"Let's face it: Food is one of life's great and dependable pleasures. If we eat well in the sense of flavor and pleasure, we will also eat well in terms of health."
—Barbara Kafka, The Opinionated Palate

Each of us has a personal range of foods we enjoy. Our preferences for some foods over others result from a complex interplay among many factors such as genetics, age, early food experiences, ethnic customs, pleasantness of surroundings when trying a new food and physiological reactions to a food.

One thing is clear: The flavor of foods is a most compelling influence in shaping our food choices. In the Food Marketing Institute's Trends in the United States (1998), consumers rank taste as the number one reason for selecting foods, with nutrition placing second. According to The American Dietetic Association's 1997 Nutrition Trends Survey, consumers are attuned to nutrition messages, but fear that eating a more healthful diet means giving up favorite foods. Nutrition communicators can combat these fears by assuring consumers that healthful and delicious eating go hand in hand.

This article explores genetic and age-related factors that influence taste, and strategies for motivating more healthful eating habits by keeping flavor at the forefront.

More to Taste than Meets the Tongue

What we commonly call the "taste" of food is really "flavor," which largely results from the interaction between the senses of taste and smell. Other sensations from foods (think of the burn of a hot pepper, the bite of a peppermint or the fizz of a carbonated drink), as well as texture, temperature and appearance all add to the flavor experience.

As much as 80 percent of what we perceive as "taste" is actually smell. Humans can discern about 20,000 different odors and 10 intensities of each. Smell occurs when odors reach olfactory receptors in the nasal cavity via two routes: inhalation through the nostrils and through the back of the mouth as we chew and swallow.

True taste occurs on the tongue. We are born with 10,000 taste buds located on the back, sides, and tip of the tongue, on the palate, and in the throat.

When taste receptor cells within the taste buds are excited by chemical stimuli, they detect five primary sensations: sweet, sour, salty, bitter and "umami," the savory taste of glutamate found in protein foods and monosodium glutamate (MSG). Each taste is sensed throughout the tongue, though we experience some tastes more prominently in certain areas: sweet on the tip, sour on the sides, bitter on the back and salty mostly around the front.

Taste Changes through the Ages

Our first flavor experiences are sweet ones, said Gary Beauchamp, Ph.D., director of the Monell Chemical Senses Center in Philadelphia, part of the University of Pennsylvania. "A variety of tastes and odors are transmitted through the amniotic fluid to the fetus," said Beauchamp. "Unborn infants appear to detect sweetness and newborns clearly sense and enjoy sweet tastes." Infants seem to experience the other primary tastes to varying degrees. The ability to detect bitter, salty, and umami tastes continues to develop throughout the first few months of life. The sour taste is at least somewhat developed at birth, but it's not clear whether further changes occur as infants get older.

Breast-fed infants receive early exposure to a variety of flavors because breast milk carries the flavor of foods and spices eaten by the mother. Whether these and other early taste experiences affect food preferences later in life is the subject of ongoing research at the Monell Center.

At about age 60, even healthy people begin to experience a modest decline in taste and more dramatic declines in smell. "Taste and smell changes in the elderly result from normal aging, medications, certain illnesses such as Alzheimer's disease, radiation therapy and even environmental factors such as pollution," said Susan Schiffman, Ph.D., professor of Medical Psychology at Duke University Medical Center in Durham, North Carolina. "It's difficult to separate out an exact cause of these declines."

Dulled taste and smell often result in a waning appetite, which puts the elderly at risk for malnutrition, weight loss and increased susceptibility to disease, and makes following a therapeutic diet especially challenging. "Amplifying food flavors for older people can enhance their appetites and help improve their nutritional and immune status," said Schiffman. She suggests using cheese, bacon bits, or butter-flavored powder to punch up food flavors. Apricot and peach nectars and pineapple juice intensify the flavor of sauces in dishes such as sweet and sour chicken.

Super Taster—A Bitterly Sensitive Bunch

When your child, client or co-worker balks at eating spinach, broccoli or Brussels sprouts, chalk it up to, well, bad taste. You may be dealing with a "super taster" whose taste buds are highly tuned in to-and turned off by-bitter compounds found in foods such as pungent vegetables, grapefruit juice, wine, green tea and espresso.

"About 25 percent of the population are genetically programmed to be super tasters who sharply detect bitter compounds in food," said Adam Drewnowski, Ph.D., director of the Nutritional Sciences Program at the University of Washington in Seattle, and an expert on taste and food choices. "Half the population detects these compounds to some degree, and another 25 percent don't detect them at all."

What makes super tasters so bitterly sensitive to some foods? Compared to their less discriminating brethren, super tasters' tongues are crammed with many more fungiform papillae, the little bumps on the tongue that house the taste buds. About two-thirds of super tasters are female and the hypersensitivity fades with age. One theory is that long ago super tasting served as a species survival mechanism. "Perhaps the characteristic discouraged pregnant women from eating poisonous plants or berries, which tend to taste bitter," said Drewnowski.

Ironically, many of these bitter substances are disease-fighting phytochemicals that may be beneficial to health. Super tasters can help the vegetables go down and optimize nutrient value by adding a bit of butter or oil to their dish. According to Drewnowski, "Fat improves the flavor of vegetables by masking the bitter taste and helps promote absorption of fat-soluble phytochemicals such as the beta carotene in carrots, the lycopene in tomatoes, and the lutein in spinach." Tasteful Recommendations

"If a food doesn't taste good, people aren't likely to eat it-nor are the health professionals who counsel them," said registered dietitian and culinary expert Mary Abbott Hess, M.S., R.D.. "Remember, we don't all like the same foods, or taste a particular food the same way." That's why it's important to work with individuals' personal food preferences. For instance, show them how to fit a favorite dish that's higher in fat, sodium or sugar into a healthful meal plan, rather than automatically suggesting an alternative.

"Effective nutrition counseling involves the art of balancing individualized nutrition advice with health needs, lifestyle factors and taste preferences," said Ms. Hess. Keeping food pleasure at the forefront is an essential ingredient for lasting success.

Taste Tidbits

• Taste buds first appear when a fetus is seven or eight weeks old, and are functioning by the third trimester of pregnancy.
• When kids stick their noses up at spinach and ask for sweets, perhaps Mother Nature is to blame. Sweet foods in nature such as mother's milk and fruit are rich in the calories infants and children need for growth; extremely bitter plants and berries may be a warning of a poisonous plant.
• Ever wonder why you can't taste food when you have a cold? It's because the cold dulls your sense of smell, which is largely responsible for taste perception.
• Burning your tongue kills some taste buds, but they regenerate within a few months.
• The taste "umami" means "deliciousness" or "wonderful taste" in Japanese. Umami is the taste effect of monosodium glutamate (MSG), which is described as brothy, meaty and savory.

Try this test to see whether you're a super taster:

Using a hole punch, punch a hole in the middle of a one-inch square of wax paper. Place the hole on the tip of your tongue. Swab some blue food coloring on the exposed part of the tongue and, using a magnifying glass and a flashlight, count the number of fungiform papillae (the pinkish circles). Super tasters will have dozens of papillae; non-tasters will have only five or six. Taste Tips, Tricks and Techniques

Hess offers this "winning recipe" to help people adopt more healthful eating habits: Combine personalized nutrition advice with a generous sprinkling of ideas for making foods delicious and appealing. Nutrition counselors can maximize the effectiveness of their advice by mixing in taste-enhancing tips such as these:

• Plan meals that include a wide palette of colors and shapes for eye-appeal, and a variety of textures and temperatures for tongue-appeal.
• Perk up food flavors with small amounts of intense-flavored ingredients such as sharp cheese, toasted nuts or fruity olive oil.
• Try a spoonful of cheese sauce, a shaving of sweet butter or a drizzle of creamy dressing to add luscious flavor to bitter vegetables and salad greens, and promote absorption of fat-soluble nutrients.
• Enhance the natural flavor of foods with reduced/concentrated stocks, monosodium glutamate (MSG), flavored vinegars, zesty condiments or an extra dash of herbs or spices.
• Stave off taste fatigue. Encourage older adults to alternate between bites of food with different tastes, temperatures and textures.
• Try shakes made with coffee or chocolate extracts to mask a bitter taste from medications.
• Be adventurous! Expand your tastes to enjoy a variety of foods. Your taste buds will thank you.