Due to the plethora of research, the American Cancer Society also emphasizes the value of plant-based foods and recommends limiting consumption of processed meat and red meat. Animal products can also have an impact on emerging risk factors for heart disease, such as the creation of trimethylamine-N-oxide (TMAO) by the bacteria in our gastrointestinal tracts, which helps cholesterol to stick to the wall of the artery. And while there is some suggestion that grass-fed beef might be healthier, we still just don’t know the health impact of eating a lot of it over the long-term.
3. Most Meat Production Takes an Enormous Toll on the Environment.
Greenhouse gas (GHG) production is considerably higher for most animal products than plant-based foods. Not only is raising (i.e., feeding) animals very resource intensive, but some livestock also release methane–a potent GHG.
A 2014 study found that grain-finished beef requires more land and water and produces more GHGs and reactive nitrogen compared to poultry, pork, eggs or dairy. Reactive nitrogen, a by-product of fertilizer use, contributes to acid rain and creates dead zones in lakes and oceans. While pasture-based operations do appear to offer some environmental benefits, they make up less than 5 percent of all meat production.
And, the most important point: We’ve heavily industrialized our animal production to support the current American diet, which is nowhere near as meat-focused as the Paleo diet. Can you imagine how much meat we’d have to produce—and how much pollution and potential climate impact it would have—if everyone went Paleo? In countries like India and China, where meat and dairy consumption has been on the rise along with the growing middle class, such a shift could have devastating global consequences.
4. The Paleo Diet is Not What Paleolithic People Actually Ate.
Unless you’re eating a varied, seasonal diet including tubers, sedges, fruits, animals, insects, worms, leaves, and bark, you’re not eating Paleo, say anthropologists Ken Sayers and C. Owen Lovejoy.
Archeological scientist Christina Warinner discussed the dietary habits of the Paleo man in her TEDTalk, “Debunking the Paleo Diet.” In a nutshell, she says the Paleo diet “has no basis in archeological reality.” Her team’s research found that the diet of our ancestors was extremely varied and depended on where they lived and the time of year. People who lived in the Artic ate more meat. Those who lived in warmer climates ate more plants.
In Mexico, for example, they ate prickly pear, legumes, fruits, agave, nuts, beans, gourds, and flowers. They also ate some wild game, but mostly rabbits when they could catch them. It’s also worth considering that most of the food people eat today–on the Paleo diet or otherwise–has been altered through plant breeding and other modern agricultural principles. In other words it’s not even remotely similar to the wild foods our ancestors ate.
If really you want to eat like early humans, keep your diet local, plant-heavy, seasonal, and go for variety.