Paleo Diet Pros & Cons

Asparagus and Pork Chops, a perfect paleo dinenr
April 15, 2014 (Updated: August 16, 2018)
Lily Moran

No doubt you’ve heard of the Paleo Diet, one of the hottest trends around. Many of my patients are asking my opinion – Is the diet healthy? Is it right for me? Is there science to back up the claims? As a result, I thought this would be a good newsletter topic. If you are curious about the Paleo approach and what it might offer you, please read on.

The Paleo Diet is loosely based on the work of Loren Cordain, Ph.D., former Colorado State University health and exercise professor, and author of numerous books, including the bestseller, The Paleo Diet. According to Cordain, the history of the movement goes back even further, to a 1985 article in the New England Journal of Medicine that suggested eating like our pre-historic ancestors might be a healthy alternative.

The thinking is that modern humans have been around for about 200,000 years, since the Paleolithic Era, while agriculture is a fairly new invention that’s only 10,000 years old. So the idea behind the Paleo Diet is to eat like the earliest hunter-gatherers did before farming and raising livestock developed, because that’s the environment in which human beings evolved.

The Birth of the Paleo Movement

Cordain has been writing about the Paleo lifestyle as an alternative to our current unhealthy ways for decades. But the movement received a significant boost back in 2005, when he released The Paleo Diet for Athletes: A Nutritional Formula for Peak Athletic Performance. The book caught on with athletes looking for an edge, and the Paleo Diet became a household word.

In essence, the Paleo Diet requires you to give up all grains (including wheat, corn, and rice), legumes, beans, dairy, salt, soy, caffeine, alcohol, and refined sugars or sugar substitutes, because none of those foods were available to prehistoric humans. No packaged or prepared foods are allowed, either, obviously for the same reason. In other words, forget about sandwiches (cavemen did not have bread), anything in a can or box, fast food, and frozen meals.

The Paleo Pantry

So what can you eat? Primarily meat, poultry, fish, eggs, fruits and non-starchy vegetables, some seeds, and certain nuts. Furthermore, the meat should be free-range and grass-fed, and the fish wild-caught, so that these foods are similar to what was eaten by prehistoric humans. Otherwise, they don’t contain the same nutrients that make those foods healthy, in particular the omega-3 essential fatty acids (EFAs). Furthermore, I recommend my patients also avoid processed and cured meats – hot dogs, sausage, and bologna, for example – because they have been linked to cancer. For reasons that are not clear, clarified butter and other oils, including coconut oil, are allowed. One rationale is that clarified butter is very similar to the fat in meat.

In exchange for giving up so many staple and convenience foods, the Paleo Diet promises to help you lose weight, lower your cholesterol and high blood pressure, and reduce the likelihood of pre-diabetes turning into Type 2 diabetes. While these specific claims are largely unproven in terms of large, long-term clinical trials, many fans of the Paleo Diet say they feel better with this eating plan, and others say they have lost weight and seen improvement in health markers.

Is The Paleo Approach Right for You?

As a physician, I can tell you what I like about going Paleo. First, it helps get people off grain-based foods. While whole grains have long been known for their health benefits, I’m concerned about the cautions regarding wheat that are being brought to light in recent books like Wheat Belly and Grain Brain.

As the authors of these books point out, the wheat we are eating today is not the same plant that our ancestors consumed, thanks to years of hybridization. As a result, wheat sensitivities and allergies are on the rise. And the fact that wheat is now an ingredient in so many foods where it is least expected – including soups, sauces and condiments, and even foods like ice cream – is another complicating factor for people who may be sensitive or allergic. And of course, for those with celiac disease, hidden wheat is a disaster waiting to happen. Completely eliminating grains from the diet reduces the amount of time you have to spend as a food detective, checking the tiny print on labels.

In addition, Paleo proponents point to substances in grains and certain other forbidden foods that are known as “anti-nutrients.” These seldom-discussed substances – all of them toxic – include things like enzyme blockers, lectins, gluten, phytates, and glycoalkaloids. Generally, these compounds are found in potatoes, beans, grains, and legumes. So far, gluten is the only anti-nutrient to become a household word. But I would not be surprised if that changed soon. Research shows that anti-nutrients can damage the stomach lining, confuse the immune system – possibly leading to autoimmune disorders – bind to insulin receptors, and interfere with absorption of minerals, to name just a few of the downsides.

But remember, anti-nutrients are a controversial topic, and not everyone believes they must be avoided. There’s also a school of thought that regards anti-nutrients as perfectly safe and even potentially beneficial. So this part of the Paleo Diet is far from settled.

I’m also pleased about the fact that processed, prepared foods and especially sugar is not part of the Paleo Diet. As regular readers know, I consider sugar to be something no one should eat, a nutrition-free food linked to obesity, cancer, diabetes, heart disease, and many other ailments. One study even found that the Paleo eating plan helped people with Type 2 diabetes improve their glycemic control (a measure of blood sugar or glucose) and reduce several cardiovascular risk factors.

Pros, Cons, and Unknowns

That said, however, I want to point out that from a medical standpoint, the Paleo Diet is not for everyone. Like most one-size-fits-all approaches, some individuals do well eating like a caveperson, while others do not. My patients Greg and Lucy are good illustrations of how the diet works – and how it can fail.

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Greg, a photographer in his 40s, was concerned about increases in his LDL (bad) cholesterol and recent weight gain, so he decided to try going Paleo. His wife, Lucy, a stay-at-home mom, just wanted to lose a little weight.

After more than a year on the diet, Greg still raves about the benefits – a 34-inch waist, something he hadn’t had since high school, and significant drops in his cholesterol, too. Because the diet does not allow sugar or simple carbs, cholesterol and triglycerides tend to go down, a boon for many people.

Lucy, on the other hand, lasted for less than two weeks on the diet. “No pasta, rice, bread, or dairy — that just didn’t work for me,” she explained. “After the second day of eating a ground beef patty wrapped in a lettuce leaf for lunch, I was ready to quit. I hung on for a little while longer, because Greg was so thrilled with it. But in the end, the Paleo Diet was boring and difficult. There just weren’t enough choices for me.”

In addition, Lucy experienced one of the downsides of low-carb diets – a serotonin shortage. Low-carb diets are popular among dieters, but here’s the problem: Carbs are involved in the production of serotonin, an important neurotransmitter that plays a major role in a number of areas, including:

  • Regulating blood pressure
  • Encouraging healthy sleep
  • Maintaining a positive emotional state
  • Moderating sensitivity to pain
  • Preventing overeating

Difficulties maintaining a positive emotional state is where many low-carb dieters run into trouble. Sometimes, in their enthusiasm for a new eating plan, people go to extremes and avoid carbs altogether. This is a huge mistake. In my earlier newsletter on macronutrients, I explained that carbs are one-third of the trio that includes protein and fat. There is simply no way to maintain good health without eating from all three macronutrient groups.

For some people, however, moodiness is a side effect of cutting back on carbohydrates. “Greg said I was crabby all the time,” Lucy explained. “Even our kids noticed that I was impatient and grouchy, even if I had plenty of sleep. Putting some starchy carbs back in my diet solved that problem, though.”

The reduction in carbohydrates did not affect Greg. In fact, he was thriving on the same diet that his wife found too restrictive, which actually is not at all unusual. Although the Paleo Diet is loaded with complex carbs, some people seem to need small amounts of starchy carbohydrates to maintain emotional stability.

However, I was concerned about Greg’s nutritional status with such a limited diet and suggested a test known as NutrEval after his first six months on the plan. The NutrEval test is a simple method of measuring levels of antioxidants, B vitamins, digestive support substances, essential fatty acids, and minerals.

It turned out that Greg was low in essential fatty acids because he was building his diet around chicken and turkey, which are not great sources of EFAs. In addition, he was low in antioxidants. This is a common problem, even for individuals who eat lots of fruits and vegetables. In theory, these foods should be excellent sources of antioxidants and minerals. But poor farming practices have robbed the soil of so many nutrients that taking nutritional supplements is the only way to guarantee you are getting proper intake of antioxidants. For Greg, the solution was supplementing his diet with EFAs and a high-quality multivitamin and mineral product.

Paleo Is Not About Food Alone

The last time I spoke with Greg and Lucy, he was still on the Paleo Diet, along with omega-3s and multivitamins, and doing quite well. Lucy, meanwhile, converted to the Mediterranean diet, something I’ll be writing more about soon. It may sound like a challenge to live in the same household while eating different foods. But in practice, it’s not that difficult. Greg simply eats the meat and most vegetables, but skips the starchy veggies, grains, and bread that Lucy needs to maintain her well-being.

One thing about the Paleo Diet that is often left out of the conversation, however, is exercise. Greg, for example, goes straight from work to the gym most days, where he lifts weights, runs on the treadmill, and stretches. Again, the idea is to be as active as prehistoric humans, who spent most of their time hunting, gathering, and moving. As I’ve said many times before, physical activity is one aspect of good health that can’t be ignored, no matter which eating plan you follow. And that’s especially true for anyone who hopes to lose weight on any eating plan.

To summarize, I like the fact that the Paleo Diet does not allow processed, prepared, or fast foods, as well as sugar. Considering the diet’s limited offerings, it may be a challenge to implement. But if you’re interested in trying it, don’t forget that is not all about food; activity is an essential ingredient in making the Paleo Diet work. Just be sure to get sufficient nutrients, even if it means supplementing. And if you’re concerned about which supplements to take, your doctor should be able to order a NutrEval test or similar service that can answer those questions.


Eliminates unhealthy ingredients, including refined flour, salt, artificial sweeteners, sugar, various additives and preservatives Restrictive, with limited choices available
No processed or fast foods allowed Long-term effects unknown; very little supporting research
Requires an increase in fruit and vegetable intake Excessive protein can be hard on kidneys
Encourages physical activity Grass-fed, organic, free-range meat and eggs are expensive

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