Do they sell mastodon at Whole Foods?

So the paleo's like, EVERYWHERE.  Books like "Practical Paleo," "Primal Cravings," and even "Living Paleo for Dummies" dominate the diet section of the bookstore.  Friends have entire boards devoted to paleo recipes on Pinterest.  Miley Cyrus, Jessica Biel and Matthew McConaughey are rumored devotees. When a 70-something year old client asked me "Do they sell mastodon at Whole Foods?" I knew it was about time for a paleo post. For those who have been living in a cave (pretty proud of myself for that one), the paleo diet is an approach to nutrition based off the theorized diet of humans living in the Paleolithic Age, a period that lasted from about 2.5 million years ago until about 10,000 years ago, when agriculture was first developed. Supporters claim that chronic disease and obesity are modern day diseases caused by our modern day diet. By eating like our paleolithic ancestors, we can reduce our risk of these diseases and achieve optimal health. Supporters of the paleo diet feel if a food wasn't around 10,000 years ago, we shouldn't eat it now. There are many adaptions, but most exclude grains, dairy, beans, alcohol, refined sugar, and refined oils. And with that goes your ding dongs, mountain dew, skittles, ritz crackers, frozen yogurt, cocoa puffs or chicken nuggets.

When I first heard of the paleo diet, I immediately dismissed it.  My exact response - "What's next?  The amoeba diet?" Again, pretty proud of myself for coming up with that on the spot. It just screamed fad diet.  But after learning more about the diet, and opening my mind, I realized good things may come from this diet craze.

First of all, I 100% wholeheartedly agree with paleo supporters that our modern diet is the main cause of our current epidemic of obesity and disease. I am incredibly happy to see a popular diet that is finally opening people's eyes to the risks of our overly processed diet.  Most popular diets have concentrated on achieving some arbitrary ratio of macronutrients or counting calories, completely ignoring where that calorie is coming from. It only has 100 calories and 15 grams of carbohydrates, so it must be healthy, right? Nevermind it's simply a mix of refined flour, sugar, artificial colors and preservatives.  The popularity of the paleo diet is starting to change popular thinking about processed foods. More people are eating clean. This is a good thing indeed.

Furthermore, the paleo diet can be healthy and balanced. Clearly, there's no biological need for the aforementioned ding dongs, cheetos, etc. but the nutrients found in the nixed food groups can be found in other foods that are allowed in a paleo diet. Take dairy for instance. Since grade school we've been told one needs 3 servings a day for strong bones, but really, only Americans and Europeans regularly eat milk and milk products.  So why are Asians and Africans not keeling over from osteoporosis?  Because our calcium (and other bone building nutrient) needs can be met through other foods, like nuts and green leafy vegetables, both green light foods on a paleo diet.  Although a paleo diet tends to be low fiber and low carbohydrate without whole grains and beans, these nutrients are easily replaced with fruits and starchy and nonstarchy vegetables.

There are small, but compelling studies indicating possible benefits with the paleo diet. One study examined 13 people with diabetes and found the paleo diet was more effective at lowering blood sugar levels than standard diet recommendations for diabetes. Another interesting study from Australia had 10 diabetic Aborigines go back to their traditional hunter-gatherer diet. Blood sugar improved dramatically, back to normal levels for some, and triglycerides were reduced by a whopping 75%.

Now, before you hop on the paleo train, there are some major issues with the logic behind the paleolithic diet.

First, the notion that there is one paleo diet is simply false. The Paleolithic lasted 2.5 million years.  The human diet must have changed during that time.  Also, just as someone living in modern day Japan eats a completely different diet from someone living in Oklahoma or Mexico, the paleolithic diet varied by location too. Lacking our industrialized food system, it's safe to presume paleolithic man had an even more geographically varied diet than modern man.  Paleolithic man couldn't ship avocados from Mexico or wild salmon from Alaska.  They were limited to what's local. Hunter-gatherers living in areas where plants do not grow, like the desert and extreme north, ate almost exclusively animal foods.  Those living in more moderate climates ate a more varied, plant-based diet.

The paleo diet is based on the popular stereotype of cavemen as brawny meat-eaters. Despite the familiar image of cavemen gathered around the campfire to a meal of wooly mammoth, science tells us a different story. Animal foods played a small role in most paleolithic diets. Rather than being hunter-gatherers, most were gatherer-hunters. Hunting requires a lot of energy compared to gathering, so for humans still at risk of starving, evolutionarily speaking, it paid off to pick berries instead. Need more evidence - just look at our digestive system. Our teeth have evolved mostly for grinding plant foods.  Our long intestinal tract and microvilli are evolved for extracting as much energy as possible out of plant foods. As this article points out, the human gut is very similar to that of chimps and monkeys, which may feast on the occasional lizard (the primate version of Thanksgiving feast), but mostly eat plants. I highly suggest you read the link - it actually makes learning about monkey guts hilarious.

There is archaeological evidence that many paleo diet no-no's were actually part of the paleolithic diet.  Archaeological evidence has been found indicating paleolithic man not only ate grains, but processed them into flour. Mortar and pestles with starch residue have been found in multiple locations dating well into the paleolithic era. Even fossilized bits of dental plaque have revealed paleolithic man ate grains. That said, I doubt grains were consumed to the degree they are today. And clearly our modern grain-based concoctions (hello fruit loops) were not present. But still, grains were there.

The theory that the optimal diet is the same one we consumed over 10,000 years ago ignores how quickly evolution can occur. If it really takes so long for us to adapt to a new food source, humans would still be swinging from trees and grooming buddies for bugs to eat. Part of the reason why homo sapiens have been so successful as a species is our adaptability to new sources of energy, or food.  Look at the example of lactose tolerance, rather than intolerance.  There's a lot of talk about the 65-75% of the world that is lactose intolerant.  But have you ever thought about those who have evolved the capability to digest dairy? About 25-35% of the human race produces the enzyme lactase, allowing them to extract energy from dairy without diarrhea, gas, bloating and general unpleasantness.  All that happened in the past 10,000 years, a blink of the evolutionary eye.

Science is one thing, but we must also consider how the diet is interpreted by others. Some take it in a too Atkinsy direction. I've heard of others who eat only raw meat...apparently humans evolved from lions?  But the most common mistake I see is with the quality of meat paleo dieters choose.

Although the paleo diet recommends grass-fed, organic meat and wild fish, many ignore this advice, presumably due to cost or availability.  But if you aim to follow a paleo diet, I think industrial meat and farmed fish should be just as off limit as processed junk foods. Meat from pastured animals and wild fish is very different from their industrialized counterparts. Grass-fed or pastured meat and poultry has more omega 3 fat, conjugated linoleic acid and carotenoids. Wild fish has a significantly higher amount of omega 3 fats versus their farm raised counterparts.

Now, as you know, I'm a dietitian, not a paleontologist. Although I do watch an absurd amount of National Geographic, I'm probably not qualified to talk about the details of the paleolithic era, so if you want to hear a palaeontologist's take on the paleo diet, click here for a pretty fascinating talk.

Clearly, this diet craze is controversial. After examining the way paleolithic man actually ate, I see a few important lessons to apply to our modern diet.

1. Seasonality is important.  I just spoke about the topic, so I won't rehash, but remember, until recently, we only ate what was in season and available in our geographic area.

2. Humans have thrived on a wide variety of diets, so it's probably pretty silly to assume one way of eating is the perfect diet.

3. Processed foods were only recently introduced to our diet.  Since then, we've suffered extraordinary rates of obesity, diabetes, heart disease and cancer.  Coincidence?  I think not...

Whether you are strictly paleo, have been eyeing the books or you think the whole thing is a crock of you-know-what, I think the paleo diet is one we should keep an open mind about. I'm optimistic that this fad diet may change conventional thinking about nutrition for the better!