By Hope Warshaw
The Washington Post
Q: Is it possible to follow a paleo vegetarian eating plan?
A: The short answer is that it's possible. But in entertaining this eating plan, you've got to examine your health goals, the plan's nutritional soundness and whether you can follow it long-term.
Let's unpack each part of the plan and look at the research and the nutritional pluses and minuses.
Paleo diet defined
This diet, also called the caveman or Stone Age diet, has recently become popular, mainly through books, the Internet and social media buzz. The premise: It's our highly processed, grain-focused food choices that are causing our rampant rate of chronic diseases. Eating like our hunter-gatherer ancestors in the Paleolithic time will help us lose weight, minimize heart disease and Type 2 diabetes and live longer.
In: Meat, fish, poultry, eggs, nuts, seeds, vegetables and fruits.
Out: Grains, dairy foods, legumes (beans and peas), processed foods and foods containing refined sugars.
Research rundown: "If you search for controlled studies on the paleo diet, meaning it was tested against another diet, you'll find a couple of short-term studies each done with a relatively small number of people," says Brie Turner-McGrievy, an assistant professor and registered dietitian in health promotion, education and behavior at the University of South Carolina. Like many diet studies, these show slightly more weight loss and some improvement in chronic disease indicators for the paleo plan. But a few short-term studies don't constitute an evidence base.
In U.S. News and World Report's 2014 ranking of Best Diets Overall (compiled with the help of top health and nutrition experts), paleo tied for last in a group of 32 diets, with this comment: "Experts took issue with the diet on every measure. Regardless of the goal - weight loss, heart health, or finding a diet that's easy to follow - most experts concluded that it would be better for dieters to look elsewhere." No. 1? The government-developed DASH (Dietary Approaches to Stop Hypertension) diet.
Paleo advocates recommend eating meat and avoiding all grains, saying the grains we eat today have been dramatically changed with modern agricultural techniques. One problem they cite is greater gluten content. "The notion that our ancestors ate more meat than grains is not based in fact. Our ancestors were constantly gathering grain-based foods," says Julie Miller Jones, a professor emeritus in nutrition at St. Catherine University in St. Paul, Minn., who has studied grains extensively. Jones adds, "Though the hunt for meat was pretty constant, the kill was rare. They didn't sit down to Tyrannosaurus steaks every day."
As for the gluten claim, Jones points to research sampling century-old wheat showing that the amount of gluten hasn't changed. But she acknowledges a small increase in the population of people with gluten sensitivity and celiac disease, as well as other autoimmune diseases, such as Type 1 diabetes. "A lot has changed in our environment. Perhaps it's changes in our grains, the gut, use of antibiotics or countless other factors," Jones says.
Is it wise to omit grains? "Absolutely not. We need a variety of whole grains, as well as legumes, fruits and vegetables, to get the gamut of dietary fibers for their unique effects on the heart, digestive system and insulin and glucose control." Plus, Jones adds, grains' and legumes' different types of fibers and amino acids make them a perfect nutritional match.
Nutrition pitfalls: Eliminating whole grains and legumes might leave people deficient in iron and zinc and some B vitamins. Deleting dairy could make getting enough potassium a challenge. And going heavy on animal-based proteins, which take center stage in the paleo diet, could raise saturated fat and cholesterol intake.
Vegetarian diet defined
The spectrum of vegetarian eating runs from the most restrictive, vegan, to lacto-ovo (eating eggs and dairy-based foods but no animals). All plant-based eaters generally consume fruits, vegetables, nuts, seeds, legumes and grains.
Research rundown: Comparatively, the evidence on vegetarian eating runs long and deep, with a host of health benefits including weight control and disease prevention.
Among the largest and longest research projects are the Adventist Health Studies, conducted over the past 40 years. The largest study in the series was conducted among nearly 100,000 Seventh-day Adventists. The researchers, based at Loma Linda University in California, use periodic questionnaires to gather data about participants' health status, disease risk factors, eating and lifestyle habits and more. Results show that Adventist vegetarians have a lower risk of overweight, insulin resistance, metabolic syndrome, prediabetes and Type 2 diabetes than non-vegetarians in this population. And the closer people abide by a vegan diet, vs. the least-restrictive lacto-ovo vegetarian plan, the healthier they are.
The Adventist Health Study and several other large observational studies have drawn a link between reduced red-meat and processed-meat consumption and lower chronic disease risk. Turner-McGrievy points out that the more people choose plant-based foods over animal-based foods, the more they can cut down on saturated fat and cholesterol. That's a healthy move.
But it's not just plants that keep vegetarians healthier. Studies show they also tend to practice other healthful behaviors such as not smoking, being physically active, watching less television and getting sufficient sleep. That might turn out to be true for long-term paleo followers, but we don't have the research yet.
Nutrition pitfalls: The more food groups a vegetarian eats, the easier it will be to meet his or her nutrition needs. Nutrients to keep an eye on: vitamins B12 and D, omega-3 fats, iron and zinc.
The only foods that overlap in the paleo and vegetarian plans are fruits, vegetables, nuts and seeds. Translated, this would be a vegan eating plan, plus eggs, minus grains and legumes. "Following this eating plan could make it difficult to get enough protein, dietary fibers, iron, zinc and B vitamins," Turner-McGrievy says.
Research shows most people can follow a regimented eating plan for a short time. That's not the challenge. The challenge is finding a healthful eating plan you can follow day after day and achieve your long-term health goals. At this point, it doesn't appear that the paleo eating plan meets these objectives for most people.
Warshaw, a registered dietitian nutritionist and certified diabetes educator, is the author of numerous books published by the American Diabetes Association and the blog EatHealthyLiveWell found on her Web site, www.hopewarshaw.com.