Gluten allergies don't exist said a leading doctor last week, which surely should have given comfort to those of us who have avoided wheat grains for fear of headaches and bloating.

But a leading neurologist, Dr David Perlmutter, has said we should avoid grains altogether, as they are contributing to some serious conditions and illnesses such as dementia, depression and chronic headaches.

For those of us who have made the switch to healthier grains such as wholemeal, this will come as disconcerting news.

But the doctor, who has just published Grain Brain: The Surprising Truth About Wheat, Carbs, and Sugar - Your Brain's Silent Killers has said that all grain-based carbs should be eliminated.

He is the founder of the Perlmutter Health Center in Naples, Florida, reported News.com.au, who reported the doctor as saying that our brains thrive on fat and cholesterol but suffer when we eat grains.

grains

"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 in a piece on Mind Body Green, The Surprising Ways Grains Are Destroying Your Brain.

It's his belief that the risk of Alzheimer's disease can be reduced by changing your diet. On his website, he says: "During an appearance on the Dr. Oz show two ago, I was asked to highlight what I would consider to be the three items we should all be working into our diets more frequently to help support better brain health. Not knowing how popular it would later become, I outlined my “Anti-Alzheimer’s Trio,” three foods high in “brain-healthy” fat including grass-fed beef, coconut oil and avocados.

"These items are all low in carbs and high in fat, helping to reduce some of that brain-bullying inflammation the root cause of so many ailments. Specifically, coconut oil is known as a rich source of beta-HBA, is one of our brain’s 'superfuels'."

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  • Walnuts

    Walnuts are chock-full of heart-healthy and anti-inflammatory nutrients, and are the only good nut source of alpha linolenic acid (ALA), <a href="http://www.huffingtonpost.com/2012/06/29/healthy-food-healthiest-list_n_1636409.html#slide=1162293">HuffPost Healthy Living earlier reported</a>. That means they help promote blood flow, which in turn allows for efficient delivery of oxygen to the brain. And <a href="Diseasehttp://alzheimers.org.uk/site/scripts/news_article.php?newsID=730">research presented at the 2010 International Conference on Alzheimer's</a> found that mice with the disease who were regularly fed walnuts had improved memory, learning and motor skill coordination, <a href="http://www.myhealthnewsdaily.com/758-best-foods-brain-health.html">according to MyHealthNewsDaily</a>.

  • Olive Oil

    Olive oil is a great source of monounsaturated fats, which have been shown to <a href="http://www.boston.com/dailydose/2012/05/18/tweaking-dietary-fat-intake-could-help-slow-brain-aging-study-suggests/OO7tmvxhB2E8V0algT7DlL/story.html">actually <em>slow</em> brain aging</a>.

  • Berries

    Animal studies have long indicated a link between berry consumption and brain health. But a recent study published in the <em>Annals of Neurology</em> found that a diet high in blueberries, strawberries and others were linked to a <a href="http://healthland.time.com/2012/04/26/brain-food-berries-can-slow-cognitive-decline/">slower mental decline in areas like memory and focus</a> in a large sample of middle-aged women, reported <em>TIME</em>'s Alice Park.

  • Sardines

    Fatty fish like sardines (<a href="http://www.webmd.com/add-adhd/slideshow-brain-foods-that-help-you-concentrate">and salmon!</a>) are a well-known brain booster, thanks to the omega-3 fatty acids, EPA and DHA, which <a href="http://www.hsph.harvard.edu/nutritionsource/questions/omega-3/index.html">have been linked to lower risk of dementia, improved focus and memory</a>.

  • Coffee

    Caffeine, the mild stimulant found in coffee, improves mental acuity, though the drink's enthusiasts -- <a href="http://www.bbc.co.uk/sn/humanbody/truthaboutfood/best/caffeinebrain.shtml">who guzzle 120,000 tons of the stuff each year</a> -- likely already know that. Aside from caffeine's brain boosting effects, coffee's antioxidant richness helps maintain brain health. And some research suggests that drinking coffee can actually <a href="http://www.huffingtonpost.com/2011/09/27/coffee-cuts-depression-women_n_982122.html">stave off depression in women</a>.

  • Spinach

    Spinach is rich in the antioxidant lutein, which is thought to help protect against cognitive decline, <a href="http://www.nutraconference.com/networknow/public/SessionDetails.aspx?SessionID=1004689&FromPage=nz_ALSessionSearch.aspx">according to researchers from Tufts University</a>. And <a href="http://www.shape.com/healthy-eating/diet-tips/11-best-foods-your-brain?page=11">a longitudinal study at Harvard Medical School</a> found that women who reported eating the most leafy green and cruciferous vegetables had a markedly lower rate of cognitive decline, compared to those who ate the least.

  • Dark Chocolate

    Antioxidant-rich dark chocolate is healthy for your whole body, but its <a href="http://www.huffingtonpost.com/2012/06/18/brain-health-foods_n_1593650.html#slide=1087860">caffeine content is thought to play a role</a> in maintaining mental acuity. What's more, chocolate is rich in flavonoids, a class of antioxidant that helps to improve blood flow (and thus brain health) by regulating cholesterol and lowering blood pressure.

  • Avocados

    Avocados are full of monounsaturated fats that <a href="http://www.webmd.com/add-adhd/slideshow-brain-foods-that-help-you-concentrate">improve vascular health and blood flow</a>, making them another brain food.

  • Water

    When a person becomes dehydrated, their brain tissue actually shrinks. And several studies have shown that <a href="http://www.ncbi.nlm.nih.gov/pubmed/20336685">dehydration can affect cognitive function</a>. Dehydration can impair short-term memory, focus and decision making, <a href="http://www.psychologytoday.com/blog/you-illuminated/201010/why-your-brain-needs-water">according to <em>Psychology Today</em></a>.

  • Beets

    Beets are a good source of naturally-occurring nitrates, which help improve blood flow to the brain, <a href="http://www.shape.com/healthy-eating/diet-tips/11-best-foods-your-brain">according to <em>Shape</em></a>.

  • Garlic

    Garlic may help stave off some forms of brain cancer, according to research published in <em>Cancer</em>, the medical journal of the American Cancer Society. Investigators found that <a href="organo-sulfur compounds found in garlic have been identified as effective against glioblastoma">the organo-sulfur compounds in garlic actually worked to kill glioblastoma cells</a> -- a type of malignant tumor cell.

Dr Perlmutter's belief that grains are not good for the body echoes what other nutritionists have been saying, which is that our body's evolutionary clock is set 10,000 years ago, when we didn't have grains in our diet.

Nutritionist and IBS expert Petronella Ravenshear says: "We’ve changed our diet in the last 10,000 years but our bodies haven't caught up yet. We didn't have things like grains and milk, and now it has become a part of our daily diet. After the second world war people were looking for cheap food sources and cereal and milk became one of them. People came into schools and said you need calcium for strong bones - well, we used to have strong bones without drinking milk because there was no such thing 10,000 years ago.

"We are the only animals that have special foods for breakfast – I say eat what you fancy. If you want eggs, smoked salmon, or a piece of chicken, have it - it doesn’t have to be cereal based – it is not good for us. Gluten is Latin for glue because it has such a sticky characteristic – milk protein is also sticky."

Dr Perlmutter, who also blogs for The Huffington Post US says: "As a practicing neurologist, I place central importance in applying current science to the notion of disease prevention."

Here are his action points to help preserve your brain health and function:

• Reduce your carbohydrate consumption immediately. Shoot for a total of no more than 80 grams of carbs in your daily diet. This means favoring vegetables that grow above ground like kale, broccoli, spinach, and cauliflower as opposed to those that store carbohydrate in the form of starch like potatoes and beets. It means limiting fruit consumption and being especially vigilant with things like fruit juice. A single 12 ounce glass of orange juice contains a full 36 grams of sugar. That's about 9 teaspoons -- the same as a can of soda.

• Eat more fat. Increase your consumption of healthful fats like extra virgin olive oil, avocado, grass-fed beef, wild fish, coconut oil, nuts and seeds. At the same time, keep in mind that modified fats like hydrogenated or trans fats are the worst choices for brain health. Cooking oils like corn oil and soy oil that have been processed to stay on the grocery store shelf for months or even years have no place in a brain healthy program.

• Get at least 20 minutes of aerobic exercise each day. Aerobic exercise actually activates the DNA that turns on the growth of the hippocampus, giving you a second chance at not only preserving, but actually enhancing memory function.

• Add a nutritional supplement providing approximately 1,000 mg of the omega-3 DHA to your daily supplements. Like aerobics, DHA also activates the gene pathway that enhances growth of new brain cells where you need them most -- in the memory center.