Tuesday, April 16, 2013

My Interpretation of the Paleo Diet

I really don't flex my dietitian muscles much, but I keep getting the same foodie question, "What do you think about the Paleo Diet?"


Do you think it healthy to take on the Paleo Diet? It looks like this...


Picture from CSPI's Facebook page


Or,
would you have at the nutrition guidelines below?



Well, read on to hear my take on the matter...


What is the Paleo Diet? Page through these tabs for the detailed answer. See recipes, a sample meal plan, reviews from health professionals, along with Paleo diet "dos" and "don'ts".  Basically, you can eat foods that are similar to what the cavemen hunted (lean, gamey, grass-fed meat) and gathered (eggs, vegetables, fruit, roots and nuts). Forget the dairy, grains, beans, alcohol, salt, refined sugar and oils.

Nutrition science gets a bad wrap for seemingly "healthy" claims, good for one day and then blasphemy. Promoting this diet with little supporting evidence would discredit me as a dietitian. I am going to wait on the sidelines for more robust, larger studies and from ones of longer duration.

Before leaping into my ballad, I'll point you to this article about 7 signs of bad nutrition advice. Hopefully, it gives you some direction for deciphering all the nutrition fallacies swirling around you.

Basic nutrition - eating the types of food that keep you healthy - breaks down simply. Stick to the right amounts of whole grains (quinoa, whole-wheat bread or tortillas, pasta, rice...) and beans (lentils, canned or dried beans, edamame...), dairy or other calcium sources, lots of fruits and veggies (canned, frozen, or fresh, sometimes dried), and some protein (meat, eggs, beans, vegetarian options, you name it!). Learn how to size up healthy portions by watching this video!


Now, onto the science of the Paleo Diet
Paleo proponents do their part by grasping onto a couple nutrition studies which I'll jump into now. 

Three of them do not have a randomly assigned Paleo diet group and a pack of people assigned to a different comparison diet. This causes a big question mark to hang over their results: did participants shed pounds because they they were on a weight loss regimen or truly because of the Paleo diet (
1, 2, 3)? It's hard to say without the typical experimental model, what's called a "randomized controlled trial." This format is first-rate at testing the real effect of a treatment or diet through the use a two groups: (1) people on the test diet (the Paleo diet) and (2) a group shoveling in the "standard" diet for comparison. Hoisting the research up one more notch would mean conducting a "blind randomized controlled trial." The experimenter does not know which diet is being administered to either group. This intentional cluelessness eliminates biases that may skew the results.

Sure enough, the experimental setup was limited by of the small sample size of many these studies. A sample that's representative of all Paleo dieters would be hard to capture in studies of 9-29 participants (1, 2, 3, 4, 5). I greeted one, 13-person study with a couple chuckles and a head shake as it was stopped early because of a lack of participation (4). And, many of the participants had pre-existing conditions like diabetes, cardiovascular issues, or obesity; they weren't healthy active individuals.  More studies are needed with dieters 
typifying the majority of Paleo followers.


I feel a pang of frustration, you know that kind sends your eyes rolling, when I hear about a 3-month study which orders a Paleo diet that chops 300 calories out of participants  diet (4). If you cut two cans of soda, two glasses of juice or even that extra large muffin from whatever you eat (Paleo or not), you would lose weight too!  I'm inclined to believe that the eating less is the prominent cause of weight loss, not necessarily foods within the Paleo diet. This great read supplements my argument by reviewing current research on the "calorie" matter.

I also don't like the timing of these studies. They were held over a couple of days or as long as six months. But, dieters might agree, that these intervals do not portray the exhausting reality of sticking with extreme dietary restrictions. Life is quick and busy. Chaining yourself with strict food rules will only put you in more of a bind.  Three studies spanned 1-2 years comparing three diets: Atkins (most comparable to the Paleo menu with meat, whole foods, dairy, and leaving the grains behind), Ornish (very low fat, high amounts of grain and whole foods, but skimping on the protein), and Weight Watchers (a well rounded, healthy diet including all the food groups in smaller portions). No one diet outcompeted the others causing more weight loss than the rest, but it seemed that more people dropped out of the study when following the extremes (Ornish and Atkins) (6, 7, 8).

If you are looking to shed pounds or gain muscle, eat enough. Mix in well rounded meals with whole grains, veggies, fruit, protein, and some dairy or calcium containing foods. Edge in healthy snacks in too!
 
Who is behind this mad-arms race to create the "right" diet for you? 
The food industry cycles through these unsupported, fad diets not to answer your dietary needs but to feed off the potential gargantuan profit. What's this year's popularized food trend? Protein! In stores near you, products with healthy-for-you protein claims will abound.

Now, take the last craze, the gluten-free diet (no wheat, barley, rye, and sometimes oats). The food industry ran with it, and these products alone, grew at a compound annual growth rate of 28% in ten years with 2012 sales reaching approximately $2.6 billion. Google "gluten-free diet," and you'll get more than 4.2 million results (9). Lucrative and a good sell, eh?

The number one reason for people purchasing these products is that they're healthier than their gluten-containing counterpart. This far-out assumption makes gluten or wheat the bad guy. When, for a person without sensitivity or allergies, it's fine!  You could actually miss out on fiber for regularity and better cholesterol levels, with the potential to lower colon cancer risk (10).


To add to it, there's too little to no proof of benefits behind eliminating gluten-containing foods for those who don't need to. As a matter of fact, adherence to this regime may result in a diet that is high in fat and low in carbohydrates and fiber, as well as low in iron, folate, niacin, vitamin B-12, calcium, phosphorus and zinc. A small number of studies with adults show a trend toward weight gain after diagnosis; further research is needed in this area (Gluten-Free Evidence Analysis Library from the Academy of Nutrition and Dietetics).

Currently, 1 in 133 people (about 1% of the population) have
celiac disease which mandates a gluten-free diet. Beyond celiacs, more people also have some sort of gluten sensitivity or coinciding (11). Slowly but surely, the number of diagnoses are rising with more patients becoming aware of the symptoms, more long-term working relationships between allergists and their patients, and improvements in clinical testing (12, 13). However, much of this progress has yet to come into fruition. The Paleo diet seems to take advantage of this diagnostic uncertainty by prodding followers to self-diagnose in order to sell them on their extreme, grain-free marketing scheme.


I can't stress enough that we are free to eat a well-rounded diet. Click the dairy, whole grains, proteinfruits and veggies links to read about some of the healthy things to follow when doing so. And, remember that a little soda or dessert along the side won't hurt! 



Beyond nutrition, that's some shaky evolutionary science.
 In regards to the evolutionary justification behind the Paleo diet, I'll take a similar view as anthropologist, Marlene Zuk, professor of ecology, evolution and behavior at the University of Minnesota and author of Paleofantasy: What Evolution Really Tells Us About Sex, Diet, and How We Live. 

1. The Paleo diet wants you to eat like a caveman. Who were the "paleolithic" people?

Which Paleolithic peeps are we talking about? Are we speaking Homo erectus? Homo sapians? How about this one...Homo heidelbergensis? Are we speaking of people living in Africa or those who moved to Asia. Could we mean the coastal fishermen, or should we move inland to the forest hunter and gatherers who relied on gamey, lean meat and rooted for plants (grains too!). Our human development has been far from homogenous. Obviously, each diet varied in time and placed, based on region and locality. How, then, can Paleo followers pin down the one, standard Paleolithic diet? 


2. Our bodies are made to eat meat, little to no grains, dairy, beans, or any refined, packaged treats? 

This tenant voiced by the Paleo followers, assumes that well-supported successes of other diets are faulty and invalidated. Supposedly, many of today's foods contribute to the chronic diseases like diabetes, heart disease, cancer, etc. Countering this point, however, is the documented health benefits of being vegetarian (Find more consumer-friendly material about the research, here.) or even the widely publicized Mediterranean diet (Here is the Mediterranean diet study and commentary about it from credible health professionals 1 and 2). Unlike Paleo eating, these diets prove healthful and include the missing grains, dairy, and beans.

3. If we're genetically inclined to eat a diet from Paleolithic times, that must mean we've stopped evolving too! Are we cave men??

The appeal of this diet is that evolutionary changes could not occur in response to the today's major dietary shifts and novel food practices. Proponents believe that modern humans' genetics are very similar to our Paleolithic ancestors making our bodies much more fit for the Paleo diet, not to the current so-called civilized diet. 


Hmmm...If our genetics haven't changed for 100,000 years, then explain this one: Let's talk to the fact that we can drink milk, though it's a no-no in the Paleo diet. Humans were one of the first mammals to continue on cow’s milk after birth. And, now the vast majority of humans have evolved with the ability to digest it. This change happened much later than the Paleolithic time, but 5-7,000 years ago. It's evidence that a genetic shift took place much later than the Paleolithic times. That doesn't go without saying that some people now have trouble digesting milk. But, that's different than saying that ALL people should avoid milk because of our Paleolithic ancestry! 



Now to amylase - Um..amy-what? It's an enzyme that breaks down starches and grains for better absorption in our mouth and small intestine. More amylase makes eating and digesting grains easier. In populations with a grain-based diet - maybe vegetarians or those people with rice as a staple food source - more than the average amounts of amylase were maintained. This change occurred wayyyy after Paleolithic times. Unlike the grain-free recommendations of the Paleo diet, people have adapted and can still eat rice, wheat, and other grains.
No discredit to Charles Darwin's evolutionary theory. I don't want to take away from the idea that we've transformed over millions of years. But, we must give credence that to our ability to adapt to our surroundings at quite a fast pace. Call this science, epigenetics! It's like an equation: the environment we live in, the actions we take, the food we eat, our stockpile of emotions, sum it all up and we get major changes in our genetic imprint that can be passed to our kids; Take for example, the passing of traits like obesity, the lengthening or shortening the life span, or an increase or decrease in disease risk. Epigenetics is proof that our environment and what we do to our body can short circuit evolution and leave an imprint on the generation. Learn more from the voices behind epigenetics here.
 

All this to say that, genetically, we cannot compare to our Paleolithic ancestors.




4. Can we even replicate the paleolithic food environment?

Earth has changed drastically since Paleolithic times. The food from the previous environment, frankly, is not available. Humans have impacted their food source since we've existed. We cultivated teosinte, a grass seed, into corn. We made the apple, plum, peach varieties into the sweet fruit we know today. Meats from our stationary animals is fattier and more tender. Our food is different.



5. Paleo diets oust grains. Did cavemen eat them?

 As grain-free, Paleo diets became popular, scientists discovered remnants of seeds and grains on the teeth of fossilized early humans and on their cooking tools. Too, they found that our ancestors cooked bread! They ground grain into a crude flour to make primitive pita-like grain.




In closing, I take this thought from Zuk. Our view of people in history is always changing. To pin down a "Paleolithic standard diet" back then is hard enough, so to identify the perfect one to follow now would be wishful thinking. Find more about Zuk's argument, here and there.



When you're looking to stay healthy, match the amount of food you need with your activity level! Eat right-sized food - a mix of fruits, vegetables, whole grains, protein, dairy, and sometimes food that satisfies your sweet tooth. It works every time!
Picture from PA NEN's Facebook page















8 comments:

  1. My own personnel eating plan is that I eat as if I were a diabetic. I feel better, less bloated and seemed to have more energy. My son who is a certified personal trainer follows the Paleo diet. When you work out as long and often as he does he needs a lot of protein. Crossfit is difficult and he has gained a great deal of muscle. I will say that if I cook something that he really loves, he will eat it and then watch what he eats the rest of the week. What a great post.

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    1. I gawk at the delights on your blog. Not only are they well-rounded, they look straight-up delicious! Who could ever turn down one of your meals?!

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  2. I can see those eyes rolling :)..You're funny..Lots of info there..Thanks

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    1. I know you can relate, Missy! Thank you.

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  3. Cool. The education paid off!

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  4. Love it, love it, love it! Thank you for writing such a well thought out and educated post. So nice to see real education in writing - and real critical thinking, as well!

    I love the last piece about eating a wide variety in your diet and smaller portions. I just live by the rule - Eat Food (real food), Not Too Much, Mostly Plants. Works for me!

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    1. Lindsey! Thanks for your kind words, and that's a fabulous stand-by food rule!

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