Nutrition 101

Consider This Before You Jump on the Paleo Bandwagon

October 16, 2015

by Melissa Owens, Dietetic Intern

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Being a former vegan I never really paid much attention to the Paleo diet craze since it’s primarily centered on eating meat. But on my recent visit to the book store I couldn’t help notice how many shelves were laden with Paleo diet books! This made me even more curious about the diet, so I decided to do a little hunting and gathering of my own (pun intended!) to find out why this one of the hottest-growing diet trends.

It seems that interest in the modern Paleo movement began after a 1985 article was published in the New England Journal of Medicine on paleolithic nutrition which argued that the “current day chronic metabolic disorders have resulted from a gene-culture mismatch and the human body’s inability to adapt from Paleolithic time” and this theory was popularized by Loren Cordain’s The Paleo Diet Book which hit the shelves in 2002.

Today there are many versions of what eating Paleo means, but the basic premise advises a low-carb diet devoid of starchy vegetables, all grains, legumes, and dairy and high in lean animal protein—a dietary pattern claimed to be best suited to meet our cavemen ancestors’ biological needs. However, the food of cavemen is hotly debated by archeological researchers and food anthropologists.

Diets of early humans would likely have varied due to regional differences and what foods were available based on climate, topography, water sources, etc. Humans and animals adapt to the resources available and, yes, some early humans adapted to living without a lot of plant foods, grains and the like. However, a recent study suggests that increases in human brain size may have evolved from a consumption of starch-rich plant foods (including legumes). While the debate about starchy foods in our heritage continues, the paleo diet can also be evaluated against current nutrition research.

What is the science saying?

Initially used to promote weight loss, the Paleo diet is frequently associated with improvements in overall health. Cordain suggests “there is now a large body of experimental evidence increasingly demonstrating that a higher intake of lean animal protein reduces the risk for cardiovascular disease, hypertension, dyslipidemia, obesity, insulin resistance, and osteoporosis while not impairing kidney function.”

However, it’s difficult to understand if the benefit is due to increased protein. A diet lower in refined carbohydrate and fat, but inclusive of whole grains, legumes and low-fat dairy can also contribute to these notable health effects. For example, one study looking at the effect of a high protein, low fat diet (which included whole grains and low-fat dairy) on cardiovascular disease suggested that cardiovascular disease markers overall do improve with weight loss, but is not necessarily a result of higher animal protein intake per se. Another study indicates high protein diets contribute to more acidic urine which can increase excretion of magnesium and calcium, thus increasing the risk for osteoporosis. And a few other studies indicate that adherence to a high protein carbohydrate-restricted diet may increase mortality, particularly for cardiovascular disease, and may have adverse effects on glucose metabolism.

What are the pros and cons?

We could debate and pick apart the science all day, but there’s no denying there are some positives to eating Paleo. For starters the diet’s emphasis on fruits and vegetables is a no-brainer, as they provide a plethora of beneficial vitamins, minerals and phytochemicals. Secondly, in the short term, the Paleo diet may be effective for weight loss, which is partly a result of the satiety afforded by the allowed foods (more protein, fewer simple carbs) and fewer calories.

So what are the cons? Any diet that is restrictive, as we mentioned in a previous post, can be difficult to adhere to, thus affecting the long term ability to keep off weight. Plus, the exclusion of grains and legumes means missing out on inexpensive sources of protein that are also high in fiber to help with satiety. Legumes and grains are also packed with vitamins and minerals such as B-vitamins, iron, folate, calcium, potassium, phosphorus and zinc; and they have some valuable antioxidants and phytochemicals not found in fruits and vegetables. Many studies have shown that whole grains reduce risks of heart disease, stroke, cancer, diabetes and obesity. The Paleo diet also promotes the use of coconut oil, however, because of its saturated fat, there's not consensus science to recommend using coconut oil over other unsaturated oils like olive oil.

What about the environment?

Lastly, and perhaps most importantly, if more meat is consumed by everybody, the sustainability of providing these foods would need to be considered due to the environmental impact of raising livestock over growing plant crops. Livestock production which includes meat, milk and eggs uses one-third of the world’s fresh water and consumes 1.3 billion tons of grain. And fish is not much better. According to the World Wildlife fund “the global fishing fleet is 2-3 times larger than what the oceans can sustainably support, and even with most of the developed world now relying heavily on aquaculture, farmed fish still requires feed made with wild fish.”

So how does the Paleo diet author answer this environmental dilemma? Eat more grass-fed pasture raised animals. Well, unfortunately it is not quite that simple. Grass-fed, free-range, and pasture-raised meat can be very costly to purchase and depending on where you are, is not always available. In particular, grass-fed beef, according to some researchers requires more land for pasture, and if there were only grass-fed beef as opposed to grain-fed there would be much less of it available. The greenhouse-gases methane and nitrous oxide emitted from grass-fed versus feedlot grain-fed animals also may be higher due to the longer amount of time it takes for grass-fed animals to be ready for slaughter, reports the Environmental Working Group (EWG). Another issue worth mentioning is that cattle being raised on pasture land is also the single largest driver of habitat loss. Wildlife animals such as badgers, coyotes, bears, foxes, mountain lions, just to name a few, are being killed off under the USDA’s Wildlife Services program at the request of corporate agriculture.

The bottom line is that some aspects of the Paleo diet are in line with an overall healthy diet, such as eating more fruits and vegetables, lean protein, and cutting out processed, sugary, refined foods. However, there is no scientific evidence in support of eliminating entire food groups such as grains, legumes and dairy from our diets. Moreover, concerns over personal health without concerns for the health of the environment are very shortsighted.

Eating healthy can be done in a way that is both better for you and better for the planet. For starters, since beef has one of the highest environmental impacts and poses higher health risks than other types of meat, shifting to an eating pattern of consuming less beef can be one way to move towards a more sustainable diet. And if you are curious how other foods compare in resource usage and greenhouse gas emissions below is a handy chart from the EWG:

All that being said, healthy eating and sustainable living is a lifestyle. It takes time to figure out how to incorporate the foods you like to eat with the foods that will contribute to overall health while keeping in mind the impacts our diets have on our environment. The most important thing to remember is to try to eat seasonally, sustainably and sensibly. Focus on eating a variety of fruits, vegetables and other complex carbohydrates like whole-grains and legumes, healthy fats and lean proteins. Try to eat the right portions and incorporate physical activity into your daily routine. If you do these things everyday and adopt sustainable food choices your health and the health of the environment will reap the benefits. For more information about sustainable choices, you can check out this nifty infographic we complied on sustainable fish and the Eat Well Guide for when you’re on the run.

nutrition advice, sustainability, paleo

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