To Go Paleo Or Not? PT 3
Diseases of Wealth and industrialisation
Although furring in arteries may be common, “diseases of wealth” like obesity, diabetes, and cardiovascular diseases have certainly gone up dramatically in the past 50 years in industrialised countries, especially compared to non-developed populations.
Over the last century — a period that is far too short for notable genetic adaptation — we have radically changed the way we eat and live in the UK.
Today, the average Brit subsists on foods that are packaged and commercially prepared. Rich in refined sugars and starches, highly processed fats, and salt, these foods are designed to be so delicious that the body’s normal fullness signals don’t work and encourage overeating.
Consider: The top calorie sources in the western diet today are
1. grain-based desserts (cake, cookies, etc.)
2. yeast breads
3. chicken-based dishes (and you know that doesn’t mean roast chicken)
4. sweetened beverages
6. alcoholic drinks
These are not ancestral foods. Nor foods that any nutrition expert, regardless of dietary persuasion, would ever recommend.
So when proponents of the Paleo diet claim that our modern Western diet isn’t healthy for us, they are absolutely correct.
But is the Paleo diet really Paleo?
Remember: There’s no single “Paleo diet”.
Our ancestors lived pretty much all over the world, in incredibly diverse environments, eating incredibly diverse diets.
Still, in most cases, primal diets certainly included more vegetables and fruits than most people eat today. So if we want to be healthier, we should do what our ancestors did and eat a lot of those. Correct?
Maybe so… but not necessarily for the reasons that Paleo proponents recommend.
First of all, most modern fruits and vegetables are not like the ones our ancestors ate.
Early fruits and vegetables were often bitter, much smaller, tougher to harvest, and sometimes even toxic.
Over time, we’ve bred plants with the most desirable traits — the biggest fruits, plumpest kernels, sweetest flesh, and fewest natural toxins.
We’ve also diversified plant types — creating new cultivars from common origins (such as hundreds of cultivars of potatoes or tomatoes from a few ancestral varieties).
Likewise, most modern animal foods aren’t the same either.
Beef steak (even if grass-fed) is not the same as bison steak or deer meat. And so on.
This doesn’t make modern produce or modern meat inherently good or bad. It’s just different from nearly anything available in Paleolithic times.
So the claim that we should eat a diet rich in vegetables, fruits, and meats because we are evolved to eat precisely those foods is a little bit suspect. The ones we eat today didn’t even exist in Paleolithic times!
Grains and grasses
Proponents of the Paleo diet argue that our ancestors’ diets could not have included a lot of grains, legumes, or dairy foods. And they contend that the past 10,000 years of agriculture isn’t enough time to adapt to these “new” foods.
This argument is compelling but doesn’t stand up to scrutiny.
To begin with, recent studies in the Proceedings of the National Academy of Sciences, using more advanced analytical methods, have discovered that ancient humans may have begun eating grasses and cereals before the Paleolithic era even began — up to three or even four million years ago!
Further research has revealed granules of grains and cereal grasses on stone stools starting at least 105,000 years ago.
Meanwhile, grain granules on grinding tools from all over the world suggest that Paleolithic humans made a widespread practice of turning grains into flour as long as 30,000 years ago.
In other words, the idea that Paleolithic humans never ate grains and cereals appears to be a bit of an exaggeration.
Are beans really bad for you?
Grains are not the only plant type that the Paleo diet typically limits. Advocates also recommend that you avoid legumes (beans, peanuts, peas, lentils) — and for a similar reason.
However, the idea that legumes were not widely available or widely consumed in Paleolithic times — like the argument that humans didn’t eat grains in the Paleolithic era — is false.
In fact, a 2009 review revealed that not only did our Paleolithic ancestors eat legumes, these were actually an important part of their diet! (Even our primate cousins, including chimpanzees, got into the bean-eating act.)
Legumes have been found at Paleolithic sites all over the world, and in some cases were determined to be the dominant type of plant food available. In fact, the evidence for wild legume consumption by Paleolithic humans is as strong as it is for any plant food.
What about anti-nutrients?
Okay. Maybe our ancient ancestors did eat a little bit of grain and some legumes — so the argument from history doesn’t really hold.
But Paleo proponents also offer another reason to avoid these foods: Their high concentration of anti-nutrients, which supposedly reduces their nutritional value to zilch.
There’s just one problem with this argument. It’s wrong.
Indeed, research suggests that the benefits of legumes far outweigh their anti-nutrient content, especially in light of the fact that cooking eliminates most anti-nutrient effects.
Lectins and protease inhibitors, in particular, are greatly reduced with cooking. And once cooked, these chemicals may actually be good for us. Lectins may reduce tumor growth, while protease inhibitors become anti-inflammatory and anti-carcinogenic.
But what about phytate?
Grains, nuts, and legumes are rich sources of this anti-nutrient, which can bind to minerals such as zinc and iron and prevent their absorption. Surely that, in itself, is enough reason to avoid grains and legumes?
While phytic acid can be toxic if we eat too much of it, in more reasonable amounts it actually offers benefits.
For example, it can:
have antioxidant activity
protect DNA from damage
be prebiotic (i.e. bacteria food)
have anti-cancer properties
reduce bioavailability of heavy metals like cadmium and lead.
And, in a mixed diet composed of other nutrient-dense whole foods, phytic acid is unlikely to cause problems.
In fact, nearly all foods contain anti-nutrients as well as nutrients — particularly plant foods.
For example, incredibly healthy foods such as spinach, Swiss chard, many berries, and dark chocolate are also sources of oxalate, an anti-nutrient that inhibits calcium absorption.
Green tea and red wine contain tannins, another anti-nutrient that inhibits zinc and iron absorption.
And so on.
Overall, phytic acid and other so-called anti-nutrients probably have a “sweet spot” (just like most nutrients).
Eating none or a small amount might be inconsequential.
Eating a moderate amount might be good.
Eating too much will hurt you.
Grains and inflammation
Another argument for a Paleo diet is that eating grains can lead to inflammation and related health problems.
While this can be true for people with celiac disease (about 1% of the population) and for those with non-celiac gluten sensitivity (estimated to be about 10% of the population, if it even truly exists), on the whole, the research does not support this argument any more than it supports the argument about anti-nutrients.
In fact, observational research has suggested that:
whole grains may decrease inflammation, but
refined grains may increase inflammation.
In other words, it appears that processing may cause problems, not the grain itself.
Meanwhile, controlled trials consistently show that eating grains, whether whole or refined, does not affect inflammation at all!
What can we make of that?
At worst, whole grains appear to be neutral when it comes to inflammation.
And overall, a substantial body of evidence from both observational and controlled trial research suggests that eating whole grains and legumes improves our health, including:
improved blood lipids;
better blood glucose control;
less inflammation; and
lower risk of stroke and coronary heart disease.
Eliminating these important foods completely from our diet to conform to anybody’s dietary ideology is probably a poor idea.
Moderation, variety, quality and as little processing as possible are the most important factors.
Eat Clean. Stay Active. Feel Great