Friday, January 19, 2007

Why not eat better food?

The pursuit of magic pills, potions and elixirs is such a common crusade that the Food and Drug Administration is currently pondering medicinal doses to cure the ills of it's 'Food Guide Pyramid'. Unable to admit that a structure which usually opitimizes sound engineering, is flawed at it's very foundation, the government agency would prefer to rely on a common tool of western medicine: address the symptoms while ignoring the underlying malady.

Though I believe that some supplementation is a good thing, I think the adoption of a 'Supplement Pyramid' to complement the 'Food Guide Pyramid' ignores prevention and better dietary practices for a quick band-aid approach to the problem. Below in italics are excerpts of a proposal by CRN to introduce a Supplement Pyramid to the populace along with information that illustrates how problems with nutrient density and absorption could be addressed with dietary changes:

The Dietary Supplement Pyramid
CRN has submitted comments to the USDA panel for reviewing the Food Guide Pyramid.

CRN's Dietary Supplement Pyramid provides an easy guide, complements food pyramid and ensure good nutrition with dietary supplements.
Scientific studies have proven that good diets and generous nutrient intakes can help optimize health and protect against serious diseases, including heart disease, osteoporosis, cancer and even some birth defects. Now, consumers can use new food and supplement pyramids to improve eating habits and build a sensible long-term supplement program.

Foods and supplements, the best plan
A good diet is the foundation for better health, but obviously even the most knowledgeable consumers don’t always eat the way they should.

It's little wonder - misleading labeling, large scale farming methods which force rapid production while depleting the nutrient density of our food, lobbying by special interests groups - all have a profound impact on our food supply and on what we think we know about food. Our produce isn't what it used to be and our markets are flooded with poor alternatives. Rather than swallowing both the argument that nutrient deficiency is inevitable and the 'enriched' alternatives the market provides, we need to respond with more tenacity by creating a demand for better quality products and more transparent labeling.

Foundational Flaws
The statement begins, of course by accepting that the foundation of the food guide pyramid is indisputably solid:
Both the food pyramid and the dietary supplement pyramid sit on a base deliberately chosen to highlight a key component–grain products in the case of the food pyramid and multivitamins in the case of the supplement pyramid.

As I'll cover later in the discussion of recommended daily allowances, grains as a foundation are a nutritionally poor base. Not only do grains lack many necessary nutrients, they can also act as an anti-nutrient. This is explained by Paul Chek in 'You Are What You Eat' Part 2, "Even more important in today’s climate of indigestion, is that phytic acid, which is a known mineral blocker, is broken down in the sprouting process. Phytic acid is present in the bran of all grains, the coating of nuts and seeds and inhibits the absorption of calcium, magnesium, iron, copper and zinc. These inhibitors can neutralize our own digestive enzymes, resulting in the digestive disorders experienced by many people." And that can mean a lack of nutrient absorption in a compromised digestive system on top of the mineral-blocking properties of phytates.

It's also important to consider that the inclusion of 9 to 11 servings of grains on top of the more nutrient-dense fruit and vegetables puts a heavy emphasis on carbohydrates as the primary macronutrient. This plan which offers paltry servings of protein may be shortening our lives dramatically. Dr. Loren Cordain sums this up in Origins and evolution of the Western diet: health implications for the 21st century, "An increasing body of evidence indicates that high-protein diets may improve blood lipid profiles and thereby lessen the risk of CVD [cardiovascular disease]. Wolfe and Giovannetti have shown that the isocaloric substitution of protein (23% of energy) for carbohydrate in moderately hypercholesterolemic subjects resulted in significant decreases in total, LDL, and VLDL cholesterol and triacylglycerols and an increase in HDL cholesterol. Similar beneficial blood lipid changes have been observed in type 2 diabetic patients in conjunction with improvements in glucose and insulin metabolism. Furthermore, high protein diets have been shown to improve metabolic control in patients with type 2 diabetes. In obese women, hypocaloric, high-protein diets improved insulin sensitivity and prevented muscle loss, whereas hypocaloric, high-carbohydrate diets worsened insulin sensitivity and caused reductions in fat free mass."

With its easy availability and limited expense, the urging of the USDA to focus on grains as a primary food source makes it easy for the average consumer to miss out on key nutrients.

Capitalism 1, Consumer 0
There are 12 minerals for which "Reference Daily Intakes" have been established by the Food and Drug Administration, for purposes of nutrition labeling.

This is the place where CRN makes it's most obvious point regarding the struggle to consume 'Daily Intakes' without the help of supplementation. But let's consider Cordain's argument which I alluded to earlier. What if the premier carbohydrates came from caloricly sparse, read: low glycemic, vegetables? Here's how Cordain explains it:

"Because whole grains and milk maintain the next to the lowest nutrient density rankings, displacement of fruit, vegetables, lean meats, and seafood by these 2 staple food groups lowers the overall micronutrient density in the diet. Wild plant foods known to be consumed by huntergatherers generally maintain higher micronutrient concentrations than do their domesticated counterparts (4, 145), as does the muscle meat of wild animals (64). Consequently, the Neolithic introduction of dairy foods and cereal grains as staples would
have caused the average micronutrient content of the diet to decline. This situation worsened as cereal milling techniques developed in the Industrial era allowed for the production of bread flour devoid of the more nutrient-dense bran and germ (35). The displacement of more nutrient-dense foods (eg, fruit, vegetables, lean meats, and seafood) by less-dense foods (refined sugars, grains, vegetable oils, and dairy products) and the subsequent decline in dietary vitamin and mineral density has far reaching health implications— consequences that not only promote the development of vitamin- deficiency diseases but also numerous infectious and chronic diseases"

Mean nutrient density of various foods groups (418-kJ samples)1

Though the chart above is hard to read, the rank score explains it best. If vegetables have a score almost twice that of grains, it would stand to reason that eating larger quantities of vegetables in place of grains would yield a lower caloric, high fiber, nutrient dense diet.

Know your Cholesterol but not your Homocysteine?
Multivitamins with folic acid may also help reduce the risk of heart disease and stroke in men and women of all ages. Folic acid, vitamin B-6 and vitamin B-12 help reduce blood levels of homocysteine (an amino acid produced in the body), and people with lower homocysteine levels have a lower risk of heart disease and stroke. It is the long-term use of multivitamins that is most beneficial, so consumers should resolve in the year 2005 to make this a lifelong habit.

Usually the first connection anyone makes to heart disease is cholesterol. Often eliminating red meat is considered the wise first step to lowering cholesterol levels. What's funny is that nobody measures homocysteine and yet we understand this connection far more clearly than we can draw conclusions about cholesterol. And that wise first step that arguably lowered cholesterol, may have increased homocysteine levels. Anthony Colpo explains this in 'The Great Cholesterol Con,' "The best way to increase one's dietary intake of B-6 and B12 is to eat methionine-rich protein foods like meat! Animal foods are the only source of bioavailable B12; compared to meat-eating omnivores, vegetarians consistently exhibit higher blood levels of homocysteine, with the highest concentrations found in vegans. A 6-month randomized, controlled clinical trial found that those assigned to a higher protein diet experienced a twenty-one percent drop in homocysteine levels, but no decrease was observed among those assigned to a low protein diet or control subjects following their usual diet."

As if the substitution of vegetables for grains didn't make enough sense, Calpo discusses studies which show the impact of changes in dietary intake of folate, "Intervention trails in which subjects increased their fruit and vegetable intake have repeatedly shown homocysteine reductions, albeit of a smaller magnitude than B-vitamin supplementation. In subjects normally consuming 162 grams of fruits and vegetables each day, four weeks of eating 500 grams daily of these folate-rich foods lowered homocysteine levels by eleven percent."

Cordain also discusses homocysteine levels in the paper cited above, "Protein intake has been shown to be inversely related to CVD in a cohort of 80 082 women (126). Dietary protein is also inversely related to blood homocysteine concentration (127), an independent risk factor for CVD. Meat-eating populations have been shown to maintain lower plasma homocysteine concentrations than nonmeat eaters (128, 129). In numerous population studies, summarized by Obarzanek et al (130), higher blood pressure has been associated with lower intakes of protein. A 4-wk dietary intervention of hypertensive subjects showed that a high-protein diet (25% energy) was effective in significantly lowering blood pressure (131)."

While trying not to be a conspiracy theorist, consumers understand cholesterol through the marketing of Statins. Perhaps the introduction of homocysteine-lowering drugs will be the only means of educating the public regarding homocysteine. For now, we have the supplement companies, which are in essence the same thing.

(or the equivalent)
High calcium intakes, preferably with vitamin D, can slow the rate of bone loss and help protect against fractures. The Food and Nutrition Board of the Institute of Medicine, National Academy of Sciences, says everyone over the age of 8 needs at least 1,000 mg of calcium per day, and teens and seniors need even more (1,200 to 1,300 mg). Even people who regularly consume dairy products may not get enough calcium. For example, a glass of milk contains about 300 mg. So if you don’t drink 3 or 4 cups of milk a day (or the equivalent), take 300 mg of calcium for every glass you fall short.

Though I don't disagree that milk is the best source of calcium, I can't help but feel the heavy hand of the dairy lobbyists here and it makes me want to protest just 'cuz.

For the sake of contrarianism, here are other food sources of calcium:
Sardines, canned 3 ½ oz/ 8 med - 370 mg
Chickpeas 100g - 190 mg
White beans 1 cup - 200mg
Turnip greens 1 cup - 190 mg
Blackstrap molasses 1Tbsp - 170mg

According to 'The Journal of the American College of Nutrition,' (JACN) in the article entitled 'The Bioavailability of Calcium', "except for newborns fed on mother’s milk (calves drinking cow’s milk) which can absorb almost all the ingested calcium, the percent of milk calcium absorbed seldom exceeds 40% under normal dietary conditions." It would appear not all milligrams are created equal when considering bioavailability which turns out to be a very complex question.

I again point a finger at grains with the help of the article cited above, "Some components of the diet, such as the phytates found in bran and most cereals and seeds, oxalates in spinach, rhubarb, walnuts and sorrel, and tannins (tea), can form insoluble complexes with calcium, thereby reducing its absorbability. This only seems to affect calcium balance if the diet is unbalanced, high-fiber strict vegetarian diets lacking dairy products (calcium), for example. This must be taken into account when comparing dairy products with soybean-based products, which are generally phytate-rich. The apparently negative influence of fiber on calcium absorption is mainly due to the phytates that are frequently associated with dietary fiber."

And, so as not to convince you that I'm just bitter from years of suffering from a wheat sensitivity, salt, another western dietary staple is also a considerable part of the problem. The JACN article goes on to say, "every extra two grams of dietary sodium increases urinary calcium excretion by an average of 30 to 40 milligrams. Clearly, dietary factors affecting the amount of calcium lost in the urine have a major influence on calcium balance and may even be more important than those that influence the intestinal availability of calcium [17]. This is why the inevitable loss of calcium in the urine (accounting for a large part of the maintenance requirement) is greater for Western-type diets that are high in unfavorable factors such as animal protein, sulfates, sodium, coffee, tea and alcohol, than for other diets with lower levels of consumption of these factors."

Other than the reference to animal protein, which I believe Cordain disputed in the protein debate, our sloppy nutritional habits account for a large part of our calcium deficiency. Though I support the idea of ingesting calcium-rich foods, it would make sense that equal effort should be put into reducing it's unnecessary excretion.

underemphasising the impact of overfeeding
Studies suggest that people who take vitamin E and vitamin C on a regular basis may get some protection against diseases or conditions caused by oxidative damage, such as heart disease, cancer and cataracts. The optimum amount for vitamin E may be more than 100 or 200 International Units (IU) and for vitamin C may be at least 200 mg.

The organization with a long name sums up the issue in an article with a complex title in a way that's both short and simple, "we discussed the evidence that oxidation is a major contributor to cellular aging and the degenerative diseases that accompany aging such as cancer, cardiovascular disease, immune-system decline, brain dysfunction, and cataracts. Also reviewed was the evidence that dietary antioxidants, such as ascorbate, tocopherol, and carotenoids, the main source of which are fruits and vegetables, protect against these degenerative diseases," said the Proceedings of the National Academy of Sciences of the United States of America, in
Oxidative Damage and Mitochondrial Decay in Aging.

In the publication noted above, the authors go on to explain that to mitigate oxidation, it is necessary to restrict caloric intake and believe me, that's a whole new post on a concept called 'Intermittent Fasting' which I will explain another time. In short, PNAS explains it like this, "The physiological mechanisms that control the conservation of energy during periods of low food availability, as observed experimentally with calorie restriction, may temporarily but profoundly affect the metabolic rate of organisms capable of entering this state. Therefore, daily torpor, by lowering the metabolic rate and oxidant production that can exert pro-aging effects, is likely to be responsible for at least some of the life prolonging effects of calorie restriction." In short, sometimes we should stop eating; a concept foreign to this snacking, noshing and pecking population.

Marion Nestle makes the point in 'Food Politics' however, that food lobbyists would never agree to a plan of limiting consumption because it's economically impactful. Selling more. How could you possibly sell more in a world that's overstuffed especially if overstuffing is the problem. Supplementation.

More Fishy Recommendations
Many other dietary supplements are available and their use is often tied to special needs or specific dietary lacks. For example, omega-3 fatty acids, found in fish oils, are believed to help reduce the risk of heart disease. People who don’t (or won’t) eat fish regularly may wish to supplement with omega-3 fatty acids.

I don't dispute that Omega-3 is a valuable supplement but increasing Omega-3 without decreasing Omega-6 is like trying to bail out the Titanic with a Dixie cup. First, let's look at the problem of our ratios with the help of Dr. Cordain, "The trend toward a higher ratio of Omega-6 to Omega-3 PUFAs [Polyunsaturated fatty acids] was exacerbated as meat from grain fed cattle and livestock became the norm in the US diet over the past 100 y. In the current US diet, the ratio of Omega-6 to Omega-3 PUFAs has risen to 10:1, whereas the ratio in hunter-gatherer diets predominant in wild animal foods has been estimated to be between 2:1 and 3:1." To compound the problem, we introduce vegetable oil. Says Cordain, "The advent of the oil-seed processing industry at the beginning of the 20th century significantly raised the total intake of vegetable fat, which directly increased the dietary level of Omega-6 PUFAs at the expense of a lowered level of Omega-3 PUFAs because of the inherently higher concentrations of Omega-6 PUFAs and lower concentrations of Omega-3 PUFAs in most vegetable oils." For those of you who know that Canola has a high Omega-3 content, you should also know that it's likely rancid due to the high heat of processing.

Wouldn't it be sad if I didn't mention something about grains and high glycemic diets here as well? Many thanks to Cordain who continues with, "A recent study suggested that the blood concentration of the inflammatory marker C-reactive protein (CRP) is a stronger predictor of CVD [cardiovascular disease] than is LDL cholesterol (106). High-glycemic load diets are associated with increased concentrations of CRP (107), as are low dietary intakes of omega-3 PUFAs [polyunsaturated fatty acids](108), and diets that encourage weight loss reduce CRP (109) concentrations. These studies indicate how multiple interrelated qualities of Western diets and recently introduced Neolithic and Industrial Era foods may drive a variety of mechanisms that promote the development of chronic diseases."