Our cravings for sweetness: nature or nurture?


Posted: 02 April 2014

Our in-built taste for sweet foods helped keep us healthy in early human evolution because it indicated the presence of vitamins and minerals in foods, Professor Hely Tuorila, of the Department of Food Sciences at Helsinki University, told the International Sweeteners Association conference in Brussels yesterday (02-04-14).

“The problem today is that the amount of sweet food we eat has grown out of proportion with the rest of our diet,” said Prof Tuorila. Added to which some people experience cravings for chocolate and other sweet foods that result in them eating “outside normal limits.”

“Likings for sweetness in food and drink also varies between food cultures,” explained Prof Tuorila. “Comparisons between Australia and Japan, for example, show Australian consumers prefer their breakfast cereal sweeter than Japanese consumers who in turn prefer much sweeter orange juice than Australian consumers.”

But how much is our preference for sweetness due to food culture or inherited genetic traits?

“About 50% of our liking for sweet food and drinks is attributable to genetic traits, about the same level of heritability as personality traits or asthma,” said Prof Tuorila.

“The frequency of eating sweet foods seems also to be an interrelated heritable trait and related to emotional, or comfort, eating.

Both findings come from trials by Prof Tuorila and colleagues who studied nearly 900 sets of identical British female twins. “Women of all ages, from 17 to 82 years old, have a strong liking for chocolate, ice cream, sweets, both sugar and low calorie sweetened soft drinks, and fruit – although they never crave fruit.”

While Prof Tuorila found women’s liking for most sweet foods fades slightly with age, their liking for chocolate (and fruit) remains consistently high.

Lifelong liking for sweet foods is similar among Finnish identical male twins, but men in general like sugar sweetened soft drinks and ice cream more than women. “Men also have a stronger liking than the women for pizzas and burgers,” commented Prof Tuorila.

“Living without sweet food and drink is difficult because of its biological, psychological and social role in our lives,” said Prof Tuorila.

Food culture might influence our preferred intensity of sweetness in food and drink, but for some people a genetic ‘sweet tooth’ makes it much harder to live without sweetness. “For those people in particular low calorie sweeteners are especially useful,” concluded Prof Tuorila.

Janette Marshall, Nutrition and Health Journalist