Tuesday, April 13, 2010

Why We Eat Grains

From Stock Photos
I scoured the internet looking for reasons to eat grains. I want to find out what grains (unprocessed, whole grains) have that fruits and vegetables do not. Is there a reason that we need to eat grains?

Reason #1 - According to the American Heart Association's Grocery Shopping tips, grains, or in this case, breads, provide fiber. This is true.

Reason #2 - The Mayo clinic states that grains contain vitamins and minerals. Again, this is a valid statement.

Reasons #3&4 - The Whole Grain Council adds antioxidants to the list of benefits as well as this statement: "The medical evidence is clear that whole grains reduce risks of heart disease, stroke, cancer, diabetes, and obesity. Few foods can offer such diverse benefits." I can agree with the antioxidant statement and will even support that there have been studies showing that grains have been shown to be effective in reducing the risks of several diseases. Although it is difficult to hold back, I will not get into the validity of those studies in this post, I will just acknowledge their existence.

Reasons #5&6 - From the Wheat Foods Council, we get the fact that wheat contains folic acid which reduces the risk of birth defects.

Reasons #7-31 - Kansas State (linked via the Whole Grain Council) states that grains provide energy, B vitamins, vitamin E, selenium, zinc, copper, magnesium, tocopherols, beta-carotene, vitamin C, folate, glutamine, phytoestrogens, lignans, flavonoids, oligosaccharides, inositol, phenolics, saponins, lectins, protease inhibitors, decrease cholesterol, and reduces the risk of type 2 diabetes and obesity.

A lot of these resources have a financial interest in the consumption of grains and I have used their information in the attempt to keep a balanced perspective. All of the resources above neglected to mention which grains were used in their nutritional studies and what the nutritional content would be after processing and cooking. Without attacking grains (yet), let's just look and see if we can get the same benefits from a couple of vegetable staples.
From Stock Photos
From Stock Photos

After looking at several nutritional websites, I found that a bell pepper and floret of broccoli contain all of the same vitamins, minerals, and other phytochemicals that make grains beneficial to our health, albeit in different amounts. An interesting thing to note is that some nutrients listed as present in grains are also produced naturally within the body, meaning there is no reason to ingest them. We can conclude from this that vegetables can provide the same health benefits as grains. I think that any rational person would agree with me so far.

My sources of nutritional info:

Seeing how veggies and grains provide similar nutrients, I'd like to take a look at the negative effects of veggies and grains.

It would be easier to look at veggies first. Well, its pretty tough to find any negative sides to eating vegetables. Some nightshade vegetables (tomatoes, potatoes, bell peppers, etc..) seem to irritate arthritis and neurological conditions in a small number of people. However, for the most part, vegetables seem to be relatively consequence free for a majority of people.

Grains, on the other hand, seem to have a few more issues. A lot of my info for the rest of this article is pulled from this study, which compiled well over 300 reputable sources into a 55 page report on the effects of grain consumption. Here, I try to sum up the directly linked effects in a concise list.

  1. Grains have been shown to lead to Vitamin D deficiencies. [pg. 14]
  2. Grains contain phytates, which blocks one pathway to iron absorption. [pg. 14]
  3. Grains contain phytates, which blocks absorption of zinc. [pg. 15]
  4. Grains increase Omega 6 to Omega 3 ratios. [pg. 16]
  5. Grains contain linoleic acid which block the formation of EPA. [pg. 17]
  6. Grains contain Alkylresorcinols which have many health implications including kidney damage. [pg. 25]
  7. Grains contain lectins which can bind to many human cells, affecting how they function. [pg. 28]
  8. Grains are directly linked to Celiac disease. [pg. 47]
  9. Grains are directly linked to dermatitis herpetiformis. [pg. 47-48]
I plan to elaborate on this list in a future post.

This list is simply the direct and proven effects grains have. I have not included the numerous secondary and implicated effects that exist (insulin spikes, grains replacing more nutritious foods, etc).

Please click on any portion of the list to see what exactly those substances or effects have to do with the human body. To answer my question at the beginning of the post, (What do grains have that veggies don't?) I would say that veggies don't have the higher chance of negative side effects.


Matthew C. Baldwin said...

A nice post, but incomplete in one crucial respect. You do a decent job of examining and comparing micronutrient and so-called "antinutrient" contents of grains vs. fruit and veggies. But you don't consider macronutrients, and they should figure into the question of whether we should eat grains.

The fact is that a diet reliant solely on veggies for cho will be extremely low carb and high in nutrients... good for weight loss, diabetics, and cardiovascular health. MAYBE good for athletics.

But the missing piece is that the greater the activity level, the greater the needs for carbohydrates. A non-grain eater will likely turn to carb rich fruits for additional carb intake. And the problem is fructose content. Most commonly consumed veggies and fruits, after excluding fiber, get approximately 50% of their carbs from glucose and 50% from fructose, give or take.

The body easily handles the glucose, and thrives. But the fructose is actually a toxin (!) that, like alcohol, can only be metabolized in the liver. There it is converted to usable glucose which is then stored as glycogen (or fat, depending on various factors such as insulin sensitivity, total carb load, etc). But the conversion of unusable fructose to usable glucose yields a bunch of toxic by products including VLDL (the most evil cholesterol), ammonia, and a bunch of other stuff. (The most useful presentation on this stuff is from Robert Lustig's video "Sugar: The Bitter Truth"... find it on youtube).

Grains, on the other hand, store their carbs as starches. Starches are long chains of glucose molecules. Our body easily breaks down these chains into glucose (hence the high glycemic factor) which is then directly available for use by the brain or for storage in the muscles as glycogen -- or in adipose tissue as fatty acids. But the glucose itself does not produce toxic side effects in metabolism.

As long as total carb loads remain within reasonable limits (e.g. between 130g and 200g daily, depending on your activity level and size), it seems reasonable to me to believe that there is a metabolic advantage to consuming some starches in the form of grain, and that these metabolic advantages outweigh the concerns about miniscule quantities of so-called antinutrients.

The real issue with grains is their contribution to the carb-heavy "Standard American Diet" -- most people just eat way too many carbs, and way too many of those carbs are sucrose sugar ( = glucose + fructose) or high fructose corn syrupe (fructose and glucose). The truth is that for most Americans, cutting out grain is a damn good idea (as long as they also cut out sugars). But for the conscientious and moderate eater, following Zone or Paleo principles for most eating, I don't see good reasons to avoid 30-40g of cho from starches per day.

Kristy A. said...

Great post! I enjoyed the perspective of what can grains give us and how we can get them from other foods just as well. Don't forget the acid-base balance disruption caused by grains and their high acidic load. Check out Loren Cordain's research for more on that:

Matthew, while I agree that fructose is dangerous, I have to disagree with your assertion that grains are the best source of starchy carbohydrates for the athlete. What about sweet potatoes and other root veggies for that starchy energy-dense carb? They fall in line with our evolutionary eating style and don't come with the same host of problems attributed to grains. I would also find fault in 'glucose itself does not produce toxic side effects in metabolism.' Insulin triggered by the presence of glucose and glucose itself can both be toxic if not removed from the bloodstream. Blood sugar spikes can definitely lead to metabolic distress.

The 130-200g 'reasonable' amount of carbohydrate a day, especially if using grain-based carbohydrate sources, is definitely putting a person on a path that ends in diabetes, heart disease, cancer, stroke, etc. I suggest you look more into low-carb approaches and check out the Paleo Diet for Athletes for more specific endurance-activity related nutrition.

Like Paleotron concludes, I can't see any reason why grains should be in a healthy diet.

Paleotron said...

@Matthew - You bring up some good points. I was hoping to elaborate on grains as an energy source in a future post and merely wanted to acknowledge that grains and vegetables provide carbohydrates that can be used for energy.

I cannot speak for all non-grain eaters, but for myself, I choose to get some of my carbohydrates from fruits and vegetables, but I rely on gluconeogenesis and ketosis for the rest of my energy needs. As my body comp approaches my personal goals, I will shift my reliance for energy from gluconeogenesis and ketosis to fruits, vegetables, and occasional starches.

I will agree that some people who are aware of their dietary needs can ingest grains with little to no current side effects, but the door is open for issues to arise from regular grain ingestion in the future.

If ingesting grains is simply a matter of taking in energy, would potatoes, carrots, and yams be acceptable alternatives? As @Kristy pointed out, these are energy sources that do not have the possible negative consequences of grains.

As for the fructose topic, this is one I am really enjoying learning about (thanks for the link to the video). It seems that, like grains, people can find good and bad sides to the issue. My research so far has led me to a conclusion similar to what you have discussed already. Fructose can have some negative consequences on the body. Because of this, many paleo eaters choose to stay away from fruits with a high sugar content and simply stick with berries as occasional treats as they have a lower fructose content. I will leave the fructose discussion at that as I am still learning a lot about the topic and am currently debating with myself on it. I won't pretend to be the expert here.

We both agree that carbohydrates can be a slippery slope and that the standard American diet is too carb heavy. We also seem to be in agreement on the fructose topic as well. I just feel that there are better energy sources in existence than grains.

Mike said...

Great article and comments. I'm bookmarking this site.

Paleotron said...

@Mike Thanks for the comment!

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