I was recently interviewed by a reporter representing “The Academy of Nutrition and Dietetics” which was formerly known as “The American Dietetic Association (ADA)” http://www.eatright.org/.
This organization certifies registered dietitian nutritionists in the United States. University level nutrition students must have met academic and professional requirements including an earned bachelor's degree with coursework approved by the Academy of Nutrition and Dietetics' Accreditation Council for Education in Nutrition and Dietetics (ACEND).
The official magazine of The Academy of Nutrition and Dietetics, is called “Food and Nutrition” https://foodandnutrition.org/ which reaches a readership of approximately 40,000 Registered Dieticians. Unfortunately, due to the length of my interview, the interview was not published in “Food and Nutrition” magazine. Below is that interview in its entirety.
Dr. Cordain responds to the reporter’s questions:
Obviously, your questions are good ones and are of interest to the Registered Dietitian (RD) Community and to all people concerned about diet/health and well-being.
I have written extensively about the "Paleo Diet" concept in high quality, peer-reviewed nutritional and medical journals including: The American Journal of Clinical Nutrition, The British Journal of Nutrition, The European Journal of Clinical Nutrition, The World Review of Nutrition and Dietetics, The Journal of Applied Physiology, Acta Opthalmolgica, The Archives of Dermatology, The Scandinavian Journal of Clinical Laboratory Investigation, Mayo Clinic Proceedings, Preventive Medicine, Nutrition and Metabolism, Proceedings of the National Academy of Sciences, Open Heart (1-39) and many other high impact factor, peer-reviewed journals. Reprints of all of my scientific papers are available as free PDF downloads at my website: www.thepaleodiet.com.
Additionally, I have written six popular books and cookbooks on The Paleo Diet Concept including: The New York Times Bestseller, The Paleo Diet, (2002, revised 2010) (1), The Paleo Diets for Athletes (2005, revised 2012 and co-authored with Joe Friel) (41), The Paleo Diet Cookbook (2011) (42), The Paleo Answer (2012) (43), The Real Paleo Diet Cookbook (2015) (44), and Real Paleo Fast and Easy (2016) (45).
Questions
What are the advantages of following a Paleo Diet?
As I originally conceived this way of eating in 2002 in The Paleo Diet (1), my intent was to mimic the food groups that our pre-agricultural ancestors ate by using contemporary foods (fresh fruits, fresh vegetables, fish, shellfish, grass produced meats, organ meats and poultry, free-ranging eggs, nuts and certain healthful oils) commonly available at supermarkets. As I have pointed out in all of my writings, clearly it would be impractical or impossible for modern people to only eat wild plant and animal foods. Built into this diet was a behavioral crutch (the 85:15 rule) (1) which allowed people to occasionally “cheat” (1, 6, 41-45) but still obtain most of the nutritional and health advantages (1-3, 5, 8-31, 33, 35-39) of The Paleo Diet.
The nutritional advantages of following a diet comprised mainly of fresh fruits, fresh vegetables, fish, shellfish, grass produced meats and organ meats, free-ranging poultry, free-ranging eggs, nuts and certain healthful oils are readily apparent to any registered dietitian who has access to nutritional software. I use Nutritionist Pro (http://www.nutritionistpro.com/) to analyze the nutritional characteristics of contemporary diets based upon ancestral food groups (16, 23).
The typical plant to animal food subsistence ratio in hunter gatherer diets ranges from about 35 to 45 percent plant food with the balance from animal food (2, 16, 23, 31). Accordingly, when a modern, westernized person emulates the food groups in ancestral diets with contemporary foods, the diet becomes exceedingly rich in fresh fruits and vegetables (16, 23). A recent (2017) report (40) from the Centers for Disease Control and Prevention (CDC) showed that just 12 percent of Americans eat the minimum daily fruit recommendation (1 ½ - 2 cups/day), and only nine percent of Americans consume the minimum daily vegetable recommendation (2-3 cups/day). Hence, adoption of The Paleo Diet represents one of the best strategies to enrich the American diet with healthful fresh fruits and vegetables (1, 16, 23, 41-45).
The Paleo Diet avoids or eliminates processed foods containing refined sugars, refined grains, refined vegetable oils, trans fatty acids, salt and added chemicals. Because fresh fruits, fresh vegetables and nuts are consumed ad libitum as the carbohydrate source in lieu of refined sugars, refined grains and processed foods, The Paleo Diet is a low glycemic load diet (1, 16, 23) which promotes normalization of blood glucose, insulin and improvement in type 2 diabetes and the metabolic syndrome (46-55).
The Paleolithic diet is a low-salt diet because it avoids or eliminates the highest salt sources in the American diet (bread, baked goods, cheese, processed meats, sandwiches, pizza, tacos, chips, condiments, etc.), and replaces these processed foods with unsalted, unadulterated fresh foods (fresh fruits, fresh vegetables, fish, shellfish, grass produced meats and organ meats, free-ranging poultry, free-ranging eggs, nuts and certain healthful oils). The average U.S. diet (per day) contains 3,584 mg of sodium (Na+) and 2795 mg of potassium (K+) yielding a K+/Na+ ratio of 0.77 (56). Few natural, unsalted foods maintain K+/Na+ ratios less than 1.00. In fact, the K+/Na+ ratio in contemporary Paleo Diets ranges from 5.0 to 10.0 (16, 23, 30, 57, 58). The high average U.S. daily sodium intake (3,584 mg) and low potassium intake (2795 mg) increases the risk for hypertension, stroke, cardiovascular disease (CVD) and gastric cancer. By adopting a contemporary Paleo Diet, people will reduce their salt intake, increase their potassium intake (1, 41- 45) and reduce their risk for CVD, high blood pressure, stroke and stomach cancer.
In vivo (in the body) all foods are either net acid producing, net-base producing or neutral (59). The typical American diet is net acid producing because it contains high amounts of acid yielding cereal grains, salt, cheese, processed meats, processed foods and condiments (23, 57, 58), and low amounts of base yielding fruits and vegetables (40). A net acid yielding diet increases the risk for osteoporosis, kidney stones, stroke and hypertension (1, 43, 57) whereas a net alkaline yielding diet, high in fresh fruits and vegetables reduces the risk for these diseases (60-62). Hence, adoption of the contemporary Paleo Diet will result in a net base yielding diet and lessen the risk for osteoporosis, kidney stones, stroke and hypertension (1, 16, 23, 41-45).
What are the nutritional advantages of avoiding foods like dairy and legumes?
From an evolutionary perspective, the majority (65 to 70 percent) of the world’s adults are lactose intolerant (63, 64) and cannot drink milk without digestive discomfort because they lack the enzyme (lactase-phlorizin hydrolase) necessary to digest the sugar (lactose) present in the milk of mammals. From an evolutionary perspective, this information indicates that milk and dairy products could not have been a component of the original adult diet that shaped the human genome until very recent times, (64).
The human consumption of milk from a foreign species throughout our life is not without physiologic consequence, even if a person has inherited the gene (LCT) which codes for adult lactase persistence (64). Fresh cow milk contains the full complement of enzymes and hormones that are present in cow blood (65).
It had been assumed that these bioactive compounds in cow’s milk were degraded in the human gastrointestinal tract and that our immune systems ultimately prevented their entry into our bloodstreams. Unfortunately, this model has been shown to be incorrect, as cow milk apparently elevates a key human hormone (IFG) known to affect insulin and glucose metabolism and promote various cancers (35, 66). Other elements in cow’s milk are implicated in human cancer and disease including miRNAs (39) and stimulation of mTORC1-signaling (35). Further, recent studies implicate prediabetes and type 2 diabetes with dairy intake in adults (67) and children (68).
Legumes (beans, lentils, peanuts etc.) contain high concentrations of various antinutrients including phytate, lectins, saponins, tannins and isoflavones, protease inhibitors, raffinose oligosaccharides, cyanogenetic glycosides and favism glycosides (43). Without long term cooking or pressure cooking, these antinutrients remain active following ingestion by mammals and may disrupt gastrointestinal and immune function (43, 69, 70, 71). Because of their antinutrient content, particularly phytates, legumes are low quality foods that are deficient in multiple nutrients (zinc, iron, magnesium, calcium) unavailable for human absorption (43, 71). From an evolutionary perspective, until humanity was able to not only control fire, but to make fire at will (72), legumes would not have been a component of the diet that shaped our current genome until recent evolutionary times.
Why do you think there is such a strong following of this diet?
In this day and age of internet connectivity, people constantly correspond with their friends and neighbors about all things in their lives, including diet. Like a loophole in tax laws, when they discover something that works, the information is passed along, and passed along and passed along again.
The Paleo Diet works -- it works to help people become healthier; to lower blood cholesterol levels, to lower blood pressure; to reduce body weight; to have more energy throughout the day; and to improve health and well-being. This information has been substantiated in the scientific and medical literature for a decade (73-101)
Many athletes follow this diet and they do need carbs for fuel. What do you recommend for athletes in order to stay properly fueled?
All athletes do not compete in similar events. The metabolic requirements of a sprinter, an 800 meter runner, a miler or a 5 or 10 K and marathon runner are completely different from a high jumper, a pole vaulter or a shot putter. These athletes compete in events which have metabolic requirements that frequently overlap with team sports including soccer, basketball, football, baseball and tennis. Hence it is unfair to suggest that all athletes need carbs for fuel at all times.
Endurance athletes who have previously trained their beta oxidation (fat) metabolic pathways have been shown to outperform athletes who solely utilize high carb diets (102).
Coconut and cauliflower are two very popular Paleo foods, but aren’t necessarily connected to the Paleolithic era. How do those connect within the Paleo diet? Are they healthy choices in the Paleo diet?
Hmm. I disagree with you that coconut would not have been consumed by Paleolithic people (> 10,000 years ago). The archaeological evidence shows that our Paleolithic ancestors occupied coastal areas in Africa and Asia where coconut trees grew. There is no evidence to suggest otherwise that this plant food was exploited from the earliest of times.
Cauliflower on the other hand is a recent genetic permutation from broccoli which is a recent permutation from cabbage. These three plants (cauliflower, broccoli, cabbage) have similar nutritional characteristics which differ little from their inherent genetic species. Additionally, I never proclaimed that modern, domesticated versions of wild plant and animal foods should not be regular components of contemporary Paleo Diets.
Anything else you would like to relay to dietetic professionals?
Always let the data speak for itself, and do not permit charismatic individuals or political organizations to interpret the data outside of scientific norms.
How would you like to be quoted?
Always let the data speak for itself.
