[Part Two in our Series on Why the Paleo Diet is a Nutrient Dense Diet]
An Interview with: Caroline Apovian, Ph.D., Director of the Nutrition and Weight Management Center at Boston Medical Center
This spring, the results of a two-year study comparing the effects of a Paleo diet to a low-fat diet in postmenopausal women were presented at the annual meeting of the Endocrine Society in Boston.1 The yet to be published study found that an ad libitum Paleo diet was effective for weight loss and produced a better lipid profile among the 70 participants randomized to the Paleo diet group.
The study received a great deal of media attention due to an article titled “’Paleo’ Diet May Help Women’s Hearts, Waistlines.” However, not everyone in the nutrition community was quick to see the positives. Even in the article, two members of the nutrition community raised concerns about the diet despite the positive results of the study.
Dr Cordain addresses these criticisms in part two of this series on nutrient density. Particularly the claims by Connie Diekman that the Paleo diet can lead to nutrient deficiencies. A criticism that is the focus of our current series.
However, other observations about the diet were made in the article by a second respected member of the nutrition community – Dr. Caroline Apovian. Apovian was able to look at the diet from both sides and raise several questions that we felt were thoughtful and very intriguing. We caught up with Apovian and dug a little deeper into the questions she raised:
The Paleo Diet Team: In the article you said that you didn’t feel the diet in the study was a true Paleo diet but a hybrid with the Mediterranean diet. Can you explain what you mean by that?
Dr Apovian: Paleo comes from Paleolithic times. We didn’t have oil at that time. So I think that was the gist of what I was trying to say. Definitions can be loosely thrown out and if someone is loosely calling something a Paleo diet, but they’re really talking about a more Mediterranean diet because there’s oils in the diet, then it’s not the Paleo diet. Then you’re talking a cross between Paleo and a Mediterranean diet.
Frank Sacks did a study altering… taking the Dash diet and adding more protein, taking the Dash and adding more oil and this was the Pounds Lost study. So you can take the base of a diet and add things and then it’s not that base diet anymore. It’s something else.
I do believe the Paleo diet was loosely defined and it was actually more… there were oils. Does the Paleo diet include oils? Not even cooking oils; oils on your salad; oils on your plants. Your plant products. I don’t think so. They didn’t know how to extract oil from nuts and seeds and olives. However, if you call the Mediterranean diet what people eat in the Mediterranean areas, yes it’s a lot of oils. Olive oils; that’s usually 40 percent but there’s also whole grains and some protein and some dairy.
The Paleo Diet Team: So it sounds like your concern was more with how the diet was defined?
Dr Apovian: My point was to address when you do studies, it is the responsibility of the study authors to define what they mean by a particular diet. But then it’s also the responsibility of the journalist to get it right as well. I’ve seen it [the Paleo diet] defined loosely in so many different ways.
I’m raising a scientific concern. How are you going to define the diet? How are you going to publish? How are you going to test the diet against other diets?
When you try to compare different studies in the literature and they are defining each type of diet differently, – I helped write the 2013 guidelines, I know what I’m talking about – it’s very difficult to try and compare studies because of the different definitions of those diets in the literature. And so we really had a hard time and had to combine and define what we meant by “Mediterranean.” We ended up calling it Mediterranean-style diet and low-carb-style diet for that reason.
The Paleo Diet Team: So how would you go about defining a diet?
Dr Apovian: I think do it the way the Dash diet did – percent macronutrient content. A Mediterranean is also not defined in the literature to the extent that there is no real Mediterranean diet in terms of percent macro-nutrient content so that’s also up for grabs. The only real diet that’s very distinctly defined is the Dash diet. Or the maybe the original Atkins diet.
Macronutrient content in percentages is very helpful to compare diets to each other. Even when people eat ad lib there are certain natural ways of eating roughly the same macronutrient content if you listen to your hunger and satiety cues. Even when it is not important for a study to calculate macronutrient ratios or percentages.
I think that you can promote science that goes beyond the calorie and really talks about the actual macronutrients and what it’s doing to fat metabolism and carbohydrate metabolism and protein metabolism and that’s the research that we’re trying to do here at BU and elsewhere in Boston to illuminate what actual macronutrients and what percentages of macronutrients in the diet are essential and promotes the best health.
The Paleo Diet Team: Then how do you deal with the fact that the Paleo diet is about what foods you should eat. There is no one set Paleo macronutrient ratio?
Dr Apovian: Yeah so you still can, even if you’re talking about specific foods, you still have an average macronutrient content that you’re talking about. You need to figure out what your typical Paleo diet is going to look like. You can still stay it’s not going to be 80 percent protein is it?
The Paleo Diet Team: You were quoted in the article saying that the Paleo diet should provide health benefits. Do you agree however with Connie Diekman that there is a danger of not getting key nutrients on the diet?
Dr Apovian: I think it’s very difficult to steer away from a diet that has all of the nutrients that we consider to be helpful for wellness and health based on the guidelines that we have in this country. So, you know, protein, fruits and vegetables, whole grains, and fats.
I think that people can subsist for long periods of time with certain eliminations but you know we really don’t have long-term studies looking at people who are on diets that have eliminated completely or almost completely certain food groups from the diet to really say for sure.
I think you need to do a long term study and look at the rates of cancer, the rates of heart disease and all the things that you can only do looking long term.
The Paleo Diet Team: What about grains and dairy specifically?
Dr Apovian: I think you need to look at risk of bone health and the risk of colon disorders and cancer specifically. But there’s a lot in the literature to suggest that whole grains are important for reducing the risk of cardiovascular disease and certain cancers. Especially colon cancer.
There’s a lot to suggest that it’s hard to get enough fiber without whole grains. Fiber content and some of the phytochemicals that are in whole grains. There are different fibers and again, this is all based on what we know about certain geographical peoples and what they do. and those people who have a high intake of whole grains seem to have a lower incidence of certain cancers.
The Paleo Diet Team: It seemed your biggest concern was not with the diet but with its availability to the people who need it the most?
Dr Apovian: We have the largest hospital in New England. My clientele, my patients are underserved. I have many homeless patients. We have a food pantry and food demonstration kitchen. We stock our pantry with fresh fruits and vegetables, lean proteins and whole grains. So I know, and I also know what my patients are eating because we talk with them. And they find it very very financially difficult to eat a healthy diet with fresh fruits and vegetables and meats and fish and fowl. And so that’s why our food pantry is stocked the way it is. And that’s one of the issues that we’re having in this country and one of the reasons why the obesity epidemic hits the underserved more than it does any other SES [socioeconomic] status group.
The Paleo Diet Team: It’s interesting that the foods you stock are basically the Paleo diet?
Dr Apovian: Well, what do you define as the Paleo diet? I think it’s very difficult for a very financially limited family to eat what I think the Paleo diet promotes. That’s also the feedback that we get from our patients is that they don’t buy fresh fruit and vegetables because they are expensive and they rot in their refrigerator before they have a chance to use them which is a double whammy for them.
The Paleo Diet Team: So what do they eat and is there a solution?
Dr Apovian: Processed food. Cheap processed food. That’s a really… I don’t have a… um. it requires an overhaul of our entire society.
The Paleo Diet Team would like to thank Dr, Apovian for taking the time to discuss the diet with us. This is the kind of open discourse that we want to encourage. While we don’t agree with everything, she raised some valid questions. We appreciated her willingness to consider the merits of the diet and define for us how she and many in the field would like to see the diet studied.
If we had one philosophical departure from Dr Apovian it is our belief that diets should not be defined by macronutrient ratios. We understand that it makes the scientific comparison of diets easier. But we believe strongly that a healthy diet is defined by the foods you eat and not the percentages of specific macronutrient. Put another way, a high-carbohydrate diet can be based on fruits and vegetables or on highly processed grain products and refined sugar. So we can’t generalize to say a high-carbohydrate diet is healthy or unhealthy. It is the specific foods that matter.
In fact, analysis of hunter-gatherer diets has shown a wide range of ratios.2 Even within a single society, the ratio could vary dramatically between winter and summer. So a single “Paleo ratio” is not possible. Instead we define the Paleo diet by the foods we should and shouldn’t eat.
 Caroline Blomquist, E.C., Mats Ryberg, Caroline Mellberg, Christel Larsson, Bernt Lindahl, Ulf Riserius and Tommy Olsson, Beneficial Effects on Fatty Acid Composition and Indices of Fatty Acid Desaturase Activity with a Paleolithic-Type Diet during a Two-Year Intervention in Obese Postmenopausal Women. 2016.
 Cordain, L., et al., Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. Am J Clin Nutr, 2000. 71(3): p. 682-92.