You raise a good question. Certain flavors can affect health – we know that the obesity epidemic in the United States likely owes a lot to our national taste for sweets. All those sweet sodas, cookies and candy cause blood sugar, insulin, and hunger to spike and then dip – often leading, in genetically susceptible people, to obesity and type 2 diabetes.
We would be better off eating fewer sweets and more bitter foods, which can have the opposite effect, moderating both hunger and blood sugar. Unfortunately, the two most common bitter ingredients in the American diet – coffee and chocolate – are usually heavily sweetened before serving.
The third popular bitter food in this country is beer, which does have some health benefits that appear to stem from a flavonoid in hops called xanthohumol that may also have antiviral, anti-allergic, anti-clotting, anti-inflammatory, and anti-tumor activity. I wouldn’t call beer a health food – the alcohol it contains can damage health when you get too much of it, and it is also is high in calories – but it is likely harmless, and perhaps healthful in limited ways, when consumed in moderation.
We have evolved to find bitter flavor off-putting because bitterness is sometimes a marker for toxicity. However, many nutrient-dense, healthful foods such as Brussels sprouts and leafy green vegetables have a measure of bitterness. The fact that a bitter flavor can activate caution in our species has an upside – it may help dampen appetite. Europeans sip bitter aperitifs before a meal, not a bad idea if you want to lose weight.
Bitter foods also affect health in that they stimulate the liver to produce bile, which is an important part of optimal digestion. Bile emulsifies fats and renders nutrients – especially fat-soluble ones such as vitamins A, D, E and K – more available.
Research has shown that up to 25 percent of the population cannot detect certain bitter flavors, 25 percent can detect exceedingly small quantities and everyone else falls between these two extremes.
You can boost your bitter intake by including radicchio, Belgian endive, and broccoli rabe in your diet. Here are other sources I recommend:
- Bitter tonics: Aside from the well-known Angostura bitters, a proprietary product bottled in Trinidad and Tobago, many small, artisan bitters are now available via the Internet, most are made with extracts of the bitter, nontoxic root of the great yellow gentian, Gentiana lutea, in an alcohol base. While typically added to cocktails, bitter tonics can also be added to nonalcoholic drinks or even taken via mouth spray.
- Bitter melon, Momordica charantia: Widely available at Asian-themed supermarkets and also easy to grow from seeds, this traditional Okinawa favorite may help explain why Okinawans have the world’s longest lifespans. (It is greatly enjoyed in China and India, as well.) Start with the milder Chinese variety, then "graduate" to the more intensely bitter Indian version.
- Dandelion greens, genus Taraxacum, multiple species: There are few healthier habits than regularly eating dandelion greens, which combine the benefits of strong but appealing bitter flavor with extraordinary nutrient density, similar to that of kale. The greens are available in natural foods stores, or pick them from your yard – after making sure no pesticides or herbicides have been sprayed on them and no dogs have visited the area.
Andrew Weil, M.D.
Pollan, Michael, "In Defense of Food: An Eater’s Manifesto," p. 156, Penguin, 2008.
Masé, Guido," The Wild Medicine Solution: Healing with Aromatic, Bitter and Tonic Plants," Healing Arts Press, 2013
Noam Cohen et al, "T2R38 taste receptor polymorphisms underlie susceptibility to upper respiratory infection." Journal of Clinical Investigation. 2012 Nov 1;122(11):4145-59. doi: 10.1172/JCI64240