It's widely accepted that processed carbohydrates, such as white bread and pasta, can contribute to weight gain and its associated diseases, doctors are increasingly concerned about a trend for excluding all carbs  even healthier wholegrains, where the grain is left intact and not processed.

London - Carbohydrates are rotting our brains and contributing to devastating diseases such as Alzheimer’s, an American neurologis says.

David Perlmutter, from Florida, believes that even “good” carbs, such as grains, are severely affecting our brains. And the staples of our modern diet aren’t only increasing the risk of dementia, but contributing to depression, epilepsy and headaches, he believes.

Instead of munching on wheat, carbs and sugar, which he calls the brain’s silent killers, we should revert back to the way our ancestors ate – with more meat and fat.

As Forbes magazine reports: “It’s in the food you eat,” he writes in his new book, Grain Brain: The Surprising Truth About Wheat, Carbs, and Sugar – Your Brain’s Silent Killers. “The origin of brain disease is in many cases predominantly dietary.”

The solution? Going back to the days when fat made up 75 percent of our diet, and carbs just five percent. Protein intake should stay the same as it is, at about 20 percent.

Human genes, says Perlmutter, have evolved over thousands of years to deal with a high-fat, low-carb diet – and despite this, we eat almost exactly the opposite.

He advocates a grain-free, gluten-free diet. “This low-fat idea that’s been drummed into our heads and bellies,” Perlmutter says, “is completely off-base and deeply responsible for most of our modern ills.”

He added: “People get a brain disorder and then wonder what the magic bullet cure will be. They want to treat the symptoms rather than the underlying disease problem. In fact, diet and lifestyle play a huge role in the destiny of a person’s health.”

Research has shown that a high-carb diet may increase the risk of dementia. A study published in Journal of Alzheimer’s Disease found that elderly people who ate a high-carb diet were more than three times as likely to develop mild cognitive impairment – which has been linked with a higher risk of dementia.

People whose diets were highest in “good” fats, such as those found in nuts and healthy oils were 42 percent less likely to get cognitive impairment. Those with a high intake of protein (such as meat and fish) had a reduced risk of 21 percent.

Lead author Rosebud Roberts, a professor in the department of epidemiology at the Mayo Clinic, said: “A high-carbohydrate intake could be bad for you because carbohydrates impact your glucose and insulin metabolism.

“Sugar fuels the brain, so moderate intake is good. However, high levels of sugar may actually prevent the brain from using the sugar – similar to what we see with type 2 diabetes.”

She added that high glucose levels might affect the brain’s blood vessels and play a role in the development of beta amyloid plaques, proteins toxic to brain health that are found in the brains of people with Alzheimer’s. It’s thought these plaques are a leading cause of the disease.

However, Perlmutter’s critics argue that diets high in meat and fat have their own risks – such as heart disease.

“Perlmutter uses bits and pieces of the effects of diet on cognitive outcomes – that obese people have a higher risk of cognitive impairment, for example – to construct an ultimately misleading picture of what people should eat for optimal cognitive and overall health,” St Catherine University professor emerita Julie Miller Jones told the website FoodNavigator-USA. – Daily Mail