It’s all in the genes, even your food preferences. And you thought that your food choices were due to your degree of sophistication or financial situation. No, you can only hope that your genetic setup doesn’t require that you survive on Australian rock lobsters, Russian caviar and French champagne. Better your cravings demand Swedish meatballs, German bratwurst and Czech beer to lighten your financial burden.
In the future you will be able to blame your Mum and Dad for your food bias and not the school lunch program insisting that you eat up the fish balls in white sauce that were so disgusting that you had to swallow them whole. You just didn’t have the fish ball gene that seems to be so common among our Norwegian friends. Sorry for digressing here, but did you know that in Norway they even have a fish-based dessert? Yes, probably genes again.
And this new information is based on the findings of Italian scientists from the University of Trieste and the IRCCS Burlo Garofolo Institute for Maternal and Child Health. They have been busy identifying genes and pathways involved in taste perception and food choice and to check their impact on diet-related disorders such as overweight, obesity, and diabetes. Most previous studies have focused on specific taste receptors, especially bitter ones, in an attempt to understand the genetics behind the perception of specific compounds such as caffeine and quinine. The new study covered the whole genome, with the aim of identifying specific genes that drive individual differences in taste perception and food preferences.
The scientists undertook genome wide association studies to try to unravel the genetic basis for certain food preferences. Over two thousand Italian subjects participated in the discovery step, and another couple of thousand from other European countries and from Central Asia were used in order to further verify the findings.
The dark chocolate gene found
Amazingly, the scientists uncovered 17 independent genes related to liking for certain foods, including artichokes, bacon, coffee, chicory, dark chocolate, blue cheese, ice cream, liver, oil or butter on bread, orange juice, plain yoghurt, white wine and mushrooms. Surprisingly, none of the genes identified so far belonged to the category of taste or smell receptors.
There is still much to be done at the detailed level. Although they identified the gene for white wine liking, they still have no idea which of the characteristics of white wine that the gene sought out. It might have been the oaky flavour of a Barossa Valley Chardonnay, or the tropical fruit aroma of a New Zealand Sauvignon Blanc. Who knows?
They also identified the gene sequence responsible for preferring salty foods. Salt perception and the related genetic variation in taste receptors are important determinants of individual differences in salt intake, which in turn represents an important risk factor for the development of hypertension and cardiovascular diseases. Such information could play an important role in the development of salt substitutes, in which there is a growing commercial interest.
Nutritional intervention could be greatly improved by tailoring it to the food preferences of each person. In a related study the gene knowledge was used to personalise diets for some of 191 obese individuals that were trying to lose weight. Half of the group was put on a standard weight-loss diet subtracting 600 calories from individual nutritional needs. The diet of the other half was modified according to the individual genetic profiles. Although there were no significant differences in age, sex and BMI between the two groups at the beginning of the trial, participants in the group with the gene-based diet lost 33% more weight than the other group over two years, and the percentage of lean body mass also increased more.
Diets based on individual genetic profiles
The ability to devise diets based on individual genetic profiles could lead to significantly better personalised nutrition plans effective not just for weight loss but also in avoiding diseases such as cancer, depression, and hypertension. Knowing why individuals prefer certain food tastes and being able to personalise health interventions based on them will help people age in a healthier way and greatly improve their quality of life, as well as engender considerable savings for health systems.
Of course the gene finding is just one part of the complexity of dietary patterns. Just the other day advice on how to get children to increase their vegetable consumption was published. By gradually increasing variety it was possible to train young children to like vegetables, but possibly not Brussels sprouts. Even the Italian scientists pointed out that further studies will be important for understanding the interaction between the environment, lifestyles, and the genome in determining health outcomes.
So Swedish meatballs with French champagne might not be your preferred combination even if your genes insist. Unless you’re born in Sweden.