The Paleo diet is gaining more and more traction and popularity. You may have heard friends talking about their recipes or seen social media posts encouraging this diet. While eating like a caveman sounds like a good approach to health, we wondered how the diet’s principles stack up against science. Let’s take a look at what we know about the diet of Paleolithic humans and how the Paleo diet works.
What is the Paleolithic diet?
The Paleolithic diet is based on the principle that human evolution can help us determine what foods to eat for optimal health. As the name suggests, promoters of the diet look to the Paleolithic era, also known as the Stone Age, for clues about what we should be eating. The Stone Age began around 2.5 million years ago and ended around 10,000 years ago, making it the longest evolutionary period in human history.
Proponents of the Paleo lifestyle believe that, during this period, human beings ate mainly meat, seafood, eggs, fruits, vegetables, nuts, and seeds. They argue that our bodies have not adapted to eating grains, legumes, dairy products, or processed foods. They are especially vehement about the supposed ill effects of grains on the human body. According to them, grains cause all sorts of health issues. These include inflammation, obesity, skin rashes, and something they call “leaky gut syndrome.”
Does the evolutionary argument hold up to scrutiny?
It’s true that evolution plays a large role in determining what foods are good for our bodies, but the specific argument that propels the modern Paleo lifestyle movement is flawed in a few ways. First, the facts cited are often exaggerated, too broadly generalized, and sometimes just plain wrong. The dietary habits of Paleolithic hunter-gatherers were ever-changing and completely dependent on their environment (which was enormously varied across space and time). Vegetables as we know them today did not exist. Archaeologists and anthropologists don’t even claim to know exactly what people were eating that long ago. What’s more, the handful of evidence they do have suggests that, yes, pre-agricultural humans sometimes ate grains.
The argument in favor of the Paleo diet also misrepresents how evolution works on a fundamental level. Even if people during the Paleolithic era did eat the way proponents of the diet claim they did, 10,000 years is plenty of time for a genetic mutation (such as the one that allows millions of people to digest lactose) to become widespread if conditions render it advantageous. Marlene Zuk, a professor of ecology, evolution, and behavior, points out that evolution is not a linear process in which life forms continuously improve. Rather, it is a constant state of adaptation to a constantly changing environment. The dramatic change in lifestyle triggered by the agricultural revolution resulted in significant changes to our biological makeup.
Could whole grains actually be bad for you?
The most glaring deviation in the Paleo diet from more traditional nutrition advice is that we shouldn’t be consuming grains at all, not even in their whole, unprocessed forms. Claims regarding raised insulin levels, nutrient-stealing phytates, and autoimmune-related inflammation abound among antigrain crusaders. However, we will once again find that these accusations are largely unfounded.
Rosane Oliveira, geneticist and founding director of UC Davis Integrative Medicine in California, points out that grains, or even carbohydrates, are not the sole culprits when it comes to high insulin levels. Any form of calories, including fat and protein, will similarly affect insulin levels and fat storage. Oliveira also breaks down the complex role of phytates in our diet, noting that 1) the “anti-nutrient” effects of phytates only develop when a low-nutrient diet is combined with a high-phytate intake; 2) cooking, soaking, or fermenting whole grains actually deactivates phytic acid; and 3) phytic acid is also a powerful antioxidant and may contribute to the prevention, reduction, and reversal of numerous diseases, including heart disease, diabetes, and many forms of cancer.
As for the alarmist position that whole grains, especially wheat, damage the lining of our intestines, causing autoimmune disorders and full-body inflammation, the evidence just isn’t there. The studies most often cited when these claims are made are either very limited in scope (only tested on rats, for example) or strictly refer to the very small portion of the population that suffers from celiac disease (1 percent) and gluten sensitivity (around 6 percent).
To be clear, refined grains (white flour, bread, and pasta) absolutely do cause inflammation and dangerous spikes in blood glucose levels. Almost everyone can benefit from limiting or eliminating them. It’s also true that some people have negative reactions to certain grains, and those people should not eat those grains. But for the vast majority of us, the addition of whole grains (intact, unprocessed grains) to the diet is one of the most effective ways to improve overall health and longevity.
Are there positive aspects of going Paleo?
All that being said, we’re not denying that a so-called Paleo lifestyle has benefits. Here are a few.
- Emphasizes whole foods: Many fad diets exist to sell processed foods, such as bars, shakes, or frozen dinners, that are low in both calories and nutrients. In contrast, the Paleo diet emphasizes whole, unprocessed, nutrient-dense foods. Our Paleolithic ancestors didn’t eat packaged foods, so why should we? Even if the evolutionary argument is flawed, most experts agree that eating fewer processed foods is a good thing.
- Common substitutions for refined grains can help increase your protein, fiber, and vegetable intake: Whether or not you buy the logic that says to eat certain things because our ancestors did, you have to admit that some of the recipe substitutions born out of the Paleo movement are objectively better for you than their grain counterparts. Almond flour, flax meal, and zucchini noodles (zoodles) are all practical, nutritious alternatives to refined flour.
- Relatively healthy weight loss strategy: While weight loss is not always inherently healthy, obesity’s correlation to a number of life-threatening diseases is difficult to ignore. And when it comes to popular weight-loss regimens, you could do worse than a Paleo diet. No fasting, no calorie counting, and no pills. Just plenty of lean protein, vegetables, fruit, and nuts. If done thoughtfully, it can result in healthy weight loss.
What are the negative aspects of going Paleo?
- Very restrictive: Strict adherence to a Paleo diet means eliminating entire food groups that are nutritious and healthful. This includes all dairy, grains, and legumes. For many people, making small changes over time is a more achievable and sustainable option for improving health. This approach may include switching to whole grains or eliminating added sugar.
- Can lead to nutrient deficiency: It isn’t impossible to get all the nutrients you need on a Paleo diet, but it isn’t easy, either. A lot of people already have limited access to fresh fruits and vegetables. Whole grains, beans, and dairy products are options for people who struggle to get a wide variety of calorie sources in their diet.
- “Unprocessed” doesn’t always mean healthy: While Paleo guidelines are relatively strict, they still leave room for high-calorie, low-nutrient foods. “Natural” sweeteners, such as maple syrup and honey, are perfect examples. Sure, our Paleolithic ancestors might have eaten them, but that doesn’t alter the reality that they break down in a similar fashion to white sugar. This is important information for the many diabetics who are trying the Paleo diet as a way to control insulin levels.
- It can get expensive: Because the diet is meat-centric, it’s important that those who follow it opt for high-quality, lean varieties in order to avoid negative health effects. That comes with a price tag. On average, grass-fed beef costs $2.50 to $3 more per pound than conventional grain-fed beef. It’s also worth noting that unprocessed, plant-based sources of protein are, on average, cheaper than animal sources. This is true even of conventionally raised animal sources.
What are some tips for staying safe and healthy if you try a Paleo diet?
If you’re still set on embarking on your own Paleo adventure, consider the following tips for staying safe and healthy.
- Stay flexible: A practical strategy for testing the waters of a Paleo diet is to eliminate foods gradually. Begin with the ones we know are harmful. Refined grains, added sugar, unhealthy oils, and low-quality meats are good places to start. If this alone is a challenge but you feel better doing it, stick with it. Eventually, if you suspect certain grains are having a negative impact on your health, eliminate them as well. Pay attention to how that makes you feel. Consider dropping altogether the notion that even complex carbohydrates are bad for you. Beans, peas, and root vegetables are starchy, nutrient-dense foods that help us feel full and stay energized.
- Eat a wide variety of foods: Any diet as restrictive as the Paleo diet creates a higher risk for nutrient deficiency. That being said, it’s avoidable. Eating a wide variety and several portions per day of colorful fruits and vegetables is important for everyone. It becomes more vital for people abstaining from other plant foods (grains and legumes).
- Limit red meat and processed meat: As of October 2015, the World Health Organization listed processed meat as a carcinogen. The organization lists red meat as a possible carcinogen. Choose fish, poultry, and nuts over beef, pork, or meats that have been cured, fermented, or preserved with nitrates.
- Talk to your doctor: Consult your doctor to determine the best strategy for your specific health needs. You should do this before embarking on any sort of diet to improve your health.