Mind & Body

Were Our Ancient Ancestors Healthier Than We Are?

When you're constantly being told to eat less processed food, spend less time in front of a screen, and get more exercise, it seems like our ancient ancestors — for whom screens and processed food didn't even exist, and who had to chase down an animal just to eat — had it made. The idea that humans didn't evolve for our modern lifestyles is what's behind everything from herbal remedies to the Paleo diet. But is this really true? The answer is complicated.

Vintage Genes

In 2017, Georgia Tech researchers analyzed the DNA of humans from a wide range of time periods, dating all the way back to 50,000 years ago. Then, they compared these genes to modern variants that we know cause disease to see how "genetically healthy" each sample was. While they found that individuals from tens of thousands of years ago were genetically sicker than we are, those who lived in the last thousand years actually had healthier genomes than modern humans.

Before you get too alarmed, it's important to put this into context. If an ancient human suffered from nearsightedness, a pollen allergy, and irritable bowel syndrome, they likely wouldn't survive to bear children. But modern advancements make it possible for people today to have all of those conditions and still meet a mate, have children, and live a long, healthy life. And that's just diseases we know have genetic variants: It's possible that these ancient DNA samples contained genes for diseases we can't identify since they were stripped from our genomes as sufferers dropped out of the family tree. That would skew the results and make these recent ancients appear healthier.

Either way, when they looked at the full breadth of their samples, the researchers concluded that things are about the same for modern people as they were for ancients. "On a broad scale, hereditary disease risks are similar for ancient hominins and modern-day humans," the authors wrote, "and the GRS [genetic risk score] percentiles of ancient individuals span the full range of what is observed in present day individuals."

Even a Caveman Could Chew It

Of course, whether or not our genes are similar to ancient humans, you could still argue that our lifestyles are less healthy. Hunter-gatherer civilizations had fewer cavities than we do since the advent of farming brought sugar and carbohydrates into our diets that scientists believe changed the bacteria in our mouths. That dietary change may have led us to start snoring more since softer food led to smaller jaws, which made it more difficult to breathe. And despite a common argument to the contrary, the lifespan of our ancient ancestors wasn't all that much shorter than ours. Sure, many died in infancy, but most of those who didn't lived to the ripe old age of 70.

So does that mean we should mimic our ancestors and rid our diets of grains a la the Paleo diet, or eat everything uncooked as raw-food proponents suggest? Well, while we could all certainly use the additional exercise of our forefathers, a lot of caveman diet advice is based on misconceptions about what our ancestors actually ate and about how we've evolved since the advent of agriculture. Wheat and other grains were domesticated around 10,000 years ago, back when mammoths and saber-toothed cats were roaming the globe, and there's evidence that ancient humans were making flour out of starchy roots 30,000 years ago. What's more, studies of modern hunter-gatherer societies show that there isn't one ancient diet that's "best." Some of these societies are vegetarian and carbohydrate-heavy, others subsist on almost entirely meat or fish and get most of their calories from fat or protein. "What makes us human is our ability to find a meal in virtually any environment," biological anthropologist William Leonard told National Geographic.

Likewise, we've evolved to thrive on different types of food than our ancestors. With the domestication of cows came a new ability to digest milk in adulthood — many of the lactose intolerant today just have a "wild type" of the gene for digesting lactose. That, along with other genetic adaptations like our smaller jaws and variations in our ability to break down starch, shows that we've evolved since our caveman days, and we're still evolving.

There is one thing we could look to our ancestors for, however. We experienced a population boom when our ancestors learned to cook since cooked food takes less energy to digest and provides nutrients that are easier to absorb. You could say that cooked food was the original processed food. Of course, as we've gotten better at processing food, nutrients and calories are getting easier and easier for our bodies to take in — and that is leading to weight gain, heart disease, and diabetes.

"Rough breads have given way to Twinkies, apples to apple juice," Richard W. Wrangham writes in his book "Catching Fire: How Cooking Made Us Human." "The big problem of diet was once how to get enough cooked food, just as it is for millions of people around the world. But for those of us lucky enough to live with plenty, the challenge has changed. We must find ways to make our ancient dependence on cooked food healthier." Eat your grains, fruit, and dairy, and cook them if you like — you'll still have plenty in common with the ancients. Just heed what modern nutrition experts are telling you.

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Food played a big part in the evolution of our big brains. Learn all about that fascinating history in "Catching Fire: How Cooking Made Us Human" by Richard W. Wrangham. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Ashley Hamer July 5, 2018

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