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  • Wheat and other glutinous grains are probably the worst starches to consume, in terms of metabolic impact versus micronutrient benefit, and many are heavy in toxins
  • Most people will need some starchy carbohydrates for optimal health; the optimal amount appears to be about 20 to 30 percent of your total caloric intake, or approximately 200 calories per day for the average person
  • The most important consideration is that your carbohydrate sources are as organic and unprocessed as possible, free of pesticides and chemical additives, and not genetically modified
  • Studies now demonstrate that your child’s diet has a direct impact on his or her cognitive function, and that both quality and quantity of carbohydrates are important
 

Grains Rob Your Brain Power - Avoid It for Clearer Thinking

January 23, 2012 | 337,276 views
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By Dr. Mercola

Grains should represent a small part of your diet, regardless of your age. I personally seek to avoid most grains, except rice.

But if you're going to eat some grain-based foods, how much is too much?

This debate heated up earlier this year when two nutritional experts, Dr. Paul Jaminet and Dr. Ron Rosedale, engaged in a debate over how many starches are too many.

Dr. Rosedale believes there is no such thing as a "safe starch" and that all starchy carbohydrates should be avoided, which of course includes all grains.

Dr. Jaminet, on the other hand, is a little more forgiving of some of the "safer starches," such as potatoes and rice. He believes some people need a small amount of these in their diets.

This is an interesting debate.

It's well thought out and well articulated, but quite lengthy.

If you have time, I do recommended you reading through all of it to see the nuances of their contrasting views.

Controversial Carbs

The amount of carbohydrates one should consume for optimal health is a widely controversial topic. Fortunately we can gain some insights as to how much we might need by examining a child's diet, which is critically important for proper brain development. As you would expect, the quality of a child's diet will directly affect his or her cognitive functioning. Two recent studies highlight just how important this is.

STUDY #1: In the first study, Japanese researchers analyzed the relationship between breakfast staples and intelligence in children. They divided 290 healthy children into three groups according to their breakfast staple—rice, bread, or both. What they found was that children in the rice group had significantly more gray matter in their brains and showed a higher perceptual organization index, which is a component of intelligence. This supports the theory that children's breakfast choices affect their cognitive function.

According to the study:

"... [O]ne possible mechanism underlying the difference between the bread and the rice groups may be the difference in the glycemic index (GI) of these two substances; foods with a low GI are associated with less blood-glucose fluctuation than are those with a high GI."

STUDY #2: A 2011 cross-sectional study in Tehran, Iran, examined the relationship between long-term refined carbohydrate intake and non-verbal intelligence among 6 to 7-year-old schoolchildren. Researchers found that refined carbohydrate consumption and non-verbal IQ were inversely related for these Tehrani children. In other words, the more refined carbs the children were eating, the lower their non-verbal IQs. So how much starch is too much starch for breakfast—or any other meal, for that matter?

My Personal Experience with an Ultra-Low Carb Diet

After trying both approaches, my experience suggests that Dr. Jaminet's position is more clinically relevant. The challenge is that most people will not be able to lower their carb level to the below 20 percent suggested by Dr. Rosedale. This very low level is a long reach from the average American diet, which is actually around 50 percent carbohydrate—it is simply too hard. Achieving Dr. Jaminet's far more carb-liberal recommendations will be enough of a challenge for most.

When I eliminated all my grains and starchy vegetables, I actually experienced some negative effects. My energy levels declined considerably, and my cholesterol, which is normally about 150, rose to over 200. It appears I was suffering a glucose deficiency and this can trigger lipoprotein abnormalities. It also seemed to worsen my kidney function. So, while carbohydrate restriction is a miracle move for most people, like most good things in life, you can overdo it.

This information really underscores how important glucose is as a nutrient, and some people can't manufacture glucose from protein as well as others, so they need SOME starches in their diet or else they will suffer from metabolic stress.

About half of your proteins have glucose attached to them, and if they don't have glucose, they simply don't work well, if at all. Your body needs glucose both as a substrate and as a fuel in order for these proteins to work well. If you drop below 200 calories of glucose per day, you might notice some negative consequences in the way you feel and even in some of your blood work, as I did.

My experience now shows me that I need to have some source of non-vegetable carbs. I still seek to avoid nearly all grains, except for rice and potatoes. I typically limit my total carbohydrate calories to about 25 percent of total daily intake, and my protein to about 15 percent, with the additional 60 percent coming from healthful fats like butter, egg yolks, avocados, coconut oil, nuts and animal fat.

However, that is what works for me. You must listen to YOUR body and perform your own experiment. The bottom line is how your body responds, and you're the ONLY one who can determine that.

So, if you are going to try eating some grain-based foods, which ones are the least likely to cause a problem? How damaging is wheat versus rice? Or potatoes? Before casting a vote on this, it is important to understand how grains contain different amounts and types of natural toxins that can create problems with your health.

Avoid Carbs that are Loaded with Toxins

Aside from providing excessive calories as carbohydrates, one of the major adverse consequences of most grains is that they are loaded with toxins. In fact, as you'll learn in the interview above, the average person gets about 1.5 grams of natural food toxins daily, which makes up more than 99.9 percent of all the toxins ingested. These are toxins made by plants, as opposed to manmade toxins, which serve to protect the plant from being eaten by mammals.

The one grain type that is virtually toxin free is white rice, which has far fewer toxins than brown rice. The vast majority of toxins in white rice are destroyed by cooking, which is why white rice is the only grain Dr. Jaminet recommends. One of the grain toxins with which you may be familiar is gluten.

"Gluten" comes from the Latin word for glue, so named because its adhesive properties hold bread and other baked goods together. Gluten is present in grains such as wheat, rye, and barley. The glue-like properties interfere with the breakdown and absorption of nutrients, including the nutrients from other foods in the same meal. The result is a sticky, constipating lump in your gut, rather than a nutritious, easily digested meal.

This undigested glutinous gut-bomb may trigger your immune system to attack the lining of your small intestine, causing diarrhea or constipation, nausea, and/or abdominal pain. Severe reactions are classified as "celiac disease," and milder reactions fall under the category of "gluten intolerance." Over time, your small intestine can become increasingly damaged and less able to absorb nutrients, such as iron and calcium. This in turn can lead to anemia, osteoporosis and other health problems.

Modern wheat (and other grains) differs greatly from the wheat our ancestors ate. The proportion of gluten protein in wheat has increased enormously as a result of hybridization. Legumes are also loaded with lectins, which is why most who follow a Paleo type diet avoid them.

Lectins: The Plant Kingdom's Weapon of Mass Destruction

Lectins are carbohydrate-binding proteins that are widespread in the plant kingdom. Plants produce lectins to ward off their natural enemies, such as fungi and insects. However, lectins are not just the nemesis of fungi and insects, but are also plaguing humans. Please refer to the excellent video above by Chris Meletis, ND, who discusses the many dangers posed by these glycoproteins.

There are many types of lectins.

Some lectins (including those in wheat) bind to specific receptor sites on your intestinal mucosal cells and interfere with the absorption of nutrients across your intestinal wall and into your blood. So, they act as "antinutrients."

Lectins are proteins that are looking to hook up with carbohydrates in your body. C-reactive protein, which is a marker of inflammation, is one example of the many lectins you have circulating right now. Lectins are also used to determine blood type. Lectins trigger inflammation, stimulate a hyper-immune response, and increase your blood viscosity—all conditions that can predispose you to disease.

Wheat Lectin (WGA) is Cytotoxic, Neurotoxic, Cardiotoxic and Immunotoxic

Wheat lectin, or "wheat germ agglutinin" (WGA), is largely responsible for many of wheat's pervasive ill effects. WGA is highest in whole wheat, especially sprouted whole wheat, but wheat isn't the only grain with significant lectin. All seeds of the grass family (rice, wheat, spelt, rye, etc.) are high in lectins.

WGA has the potential to damage your health by the following mechanisms (list is not all-inclusive):

  • Pro-Inflammatory: WGA lectin stimulates the synthesis of pro-inflammatory chemical messengers, even at very small concentrations
  • Immunotoxic: WGA lectin may bind to and activate white blood cells
  • Neurotoxic: WGA lectin can pass through your blood-brain barrier and attach to the protective coating on your nerves, known as the myelin sheath. It is also capable of inhibiting nerve growth factor, which is important for the growth, maintenance, and survival of certain neurons
  • Cardiotoxic: WGA lectin induces platelet aggregation and has a potent disruptive effect on tissue regeneration and removal of neutrophils from your blood vessels
  • Cytotoxic (Toxic to cells): WGA lectin may induce programmed cell death (apoptosis)

Research also shows that WGA may disrupt endocrine and gastrointestinal function, interfere with genetic expression, and share similarities with certain viruses.

The following foods contain chitin-binding lectins, which are very similar to wheat lectin:

Chitins are the primary binding target of wheat lectin; therefore, wheat lectin and chitin-binding lectin are functionally identical. This could be important information if you are struggling with celiac disease or other gastrointestinal issues. For a complete understanding about chitin-binding lectins, please read this article by Sayer Ji.

If You're Sugar Sensitive, Beware of the SWEET Potato

Although sweet potatoes have some excellent nutritional components and are considered a "safe starch" by Dr. Jaminet, many people have problems from eating them because of their high fructose content. Dr. Jaminet actually recommends white potatoes over sweet potatoes. There are many different varieties of sweet potato, all varying in sugar content. An article on the Perfect Health Diet website discusses the difference between conventional sweet potatoes and other varieties.

The American sweet potato has been literally bred for sweetness. If you are trying to tease out the nuances of your potential carbohydrate foods, it's worth noting the differences in the varieties.

The American sweet potato has nearly half the sugar content (6.5g per 100g) of grapes (15.5g per 100g). They are sort of half fruit, half starch! By contrast, yams are far less sweet, with only 0.5g of sugar per 100g. White potatoes actually contain more sugar than yams, at 1.2 g.

The Bottom Line

My conclusion is that there is a certain minimum carbohydrate threshold that you should not drop below. The sweet spot for most is 20 to 30 percent of your diet as carbs, but most likely 25 to 30 percent. Most of those calories can come from non-starchy vegetables, but you'll probably need some starchy carbs, such as white potatoes or white rice, and starchy vegetables like carrots and squash.

Breast milk is considered by many to be the perfect food for infants. Breast milk is 40 percent carbohydrate, which is great for babies because they have an increased glucose demand related to their rapid brain development. Adults simply need less.

Regardless of which starchy foods you put on your plate, make sure they are as organic and unprocessed as possible, free of pesticides and chemical additives and NOT genetically modified. I believe that low toxicity, high quality nutrient-dense foods are the MOST important consideration for you and your child's optimal health, as well as your child's brain development.

Regardless of your dietary choices, please remember to ALWAYS listen to your body, as it will give you feedback about whether or not the approach you've chosen is right for your unique biochemistry and genetics. Listen to that feedback and adjust your program accordingly.

For more information on this topic, you can follow the still-ongoing discussion between Dr. Rosedale and Dr. Jaminet in the Perfect Health Diet: Safe Starches Symposium.

References: