What’s Really in Your Soda?

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Soda cans
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Coca-Cola made headlines recently for hiring fitness and nutrition experts to proclaim Coke healthy.

Perhaps they were hoping this marketing maneuver would cause consumers to ignore the ingredient list on the side of the drink. Because those ingredients tell a story that’s more complex than the paid experts imply.

We’ve broken down the most common ingredients found in the most popular sodas.

Perhaps the only clear-cut ingredient among them is carbonated water, which experts like Laureen Smith cite as an alternative to soda.

An associate professor at the Ohio State University College of Nursing, Smith has studied how to keep kids away from sugary sodas.

“For those who choose carbonated sodas, it may provide the sought-after carbonation without the sugar,” she told Time.

Carbonated water is generally without a host of other soda ingredients, too.

High-fructose corn syrup

This controversial liquid sweetener is man-made.

The process involves breaking down corn starch into corn syrup, which is essentially 100 percent glucose, a type of simple sugar. It also involves adding more fructose to the mix than glucose, thus the name high-fructose corn syrup, or HFCS.

The problem with HFCS, according to Harvard Medical School, is all that fructose, another simple sugar.

In the early 1900s, Americans consumed about 15 grams of fructose per day, mostly from fruits and vegetables that contain natural fructose, Harvard states. Today, we consume 60 grams to 75 grams per day, mostly from sweeteners added to processed foods and drinks.

Unlike glucose, which can be broken down by almost any type of cell, fructose can be broken down only by liver cells. Overconsumption of fructose can therefore cause tiny fat droplets to accumulate in liver cells, also known as nonalcoholic fatty liver disease.

Harvard says overconsumption of fructose can also cause:

  • Increased blood pressure.
  • Increased LDL cholesterol, also known as bad cholesterol.
  • Increased triglycerides.
  • Buildup of fat around organs.
  • Insulin-resistant tissues, a precursor to diabetes.
  • Increased production of free radicals, which can damage DNA and cells.

The Mayo Clinic is less critical of HFCS but is wary of all added sugars:

Research has shown that high-fructose corn syrup is chemically similar to table sugar. Controversy exists, however, about whether or not the body handles high-fructose corn syrup differently than table sugar.

At this time, there’s insufficient evidence to say that high-fructose corn syrup is any less healthy than other types of sweeteners. We do know, however, that too much added sugar — not just high-fructose corn syrup — can contribute unwanted calories that are linked to health problems, such as weight gain, type 2 diabetes, metabolic syndrome and high triglyceride levels. All of these boost your risk of heart disease.


Some sodas contain sugar in addition to or instead of high-fructose corn syrup.

Either way, these ingredients account for the number of grams of sugar in a beverage. For example, a 12-ounce can of Coke has 39 grams of sugar, and the same size Pepsi has 41 grams — more than some experts say a person should consume in an entire day:

  • The World Health Organization recommends that children and adults limit their consumption of added sugars to roughly 50 grams per day, preferably 25 grams per day.
  • The American Heart Association recommends that the average woman limit her consumption of added sugars to roughly 25 grams per day and that the average man limit his to 37.5 grams per day.


This low-calorie man-made sweetener, marketed under such brand names as Equal and NutraSweet, primarily comprises two amino acids: aspartic acid and phenylalanine.

The U.S. Food and Drug Administration and European Food Safety Administration consider aspartame safe.

“Aspartame is one of the most exhaustively studied substances in the human food supply, with more than 100 studies supporting its safety,” the FDA website states.

The U.S. Department of Health and Human Services, which includes the FDA, warns certain people about aspartame, however:

People with the genetic disease phenylketonuria (PKU), those with advanced liver disease and pregnant women with hyperphenylalanine (high levels of phenylalanine in blood) have a problem with aspartame because they do not effectively metabolize … phenylalanine… High levels of this amino acid in body fluids can cause brain damage.

Aspartame is also rumored to be associated with cancer, but the American Cancer Society disagrees:

In the largest study of this issue [of cancer], researchers from the [National Cancer Institute] looked at cancer rates in more than 500,000 older adults. The study found that, compared to people who did not drink aspartame-containing beverages, those who did drink them did not have an increased risk of lymphomas, leukemias or brain tumors.

Caramel color

This term can refer to any of four types of caramel coloring that manufacturers add to sodas like Coke and Pepsi, primarily to give them their dark color, according to Consumer Reports.

Some types of caramel coloring contain 4-methylimidazole, or 4-MEI, which Consumer Reports described as “a possible cancer-causing chemical” and a Johns Hopkins researcher recently called “a threat to public health.” (Check out “Could Your Favorite Soda Give You Cancer?” to learn more.)

Consumers can’t necessarily tell whether a soda contains 4-MEI, however. Federal food labeling laws do not require manufacturers to specify which kind of coloring they put into a soda.

Natural flavor(s) and/or artificial flavor(s)

Similar to caramel color, these are categorical terms that, by federal law, a manufacturer can cite in an ingredient list instead of naming the specific flavoring agent. (Check out “When Foods Go ‘Natural’ — Does That Really Make Them Healthier” to learn more.)

Now for the ingredients that are hardest to pronounce.

Sodium benzoate or potassium benzoate

Shape counted these preservatives among nine ingredients that nutritionists won’t touch.

As registered dietitian Leslie Bonci told the magazine in 2013:

Sodium and potassium benzoate are added to some diet soft drinks and fruit drinks. They can form benzene, which is a carcinogen, when combined with vitamin C, the ascorbic acid in juice or soda.

The FDA also describes benzene as “a carcinogen that can cause cancer in humans,” explaining that it can form in some drinks that contain benzoate salts (like sodium or potassium benzoate) as well as ascorbic acid or erythorbic acid, all of which can be found in some sodas.

The federal agency says, however, that the level of benzene found in drinks does not endanger public health, based on its tests of almost 200 samples of sodas and other drinks.

The U.S. Environmental Protection Agency set 5 parts per billion as the maximum allowable level for benzene in drinking water. The FDA adopted the same level for benzene in bottled water.

The FDA’s tests for benzene revealed that almost all drink samples contained either no benzene or levels below 5 ppb, the agency says. As for the rest of the samples, the FDA “is working with the beverage industry to minimize benzene formation in products.”

Phosphoric acid

This ingredient might explain why some experts and studies associate sodas with bone loss, as WebMD explains:

Phosphorus itself is an important bone mineral. But if you’re getting a disproportionate amount of phosphorus compared to the amount of calcium you’re getting, that could lead to bone loss.

Another possible culprit is caffeine, which experts have long known can interfere with calcium absorption. In [a Tufts University] study, both caffeinated and non-caffeinated colas were associated with lower bone density. But the caffeinated drinks appeared to do more damage.

Studies have shown that the bone-loss association is specific to carbonated sodas, though. It does not extend to other types of carbonated drinks, like carbonated water — another reason experts recommend carbonated water as a healthy alternative to soda.

Do you agree with Coca-Cola that sodas are a healthy treat? Let us know in the comments & discussion section below or on our Facebook page.

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