If you can drag your mind back to your biology classes at school, you may remember learning about how we taste food. The tongue has different receptors for the five main categories of taste: sweetness, sourness, saltiness, umami (savory) and bitterness. For a lot of people, sweetness and saltiness are a lot more enjoyable than the sour and the bitter, but those more acquired tastes actually serve an important biological role.
In the case of bitterness, the taste we associate with the darkest chocolate, unsweetened, milk-less coffee, some vegetables and fruit peels, certain cheeses and particular types of alcohol, being able to detect it serves a protective function. A lot of poisons and toxins have a bitter note, which might explain why not everyone appreciates it. It’s a warning system.
Some plants become more bitter as they age. Even when they’re not outright poisonous, this can reflect a reduction in nutritional content such as protein and fiber. As a result, animals that eat leaves tend to be attracted to the younger, tenderer shoots, which also happen to be the ones with the sweeter flavor.
Humans have put the deterrent effect of bitterness to good use. Bitterants, chemicals that make something smell or taste bitter, are added to potentially toxic substances to make them less enticing. For example, some places have laws that bitterants have to be added to antifreeze. Without this additive, the sweetness of the ethylene glycol can prove irresistible – and potentially deadly – to both children and pets.
All this may make it sound like you should avoid bitter-tasting food. It may certainly be cause for caution if you’re trying something unfamiliar. Bitter food does have value, though, making an interesting and gastronomically exciting contrast to the regular sweet and savory. It can be pretty boring to eat when everything tastes the same.
More than this, however, there’s some research that suggests that the receptors we use to detect bitterness may also have a role in keeping our skin healthy. One study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8784259/) found that bitterness receptors aren’t just found on the tongue, but also in skin. There they also have a protective role, helping heal wounds and generally reducing the impact of skin aging.
So, if you’re one of those people who instinctively avoids bitter tastes, don’t worry. It’s natural, but there may be a benefit to trying bitterness anyway.