advertisement
13 March 2012

Meat-eating animals lose taste for sweets

European and US scientists said that many meat-eating animals lose their ability to taste sweet flavours over time, a finding that suggests diet plays a role in evolution.

0

European and US scientists said that many meat-eating animals appear to lose their ability to taste sweet flavours over time, a finding that suggests diet plays a key role in evolution.

Most mammals are believed to possess the ability to taste sweet, savoury, bitter, salty, and sour flavours, said researchers at the Monell Chemical Senses Centre in Pennsylvania and University of Zurich, Switzerland.

After previously describing how this sweet-sense is lost in domestic and wild cats due to a gene defect, the same team examined 12 different mammals who subsist mainly on meat and fish and focused on their sweet taste receptor genes, known as Tas1r2 and Tas1r3.

Seven of the 12 were found to have varying levels of genetic mutations in the Tas1r2 gene that make it impossible to taste sweets, including sea lions, fur seals, pacific harbour seals, Asian small-clawed otters, spotted hyenas and bottlenose dolphins.

Dolphins have inactivated receptor genes

Sea lions and dolphins – both believed to have evolved from land mammals who returned to the sea tens of millions of years ago – tend to swallow their food whole, and show no taste preference for sweets or anything else for that matter, the researchers said.

In addition, dolphins appear to have three taste receptor genes inactivated, suggesting they do not taste sweet, savoury or bitter flavours.

However, animals who are exposed to sweet flavours – such as raccoons, Canadian otter, spectacled bear and red wolf – maintained their Tas1r2 genes, suggesting they can still taste sweets even though they consume mainly meat.

Sweet taste is a universal trait in animals

"Sweet taste was thought to be nearly a universal trait in animals. That evolution has independently led to its loss in so many different species was quite unexpected," said senior author Gary Beauchamp, a behavioural biologist at Monell.

"Different animals live in different sensory worlds and this particularly applies to their worlds of food," he added.

"Our findings provide further evidence that what animals like to eat – and this includes humans – is dependent to a significant degree on their basic taste receptor biology," said Beauchamp.

The research appears in the US journal the Proceedings of the National Academy of Sciences.

(Sapa, March 2012)

Read more:

Animals

Seals

  

 
NEXT ON HEALTH24X
advertisement

Read Health24’s Comments Policy

Comment on this story
0 comments
Comments have been closed for this article.

Live healthier

Mental health & your work »

How open are you about mental illness in the workplace?

Mental health in the workplace – what you can do to help

If you know that one of your colleagues suffers from a mental illness, would you be able to help them at work? Maligay Govender offers some helpful mental health "first aid" tips.

Sleep & You »

Sleep vs. no sleep Diagnosis of insomnia

6 things that are sabotaging your sleep

Kick these shut-eye killers to the kerb and make your whole life better – overnight.