Britons with a common heart problem may not have to worry about their caffeine consumption in the future, as up to five drinks a day could reduce their risk of dementia.
Scientists at the University Hospital of Basel, Switzerland, found that people over 65 who suffered from an irregular heart rhythm were less likely to suffer memory-robbing symptoms if they drank a lot of coffee.
Participants who drank more than two beers a day, on average, also had lower levels of inflammatory blood markers associated with the degenerative disease, compared to those who drank less.
Discussing the findings, the researchers said the protective effect may be because the caffeine in coffee reduces oxidative stress, an imbalance of free radicals and antioxidants in the body that usually fight infections.
The study authors also suggested that caffeine decreases the buildup of amyloid (a protein that clumps together to form plaques) and reduces inflammation and cell death in the brain, which may reduce the risk of dementia.
But the Alzheimer’s Society explains that this has only been shown in mice and not humans, meaning the connection is not yet certain.
This follows previous studies showing the benefits of caffeine in old age.
an italian study 2023 found that espresso extracts reduced the buildup of the toxic protein called tau, which fuels dementia, when mixed with brain samples in Petri dishes.
Drinking up to five cups of coffee a day may be enough to reduce the risk of cognitive decline, especially in people with atrial fibrillation (AF), who are vulnerable to the disease.
Other study published in 2021 found that people who drank two to three cups of coffee and two to three cups of tea a day had a 28 percent lower risk of developing dementia compared to those who did not drink at all.
For the study, published in the Journal of the American Heart Association, experts recruited 2,413 adults over 65 years of age with atrial fibrillation (AF).
AF affects 1.5 million Brits and causes random electrical impulses to fire from the upper chambers of the heart (atria), causing the heart rhythm to be erratic.
The condition is also known to increase the risk of cognitive decline because it can increase the risk of suffering a stroke which can trigger vascular dementia, a type of dementia caused by a lack of blood supply to the brain, explains the British Heart Foundation.
Participants were given a nutrition questionnaire and asked to report how much coffee they drank per day.
They also underwent neurocognitive testing using the Montreal Cognitive Assessment, which asks participants to name animals and write down the date and time, and is used to detect signs of dementia.
Blood tests were also performed to measure levels of inflammation in the body, which are used to estimate the risk of heart disease and stroke.
Excessive inflammation is also thought to play a role in triggering dementia by causing brain cells to die, according to the Alzheimer’s Society.
Alzheimer’s disease is the most common cause of dementia. The disease can cause anxiety, confusion and short-term memory loss.
The results were combined to calculate a “cognitive construct score,” which reflected the neurocognitive testing, the Montreal Cognitive Assessment score, and the blood test.
The results showed that those who drank the most coffees (about five per day) scored twice as high as those who drank just one cup.
Montreal Cognitive Assessment score results were also higher among those who drank two or three cups of coffee a day compared to those who drank one.
Additionally, blood tests revealed a decrease in a protein called interleukin-6, which is a marker of inflammation, in the blood with increasing coffee consumption.
High levels of this protein in the blood mean inflammation: the immune system’s response to injury or infection.
Although inflammation can be a good thing because it treats damage or infection, if it lasts a long time and is not resolved it can cause problems.
Common signs of inflammation in the body include fever, mental confusion, and swelling.
Excessive inflammation is thought to trigger dementia by causing nerve cells to die, according to the Alzheimer’s Society.
“Coffee consumption in patients with atrial fibrillation may be associated with improved cognitive performance and a reduction in inflammatory markers,” the study authors concluded.
“Further studies are required to confirm an optimal exposure of three to five cups daily in this elderly population… Coffee consumption should not be discouraged in elderly patients with (atrial fibrillation),” they added.
Around one in 50 people in the UK have been diagnosed with AF.
An estimated 270,000 more people are thought to have AF but remain undiagnosed and unaware of the danger, according to the British Heart Foundation.
AF tends to affect certain groups of people, such as older people and people living with chronic illnesses (such as heart disease, high blood pressure, or obesity).
It can be triggered by certain situations, such as drinking too much alcohol or smoking.
The British Heart Foundation says that caffeine is not a cause of AF. However, the effect of caffeine will vary between people who suffer from the condition.
Although drinking caffeine has proven health benefits, some people are more sensitive than others and may experience palpitations.
The British Dietetic Association (BDA) reports that most people can safely consume up to 300 mg of caffeine a day, the equivalent of three cups of coffee.
This is because studies have shown that an intake of more than 600 mg per day (twice the recommended amount) is linked to insomnia, nervousness, irritability, increased blood pressure and upset stomach.
But if you are pregnant you should not consume more than 200mg of caffeine a day, as this could increase the risk of miscarriage or low birth weight, the NHS warns.