FA-RM: Thinking "Outside the Box" on Diet

What box? The low-carb box.

You've just heard me praise the benefits of a low carb diet for glucose control in diabetics in the past post. While this is true, we should always be on the lookout for controlled studies or good observational studies that contradict what we think we know. More specifically, we should refine our understanding of exactly what entities are problematic in certain food groups which we are already suspicious of as causing health problems.

I recently read a blogger who said that maybe people are too uptight about carbs. I think this is true, but perhaps not for the same reasons. What do I mean by that? Well, there's a certain attitude out there that health is largely genetically determined and that we can eat whatever foods are available to us so long as we do so "in moderation." In other words, it's not really up to us whether we get obese or get heart disease or diabetes. It's pretty much genetically determined. The only thing we can do is try not to eat too many calories, exercise a bit, hope for the best, and then throw drugs at a health problem once it arises. I strongly disagree and the best science available to us does not support such an assertion. When you come to learn that certain foods are a type of slow-acting poison, the idea of "moderation" seems absurd.

That said, we really do need a better understanding of what types of foods and what entities in those foods cause health problems before making swift or premature judgments. We do have solid ideas, but limiting "carbs" may be too simplistic. Perhaps not all carbohydrate-laden food is bad for our health. (I'm speaking strictly from a standpoint of health, not temporary enjoyment. If you are after temporary enjoyment in the absence of context of any health goals, you can justify eating just about anything.)

There are some foods with a pretty high carbohydrate fraction that I believe could be part of a healthy diet. For instance, I'm not at all convinced that potatoes are harmful to anyone but the glucose-intolerant (i.e. the obese, pre-diabetic, and diabetic). We know that the Irish ate a heck of a lot of potatoes. Until the potato famine, the Irish were almost completely dependent upon potatoes. My guess is that they would have done poorly if they did not have any source of animal protein or fat, but I wonder if there is any evidence of diabetes, heart disease, etc. at that time. It would be fascinating to know whether this population from 1600s to the mid 1800s was exempt from other western diseases of civilization that some increasingly believe are caused by carbohydrate.

Not only did the average Irish family of six consume 250 lbs. potatoes weekly, the population doubled from 1800 to 1845. Because the climate was so remarkable for growing potatoes, people were able to be fairly leisurely and abandon other food production — and married earlier, had larger families, and were able to nurse more newborns. That means an average of 6 lbs. potatoes per person per day. Although potatoes are starchy -- in other words, full of sugar, yes -- they have a fair amount of complete protein unlike other vegetables. Six lbs of potatoes is 2500 calories, with 63 grams of protein if one just eats potatoes. That makes potatoes start to sound pretty decent as a major part of the diet and a source of all essential amino acids. (All of the historical information comes from Magical Mushrooms, Mischievous Molds by George Hudler.)

Although these numbers above may be a bit off for average daily intake (6 pounds is a lot -- this means men would have had to eat more to compensate for less intake among women and children), we do know that the Irish relied on potatoes heavily. When corn was imported from America to aid in alleviating the famine, the Irish rejected it, even though they were starving. Apparently their digestive systems were very conditioned to potatoes. In light of this, it would be fascinating to discover more about Irish health at that time. Were they fat? Did they get heart disease? What about diabetes?

This reflects an evolution in my thinking on such dietary matters over the past year. Gary Taubes calls for a more heavy evaluation of the carbohydrate hypothesis at the end of his book Good Calories, Bad Calories. He wouldn't have called for such an evaluation if he considered it proven. Many cultures enjoy a heavy carbohydrate intake with seemingly few health problems (diabetes, cancer, obesity, heart disease) that plague western civilization. Notably, these cultures often chiefly eat starchy tubers or rice. Potatoes lack some of the toxins found in grains and legumes that are suspected of causing modern health problems. In light of this, it would be fascinating to know more about the body composition and health of the Irish just prior to the potato famine if such case studies exist (I'll leave it to health experts to search for and evaluate that information, though). Such information could provide a basis for the types of experiments that Taubes calls for at the end of his book.

I think this excerpt from Stephan's most recent post adequately sums up my evolving thoughts on carbohydrate:

...there's a difference between post-meal glucose and insulin surges and chronically elevated glucose and insulin. Chronically elevated insulin is a marker of metabolic dysfunction, while post-meal insulin surges are not (although glucose surges in excess of 140 mg/dL indicate glucose intolerance). Despite what you may hear from some sectors of the low-carbohydrate community, insulin surges do not necessarily lead to insulin resistance. Just ask a Kitavan. They get 69% of their 2,200 calories per day from high-glycemic starchy tubers and fruit (380 g carbohydrate), with not much fat to slow down digestion. Yet they have low fasting insulin, very little body fat and an undetectable incidence of diabetes, heart attack and stroke. That's despite a significant elderly population on the island.

Yes. And we're also aware of two other native groups in Europe through Weston Price's research that apparently did not suffer from modern health problems yet they had high carbohydrate intake from soaked/sprouted grains. These are are a world of difference biochemically from "whole grains" advocated by health authorities today in phytate, lectins, protease inhibitors, and even gluten content in the case of long sourdough fermentation. Traditional processing of grains removes or greatly reduces these entities. Modern processing does not (and especially since quick-rise techniques have been adopted). Again, from the same post:

Let's take a look at how healthy cultures eat their carbohydrate foods. Cultures that rely heavily on carbohydrate generally fall into three categories: they eat cooked starchy tubers, they grind and cook their grains, or they rely on grains that become very soft when cooked...

The human digestive system is delicate. Cows can eat whole grass seeds and digest them using their giant four-compartment stomach that acts as a fermentation tank. Humans that eat intact grains end up donating them to the waste treatment plant...

Grain consumption and grinding implements appear simultaneously in the archaeological record. Grinding has always been used to increase the digestibility of tough grains, even before the invention of agriculture when hunter-gatherers were gathering wild grains in the fertile crescent. Some archaeologists consider grinding implements one of the diagnostic features of a grain-based culture.

Carbohydrate-based cultures have always prioritized digestibility and nutritional value over GI. Have nutrition authorities suddenly gotten smarter than them in the last 20 years?

I recommend his blog and the comments line of each post for some good skeptical thinking on the glycemic index, what types of carbohydrate are probably unhealthy, what types of processing are healthy and even necessary for our foods, and what we know about human health throughout human history. Much of the information on historical use of carbohydrate seems lost on, or ignored by, the larger "paleo" and "low carb" communities. All of the information on the effects of agricultural products on human health is lost on, or ignored by, our modern nutritional "authorities" and thus, the vast majority of the population.

The same type of critical thinking needs to be applied to "processed food." It's critical to examine the definition of a processed food as well as what types of processing are good and bad for our health. That said, when it comes to human diet, which we know from anthropological studies experiences heavy selection pressure, the precautionary principle is in order. In other words, deviating from the evolutionarily prescribed path needs to be proven to be healthy. What does that mean? It means that the burden of proof is on new foods in use for only 10,000 years or 40 years -- not the foods that humans have been eating for millions of years, foods that were selected for by evolution over time.

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