Getting older is an
experience which is mixed for most of us. Experience grows as faculties slip
away. Of course, most of us will agree that things don’t taste like they used
to. Vegetables and fruit from the supermarkets have been extensively bred and,
in some cases, genetically modified to be better shelf products at the cost of
flavor.
We can tell our
grandchildren about how things tasted when we were their age and they listen
politely, look at each other and roll their eyes. But Campa et al have been putting this to the test
in that they have published their study of how our judgment of bitterness
changes with age (1).
They started from the
knowledge that 25% of the variation in human lifespan is at the mercy of our genetic
make up. Taste sensations are favorite metrics among psychologists and ‘bitter’
is one of the five classifications used. Geneticists like to find alleles that
correspond to almost anything that we do, suffer from or enjoy, and they have
‘bitterness’ nicely tagged.
Current wisdom is that
taste and hence the genes sequences that play their part in taste functioning
also play a part in things like appetite, but more importantly in our endocrine
systems secretions so that the function of our livers, pancreases etc. are
influenced by these sequences in our DNA.
As all of this goes
together we see that changes in our tastes may parallel our body aging in a
more important manner than just our complaints about flavors not being what
they used to be. This is what the study of Campa et al went into (1). They chose a group of 941 individuals ranging
from 20–106 years old and checked out their genetic make up. They showed that
the frequency of part of the gene associated with bitter taste sensation
increased with age from 35% to 55% as the age range went from middle age to centenarians.
So it seems that getting
older is a bitter pill to take.
