A common stomach bug carried by two in three people may increase the risk of developing Alzheimer’s, a study has found.
Researchers at McGill University found that people who contracted helicobacter pylori had an 11% higher risk of developing the condition.
Helicobacter pylori is a bacterium which is found in contaminated food, water and soil.
Around 40% of Britons and two thirds of the world’s population carry the bacteria in the stomach.
However, just 15% of people will suffer symptoms including indigestion, gastritis, ulcers and even stomach cancer.
The bacteria can be spread from person to person through bodily fluids. Risk factors for infection include crowded living conditions, lack of clean water and living close to someone who is infected.
For the study, academics studied the health records of more than four million Britons aged 50 and above between 1988 and 2019.
The increased risk of developing Alzheimer’s peaked at 24% between seven and 10 years after infection with the bacteria. It then declined after a decade.
Experts said the results suggest that the bacteria could access the brain, potentially leading to inflammation and neurodegeneration.
It could also affect the gut, causing an overproduction of amyloid – a protein that clumps together in the brains of Alzheimer’s patients and is believed to be toxic to cells.
The team at McGill said that eradicating the bacteria could prevent 200,000 cases of Alzheimer’s every year.
There are currently 900,000 people living with dementia in the UK and this is projected to rise to 1.6 million by 2040, according to the Alzheimer’s Society.
Dr Paul Brassard, the study’s senior author and a Professor in McGill’s Department of Medicine, said: “Given the global ageing population, dementia numbers are expected to triple in the next 40 years. However, there remains a lack of effective treatment options for this disease.
“We hope the findings from this investigation will provide insight on the potential role of H. pylori in dementia in order to inform the development of prevention strategies, such as individualized eradication programs, to reduce infections at the population level.”
The study was published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
