Mixtures of artificial sweeteners can change what we taste, and a new study explains how.
Scientists have long known that any artificial sweeteners have a bitter ‘off-taste,’ but when two are combined they taste less bitter.
This new study explains that two artificial sweeteners, saccharin and cylamate, each block the taste receptors that make the other taste bitter.
This means that when you eat or drink something with artificial sweeteners, they could be keeping you from tasting other bitter flavors in the rest of your meal.
Researchers from the German Institute of Human Nutrition analyzed the responses of taste receptors to two artificial sweeteners, saccharin and cyclamate, and how those responses varied when the two sweeteners were combined.
Saccharin and cyclamate were the first two artificial sweeteners to be combined, and it was discovered over sixty years ago that together they were ‘superior to single compounds.’ But no one has known why until now.
The team of German researchers, led by Dr Maik Behrens, identified which bitter and sweet taste receptors each sweetener activated.
They found that saccharin suppresses one of the bitter receptors activated by cyclamate, and cyclamate suppresses two receptors activated by saccharin.
When you ingest the combination, some of your 25 bitter taste receptors are effectively being switched off momentarily (though ‘it’s definitely over a few seconds after you taste it,’ Behrens says).
The two sweeteners in the experiment are some of the oldest sugar-substitutes still in use. They’re also some of the most controversial.
In fact, while it’s legal in Germany, cyclamate is currently banned in the United States. Studies in the 1960s showed that the combination of cylamate and saccharin caused cancer in rats. Though there are no conclusive findings that the combination has the same effect on humans, the FDA has not approved it for use.
Saccharin is still used here, but, more importantly, Behrens says that his team’s method can be used to work out what receptors are activated and suppressed by other combinations of artificial sweeteners and other flavors.
‘If we consider that we usually eat much more complex compounds than these, we can [come to] better understand how we taste,’ using this method he says.
This new knowledge could help the food industry to come up with more natural tasting alternatives to sugar.
Combinations of artificial sweeteners do not taste more intensely sweet together than they would individually, even though they have ‘maximal sweetness.’
In the course of the experiment Behrens and his team found that taste receptors on the tongue are not responsible for this phenomenon, and speculate that ‘information mixing in the brain,’ may be the cause.
It means that our brains may be telling us where our sweetness maximum is. When we drink sodas like Diet Pepsi that use combinations of artificial sweeteners, we are feeding our tongues and our brains a lot of complex, mixed signals.
Bitter taste suppression caused by these combinations of artificial sweeteners can also mask things that should taste bitter, like certain alcoholic drinks, or, more worryingly, other chemicals.
But Behrens says that’s not a bad thing, necessarily.
He hopes that ‘in the far future,’ this new understanding can help make medicines taste better.
‘Some drugs for small children for example can’t be encapsulated, because of risk of suffocation, so it would be very good to have that kind of bitterness blocker,’ he says.