Eating plenty of leafy greens, seafood and nuts could stave off Alzheimer’s disease, according to new research.
The study suggests iron rich foods help combat the blood disorder anaemia – which affects one in 10 older people.
Researchers say that raises their risk of developing dementia – up to a decade or more later.
Anaemia is caused by low levels of haemoglobin – a protein in red blood cells that carries oxygen to the brain and other organs.
Lead author Professor Mohammad Arfan Ikram, of Erasmus Medical Centre in Hooland, said: “With around 10 per cent of people over age 65 having anaemia in the Americas and Europe and up to 45 per cent in African and southeast Asian countries, these results could have important implications for the burden of dementia.”
He added: “Especially as the prevalence of dementia is expected to increase threefold over the next decades, with the largest increases predicted in the countries where the anaemia rate is the highest.”
Other foods with high amounts of haemoglobin fuelling iron include meat, soy products including tofu, dried fruits such as dates, eggs and seeds.
The study, published in the journal Neurology, found those with anaemia were 41 per cent more likely to develop Alzheimer’s disease, the most common form of dementia. The risk of any type rose by 34 per cent.
It involved 12,305 people with an average age of 65 who did not have dementia at the outset and were tracked for an average of 12 years.
Their haemoglobin levels were measured at the start of the study. Overall, 745 (six per cent) were anaemic.
During the follow-up period, 1,520 of the participants developed dementia. Of those, 1,194 had Alzheimer’s disease.
Of those with anaemia, 128 developed dementia, compared to 1,392 of the 11,560 who did not.
People with high levels of haemoglobin were also more prone to the devastating neurological illness.
This is more rare and usually means there are too many red cells, a condition called polycythaemia
High levels can also be caused by a health problem, dehydration, smoking or living at high altitude.
In the she study participants were divided into five groups based on their haemoglobin levels.
Compared to the middle group, those with the most were 20 percent more likely to develop dementia.
Those with the least were 29 percent more vulnerable than those with average amounts.
The results stayed the same after researchers adjusted for other factors that could affect the risk of dementia such as smoking, high blood pressure, high cholesterol and alcohol use.
Prof Ikram said as the study was observational it does not prove low or high haemoglobin levels cause dementia – it only shows a link.
He added: “More research is needed to determine whether haemoglobin levels play a direct role in this increased risk or whether these associations can be explained by underlying issues or other vascular or metabolic changes.”
In the UK, around 850,000 people have Alzheimer’s or other forms of dementia. This figure is set to rise to 2 million by 2050.
There is still no cure, despite years of research, so there has been increasing focus on ways to prevent it.
The participants were mainly of European descent, and the results may not apply to all populations.
For example, Prof Ikram pointed out a genetic mutation common among people of African descent makes them more likely to have anaemia.
He also noted the prevalence of malaria and sickle cell disease, which can contribute to anaemia, varies around the globe.
