Lentils Alzheimer's Disease accounts for about two thirds of dementia cases in the elderly, so developments in tackling this condition are vital. Although still at an early stage, a recent study, published in The Journal of the Federation of American Societies for Experimental Biology, makes interesting reading. However, it hasn't yet convinced everyone.
Researchers at Temple University in the USA found in a previous study that when mice were fed a diet rich in the amino acid methionine, it could increase their risk of developing Alzheimer's disease. Methionine is found in red meats, fish, beans, eggs, garlic, lentils, onion, yogurt and seeds.
In this latest study their aims moved on to the next stage. "The question we asked now as a follow-up is if, for whatever reason, you had made bad choices in your diet, is there a chance you can slow down or even reverse the disease or is it too late – there is nothing you could do," explained Domenico Praticò an associate professor of pharmacology at the University, who led the research.
The mice were put in two groups. For three months one group was given a diet high in methionine and the other was fed a normal, healthy diet. Then half the group on the methionine diet was changed to a healthy diet for two months. The other group’s diet remained the same as before.
"At the end of the study, when we looked at these mice, what we found – very surprisingly – was that switching to a more healthy diet reversed the cognitive impairment that had built up over the first three months of eating the methionine-rich diet," said Praticò.
"This improvement was associated with less amyloid plaques – another sign of the disease – in their brains." Praticò went on to explain that the cognitive impairment that had been seen after the mice had been on the methionine-rich diet for three months was reversed. After two months on the healthier diet this group of mice were able to function normally.
"What it tells us is that the brain has this plasticity to reverse a lot of the bad things that have occurred: the ability to recoup a lot of things such as memory, that were apparently lost, but obviously not totally lost."
This is not a remedy for Alzheimer’s. It is too early to know how much difference it will make, but the research team are optimistic that a change in diet, alongside a regimen of physical and mental exercises could improve some existing brain impairments.
"This combination won’t cure you, but we believe, as we saw in this study, that it will be able to slow down or even possibly reverse the effects on cognitive impairment," said Domenico Praticò.
"Diet and lifestyle factors remain a magnet for research because they could offer relatively inexpensive ways to fight a disease that ruins countless lives," said Rebecca Wood, Chief Executive of the Alzheimer’s Research Trust
"This research is on mice, but the Alzheimer’s Research Trust is supporting work looking at the effects of this type of diet on people. We look forward to the results but at the moment we don’t yet know if this type of diet could have beneficial effects for people with Alzheimer’s. However, it is important to ensure Alzheimer’s patients eat regularly and healthily as they can be at a high risk of malnutrition.
"Diet can also play a part in Alzheimer’s risk. By taking regular exercise and eating a healthy diet, especially in mid-life, we may help reduce our risk of developing dementia as well as reaping numerous other benefits from living a healthy lifestyle."
As things stand at the moment, dietitian Alison Smith, Public Relations Officer for the Nutrition Advisory Group for Older People (NIAGE) urges caution. “There is no evidence yet that this will have any impact on humans,” she says.
"Dementia has a massive impact on eating, and the impact of Alzheimer’s on nutrition can happen fairly on in the disease. It can be a real struggle to get loved ones with Alzheimer’s to take in enough food. So see a dietitian before making such a significant change as removing protein sources from the diet of someone with this condition."
"Remember that what’s good for your heart is good for your head too," says Alison Cranage, Science Communications Officer at Alzheimer’s Research Trust. "Eat a balanced diet, with plenty of fruit and vegetables and make sure you get enough B vitamins from green vegetables and milk and dairy products.
"Keep your intake of salt and saturated fats low. It’s also a good idea to keep your cholesterol low and your blood pressure at healthy levels."