Is like or dislike for dark chocolate genetically determined?

I have friends who can take a good-sized bite out of a raw jalapeno, chew it, and enjoy it. If I tried that, I would turn fire engine red, sweat profusely, and smoke would seep from my ears. I like jalapeno, but can tolerate only small amounts.I was reminded of differences in taste when my family was experimenting with different strengths of dark chocolate bars, starting with 65% cacao, then 70%, 72%, 86%, and finally 100%. I enjoyed all of it except for 100% (which is made for cooking).On the other hand, Mrs. Parker and my daughter had to spit all of it out, and my daughter wiped her tongue with a paper towel hoping it would rid her of the taste. "Repulsion" comes to mind.Dark chocolates tend to have chocolate listed as the first ingredient, as either chocolate, unsweetened chocolate, bittersweet chocolate, or semi-sweet chocolate. Generally, dark chocolates have 60 to 75% of total calories derived from fat. As the cacao and fat percentages rises, you often see less sugar contributing to total calories in a serving. And the bitterness factor rises, thanks to polyphenols. Bitter, acrid, pungent - its all the same to me. Sugar and fat counteract the bitterness.The heat of a jalapeno and the bitterness of dark chocolate are detected by different taste receptors on our tongues.The best-known bitterness receptor detects the chemical called PROP (6-n-propylthiouracil). One fourth of us cant taste it; half of us are moderate tasters; one fourth of us are supertasters. Supertasters can detect PROP in minute concentrations undetectable to others and find it repulsive.But PROP receptors are not the only bitterness detector. So far, about 25 have been identified from human genome sequences. For example, PTC (phenylthiocarbamide) is another bitter chemical taste controlled by genetics.ScienceDaily on Feb. 5, 2001, reported on a study in women that found no difference from PROP tasters and non-tasters in evaluation or enjoyment of white, bittersweet, or bitter chocolate. Researchers noted that fat and sugar counteract bitterness.Nevertheless, I suspect my wifes and daughters strong aversion to dark chocolate is genetic rather than a simple preference or I can take it or leave it attitude. Must be in one of those 24 other bitter-detection genes.What do you think?
updated by @steve-parker-md: 04/25/15 07:31:21AM

Hi Steve,Your comments above made me remember an incident with a Japanese exchange student I once met years ago. We swapped foods: she gave my family dried seaweed, we gave her Vegemite (Australian spread made from yeast extract. Yes it is an acquired taste, preferably from birth for best results). The look that came over her face just from smelling the stuff said it all, there was no way she was going to try it. We didn't fare any better with the seaweed.The point of the above is that while I agree that genetics will make you more or less able to detect taste and odors, what I think matters most is what you have learned to enjoy during your lifetime. Vegemite is similar in falvour and strength to other products like Promite and Marmite, but I can't stand either of the latter. Vegimite is just what I was brought up to eat.So here's a question for you in return: did your wife and daughter grow up only eating milk and white chocolate (as many of us did)?It would be interesting to do a test with your family (if such things are ethical!) I have heard it said that children need to try a new food at least six times to learn to enjoy it. Perhaps you could try this with 60% dark chocoalte over a week or two with your family and see what happens?Langdon

Good points, Langdon.My wife and 12-year-old daughter had little, if any, exposure to dark chocolate in childhood. But neither did I.Neither of them will try the dark chocolates again in the near future!I'm thinking about how our tastes change over time, too. In childhood I couldn't stand tomatoes, broccoli, and Brussel sprouts. Now I enjoy them. Still, could be age-related alterations in gene expression. Complicated and interesting issue.-Steve

Steve:You are on to something here. From what I have read, bitterness receptors in the mouth develop over time: as children we don't have them (or not many of them) and it is not until we hit puberty that they start to develop, and we start to develop a taste for bitter foods.Something similar happens with Brussels sprouts, broccoli, etc. People who are missing a receptor or enzyme in the tongue generally don't like a class of foods; without the enzyme or receptor these foods taste nasty. For example, as a kid if you don't like Brussels sprouts it's highly likely that you won't like other cruciferous veggies: cabbage, collard greens, broccoli, kohlrabi, kale, etc. As their bodies mature, many people develop the receptors or the enzyme and find that foods they have long found they have never liked can actually taste good.One thing I suggest you try in getting your family over the hump so to speak is to take a look at some very high cocoa content milk chocolates. Bonnat makes three milks with 65% cocoa content. They deliver the intensity of chocolate flavor we expect in a dark chocolate and the creaminess we expect in a milk - and they tend to be less sweet than dark chocolates of the same percentage because the milk replaces some of the sugar.


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clay - http://www.thechocolatelife.com/clay/

Thanks for the comments and tip, Clay. Will try Bonnat.-Steve