What does scientific evidence say about the paleo diet?

Paleo diet: Is there any evidence that it benefits health?
Despite it being one of the most popular diets, not all healthcare professionals and researchers support the paleo diet. They believe this eating pattern may negatively impact health because it excludes certain food groups. In this Honest Nutrition feature, we investigate the studies behind the paleo diet and consider its health benefits and potential risks.
The promotion of certain eating patterns as a way to improve overall health is very common. In recent years, an eating pattern called the Paleolithic diet — also known as the paleo diet, for short — has taken the health and wellness world by storm.
Despite the popularity of the paleo diet, many researchers and healthcare professionals argue that it is not necessarily the best diet to benefit overall health. In fact, some believe that it may be harmful.
In this Honest Nutrition feature, we dig a little deeper into the research behind the paleo diet to uncover its potential health benefits. We also discuss the risks that may come with following a paleo diet.
Supporters of the paleo diet believe that the change from a hunter-gatherer style diet to an agricultural diet has increased the worldwide prevalence of chronic diseases, including heart disease, obesity, and diabetes.
They believe that the human body is not genetically equipped to consume the modern day foods that farming practices have introduced. As a result, they think that our overall health will improve by following a diet similar to that of our ancestors.
Several breakthroughs in science and research have allowed us to explore further the potential benefits of the paleo diet to determine whether it should become a diet that healthcare professionals routinely recommend.
A 2015 review looked at four randomized control trials with 159 participants who had one or more of the five components of metabolic syndrome.
The researchers found that Paleolithic nutrition led to more significant short-term improvements in the following areas compared with the control diet:
waist circumference
triglyceride levels
blood pressure
levels of high-density lipoprotein (HDL), or “good,” cholesterol
fasting blood sugar
A study published in the Nutrition Journal evaluated several randomized control trials to establish a relationship between the Paleolithic diet and the prevention and control of chronic diseases and anthropometric measurements.
The study found a mean weight loss of 3.52 kilograms plus a decreased waist circumference and body mass index (BMI) in those who followed a Paleolithic diet compared with those eating other commonly recommended diets.
The researchers behind this study suggest that following a paleo diet may reduce the risk of chronic diseases, as having excess body weight is one of the main risk factors for their development.
Is the paleo diet better than other diets?
The study found that those who followed a paleo or Mediterranean diet had reduced all-cause mortality, lower oxidative stress, and decreased mortality from heart disease and cancer.
A meta-analysis from 2020 reviewed four studies to compare the paleo diet with the Mediterranean diet, the diabetes diet, and another diet that the Dutch Health Council recommends. The researchers looked at the effects of these diets on glucose and insulin homeostasis in individuals with altered glucose metabolism.
They found that those who followed the paleo diet did not experience any significant improvements in fasting glucose, insulin levels, or HbA1c levels compared with those following the other diet types. The study authors conclude that the paleo diet is not superior to other nutritious diets in people with altered glucose metabolism.
Additionally, a study featuring in the journal Nutrition in January 2020 looked into the effectiveness of different diets, including the paleo diet and intermittent fasting.
Its authors found that, to date, there is no one specific diet that can effectively support weight loss in all individuals. They concluded that the best diet for weight loss consists of a negative energy balance while focusing on food quality.
Cutting out certain food groups may improve some health markers and lead to weight loss, but it can also result in nutrient deficiencies and increase the risk of long-term health consequences.
For example, a paleo diet restricts dairy products, which are high in calcium and vitamin D, two nutrients essential for bone health. A deficiency in these nutrients can lead to osteoporosis and bone fractures.
This diet also cuts out beans and legumes. Beans are a great source of minerals, fiber, and plant-based protein. They also can help lower cholesterol and promote satiety, the sensation of being full after a meal.
What is more, many people who follow a paleo diet claim that it promotes gut health, but new research says otherwise.
Some studies suggest that those who follow a paleo diet have different gut microbiota and higher levels of trimethylamine N-oxide (TMAO), a compound tied to cardiovascular disease.
This research reinforces the current dietary recommendations of including foods high in fiber and whole grains to maintain cardiovascular function and gut health.
Those who take a modern-style approach to the paleo diet often use it as an excuse to overeat meat. Eating more than the recommended servings of meat, specifically red meat, daily can lead to chronic disease.
The paleo diet is also typically very high in saturated fat. According to the American Heart Association (AHA), a person should limit saturated fat intake to no more than 13 grams per day to avoid high cholesterol and heart disease. Overeating red meat can also lead to kidney damage.
A person should aim to eat a maximum of 12–18 ounces (approximately 350–500 grams) of red meat each week. Those with existing heart conditions should limit red meat consumption to less than this amount.
According to an article in the Australian Family Physician, the paleo diet is overhyped and under-researched. The author calls for more long-term studies to continue to weigh the benefits and risks of this dietary pattern.
However, the paleo eating pattern can be difficult to adhere to fully in the long term, making it difficult to form more conclusive recommendations.
Unless a person has a health condition that requires them to restrict a specific food group, there is no scientific evidence to show that the paleo diet is superior to other well-known diets, such as the Mediterranean diet.
Diets rich in fruits, vegetables, lean proteins, and whole grains allow for more variety, are more sustainable, and are scientifically proven to provide health benefits.
It is possible to get in all of the necessary nutrients from the permitted foods on the paleo diet, but it can be challenging. For instance, people will need to focus on getting calcium from nondairy sources, such as dark green, leafy vegetables.
Anyone who is considering changing their diet should speak with a doctor or registered dietitian beforehand.