A curry may be the nation’s favourite meal – but research suggests overindulging in spicy foods could trigger memory loss.
A study of more than 4,500 people found those who consumed 50g of chili a day were twice as likely to complain of having a poor memory.
Eating lots of chili was also linked to a 56 per cent decline in memory over 15 years, the research revealed.
Scientists are unsure as to why the link exists, with some studies suggesting chili’s active component capsaicin could keep us sharp.
However, high doses of capsaicin have been used to ‘deactivate’ nerves that cause pain.
The researchers claim it could therefore affect nerve ‘viability’ and accelerate – but warned the theory is ‘highly speculative’.
Adults who eat more than 50g of chili a day ‘face a higher risk of memory loss’ (stock)
Scientists at Qatar University led the study, which also involved academics from the University of Southern Australia.
‘Chili consumption was found to be beneficial for body weight and blood pressure in our previous studies,’ lead author Dr Zumin Shi said.
‘However, in this study, we found adverse effects on cognition among older adults.’
Dementia – of which the most common form is Alzheimer’s – affects 850,000 people in the UK, according to the Alzheimer’s Society.
And in the US, 5.7 million people live with the disease, according to the American Speech-Language-Hearing Association.
Diet is a ‘modifiable risk factor’, along with smoking and inactivity, the researchers wrote in the journal Nutrients.
Chili is one of the most widely used spices in the world, with intake being particularly high in Asia.
Study co-author Dr Ming Li said: ‘In certain regions of China, such as Sichuan and Hunan, almost one in three adults consume spicy food every day.’
WHAT IS DEMENTIA?
Dementia is an umbrella term used to describe a range of progressive neurological disorders, that is, conditions affecting the brain.
There are many different types of dementia, of which Alzheimer’s disease is the most common.
Some people may have a combination of types of dementia.
Regardless of which type is diagnosed, each person will experience their dementia in their own unique way.
Dementia is a global concern but it is most often seen in wealthier countries, where people are likely to live into very old age.
HOW MANY PEOPLE ARE AFFECTED?
The Alzheimer’s Society reports there are more than 850,000 people living with dementia in the UK today, of which more than 500,000 have Alzheimer’s.
It is estimated that the number of people living with dementia in the UK by 2025 will rise to over 1 million.
In the US, it’s estimated there are 5.5 million Alzheimer’s sufferers. A similar percentage rise is expected in the coming years.
As a person’s age increases, so does the risk of them developing dementia.
Rates of diagnosis are improving but many people with dementia are thought to still be undiagnosed.
IS THERE A CURE?
Currently there is no cure for dementia.
But new drugs can slow down its progression and the earlier it is spotted the more effective treatments are.
Source: Dementia UK
Chili has been linked to a reduced risk of obesity, high blood pressure and even an early death. This is thought to be due to capsaicin lowering ‘internal stress’.
However, animal studies that looked at capsaicin’s role in cognitive function have produced mixed results, with some suggesting it is ‘neurotoxic’.
To learn more, the researchers analysed 4,582 adults over 55 who were part of the China Health and Nutrition Survey between 1991 and 2006.
Of these, 3,302 had their cognitive function assessed in at least two sessions in 1997, 2000, 2004 or 2006.
This involved them being asked to recall 10 words from a list and count backwards from 20.
The participants were also asked to rate their memories on a scale of ‘very good’ to ‘very bad’.
Chili intake was monitored via a three-day food questionnaire during each survey. This included both fresh and dried chili peppers, but not capsicums or black pepper.
Results revealed the more spicy food a participant ate, the lower their cognitive function.
Compared to the participants who never ate chili, those who consumed more than 50g a day had over twice the risk of a self-reported poor memory.
However, the researchers noted 50g of chili a day is ‘not common in Western countries’.
But the participants who ate this much were 56 per cent more likely to report memory decline over the study’s 15 year duration.
The risk was greatest among those with a low BMI, which the researchers called ‘borderline significant’.
Those with an underweight or healthy BMI may be more sensitive to chili than heavier people, they added.
The participants who ate a lot of chili also had a lower income and were more physically active than non-consumers.
Exactly why chili may cause cognitive decline is unclear, with some animal studies even suggesting it promotes having a good memory.
Capsaicin has previously been shown to speed up metabolism, aid weight loss and prevent vascular disorders like strokes.