October 12, 2010

Nobel Conference: Linda Bartoshuk

"Variation in sensation and affect: We live in 'different taste worlds'"

Linda Bartoshuk, Ph.D., Presidential Endowed Professor of Community Dentistry and Behavioral Science, University of Florida, Gainesville

Linda Bartoshuk's lecture was all about supertasters, and it started with a short (optional) questionnaire and a test to find out whether we were supertasters, nontasters or somewhere in the middle of the spectrum. I'm dull. As before, below is my summary of the lecture in tweets. The full lecture, including the Q&A afterward with all the invited speakers, is available on YouTube.
  • Five senses is an oversimplification based on collapsing many types of somatic sensation.
  • Traditional tongue map bogus. Based on a mistranslation of a thesis.
  • Flavor is a combination of retronasal olfaction (flavor forced up from the mouth) and taste.
  • Brain can sense difference from nasal odor sources and retronasal sources, sniff vs. chew. Treated differently.
  • Can't taste or smell fats, only impurities in the fat. Fat molecules too large.
  • Tongues of supertasters have 4-12 times as many fungiform papillae as normal tasters.
  • Supertasters match normals on relative ratings of sweetness but rate twice the sweetness on an external intensity scale.
  • Supertasters experience greater reaction to capsaicin, greater oral pain, more intense mouth feel from food.
  • Adding a taste sensation (sweet, salt) intensifies perception of flavor. Supertasters experience more flavor.
  • Supertasters experience less cardiovascular disease, have lower BMI. Fat becomes cloying.
  • Supertasters drink less; alcohol is bitter. They also eat fewer veggies; experience higher risk of colon cancer.
  • None of the differential health risks discussed are large, merely present.
  • Bitter is a poison-detection system. Taste nerve vulnerable to simple ear infection. "I wouldn't have designed it that way."
  • Ear infections can also damage fat sensation, leading to weight gain.
  • Among sample of male supertasters with a history of otitis media, two were not overweight or obese. Large effect.
  • Supertasters have extreme food likes and dislikes. Now testing to see whether they have more extreme preferences in general.
  • Currently a project going on to determine which volatiles make tomatoes the most palatable by inclusion or exclusion.
  • Umami originally a marketing campaign for MSG. Are glutamate receptors on the tongue, but not a basic taste.
  • Protein breaks down in digestive tract, binds to glutamate receptors in stomach & produces conditioned food preference.
  • Can use a novel food as a "scapegoat" to avoid conditioned food aversion to normal diet in kids receiving chemo.
  • About 25 genes for bitter taste. All are on a continuum, but a supertaster for bitter is for sweet, salt, sour as well.
  • Fake fat is foiled by our conditioned food responses. If it isn't real fat, we stop responding to it.


Glendon Mellow said...

These are fascinating posts, Stephanie.

Jason Thibeault said...

I actually blogged a while back about how I learned the taste map was completely wrong. If you don't mind a self-pimp, it's right here.

I've always been kind of jealous of supertasters. But then I remember that I like coffee, and I get over my jealousy.

Stephanie Zvan said...

I'm glad you're enjoying them, Glendon. I wasn't planning to do that much tweeting and otherwise promoting the conference, but they didn't have a lot of other social media resources available, and I do have an audience that's likely to be interested in this sort of thing. I may contact them about using Twitter and their blog more effectively, even if that means I do part of it for next year. I'm pretty excited about the topic for that one too, "The Brain and Being Human."

Jason, pimp away. I use my blog to promote yours. I don't see why you shouldn't. I'm laughing my ass off over you "liking" coffee, though. Addict. :p