A new understanding of how genetics affects individual tastes and food preferences may soon bring an age of personalized nutrition with diets specially tailored for predispositions to depression, obesity, and other chronic diseases.
Italian geneticists Nicola Pirastu and Antonietta Robino plan to present findings Monday to the European Society for Genetics after identifying novel genes and pathways associated with one of the most basic questions of human existence: What’s for dinner?
"To date most studies have focused on specific taste receptors, especially bitter ones, and this has been partly successful in an attempt to understand the genetics behind the perception of specific compounds such as caffeine and quinine," Robino said in a press statement. "Our work has expanded these studies to the whole genome, with the goal of clarifying which specific genes drive individual differences in taste perception and food preferences."
In unraveling the genetic cipher, the researchers conducted a pair of genome-wide association studies on more than 2,300 Italians along with another 1,755 people from countries elsewhere in Europe and in Central Asia. In the analysis, 17 independent genes appeared to influence tastes for foods including artichokes, bacon, coffee, chicory, dark chocolate, blue cheese, ice cream, liver, oil or butter on bread, orange juice, plain yogurt, white wine, and mushrooms.
Yet none of those genes belonged to genetic categories associated with receptors for the senses of taste or smell, suggesting a far greater complexity, according to Pirastu.
"There is still much that needs to be done to understand what are the characteristics of certain foods affected by the genetic makeup of an individual," he said in the statement. "For example, we found a strong correlation between the HLA-DOA gene and white wine liking, but we have no idea which of the characteristics of white wine this gene influences.”
The work may also provide new insights into the study of obesity, which typically focuses more on human physiology rather than one’s taste preferences for food, otherwise known as gluttony.
“Although there has been a lot of work on food-related diseases such as obesity, this has rarely taken food preferences into account, Pirastu said. “This is a major limitation which our work attempts to remedy, and as yet, we have only really scratched the surface of this issue."
In the second part of the study, the researchers found a correlation between salt preferences among 900 healthy adults from northeastern Italy and a DNA sequence variation on the KCNA5 gene, a known associated with genetic preferences for salt in mammals. Not surprisingly, such genetically based preferences for salt have been pinpointed as a risk factor for hypertension and cardiovascular disease, Robino says.
“Genetic variations for taste perception are well known for bitter, sweet, and umami taste, but until now we knew little about their role in salt perception and liking," she said. "Identifying the receptor associated with individual differences in the perception of salt could help us better understand how chemosensory differences can interact to influence and predict food choices, and hence, human nutritional behavior.”
With a greater understanding of genetics, the researchers hope industries will work to meet the emerging dietary requirements of the new age.
Source: Pirastu, N., Robino, A. At The Annual Conference Of The European Society of Human Genetics. 2014.