Researchers pinpoint diet followed by millions that may beat dementia

Cutting back on carbohydrates could potentially stave off Alzheimer’s, researchers suggested today.

Calling the strategy a ‘powerful tool for combatting dementia’, they showed reducing the amount of blood sugar in the brain via diet could slash the number of harmful proteins that trigger dementia symptoms.

Carbohydrates are converted to a type of sugar called glycogen, which is a form of energy that’s used by the brain to function. 

While a small amount is needed, the California-based researchers discovered that an excess can bind to a toxic protein in the brain called tau, stopping it from breaking down.

Significant clumps of this protein, as well as another—amyloid—can form plaques and tangles—and this is thought to be behind the symptoms of Alzheimer’s, the leading cause of dementia. 

The latest experiments found high levels of enzymes that break down glycogen in the brain could help destroy the build-up of tau. 

And eating fewer carbohydrates, the researchers, said was an effective way to increase the presence of this enzyme. 

Professor Pankaj Kapahi, an expert in metabolism and brain ageing at the Buck Institute for Research on Ageing in California and study co-author, said the team may have uncovered a new ‘therapeutic strategy’ to tackle dementia early-on.

He added: ‘As we continue to age as a society, findings like these offer hope that better understanding our brain’s hidden sugar code could unlock powerful tools for combating dementia.’ 

In the new study on fruit flies, the scientists found when glycogen can’t be broken down, brain cells lose an essential mechanism for managing oxidative stress that ultimately kills them.

But, by restoring the activity of an enzyme called glycogen phosphorylase (GlyP)—which triggers glycogen breakdown—they could reduce this damage. 

Writing in the journal Nature Metabolism, they said that by restricting certain foods that are converted to glycogen such as carbohydrates, GlyP activity is ‘enhanced’ and sugar levels in the brain reduced.

Professor Pankaj Kapahi also said: ‘This work could explain why GLP-1 drugs, now widely used for weight loss, show promise against dementia, potentially by mimicking dietary restriction.’ 

Slimming injections, known medically as GLP-1 drugs, have ushered in a new era in the war on obesity.

The treatment spurs weight loss by mimicking the actions of a hormone released in the gut after eating—GLP-1.

As well as telling the pancreas to make more insulin, the GLP-1 hormone feeds back to the brain and makes us feel full—stopping patients from over-eating.   

The team hopes that by raising awareness of risk factors—which change as we age—people can take steps to reduce their chances of getting the disease. 

Surveys suggest roughly six per cent of British adults, around two million, follow a low-carb diet or keto diet. 

The trendy diet, previously promoted by celebs including Kim Kardashian and Jennifer Aniston eliminates energy dense carbohydrates like bread, pasta and rice but permits some vegetables—primarily leafy greens.  

There is no calorie counting. Instead, foods must be high fat, and high protein.

This puts the body into a state of ketosis—forcing it to ‘burn’ fat, rather than carbohydrate, for energy.

And this, believe advocates, brings about weight loss. 

But studies have suggested the low-carb plan could raise the risk of heart disease and other deadly cardiovascular conditions.

It comes as a landmark study last July suggested almost half of all Alzheimer’s cases could be prevented by tackling 14 lifestyle factors from childhood. 

World-leading experts found two new risk factors—high cholesterol and suffering vision loss—were, combined, behind almost one in ten dementia cases globally.

They join 12 existing factors, ranging from genetics to smoking status, that experts have identified as increasing the risk a person would suffer dementia.

Experts claimed the study, published in the prestigious journal The Lancet, provided more hope than ‘ever before’ that the memory-robbing disorder that blights the lives of millions can be tackled.

Alzheimer’s Disease is the most common form of dementia and affects 982,000 people in the UK. 

Memory problems, thinking and reasoning difficulties and language problems are common early symptoms of the condition, which then worsen over time.

Alzheimer’s Research UK analysis found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier, making it the country’s biggest killer.