Research on genetics is exploding. Every day we learn more about the influence of genetics on individual behaviors. One set of genes currently being explored are those that affect food preferences. Did you know that there are genetic variations in taste and smell receptors? Receptors are a type of nerve found in the body. One of their jobs is to send signals from the gut to the brain. Individual differences in these receptors may contribute to why some of us identify as having a sweet tooth and others prefer salty flavors.
The science behind how some of these receptors work may explain why some people think cilantro tastes soapy, smell a fragrant odor after eating asparagus or find cruciferous vegetables extremely bitter.
Commonly used in Mexican cooking and Indian chutneys, individuals with ancestry tied to certain regions may be more likely to prefer cilantro than those from other areas. Genetics are thought to be responsible for the difference that leaves some individuals with a soapy taste in their mouth after eating it. However, not everyone with those genes may detect this soapy flavor.
Genes related to the sense of smell, called olfactory genes, come into play with the taste of cilantro. Individuals with an aversion to cilantro possess both the gene that detects the soapy flavor and a variant of an olfactory gene. This olfactory gene variant may make them more sensitive to bitter tastes and be a factor in why individuals find the herb unpleasant tasting.
What's a cilantro hater to do?
- Avoid the herb.
- Crush the herb with a mortar and pestle to break down some of the compounds in the herb that contribute to its taste.
- Substitute other herbs for cilantro such as parsley and basil.
There are many varieties of asparagus - some green, some white and some purple. After you enjoy asparagus, does your urine have a distinctive odor? If so, you are not alone. Studies estimate that about 50 to 65% of people detect this smell after eating the folate-packed vegetable, regardless of the color of the vegetable.
"Asparagus pee" as many call it, is believed to be caused by several compounds found in the vegetable. The exact culprit is not known and a number of chemicals that occur naturally in asparagus are suspect such as asparagusic acid, methanethiol and dimethyl sulfide.
Similar to the genetic profile of cilantro aversion, the gene pattern behind asparagus pee is complex: To smell the fragrant odor, individuals must be genetically wired to produce the right amount of these smelly compounds. Too few and the odor they produce is not detectable by the human olfactory system. Plus, they must have the olfactory gene that transmits the signal to the brain about the asparagus fragrance. Not everyone has the gene needed to detect the odor.
Don't like asparagus? Broccoli, green beans and even canned hearts of palm can be substituted for asparagus in many recipes.
Bitter Brussels Sprouts and Broccoli
Bitter taste perceptions are even more complicated. Take, for instance, vegetables in the cabbage family such as broccoli, Brussels sprouts, cauliflower and kohlrabi. These nutrient-dense veggies are often referred to as cruciferous. Despite the health benefits of these vegetables, many people do not find them tasty.
Many cruciferous vegetables are good, if not great, sources of folate, as well as vitamins C and K. They provide dietary fiber and are low in calories. However, these vegetables also contain several different types of naturally occurring, sulfur-based compounds.
When you eat Brussels sprouts and broccoli, these compounds bind to a bitter taste receptor. That receptor sends a message to the brain. The brain processes that taste sensation as bitter. Depending upon genetics, each of us responds differently to that message of bitterness. Those who like it may be detecting a less intense bitter flavor and odor.
The good news is that many of those who turn their nose up at eating these veggies raw, find their flavor more acceptable after cooking. The reason is that the heat destroys some of the compounds that produce the bitter taste sensation. Try roasting Brussels sprouts and broccoli in the oven.
The Bottom Line
Your genes may be more influential in your food choices than you realize. If you dislike the flavor of certain herbs and vegetables, choose others that you enjoy. With so many tasty options, you don’t have to eat foods you don't like. For personalized nutrition guidance, contact a registered dietitian nutritionist.