How do we taste things?

Is it possible that the sensitivity of your taste buds may determine how likely you are to get cancer? Although it sounds too strange to be true, this is exactly what some researchers are finding.

It used to be thought that taste perception could be mapped on your tongue: sweet was perceived at the tip, sour at either side, bitter at the back, and salty in the middle. Recent research, however, has indicated that this is incorrect. By cutting the taste nerves that go to the front of the tongue, one would expect a loss in the ability to taste sweet foods. But this doesn't happen. The reason is because taste nerves "talk" to each other. When one is stimulated, it shuts the others down. In other words, cutting a nerve no longer inhibits the other taste nerves, so taste experiences continue.

Supertasters avoid bitter foods that may reduce cancer risk

Our ability to taste, particularly bitter foods, seems to be genetically determined. About 25% of the population (more women than men) are supertasters. Supertasters have 4 times as many tastebuds as nontasters. In these people, the taste nerves (papillae) are densely packed on the tongue, and they are very sensitive to bitter tastes. This means that supertasters don't like to eat bitter-tasting foods like dark breads, some fats, tart citrus fruit, coffee, and certain vegetables.

However, it turns out that bitter-tasting foods like cruciferous vegetables and citrus fruits tend to contain ingredients that may reduce the risk of cancer.

Cruciferous vegetables belong to the cabbage family and include:

  • broccoli
  • cauliflower
  • Brussels sprouts
  • Swiss chard
  • watercress
  • radishes
  • kohlrabi
  • rutabagas
  • turnips
  • bok choy
  • arugula
  • collards
  • mustard greens
  • kale

They contain cancer-fighting antioxidants like vitamin C, as well as phytochemicals, which often act like antioxidants. Antioxidants are beneficial because they "mop up" harmful free radicals that can cause cell or genetic damage that can eventually lead to cancer.

Cruciferous foods also contain plenty of fibre, which can keep foods moving efficiently through the intestines, giving cancer-causing substances less time to cause damage.

So, how do supertasters deal with bitter-tasting foods? Often, they try to mask the bitter taste, perhaps by putting a rich cheese sauce on broccoli, or cream and sugar in coffee. This means they could be eating a lot more fat which, in turn, may increase their cancer risk.

Nontasters like bitter foods and alcohol

At the other end of the taste spectrum are the nontasters, who comprise about 25% of the population. These people have very weak tastebuds, so they like foods with strong flavours - either really sweet or really bitter. However, even though nontasters may enjoy the taste of bitter foods like the cruciferous vegetables, they tend to have problems with alcoholism. Alcohol can be bitter, even irritating to the tongue, a sensation that nontasters don't mind.

Research on supertasters and nontasters may eventually result in some different nutrition recommendations for reducing the risk of disease. Currently, nutrition recommendations for reducing the risk of cancer include eating plenty of fibre, eating less fat, choosing a wide variety of foods, and including plenty of fruits and vegetables. One day, recommendations may include determining if you are a supertaster or a nontaster, and developing specific eating tips for each group.

Ingrid Verduyn, RDN 
in association with the MediResource Clinical Team