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If you start asking around, you’ll find that a surprising number of people have GI issues. The incidence of gut problems, major and minor, seems to be on the rise – and it seems to be distinct to humans. After all, it’s hard to imagine that many lions are battling irritable bowel syndrome (IBS) out on the savannah, or that wild deer are reaching for the Tums. This is probably because unlike other animals we humans have had a proclivity for incorporating strange new foods into our diets. If our guts are too antiquated to handle our brain’s progressive desires, what should we be eating?
On some level, we know that we’re not eating what we’re supposed to. The feeling of bloated agony after a platter of fried food or that comatose sensation after a huge bowel of pasta should tip you off. But looking at our food habits over time tells us more. Without even touching genetic engineering, it’s easy to see that we’ve changed our diets a lot over the past few thousand years. So it’s hard not to wonder if our venture into these bizarre new food realms isn’t what’s behind the rise in diseases of the bowel – and, likely, larger health problems as well.
The simplest example of this idea is lactose intolerance. Though often thoughts of as a dysfunction, it’s actually the normal state for many people, evolutionarily speaking. Most mammals, a good chunk of humans included, stop producing lactase, the enzyme needed to break down lactose, after they are infants and stop relying on their mother’s milk for fuel. At this point, the body saves energy by shutting down lactase production. So, if you are above the age of about two, the healthy state should be lactose intolerance. But about 10,000 years ago – a blink of the eye in evolutionary time – certain groups of humans decided it would be interesting, in adulthood, to drink the milk of other animals.
As David L. Katz, MD, MPH, Director of the Yale University Prevention Research Center, points out, “Almost all Chinese and Native Americans are lactose intolerant, because lactose intolerance is the normal, native condition of all adult mammals – and these groups never encountered a situation where their survival depended on dairy. But Scandinavians did, and those who could digest dairy had a survival advantage over those who could not.” So aside from the select groups of people who needed dairy to survive and adapted quickly to handle it, an awful lot of humans are still unable to. For those of us who come from lactose intolerant forebears, eating dairy foods just a strange (albeit delicious) addition to the diet, and probably responsible for a certain amount of GI distress and general feelings of ickiness.
Eating grains is a better example of a practice that’s relatively new, within the last 12,000 years or so, and which our bodies are not exactly set up to do. The consumption of wheat, or more specifically, gluten, the boogieman du jour, has gotten a lot of attention in recent years. Celiac disease is, however, a serious condition in which the person’s body wages an immune attack when the protein gluten is encountered, and has risen markedly in the last century. Gluten sensitivity is a separate immune-mediated condition, and wheat allergies are fairly common as food allergies go. Is the rise in these wheat/gluten reactions due to the fact that we’re just not “adapted” to eat grains? It’s certainly possible. That 12,000-year time span, some argue, is just not enough time for our GI systems to evolve the capability to handle the consumption of grains – let alone genetically engineered and processed grains – especially in the amount we consume today.
Katz agrees that “in general, we can get in trouble eating food we are 'not adapted' to eat.” And this mismatch between what we like to eat and what the machinery of our guts evolved to eat may have played a role in everything from IBS to the more serious inflammatory bowel diseases (IBD) to, if we want to go further, colon cancer, which has been widely linked to dietary considerations. The full range of conditions, both GI and non-GI, is unclear, but possibly extensive. If our bodies are trying to tell us something, and it seems like they are, we’re awfully slow to pick up the hint.
What’s the solution? Going back to the diet of our ancestors is the obvious fix, say a growing number of proponents of the Paleolithic diet. Intuitively, this makes sense, but practically, it’s hard to do. Katz points that “no truly Stone Age foods are available today, so we are left to 'approximate' our native diet.” And as he’s pointed out in his own writing, mammoths are hard to come by.
Even an approximated Paleo diet would exclude dairy, grains, legumes, processed sugar, salt, and vegetable oils. And certainly no Krispy Kremes, deep fried cheese, or salami. It would, however, include lean beef (grass-fed, not grain-fed), game birds, root vegetables, fruits, and a smattering of other foods. Advocates of the diet say that it cuts down not only on GI-related issues, but on the litany of chronic diseases we suffer from today, like obesity, heart disease, and metabolic syndrome. Though these diseases have spiked in recent years, it’s probably a good bet that the Cave Men who did live past 40 weren’t suffering from much type 2 diabetes or high blood pressure.
While some version the Paleo diet may warranted, striking a middle ground may be wiser. For example, says Katz, we need to consume far more fiber than most people actually take in, and whole grains help us do this. ”On the one hand, we are not specifically adapted to eat grains,” says Katz. “On the other, we are adapted to a fiber intake of 50 - 100 grams a day. Good luck getting anywhere near that target without grains. For those who are not gluten sensitive - the majority - the upside of whole grains clearly wins out.”
There is something to this diet debate, clearly, but it’s important to remember that there are other realities of the modern world that no doubt contribute to our woeful disease status, like sitting at a desk all day. Katz points out that aside from the food we eat, “we also have a world full of chemicals, drugs, antibiotics, pollutants, artificial light, insomnia, and new-age stresses like income tax.” That said, it’s easier to substitute a sweet potato for a slide of bread than it is avoid Uncle Sam. So maybe we should do what we can.
Have you tweaked your diet and felt better as a result? Please share your story, below.
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