Since ancient times, humans have experimented with ways to increase the sweetness of foods and beverages without the use of sugar. Ancient Romans used sugar of lead (a.k.a. lead acetate) as a sugar substitute. For obvious reasons, using lead as a sweetener caused some serious health problems and its use was abandoned, though not for many centuries. With the accidental discovery of saccharine in 1879, the modern era of non-sugar sweeteners was born. Cyclamate, aspartame, acesulfame potassium, sucralose, neotame, stevia, and sugar alcohols have followed saccharine into the US market over the ensuing 131 years. However, despite their many benefits to the public, artificial sweeteners have come under almost constant fire from watchdog groups and the FDA since the early 1960s. Fortunately, almost all of the information underpinning the negative stigma surrounding sugar substitutes is based on either horribly faulty research or simply misinformation and ignorance. Let’s look at each sweetener and finally see where the truth actually lies.
First up is the 19th century granddaddy of them all: saccharine. Saccharine is about 300 times as sweet as sugar but can impart a bitter or metallic taste to a product, worsening as the concentration of saccharine increases. Its best use is often as one part of a sweetener system made up of two or more artificial sweeteners. Saccharine is best known in the US by the brand name Sweet’N Low, which is found in most restaurants in the pink single serving package. Though its use as a commercial sugar substitute was immediately recognized upon its discovery, saccharine’s use in mass-market food products was limited until World War I. During WWI and WWII, sugar was rationed due to military demands and so saccharine became a popular sugar substitute. Saccharine gained even more popularity in the 1960s and 1970s due to America’s growing interest in weight control at the time.
However, in the 1960s, fear began to spread over saccharine’s purported carcinogenicity due to a study that showed an increased incidence of bladder cancer in rats that were fed saccharine. In 1977, the FDA proposed a ban on saccharine, but congress acted to prevent the ban from taking effect. Though the sweetener was still allowed on the market, a warning label was required on all products into which it was incorporated. However, in 2000 the warning labels were removed due to recent discoveries proving that the mechanism by which saccharine causes cancer in rats does not apply to humans. The bottom line here is that saccharine is NOT dangerous unless you are a rat. Even California has accepted the truth by now, so you KNOW that there’s no reason to worry.
Second in line is cyclamate. Though it is approved for use in food in over 55 countries, cyclamate has been banned in the US since 1969. Cyclamate is 30-50 times as sweet as sugar, making it less powerful than some other artificial sweeteners, but it is inexpensive and generally has a good sweetness profile with little off-flavor. In many applications, it is blended 10:1 with saccharine for optimal sweetness while minimizing negative taste characteristics.
Problems for cyclamate began in 1969 when a study was published indicating that cyclamate cause bladder cancer in rats. Though the cyclamate exposure levels used in the study were gigantic compared to those seen in human consumption, the government banned the sweetener later that year. However, within 4 years, new evidence was presented to the FDA to repeal the ban on cyclamate. A scientific review panel was convened to interpret the new studies, which included over 20 experiments using mice, rats, guinea pigs, and rabbits. The panel concluded that there was no evidence indicating that cyclamate acted as a carcinogen. However, in 1980 the FDA denied the petition to allow cyclamate back into the US food supply. Since then, research into cyclamate’s safety has continued. To date, over 70 studies using a plethora of techniques have shown cyclamate to be non-mutagenic (not damaging to DNA). As well, the World Health Organization and other governing and regulatory bodies the world over have repeatedly affirmed cyclamate’s safety over the last 30 years. Unfortunately for those of us in the US, cyclamate got off on the wrong foot in this country and, while the rest of the world relies on the vast body of evidence indicating cyclamate’s non-harmful properties, our government instead has chosen to favor paranoia and fear as their regulatory guides in this case.
Next up is aspartame, possibly the most hated of all sugar substitutes. Aspartame is about 180 times as sweet as sugar and can lend a bitter taste to foods and drinks. Like saccharine, it is often used in combination with other artificial sweeteners to maximize its beneficial properties while minimizing its off-flavors. Aspartame is best known in the US as Nutrasweet or Equal and is often found in blue single serving packages. It was approved for use in all food products in 1996, though it had been previously approved for certain uses. Aspartame has been accused of causing brain cancer and numerous other problems due to three of its metabolites (breakdown products): methanol, aspartic acid, and phenylalanine.
The approval process of aspartame began in the mid 1970s and included a review of almost 200 studies on aspartame. Following its approval, aspartame has been comprehensively studied, finding no evidence of carcinogenic action at the levels currently consumed by humans. Studies with mice, rats, hamsters, and dogs, using aspartame doses as high as 4000 mg/kg bw/day (milligrams per kilogram of bodyweight per day [that equals 272 GRAMS(!) of aspartame per day for a 150 pound man]) have all found no evidence for adverse effects caused by the sweetener. Meta-analyses of aspartame safety studies have also failed to find evidence of carcinogenicity or genotoxicity. Aspartame is one of the most heavily studied food additives of all time due to the ongoing negative attention it has gotten over the past 40 years.
As far as its metabolites, research has shown conclusively that exposure from aspartame metabolism to methanol, aspartic acid, and phenylalanine is far outweighed by that from other dietary sources. The only legitimate risk of aspartame is to those individuals who suffer from the genetic disorder phenylketonuria (PKU). Fortunately, everyone is screened for PKU shortly after birth, so if you have it, you know about it. If any sugar substitute has run through the scientific gauntlet and come out the other side intact, it is aspartame. It has been studied extensively for decades and its safety is without question.
Another popular sweetener in the US is acesulfame potassium, also known as Ace K. IT is about 200 times as sweet as sugar and is known in the US by its brand names Sunett and Sweet One. It was discovered by accident (common theme, it seems!) in 1967 by a German chemist. Ace K is often found blended with sucralose (a.k.a. Splenda) to produce a more sugar-like sweetness profile while masking the sometimes bitter aftertaste of Ace K. It has also been widely used in conjunction with aspartame in the past, though in recent years sucralose has become favored due to its superior heat stability and taste profile. Ace K was approved by the FDA in 1988, but has since come under scrutiny. Animal studies have shown no evidence for carcinogenicity of Ace K, though a rat study did indicate that Ace K stimulates the release of insulin much like sugar. Despite the fact that the insulin-related study showed no hypoglycemia (low blood sugar) resulting from even the VERY large doses of Ace K given to the rodents, opponents of Ace K suggest that human consumption at much lower levels could produce a low blood sugar condition. However, more than 20 years worth of science and empirical data speaks for itself, showing Ace K to be an extremely safe and effective sugar substitute.
Our next sugar substitute is sucralose the current heavyweight champion of artificial sweeteners. Sucralose is widely marketed in the US under the Splenda brand name, but is available in other guises. It was discovered in 1989 in England and is approximately 600 times as sweet as sugar. In fact sucralose is based on sucrose (table sugar). The difference between sucrose and sucralose is that in the latter, three hydroxyl groups (an oxygen bound to a hydrogen) have been replaced by chlorine atoms. This change in structure makes sucralose indigestible to humans and much, much sweeter at the same time. However, sucralose retains some excellent properties such as acid and heat stability, very good solubility in water, and a sugar-like taste profile.
Sucralose has been studied extensively before and since its approval in the US in 1998. Over a hundred animal studies have unanimously shown no evidence of toxicity, carcinogenicity, mutagenicity or other detrimental effects from sucralose consumption. In fact, even a dose equivalent to 1,000 pounds of sucralose consumed in a single day by a 165-pound human produced no negative effects in rats. Even the crazies at the Center for Science in the Public Interest have deemed sucralose safe.
Of course, despite the library of evidence proving the safety of sucralose, someone will come out of the woodwork to try and throw a wrench in the works. The claim this time is that sucralose is harmful to humans because it is a member of a chemical class known as cholorocarbons that also contains many toxic substances. However, these claims are unfounded for a couple of reasons. First, sucralose is almost completely insoluble in non-polar solvents like fat. Therefore, sucralose will not accumulate in human fatty tissue like some other chlorocarbons. Secondly, sucralose does not dechlorinate in the human body. About 99% of ingested sucralose is excreted unchanged, with the other 1% undergoing limited metabolism and producing non-toxic metabolites. Sucralose is not processed within the body in any way similar to other, toxic chlorocarbons and so generalizations about chlorocarbon toxicity made to cover sucralose are simply wrong. Sucralose has been proven to be completely safe in all respects for human consumption.
Neotame is the most powerful sugar substitute approved for use in the US. A chemical cousin of aspartame, it is 10,000 times as sweet as sugar. Despite being on the commercial market since 2002, neotame is used only rarely in the US. It has a sweetness profile similar to aspartame and can also impart a similar bitter aftertaste. Because of its incredibly high sweetening power, it may be difficult for many food manufacturers to use precisely. Despite its drawbacks, one area in which neotame has an advantage over aspartame is in its metabolic byproducts. While aspartame is broken down into its two component amino acids, aspartic acid and phenylalanine, neotame contains an extra group of atoms that physically blocks access to the molecule by enzymes that would normally perform the amino acid cleavage. Metabolism of neotame produces very little phenylalanine and is therefore safe for consumption by those people suffering from PKU, unlike aspartame.
Neotame has come under similar fire as its cousin aspartame. However, due to its limited use no large-scale battles have erupted. The FDA approved neotame after reviewing 113 animal and human studies that evaluated the potential toxic, carcinogenic, mutagenic, and neurological effects of neotame. They determined that neotame posed no risk in any category to humans.
The last two sugar substitutes included in this review separate themselves from the rest of the class in that they are considered natural sweeteners by the FDA. First up for the naturals is stevia. Widely available under the brand names PureVia and Truvia and also known as Reb-A and rebiana, stevia was approved for use as a dietary supplement in the US in 1995 and as a food additive in 2008. Commercial stevia is made from high purity extracts from the species Stevia rebaudiana and is generally 200 to 300 times as sweet as sugar. Though it has a sweet taste, stevia’s taste profile and sweetness dynamics are quite different from that of sugar. In addition, it can impart a significantly bitter and/or metallic aftertaste to a food product. However, stevia is gaining in popularity as masking technologies tailored to the ingredient come of age and methods are found to make the best use of the sweetener.
Stevia’s long history begins in South America where it has been used for centuries as a sweetener and as an ingredient in local medicinal traditions. Stevia’s regulatory problems began in 1991 when the FDA restricted the import of stevia and labeled it unsafe after receiving complaints about toxicological concerns about the plant. However, between 2006 and 2008, a number of comprehensive reviews of stevia safety studies performed by both the World Health Organization and individual researchers concluded that the high purity extracts used commercially in the food industry do not have any carcinogenic, mutagenic, or toxic effects in humans, even at extremely high consumption levels. In early 2009, the FDA awarded rebaudioside A, the active ingredient in modern stevia extracts, GRAS (generally recognized as safe) status. Though stevia had a rough start in the US, the evidence now is clear and has been recognized properly by the FDA. Stevia is a safe sugar substitute and will likely carve out a well-deserved spot in the food industry’s reduced-calorie and natural products markets.
Last but not least, we have sugar alcohols. The name sugar alcohol can actually refer to a number of different, but chemically related compounds, including sorbitol, maltitol, mannitol, xylitol, erythritol, and others. They generally have less energy (calories per gram) than sugar’s four, but they also often provide less sweetness. However, they can be paired with other, high-power sugar substitutes to compensate for their low sweetening power. Xylitol and other sugar alcohols are commonly used in chewing gums because they cannot be digested by the bacteria resident in our mouths and therefore do not contribute to tooth decay. In addition, a number of sugar alcohols give a significant cooling sensation when their crystallized forms are put in the mouth due to their negative enthalpy of dissolution. It’s also worth mentioning that sugar alcohols do not have anything to do with ethyl alcohol, the compound we consume to get drunk. They are called alcohols simply because they have a hydroxyl (oxygen and hydrogen, also known as “alcohol”) group where a normal sugar would have a carbonyl (carbon double-bonded to oxygen) group.
With the exception of erythritol, the common sugar alcohols have one big drawback: gastrointestinal upset. Like normal sugar, sugar alcohols attract water. When sugar alcohols pass into the large intestine, they bring quite a bit of water along for the ride. This excess water can cause diarrhea and bloating, with the effects getting worse as the dose of sugar alcohol increases. In fact, sorbitol is used as a laxative in certain circumstances when a quick bowel movement is needed without the use of stimulants. The amount of sugar alcohol that will produce gastrointestinal problems varies between individuals as well as types of sugar alcohols. Some people can consume quite a bit of sugar alcohols with little to no ill effect, while others may have somewhat severe diarrhea with a light dose. You just have to try them out and see.
Erythritol is unique in that it has a much higher threshold for gastrointestinal upset than other sugar alcohols. Unlike other sugar alcohols, it is absorbed by the small intestine and excreted in the urine. Because it never makes it to the large intestine, diarrhea is generally avoided. In addition, while most sugar alcohols have 2-2.5 calories per gram, erythritol has only 0.2, making it a useful sugar substitute in low-calorie products. However, with only 60-70% of the sweetening power of sugar and government regulations limiting its maximum concentration in food products, erythritol almost always is seen in combination with other sweeteners, whether natural of artificial.
Artificial sweeteners and sugar substitutes have always come under attack from those especially wary of new additions to the food supply. However, in all of the cases mentioned in this article, scientific evidence has proven their worries to be misplaced. Sugar substitutes offer viable solutions to the fight between the human desire for sweet tastes and the global epidemic of obesity. As well, in most cases these compounds are also a blessing for people with diabetes because they don’t cause the large fluctuations in blood sugar seen with the use of sugar. Finally, sugar substitutes allow anyone with the desire to control their body composition and overall health to more easily control their body’s output of insulin and to keep their daily energy levels high and stable. Sugar substitutes are a fantastic resource and, while the safety research must be done to protect consumers, they should be valued and used whenever appropriate to benefit the health of the public.