to eat such foods,” says Bremer. “Don’t give up too soon.”
The key to good health is eating a well-balanced diet with a variety of
foods and getting plenty of physical activity. Focus on nutrition-rich
whole foods without added sugars.
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