Paleo diet got you down? All that heavy meat and bacon can leave your taste buds and digestive system screaming for something refreshing, like an orange. There’s good news: according to a recent essay in Scientific American, our Paleo ancestors ate lots of other stuff besides meat. In fact, they probably ate little meat, and definitely no bacon.
The essay by science writer and biologist Rob Dunn, examines evidence for what our human and primate ancestors ate, as well as what primates eat now. The vast bulk of food stuff is from plants: fruit, leaves and nuts. “Meat” may be more from insects than mammals or fish. Analysis of dental remnants from Neaderthals shows significant consumption of plant food. The manly image of our primitive ancestors running down large animals every day and gorging on meat doesn’t jive with reality. Our ancestors ate whatever they could find, and most of that was plant food. Conclusion: they were primarily vegetarians, just as most primates today are.
Things could be worse. In fact, there’s plenty of evidence that plant-based diets are especially healthy. Preliminary results from an ongoing study of 96,000 subjects shows that the vegetarians live years longer than people who eat meat-heavy diets. On average, men live 9.5 years longer and women 6.1. Vegans in this study are 30 lbs lighter and have much less insulin resistance, a risk for Type 2 diabetes.
Dunn mentions another interesting issue in his essay: the effect of diet on our gut microbe population. By coincidence, I came across an article on bacteria, in particular the bacteria that make humans their home. Or not. Our gut bacteria has been fundamentally changed by modern life, notably frequent use of antibiotics. It turns out there’s a link between significant changes in our gut bacteria and obesity. For example, wiping out certain bacteria with antibiotics causes mice to gain weight, even though they aren’t eating more calories. Livestock like cattle and chickens are routinely given antibiotics, because those drugs make the animals gain weight quickly. This indiscriminate use of antibiotics is a major complaint of organic food advocates.
The effect of gut bacteria on weight gain in humans is likely to turn out to be a very complicated system. Simply taking capsules of a bacteria isn’t likely to help. Our gut microbe populations reflect what we eat. If your diet is heavy on meat and processed food, your gut bacteria will be fundamentally different from a person who eats a plant-based diet and few processed foods. Vegan diets are known to help people lose weight. But is it the vegan diet? Or is it the effect of that diet on gut microbes? We don’t yet have the answer to that question. Meanwhile, you can hedge your bets by moving to a more vegetarian type diet.