Download Taste, food preferences and diet

Taste is the most important factor of food preference/choice. The recent identification of taste
receptors provides new perspectives on the interaction between genes versus the environment
and food preferences and intake.
Genetic variations in taste perception are well known for bitter, sweet and umami taste. In
particular, TAS2R8 gene polymorphisms have a key role in determining differences in the
capacity to perceive bitter compounds such as PROP (6-n-propylthiouracil) and PTC
(phenylthiocarbamide) which are tasted bitter to some people, “called tasters”, but are tasteless
to others, so-called “no tasters”. However, TAS2R38 gene accounts for up to 85% of phenotypic
variance in PTC/PROP perception, suggesting that other factors (genetic or not) may also
contribute to PROP/PTC responsiveness. Little is known on the genetic bases of human salt
and sour perception. Updated data on genetics of taste will be presented and discussed.
Moreover, sensitivity to the bitter taste of PROP or PTC has been associated with differences in
food preferences, although this relationship has not been fully elucidated yet. Food preferences
are the first factor driving food choice and thus nutrition. They involve numerous different senses
such as taste and olfaction plus numerous other factors such as personal experiences and
hedonistic aspects. Although it is clear that all of these have a genetic base up to now very
limited studies have been conducted. Moreover recent literature suggests that food likings and
preferences probably reflect actual consumption better than food frequency questionnaires. For
these reason we have conducted the first large scale GWAS on food likings that comprises
more than 4000 people coming from Europe and Central Asia. Food likings were assessed for
42 individual food likings through a standard 9-point scale questionnaire. Finally genome wide
association analysis was conducted on each population. Two step meta-analysis revealed a
series of genes most likely involved in food preferences for Artichokes, Bacon, Broccoli, Coffee,
Chicory, Dark Chocolate, Blue Cheese, Ice Cream, Liver, Oil or Butter on Bread, Orange Juice,
Plain Yogurt, White Wine and Mushrooms. None of the identified genes encode for taste or
olfactory receptors highlighting new genes and pathways correlated to food preferences.
These results represent a first step in uncovering the genes that underlie liking of common foods
which in the end will greatly help understanding the genetics of human nutrition in general.
Finally, the comprehension of the genetic basis of taste perception, food preferences, and their
relation to obesity and eating disorders in specific populations is essential to elaborate
preventive plans.