IF you had cereal for breakfast or just scoffed a sandwich for lunch, maybe don't read this. Because grains are destroying your brain, according to this doctor.

David Perlmutter, a renowned neurologist and president of the Perlmutter Health Center in Naples, Florida, says there's a close relationship between lifestyle, our modern diet and dementia.

Dr Perlmutter, who has just released a New York Times best-selling book Grain Brain: The Surprising Truth About Wheat, Carbs, and Sugar - Your Brain's Silent Killers says it's not just unhealthy carbs that should be cut.

He says eating grains can lead to dementia, chronic headaches, depression, epilepsy and other health problems.

"Even healthy ones like whole grains can cause dementia, ADHD, anxiety, chronic headaches, depression, and much more," his website says.

Dr Perlmutter, a Fellow of the American College of Nutrition, says our brains thrive on fat and cholesterol but suffer when we eat grains.

He says that Alzheimer's and other debilitating diseases are preventable with major lifestyle and dietary changes.

News_Image_File: Fresh bread is hard to give up. Picture: Thinkstock.

In a piece on Mind Body Green, The Surprising Ways Grains Are Destroying Your Brain, Dr Perlmutter says that despite advances in medical science, society is desperately losing the battle when it comes to the condition.

"Lifestyle factors are profoundly influential in determining risk for Alzheimer's, and yet, perhaps because they cannot be monetised, no one is bringing this information to public awareness," he wrote.

He says the risk of Alzheimer's disease can be reduced by adopting a dramatically lower carbohydrate diet (below 60-80 grams daily), adding more fats - such as extra-virgin olive oil, coconut oil, grass-fed beef, and wild caught fish - to the diet, doing aerobic exercise and taking a DHA supplement.

Dr Perlmutter told Forbes his suggested menu adheres more closely to the way mankind has eaten for most of human history.

"Perlmutter says we need to return to the eating habits of early man, a diet generally thought to be about 75% fat and 5% carbs. The average U.S. diet today features about 60% carbs and 20% fat. (A 20% share of dietary protein has remained fairly consistent, experts believe.)" Forbes reports.

"Human genes, he says, have evolved over thousands of years to accommodate a high-fat, low-carb diet. But today we feed our bodies almost the opposite, with seemingly major effects on our brains."

News_Image_File: Even ancient grains aren't safe, according to Dr Perlmutter. Picture: PERSONAL OZ.

Dr Perlmutter told Forbes low-fat diets are "deeply responsible for most of our modern ills".

He says people who eat more fat tend to store less fat in their bodies.

"We like to think a wholegrain bagel and orange juice makes for the perfect breakfast but that bagel has 400 calories, almost completely carbohydrates with gluten," he told Forbes.

"And the hidden source of carbs in this picture is that 12-ounce glass of fresh-squeezed orange juice. It has nine full teaspoons of pure sugar, the same as a can of Coke. It's doing a service with vitamin C, but you've already gotten 72 grams of carbs.

"It's time to relearn, You can have vegetables at breakfast - the world won't come to an end. You can have smoked salmon, free-range eggs with olive oil and organic goat cheese and you're ready for the day. And you're not having a high-carb breakfast that can cause you to bang on a vending machine at 10am because your blood sugar is plummeting and your brain isn't working."

News_Image_File: No more trips to the bakery. Picture: Getty.

In a recent interview with Next Avenue Dr Perlmutter said food is information.

"It interacts with and instructs our genome with every mouthful, changing genetic expression".

While Dr Perlmutter's position is supported by a range of studies, the controversial author has his critics, who say his book is "misleading and sensationalist".

The Grains & Legumes Nutrition Council (GLNC) strongly contests the theories put forward in Dr Perlmutter's book.

GLNC nutrition program manager Michelle Broom says that current evidence-based science about the impact of grain foods on nutrition and health benefits is contrary to his theories.

"Based on this body of scientific evidence about the impact of grain foods on nutrition and health benefits, GLNC encourages Australians to enjoy grain foods 3-4 times a day, choosing at least half as whole grain or high fibre foods within a balanced diet," she said.

"Dr Perlmutter draws on personal experiences, individual case studies, studies and opinion pieces to substantiate his argument rather than considering the entire body of evidence in a balanced way. As such, Dr Perlmutter's position lacks a conclusive scientific base.

"When the total body of evidence is considered, it is clear the claims that all carbohydrate foods, particularly grain foods, are harmful to the majority of the population don't stack up. In fact the book contradicts this main premise, as Dr Perlmutter's dietary recommendations allow a range of carbohydrate foods in moderation including grains such as amaranth, buckwheat, rice, millet, quinoa, sorghum, teff, oats as well as legumes, fruit and dairy."

Food industry experts have also labelled as nonsense the notion that avoiding carbohydrates is a magic bullet that could head off many cognitive impairment conditions at the pass.

Other medical experts are reportedly worried his readers will interpret the book as a green light to load up on meat and dairy instead, a choice that has its own well-documented cardiovascular heart risks.