Food tastes better when you’re hungry because nerve changes in the brain ‘make you less fussy about bitterness’
- Electric signals in the brain were seen to change in mice when they were hungry
- These made them less averse to bitter tastes and more attracted to sweet
- Researchers were able to control the mice’s taste preferences deliberately
- And they say this could pave the way to therapies for eating disorders
Food may taste better when you’re hungry because signals in the brain make you less picky, according to research.
Scientists have found that bitter tastes become less offensive to the palate and sweet tastes even more appealing when someone is craving food.
In a study on mice they discovered that electrical activity in the brain changes in direct proportion to hunger.
The Japanese researchers discovered that, when a mouse was hungry, certain electrical pathways out of the hypothalamus area of the brain could alter how their taste buds worked
Researchers from the National Institute for Physiological Sciences in Okazaki, Japan, tested their theory on mice that they had starved.
They looked at a specific type of nerve cell in the hypothalamus region of the brain which are already known to be activated when the animals are hungry.
The hypothalamus is a small region of the brain which plays a role in controlling the appetite, sex drive and emotional responses.
Looking closer at these nerves the Japanese researchers found that they actually controlled the mice’s perception of taste.
When they were activated, they made bitter foods easier to eat.
Researchers said being able to manually switch on or off certain preferences – which they could do in the mice – could point to a way to help obese people eat less (stock image)
Usually, the body does not find bitterness appetising because it tends to be a sign that something has gone off.
And sweet-tasting foods became even more enticing than usual, the tests found – although sweetness is almost always exciting because it indicates something is high in calories and therefore a good source of energy.
Because of this, the animals became more keen to eat either sweet or bitter food.
‘[The] neurons are found in the hypothalamus, which is a brain region that plays a vital role in appetite regulation,’ said author of the study, Ou Fu.
‘We selectively activated these… neurons in mice… to see whether they influence the perception of tastes observed under fasting conditions.’
The team were able to activate the nerve cells in the brain using special fibre-optic light and they could artificially mimic the effects of hunger.
They suggest that being able to control someone’s tastes and how much they enjoy food could help to treat people with eating disorders.
Another author of the study, Yasuhiko Minokoshi, added: ‘The next steps will be to investigate whether these hypothalamic neuronal pathways are altered in pathophysiological conditions such as diabetes and obesity.
‘For example, we already know that people with obesity have a strong preference for sweetness.
‘This might be associated with a change in the activity of [nerve cells in the study].’
The research was published in the journal Nature Communications.
‘EMOTIONAL’ GENES MAY DICTATE SWEET OR BITTER PREFERENCES
The reason you love a dark roasted coffee, a hoppy beer or a sweet cola could be the way it makes you feel rather than its taste, a study found earlier this year.
Researchers from Northwestern University Feinberg School of Medicine in Chicago, Illinois, say they found that it actually come from genes related to the psychoactive properties of these beverages.
This means we actually make our beverage choices based on the mental reward rather than whether we think it tastes good.
Researchers recruited 336,000 people from the UK Biobank study, a long-term study on how genetic predisposition and environmental exposure contributes to the development of disease.
Participants recalled what they ate and drank over a 24-hour period and answered questionnaires.
The team found that the adults made their choices based more on mental reward rather than taste.
For example, people may like the way stimulants, such as caffeine, found in coffee and sodas, wakes them up or causes a euphoric feeling.
Or people may enjoy the calming, anxiety-reducing effects caused by ethanol found in alcoholic beverages.
‘The genetics underlying our preferences are related to the psychoactive components of these drinks,’ said lead author Dr Marylin Cornelis, an assistant professor of preventive medicine at Northwestern University.
‘People like the way coffee and alcohol make them feel. That’s why they drink it. It’s not the taste.’
The research was published in the journal Human Molecular Genetics.