Aspartame (E951)


Aspartame is the artificial sweetener known in the English-speaking world as Nutrasweet, Equal, and Canderel. In other countries it is better known as AminoSweet or Sanecta. In the European Union, it's sometimes identified as E951.

It's impossible to publish an article on aspartame without stirring up controversy. Some experts insist it is absolutely always safe. Other experts insist that it is absolutely always dangerous. Both parties have some of the facts but not all of the facts on their side.

This article, however, will take a simple factual look at what aspartame is and isn't, with a view more to the potential of getting the maximum benefits of juicing—without aspartame—rather than with a view to scare the bejeezus out of you with questionable chemistry. The real problem with aspartame, this writer thinks, isn't what manufacturers put into juices when they add aspartame. It's what the take out.

What Is Aspartame?

Aspartame was invented in 1965 by a chemist named James M. Schlatter, who worked for the pharmaceutical company G. D. Searle. Dr. Schlatter was trying to create a new medication for peptic ulcers. He accidentally dropped a combination of chemicals on a piece of paper on his desk. After he picked up the paper, he licked his finger, and noticed an intense sweet taste. G. D. Searle patented the formula and sold it to the infamous agrochemical manufacturer Monsanto, which was responsible for getting aspartame approved for use in the United States. Monsanto sold its Nutrasweet business nearly 20 years ago as its patents were expiring.

The artificial sweetener aspartame is a chemical combination of two amino acids that appear naturally in many of the foods that we eat, L-phenylalanine and L-aspartic acid. The exact details of how these nutrient amino acids are assembled into aspartame has not been explained to the public, but there are two basic ways to make the sweetener. One method is combine the amino acids under heat and pressure. This method produces a bitter byproduct. The other method is to mix the amino acids with an enzyme extracted from the bacterium Bacillus thermoproteolyticus, which creates aspartame without bitterness.

Aspartame actually isn't a zero-calorie food additive. It contains as many calories as any protein food, and just slightly fewer calories than sugar. The difference between aspartame and sugar is that aspartame is about 180 times sweeter than sugar. A gram (1/28th of an ounce) of aspartame is as sweet as half a cup of sugar (about 140 grams, enough to fill a 120 ml measuring cup). Just 1/25th of a gram of aspartame is enough to sweeten a cup of coffee.

It's impossible to measure out teeny-tiny amounts of aspartame, of course, so the sweetener is cut with relatively large amounts of real sugar. About 99% of the contents in a packet of Nutrasweet is one or more of about a dozen low glycemic index sugars, such as mannitol, xylitol, polydextrose, maltitol, or isomalt. These bulking agents have calories, too. So little of the bulking agent is needed to blend with the aspartame, however, that a packet of Nutrasweet or similar aspartame sweetener has so few calories that most people don't worry about counting.

Why Would Anyone Put Aspartame in Juice?

One of the unusual properties of aspartame is that, while it is much sweeter than sugar, the sensation of sweetness from aspartame does not “kick in” for a second or two, but the sweet taste also lingers for a second or two. Some manufacturers add tiny amounts of aspartame not to make juice taste sweeter but to make the juice taste sweeter for just a second or two longer so the consumer will drink the juice continuously, gulp, gulp, gulp. People finish the container of juice faster and marketing surveys confirm that they buy more, even if the difference in the total sweetness of the beverage is imperceptible. Of course, the scientific publications explaining the principle all say that smaller amounts of juice would yield greater flavor with fewer calories, but that's not how it works out in the real world!

Other manufacturers add aspartame to juices to make sour juices palatable. Cranberry juice, for example, contains complex polysaccharides that keep bacteria and fungal infections from “taking root” in the lining of the urinary tract. It's a well known remedy for bladder infections. The downside to drinking cranberry juice for bladder health is that cranberries are so sour that most people find them inedible, and sugar feeds the very bacteria one seeks to treat by drinking cranberry juice.

Aspartame is any more nutritious for bacteria than it is for people, so it's a logical addition to sweetening cranberry juice. It's also understandable that manufacturers put aspartame in low-calorie lemonade, green tea drinks, açai berry drinks, and pomegranate juice drinks, in almost any juice product that has to be imported from another country at a distance.

To save transportation costs, juice makers transform juices into concentrates. Fresh juice is collected into enormous stainless steel vats. The juice is pasteurized to kill germs that might cause spoilage during the 6 to 18 months it will be stored. The pasteurization process boils down the juice and removes its flavor profile as well as most of the oxygen in the juice. This boiled down juice can be shipped around the world and reconstituted with water and an artificial flavor pack that adds flavor—just not natural flavor—back into the juice. To keep you from noticing the artificiality of the juice flavor, manufacturers used to add sugar, but now they add aspartame, which not only lower in calories but cheaper than using a natural sweetener.

Even not-from-concentrate juices sometimes include aspartame. These juices are also pasteurized and stored in giant vats. They just aren't boiled down to reduce their volume. They still lose their natural flavor. “Juice flavor” is added to not-from-concentrate juices the same way it is added to juices made from concentrate. The flavor additives just are not required to be listed on the label.

So Does This Mean Pasteurized Juices are Deadly?

Most of the articles about aspartame-sweetened juices try to describe aspartame as a horrible poison that turns simple juices into toxic elixirs. That's not the real problem with juice sweetened with aspartame. The real problem with juice that has been sweetened isn't that the aspartame will kill you. It's that the juice is devoid of natural flavor and nutrition.

As hard as it may be to believe, aspartame is not a particularly toxic food additive. Let's go through the screaming headlines about aspartame one by one.

Aspartame is made with methanol! Actually, it's not. The process of making aspartame from the two amino acids phenylalanine and aspartic acid doesn't use methanol, but the process of digesting aspartame back into phenylalanine and aspartic acid inside the body releases tiny amounts of methanol. A 12 oz (180 ml) can of Diet Coke or aspartame-sweetened lemonade releases about 24 milligrams of methanol when it's digested in your body. A 12 oz (180 ml) glass of fresh-squeezed orange juice releases about 18 milligrams of methanol when it's digested in your body, and this is methanol that Mother Nature included in the juice. The same amount of fresh-squeezed grape juice releases 46 milligrams of methanol, nearly twice as much as is in Diet Coke.

Why aren't these 1/100th of an ounce amounts of methanol toxic? The simple reason is that fruit also contains tiny amounts of naturally occurring ethanol, the kind of alcohol in alcoholic beverages. Before methanol (the toxic alcohol) can do damage, it has to be activated by an enzyme in the liver called alcohol dehydrogenase. If the liver receives both methanol and ethanol, it transforms methanol first. This gives the bloodstream time to carry the tiny amount of methanol to the kidneys, where they are flushed out with the urine. And, yes, the liver will work on the non-toxic alcohol first every single time.

It takes about 400 times as much methanol as there is in a Diet Coke or in a glass of aspartame-sweetened juice to overwhelm the liver's enzymes and cause toxic symptoms. You can't fit more than than about 4 Diets Cokes or 4 glasses of juice in your stomach at one time, so aspartame is non-toxic. If beverages contained appreciably more aspartame they would taste awful and you wouldn't drink them. Or if they contained less you would notice the “canned” taste and reject them. But there are other concerns about aspartame.

“Aspartame breaks down into formaldehyde!” the critics of aspartame tell us. That's true. When methanol is processed by alcohol dehydrogenase in the liver, it does form formaldehyde. But since methanol isn't processed by alcohol dehydrogenase in the amounts we encounter in even whole buckets of juice, there is no damage to the body through this chemical route.

Another exception to the use of aspartame is “Aspartame triggers the release of insulin!” That would be a serious problem. The human body doesn't just have taste receptors on the tongue. It also has taste receptors in the stomach and small intestine. When the taste receptors in the digestive tract sense sweetness, they send a signal to the pancreas to release both insulin, to store sugar, and glucagon, to release sugar from the liver just in case there isn't any sugar actually delivered to the bloodstream. You would think that aspartame would trigger the release of insulin, which also stores fat, and the release of glucagon, which depletes energy reserves. Scientists thought that for years. But when they actually examined the taste receptors in the digestive tract they found that this doesn't happen.

If there were this kind of insulin reaction to aspartame, juices and soft drinks sweetened with it would cause weight gain because of the extra insulin. And studies have found that women who use aspartame-sweetened soft drinks tend to be heavier than women who drink soft drinks sweetened with real sugar. But it turns out that gaining weight leads to drinking diet sodas, not the other way around.

And what about the other common objections to aspartame?

  • There isn't any scientifically confirmed evidence that aspartame aggravates ADD or ADHD. The caffeine in aspartame-sweetened soft drinks, however, may be a serious problem.
  • There isn't any scientifically confirmed evidence that aspartame cause allergies. The preservatives in juices and soft drinks, however, often do, especially in people who are allergic to aspirin or dried fruit, which contain chemicals similar to preservatives naturally or, in the case of dried fruit, added to the product.
  • There isn't any scientifically confirmed evidence that aspartame causes diabetes. There isn't any evidence that sugar causes diabetes, for that matter. It can be dangerous for diabetics to consume large amounts of high-carbohydrate foods that are sweetened with aspartame, but because of the sugar released when the carbohydrate is digested, not because of the aspartame itself.
  • A study conducted at the Istituto di Ricerche Farmacologiche Mario Negri in Milan (Italy) even found that using aspartame reduced the risk of cancers of the small intestine, stomach and pancreas.

As hard as it may be to believe, hand-squeezed juices usually contain more methanol than heat-processed juices. While it goes against what one might think, it's not hard to understand. Heat boils off alcohols of all kinds including methanol—and methanol was one of the reasons people object to aspartame. But the teeny, tiny amounts of methanol in any juice are not a reasonable cause for concern. A toxic dose is 200 to 2000 times the amount in any glass of juice.

So using juices sweetened with aspartame is OK? Not really. The problem isn't that aspartame is a toxin. The problem is that juices that have to be sweetened with aspartame to be palatable have limited nutritional value. They become sources of empty calories are at best empty calories with nutritional supplements including vitamins and antioxidants stirred in.

How Many Nutrients Are Lost When Juices are Pasteurized or Irradiated?

If you are going to have juice sitting around in tank for a year or more, you really have to get rid of the germs that might be in it first. Microbes that are relatively harmless on fresh fruits and vegetables, because they are consumed before germs get a chance to multiply, can be deadly in stored juices. The process of pasteurization or irradiation, however, changes vitamin and antioxidant content.

  • Vitamin C breaks down more than any other nutrient component of fresh juices.
  • The longer any kind of juice is stored at any temperature or in any kind of container, the more vitamin C it loses.
  • Reducing the volume of a juice does not slow down the breakdown of vitamin C.
  • Some juices such as mango lose almost all their vitamin C in just three weeks of cold storage.
  • Some juices keep such as carrot retain most of their vitamin C and antioxidant content for about two weeks (although carrot juice is not a good source of any antioxidant other than beta-carotene).
  • The longer orange juice is stored, the less it helps to prevent oxidation of cholesterol into artery-hardening forms after it is drunk.
  • About 77% of the vitamin C content of strawberry juice is destroyed during pasteurization. Companies can add artificial vitamin C back to the finished product without listing this fact on the label.
  • About 25% of the vitamin C content of tomato juice is destroyed during pasteurization.
  • Heat-treated vegetable juices lose riboflavin (vitamin B2). Again, companies add artificial riboflavin during the bottling process to account for losses during processing.

Sometimes companies add back the vitamins lost in processing. Sometimes they don't. But if a juice tastes so bad that the manufacturer has to add aspartame to keep you from gagging on the “canned” taste, chances are it doesn't have the vitamins and antioxidants you need, either.

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About Andy Williams

In a processed food culture, simply eating may not be enough. Andy Williams, B.SC., Ph.D. is a scientist with a strong interest in Juicing and how it can supply the body with the nutrients it needs to thrive in modern society. You can subscribe to his free daily paper called Juicing The Rainbow and follow him on Facebook orTwitter. You can also follow me on Google +

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