London - Eating too much red meat could raise the risk of Alzheimer’s disease, researchers have claimed.
A study has found patients with the illness have increased levels of iron in the part of the brain responsible for memory.
The accumulation of the mineral – abundant in red meat – was found to have begun in the part of the brain which is generally damaged in the early stages of the disease.
Scientists studied the brains of 31 Alzheimer’s patients and compared the results against a separate set of brain scans.
They found iron levels were linked to tissue damage in Alzheimer’s patients but not in healthy older folk.
It was not clear whether the build-up of iron was a cause or consequence of the disease but researchers said the results suggest it “may indeed contribute to the cause”.
Professor George Bartzokis told the Journal of Alzheimer’s Disease: “The increase in iron is occurring together with the tissue damage.
“We found that the amount of iron…is associated with tissue damage in patients with Alzheimer’s but not in the healthy older individuals.
“So the results suggest that iron accumulation may indeed contribute to the cause of Alzheimer’s disease.”
He added the accumulation of iron in the brain could be influenced by “how much red meat and iron dietary supplements we consume”.
By reducing the amount of red meat and iron dietary supplements we consume, the amount of iron which builds up in the brain could be reduced, the US researchers claimed.
Professor Bartzokis, who led the study at the University of California, said most Alzheimer’s studies have focused on the build-up of proteins called tau or beta-amyloid. They collect in the brains of sufferers and are thought to either disrupt nerve cells or kill them.
But the latest study suggests iron accumulation is a third possible contributing factor.
Iron is an essential part of our diet and is needed in order for cells to function properly. Too little can be harmful to health but researchers believe it can become toxic if too much is consumed, for example if someone eats a lot of red meat.
The highest iron concentrations in the brain are found in cells which produce myelin – the fatty tissue which coats nerve fibres and allows them to communicate with one another.
The destruction of myelin disrupts communication and leads to the build-up of plaques.
Researchers studied two parts of the brain in the Alzheimer’s sufferers – including the hippocampus, which plays an important role in memory and is usually damaged early in the disease, and the thalamus – which is involved in sensory perception and motor skills.
The thalamus usually remains healthy until a later stage. The scientists found unusually high levels of ferritin – a protein which stores iron – were found in the hippocampus of sufferers but not in the thalamus.
Dr Marie Janson, of Alzhiemer’s Research UK, said: “This study suggests iron could accumulate in an area of the brain critical to memory but it is not clear whether this build-up might be a cause or consequence of the disease.”
Earlier this week US scientists claimed copper could be a major cause of Alzheimer’s progression.
They found copper helps to promote changes in the brain which may both cause and exacerbate the disease.
But they said little could be done as the metal, found in food and drinking water, plays important roles in nerve function, bone growth, the formation of connective tissue and hormone secretion. - Daily Mail