I have been so busy preparing for the coaching project that this blog has been on a backburner for the past couple of weeks. I hope things get a bit quieter now so I can do some writing.
A week ago in a friend’s housewarming party I ended up having a conversation about diets, nutrition, and health (I wonder why this always happens… Is it just me or is this such a common topic?). The person I was talking with asked me for my opinion on paleo, or paleo diet, also known as primal or caveman diet. I thought it was such a good question that it definitely should warrant a more detailed answer – especially considering that a lot of the things I would recommend to people if they want to improve their health and performance are rooted in the paleo mindset.
Paleo diet, in short, consists of foods that humans ate and had access to during the paleolithic era. Foods such as meat, fish, shellfish, eggs, nuts, tubers, vegetables, roots, berries, fruit, mushrooms etc. – basically whatever you could get by hunting and gathering.
This is in stark contrast to neolithic era foods which include grains, legumes, dairy, beans, and potatoes. Also processed foods are on the off-list for those following paleo diet as those have been around for only about a century.
The underlying reason why we should eat paleolithic foods instead of neolithic ones is that during the course of human evolution we have adapted to a specific type of diet. Those individuals who have been able to thrive best with the foods available prior to agriculture are the ones who have survived and produced offspring.
The paleolithic era lasted from around 2.6 million years BC until the advent of agriculture around 10.000 years BC. Agriculture meant a major change in the diet of our ancestors, and considering that we spent hundreds of thousands of years on a very different kind of diet, our genes have not yet had enough time to adapt to do well with agricultural products. We tolerate them to some extent, but they do more harm than good if you want to optimize health and performance. Same logic can be used to processed foods which have been around for an even shorter time.
When talking about paleo diet, there are couple caveats that I think should always be considered:
Selection bias
The evidence we have on how our paleolithic ancestors ate is mainly based on archaeological findings (e.g. stone tools, spearheads stuck in the bones of huge game animals, fossilized remains) and research done on the modern-day hunter-gatherer populations such as the Masai and the Kitavans.
In other words, we do not have a complete, 100% accurate picture of what our ancestors ate. There may be relevant factors of which we have absolutely no idea because we have not found any evidence of them. Also, there is no consensus on things like the ratio of animal based vs. plant based foods, or cooked vs. raw foods.
Grey areas
A quick Google search will show you just how many different paleo diet and lifestyle websites there are, so it shouldn’t be a surprise that even amongst the proponents of paleo diet there are different perspectives and viewpoints on what the optimal diet should and should not consist of.
Practical application
Should we all go out and start hunting and gathering our food? Should we leave everything out of our diet that was not available to our paleolithic ancestors? I think not. Partly because of the selection bias and the limited information we can gather, but also because even though our ancestors did not eat something, it does not automatically mean that it would be bad for us.
Now we can get to the point I want to make about paleo, or at least share my personal opinion on paleo diet and lifestyle: paleo is a template, a framework, and a standpoint. It is rooted in evolutionary biology and gives us a solid foundation from which to generate hypotheses for testing. We can use the paleo framework to ask questions such as “if macronutrient composition is the same, but Group A uses grains as a carbohydrate source and Group B uses tubers, how does that affect biomarkers of health and disease?”
The premise of paleo diet would indicate that tubers are more healthy for us than grains. However we cannot make that conclusion without any evidence. Similarly we should not try to perfectly emulate the ancestral diet or lifestyle “just because.” For example, I’m sure my paleolithic ancestor did not drink espressos, but it doesn’t mean that I shouldn’t – unless we start seeing proof that coffee consumption causes significant health issues.
We need to ask questions, do research, and through that process find out which aspects of the ancestral diet we should incorporate into our lives, where we can have some leeway, and what kind of trade-offs are required to optimize health. Individual variations will also come into play here. For example, I don’t experience problems if I keep my dairy intake relatively low; butter for cooking and a shot of milk with coffee. Feed me a bagel or some cake and within 24-hours I get stomach pain and bloating. Every time I choose to eat something like that I am making a conscious choice of trading momentary pleasure for some future pain.
The next question is, can you actually benefit from following a paleo diet? I would say yes. A growing body of research indicates that grains, legumes and dairy are behind many of the so called diseases of civilization, and even if you don’t have any direct gastrointestinal problems or a clear-cut case of celiac disease most – if not all – people can improve their health by eliminating these foods from their diets.
And as Robb Wolf puts it; give paleo diet a 30-day trial. See how you look, feel, and perform. Then you can start reintroducing neolithic foods and see how well you tolerate them. You have nothing to lose with this approach, but you’re likely to end up feeling better than you ever thought possible, and by introducing foods back one at a time you can track your reaction to them with relative ease.
Great post Sami! I am currently following a paleo-style diet and I believe it potentially works well, but there are couple things that have always bothered me about paleo. Perhaps you have answers.
1. Paleolithic era may have lasted for 2.6 million years, but as far as I know homo sapiens originated in Africa around 200k years ago. If you were to follow back the history of evolution you would likely find quite extreme changes in physics as well as diet during this time. There has also been evolution from homo sapiens to the current day humans over the past 200k years, so I suppose it’s not far-stretched to assume that there have been changes in the past 10k years.
I have also read that Europeans or people with roots in Europe are more tolerant to dairy than Asians, due to the fact that dairy products have been consumed in Europe for hundreds of years. If true, this would indicate even much more rapid pace of evolutionary changes.
2. While it may be true that our paleo ancestors didn’t die of the old age diseases people die these days, it is my understanding that they didn’t really live beyond 30. So, the diseases of civilization may quite as well be due to longer life spans, as we didn’t evolve to live as long as we do? This theory would be supported by the fact that our bodies remain healthy and active until around 25 or so, and then start to degenerate and require more and more upkeep no matter what.
Comments? :)
Excellent points Jani. I’ll try to address them to the best of my current knowledge.
1) Even though modern day human, or homo sapiens, is estimated to have arrived around 250.000 years ago it does not mean that we can ignore the steps in human evolution that came before it all the way to Australopithecus around 4 million years ago. I also remember reading recently that genetic evidence has been found that there has been cross-breeding between homo sapiens and homo neanderthalensis which may have contributed to the ability of our race to spread out from Africa, and means that human evolution has not been linear.
When it comes to evolution in neolithic era there are actually indications that the speed of it has increased. I also remember reading that some of these changes have actually improved our tolerance to neolithic foods. However I’d like to point out that even if you can tolerate something, it does not mean it’s optimal from the health and performance point of view. Do a google search on terms such as lectins or gluten and autoimmune disease and you can find a lot of material suggesting that in large scale we simply cannot yet handle these neolithic foods all that well.
Europeans and especially the Nordic people generally tolerate dairy much better than the Asians, so you’re right about that. However, I don’t agree that we can draw any conclusions regarding the speed of evolutionary changes from this information alone. One reason for my argument is that for example human breast milk contains lactose, and lactose intolerance is the most common form of dairy intolerance. We all should have the gene that allows us to use lactose from birth, but for most people in the world this gene gets turned off as they grow older. In this regard dairy tolerance would have more to do with gene expression and epigenetics instead of evolutionary changes – although both may play a role.
2) There are couple things going on here. First of all, life in the paleolithic era was much more hazardous. Consider that if you break a leg or an arm, or you get maimed by a bull your chances of survival are much lower than today. Even if you don’t catch an infection and die on that, you’re not very likely to be able to hunt as well as before. To my understanding the short lifespan has way more to do with environmental hazards, and the number itself is so low because it’s an average. Child mortality was high and if you have two people, one dying at the age of 80 and the other dying at birth, you get an average lifespan of 40 years which is not all that impressive.
The prehistoric people who managed to avoid accidents did seem to live healthy to the ripe old age. Here is a very good article you might want to check related to this.
Also studies of modern-day hunter-gatherer populations contradict the argument that we would become sick because we get older. For example, when Staffan Lindeberg studied the Kitavans, 6% of the population were of ages 60-95, whereas average lifespan was 45 – mainly due to relatively high incidence of child mortality. He writes that “The elderly residents of Kitava generally remain quite active up until the very end, when they begin to suffer fatigue for a few days and then die from what appears to be an infection or some type of rapid degeneration.” No signs of e.g. cardiovascular disease, rheumatoid arthritis, cancer, or diabetes were found.
I hope this answers most of your questions :)
//sami