Kids' food aversion in the genes

Avoidance of new foods, a common complaint amongst children, may be influenced by genetic factors, says new research that could have implications for formulators.

By obtaining a deeper understanding of food preferences and taste, formulators may improve acceptability of new products, tapping into favourite taste and flavours.

"To our knowledge this was the first study to examine the relative influences of genetic and environmental factors on food neophobia measured with a standard scale," wrote lead author Lucy Cooke in the American Journal of Clinical Nutrition .

"The model-fitting analyses produced broadly similar results.

Variation in neophobia scores because of heritable genetic differences was estimated at 78 per cent.

A further 22 per cent of variance was due to non-shared environment effects," added Cooke from Cancer Research UK Health Behaviour Unit.

Childhood food neophobia is problematic because parents stop feeding new foods that children appear to dislike.

Such practices have potentially long term health consequences of low fruit and vegetable intakes during childhood.

Such research may also help explain why children and adults like and dislike foods and could be important for the understanding of eating problems, such as obesity with over 22 million children under five are severely overweight.

For the new study, Cooke and co-workers studied 1913 pairs of identical (monozygotic) and 3477 pairs of non-identical (dizygotic) twins to investigate how genetic and environmental factors contribute to food neophobia.

After asking the parents to answer questions about their children's attitudes and behaviours toward new foods, the researchers calculated that scores were much more similar between monozygotic than dizygotic twins, suggesting that food neophobia is highly heritable.

Indeed, heritable genetic differences explained 78 per cent of the variation in neophobia scores, while factors unique to the individual alone (environmental factors) accounted for only 22 per cent of the variation.

In an attempt to explain the influence of non-shared environmental effects, Cooke and co-workers stated that parents may play a key role by pigeon-holing their children by classing one child as a "picky eater" and treating that child differently at mealtimes.

"[A] focus for future research is the implication of these findings for basic taste acceptance.

Recent work has used twin data to examine the heritability of food preferences, finding that heritability was modest for dessert foods (0.20), moderate for vegetables (0.37) and fruit (0.51), and high for protein foods (0.78)," wrote the researchers.

"It would be of value to gather the information on the general trait (neophobic) and the specific behaviors (food acceptance) in the same study and carry out cross-twin, cross-trait investigations.

"This may suggest directions for linking behavior, biology, and genetics in the field of taste perception," they concluded.

Source: American Journal of Clinical Nutrition Volume 86, Pages 428-433.

"Genetic and environmental influences on children's food neophobia" Authors: L.J. Cooke, C.M.A. Haworth, and J. Wardle