In our culture, bitter gets a bad rap. Case in point: the saying “That’s a bitter pill to swallow.” When it comes to food, we tend to avoid or mask bitter tastes. But should we? The answer—as we talked to experts and waded through studies—is complicated, but, in general, we would do well to embrace the bitter.
The Science of Bitter
It’s no fluke that we tend to react negatively to bitter tastes, says Paul Breslin, Ph.D., professor of nutritional sciences at Rutgers and a Monell Chemical Senses Center researcher. “Most bitter compounds we encounter in the world are toxins,” he explains. “If you taste something that’s extremely bitter, it’s a safe bet there’s probably a lot of toxin in there.” According to Breslin, our bodies contain 25 bitter-taste receptors, designed to act as alarm bells to warn us if we’re ingesting something toxic.
But here’s the catch: Toxins aren’t necessarily bad for us; in fact, they can be very good. “A lot of toxins are also medicines, or another way of putting it is: All medicines are also toxins,” Breslin says. That’s why medicine by itself is unpalatable. And it’s one reason why mildly to moderately bitter foods tend to be nutritious. “Low-level bitter compounds in our foods are good for us,” Breslin says. “They’re little bits of medicine we’re taking all the time.”
Beyond the Mouth
Our bodies’ alarm-bell reaction to bitter tastes may also trigger digestive benefits, studies show. Taste receptors exist not just in our mouths but throughout our whole digestive system—in our nose, lungs, intestines, pancreas, thyroid, liver and more. A lot is still unknown about the roles of the various receptors, but one function is to activate our systems to process what’s coming in.
Bitter herbs have been used before meals since ancient times to improve digestion and maintain blood sugar balance, and researchers are just starting to discover scientific evidence behind that practice. For example, a study published in the International Journal of Food Science and Nutrition found significant digestive benefits in many bitter foods. Multiple other studies show that stimulating the gut’s bitter-taste receptors can reduce appetite and subsequent calorie intake.
To complicate matters more, the experience of bitter is not the same for everyone. For each receptor, we have different genetic sensitivities to how bitter a compound tastes, and different compounds activate different combinations of receptors. That’s why broccoli may taste bitter to one person and not at all to another.
What we don’t know, Breslin says, is whether the digestive benefits of bitter foods diminish when we don’t taste them as acutely. Regardless, bitter foods tend to be loaded with fiber and other nutrients with benefits that outlast any momentary displeasure we might experience.
Did you Know?
If at first you don’t like the bitter…try, try again. A 2019 University of Buffalo study found that people tend to like bitter foods more—or at least dislike them less—the more they eat them.