People who know me in real life know that I am always hesitant to recommend a particular diet book. Why? Because even though I know there are some books out there that have more evidence base than others, when you are trying to sell a book, sometimes you might find that you have to promote your lifestyle as the only way. Or I find that the book has a lot of things in it that are fascinating, but I don't agree with everything they said (i.e. maybe they get a little too into politics for my taste), so whenever I do recommend a book to another person I usually have to give a list of caveats. One of said series of books that I have used for recipes for myself is Dr. Loren Cordain's The Paleo Diet, I think he does strive to be evidence based and basically, well, its nice to know that most of the recipes are going to be safe for a no dairy/gluten/soy/legume person like me. But I also use the caveats that the posters at Nothing in Biology Makes Sense were nice enough to lay out for us; mostly that we didn't stop evolving over the past 10,000 years (and that cutting back and/or cutting out processed foods is a good thing).
The reason I mentioned all of that is that one of my friends sent me this article about some mummies who were x-rayed and found to have atherosclerosis (aka hardening of the arteries). Now, I hope you all followed the link so you actually know what I am talking about, but I do want to highlight this quote: “We found that heart disease is a serial killer that has been stalking
mankind for thousands of years,” Thompson said. “In the last century,
atherosclerotic vascular disease has replaced infectious disease as the
leading cause of death across the developed world. A common assumption
is that the rise in levels of atherosclerosis is predominantly
lifestyle-related, and that if modern humans could emulate
pre-industrial or even pre-agricultural lifestyles, that
atherosclerosis, or at least its clinical manifestations, would be
avoided. Our findings seem to cast doubt on that assumption, and at the
very least, we think they suggest that our understanding of the causes
of atherosclerosis is incomplete, and that it might be somehow inherent
to the process of human aging.”
I wanted to highlight that quote because I think this is such an excellent example of what science is. Somebody has an assumption, someone does more research, the evidence shows the assumption is wrong or incomplete, and we start to do more research and re-evaluate what kind of recommendations we make about how this plays out in real life. As in maybe there is something more than out diet at play here! I'm not an archaeologist, but it looks like the archaeologists are going to start doing more studies to see if maybe these people might have suffered from infection or if there are other things, like our genetics, that cause that nasty inflammation of the arteries.
Now I am sure that Dr. Cordain and other people who follow a paleo plan have gotten flooded with e-mails about this and are formulating responses right now, but I will give my take on it. First of all, if you are following a plan as outlined by him and you have lowered your blood glucose levels, lost weight, etc, good for you, I do not see any reason to change! Will it cause you to live longer or change the genetics you were handed? Maybe not, but we don't know. Second of all, remember that grains were apparently introduced about 10,000 years ago, and it looks like the mummies that were x-rayed were from about 3000-5000 years ago (if I read that correctly), so their diets might have started to be different than older/Paleolithic humans. Keep in mind also that we as humans did not go from hunter-gatherers to farmers overnight, we appear to have gone through a period called sedentism, sort of an in between "following the herd" and farming stage. One of the things I found fascinating when reading about that period was that there was evidence that rodents were starting to hang around people and their homes, and we all know the role that rodents have played in the spread of disease throughout history; perhaps between that and people, um, not having figured out sanitation/burials just yet could have contributed to infection and possible inflammation of the arteries (my speculation). Like I said, I am not an archaeologist, I just like to speculate on the Internet and see what the real archaeologists and evolutionary biologists come up with in the future. Particularly if it impacts the type of information I give people to help make decisions about diet and their current state of health.
Take home message--there is strong evidence that changing our diet can reduce our risk for cardiac events. We need to understand, however, that the understanding of how other lifestyle factors and genetics impacts our cardiovascular health.