They tortured that poor molecule. They heated it, froze it, dissolved it in acid, baked it into cakes, stuffed it into people’s mouths, and fed it to rodents. They even made it radioactive so they could follow its path through the animals’ bodies. Then they extracted it from the rodents’ poop to see how it had fared. And it fared well. In fact, it passed every indignity with flying colors. As a result, we now have an artificial sweetener on the market that promises to sugarcoat our lives—but without actually using sugar. Sucralose (Splenda) is ready to challenge aspartame as the leader in the artificial sweetener sweepstakes.
We love sweets. There’s no doubt about that. Our palates lust for ice cream, our mouths water at the thought of glazed doughnuts, our parched throats yearn for soft drinks, and visions of sugarplums sometimes dance in our heads. To satisfy these cravings, we gorge on caloric sweeteners such as sugar or high fructose corn syrup. This is not exactly ideal for our teeth, our waistline, or our general health. Thus, it isn’t surprising that artificial sweeteners and artificially sweetened products have attracted greater and greater consumer interest.
Unfortunately, none of the sugar replacements has been completely satisfactory. Aspartame, or “Equal,” is about 180 times sweeter than sugar but is not stable in acidic conditions or when exposed to heat. This presents significant problems for diet drink manufacture, and for baking. Saccharin and the cyclamates are sweet enough, but leave an aftertaste. There have also been some lingering health concerns. Aspartame cannot be consumed by individuals with an inherited condition called phenylketonurea (PKU), because their bodies lack the ability to metabolize phenylalanine, one of this sweetener’s breakdown products. In rare cases, people may have adverse reactions to aspartame, including headaches and visual disturbances. Saccharin and the cyclamates, in turn, have had to cope with the shadow of cancer. Some studies, probably of no relevance to humans, have suggested a slightly elevated risk when test animals were fed massive amounts of these sweeteners. In any case, the nutritional world was primed for a new kid on the block.
The kid was born in a laboratory at Queen Elizabeth College, University of London, in 1976. The researchers studying the chemical reactions of ordinary table sugar, or sucrose, certainly did not have artificial sweeteners on their minds. But when they managed to incorporate three chlorine atoms into a sucrose molecule, they aroused a sugar company’s interest. A company representative called one of the researchers to ask for a sample to be tested. As luck would have it, the young foreign chemist misunderstood and thought the request was for a sample to be “tasted.” So with a bit of bravado he plopped some of the chlorinated sugar into his mouth and told his supervisor about the sweet experience. The supervisor immediately recognized the potential value of this discovery, seized the moment, and redirected the laboratory’s research efforts. Sucralose, as the new compound came to be called, turned out to be 600 to 1,000 times sweeter than sugar, depending on what it was added to!
But many years of testing faced the energized chemists before the new product could be brought to market. Their enthusiasm increased when sucralose turned out to be very water soluble as well as stable to heat and acid. This meant that it could easily be used in diet drinks and baked goods. Since sucralose is so sweet, much less of it is needed than if sugar is used. But this presents a problem. Sugar provides not only sweetness, but also bulk in bakery products. However, when sucralose is combined with maltodextrin, a type of starch that provides bulk, the mixture can be substituted for sugar, measure for measure. The end product isn’t necessarily identical, however. Since sugar is also responsible for the browning effect produced by baking, the color of some cookies, for example, may look rather anemic. One thing sucralose is not good for is making fudge! It comes out much too syrupy.
Safety testing of sucralose has been extensive. For fifteen years, it was subjected to a battery of short-term and long-term animal feeding studies. The results were conclusive. Most of the sucralose dose was excreted unchanged, and even the small percentage that was metabolized yielded compounds that were also excreted. Every bit the animals were fed could be accounted for in their excreta. Any concerns about storage in the body or interference with metabolic pathways essentially evaporated. So diabetics can safely use sucralose. As an added benefit, unlike sugar, this sweetener has no detrimental effect on the teeth. While our bodies cannot break down sucralose, microorganisms in water and the soil readily do so. In other words, the stuff is biodegradable and poses no environmental hazard.
Is there anything, then, to criticize about sucralose? We might be wary of some of the marketing approaches that have trumpeted the safety of this compound by referring to the fact that it is made from “natural sugar.” What a substance is made from is irrelevant; what matters is what the final product is. Its properties are determined not by its ancestry, but by its molecular structure. Hydrogen gas, for example, can be made from water, but it would be absurd to suggest that it therefore has the same safety profile. It’s a different substance, just like sucralose is different from sugar. Incorporation of three chlorine atoms into the sugar molecule converts it into a totally new substance. Sucralose is safe because it has been extensively tested, not because it is made from sugar! One of its other attributes is that it leaves no bitter aftertaste, but unfortunately, I cannot say the same thing for some of the advertising hype about the product.