Are you a supertaster: DNA testing

In the last two posts I’ve discussed counting the taste bud containers (papillae) on your tongue or using a bitter test strip to determine taste sensitivity. There’s one more option: genetic testing. A DNA analysis will reveal whether you’ve inherited the dominant gene for bitter taste sensitivity from both parents. If you have, there’s a high probability you’ll experience food and drink with the taste buds of a supertaster.

An analysis of your genes will not only tell you about inherited traits, like bitter taste perception and earwax type, but about your ancestry and your risk for certain diseases. Do-it-yourself genetic testing is now available on the Internet. You simply send a test tube full of saliva to a lab and the results are sent directly to you, the customer. There’s controversy in the medical profession about whether this is an advisable practice. Is it wise to absorb confusing and potentially disturbing medical information on your own or should a physician/genetics counselor spoon feed you the results?

What your genes tell you (for a price)

Image source: Newsweek

Currently there are three high-profile, do-it-yourself DNA-testing companies: deCODEme, Navigenics, and 23andMe.

deCODEme will calculate your “genetic risk” for bitter taste perception, but only as part of their complete scan. Price: $985.

Navigenics position themselves above the fray of the merely curious. They pride themselves on testing only for conditions that are actionable, for example, can you delay onset of a disease or benefit from early detection. They also limit testing to conditions where quality research shows a definitive link between genetic findings and disease. An additional constraint is that the condition must be “medically relevant.” You could make a case that bitter taste perception, which influences what we eat, is relevant to heart disease and diabetes, but the quality research is scarce. The price tag for Navigenics’ premium genetic test, the Health Compass, is $2499.

23andMe is a Silicon Valley start-up that’s received a lot of good publicity, like being the number one 2008 Invention of the Year in Time Magazine. For $399 the company will read 500,000+ locations in your genome and return the data to your computer. They provide research information on 100+ diseases, conditions, and traits. One of those traits is bitter taste perception.

Think twice, order once

There are a few reasons you might not want to go the genetic test route.

One, it’s expensive. If all you want to know is your supertaster status, look at your tongue or take the taste strip test.

Two, the genetics of bitter taste sensitivity is more complex than knowing if you have dominant or recessive genes in the one location clearly associated with sensitivity. As I mentioned in The Genetics of Supertasting, there are up to 35 other genes that could be involved in bitter taste sensitivity. Although it’s rare, it’s possible to be highly sensitive to bitter tastes even when your DNA test predicts otherwise. The science of genomics, which studies the interaction of genetics and the environment, is still young.

Three, as I mentioned above, the medical profession has serious reservations about do-it-yourself genetics testing. Cynics might think doctors object because they’re afraid of losing your business, but if anything they appear concerned that you’ll come into the office with your genetic test results and they won’t know what to tell you. Reasons for medical caution include:

• The accuracy of the testing is not known.
• The relationships between the genetic data and disease are highly complex and not fully understood.
• It’s questionable whether risk factors such as genetic markers are actually associated with subsequent disease.
• There’s no evidence (yet) that awareness of genetic risk markers leads to modifying behavior, for example, losing weight if the test indicates a predisposition for heart disease or diabetes.
• Conversely, there’s some concern that if a test tells you you’re not at risk, this may lead to unhealthy behavior, for example, overeating and not exercising.

Given all this, it’s not clear that do-it-yourself genetic testing is worth the price. If you’re concerned about disease, you’d probably be better off with a healthy diet, not smoking, and moderate exercise.

Related posts:
A matter of taste
How do you taste?
Orange juice and toothpaste
What is a supertaster?
The genetics of supertasting
Are you a supertaster: Do you really want to know?
Are you a supertaster: Look at your tongue
Are you a supertaster: How does PROP Taste to you?
Why do we love high-fat foods?
Do we taste fat?
The taste advantage
“Killer” grapefruit?
Grapefruit and the Pill
This is your brain on sugar — and sugar substitutes
The Pepsi challenge: How beliefs affect what you taste