Food Perspectives

by Kevin Ferguson

Paleo? Vegan? Let's See...

Here's a nice simple summary of some of the issues both paleo advocates and vegans commonly see as important, taken as a direct quote from the Physicians For Social Responsibility website, "Food Matters: A Clinical and Public Health Framework" (Ref [0]):

The dominant industrialized food system 

  Produces large quantities of calorie-rich, nutrient-poor food 
 
  
Is a major driver of obesity, diabetes, cardiovascular disease, 
some kinds of cancer, malnutrition, and other chronic diseases 
 
  
Depends on extensive inputs; fuels, fertilizers, pesticides, 
chemical additives, packaging, etc 
 
  
Contributes significantly to environmental degradation, 
including air and water pollution, climate change, and loss of 
biodiversity 
 
  
Is a source of exposure to environmental contaminants and 
other chemicals"

This same document points out high glycemic index leads to health issues, a point central to the reason for advocating a paleo diet. Another paleo point included is that grass fed animals have less saturated fat, and thus their meat is less inflammatory.

While these facts are well supported by much research, health and nutrition science also supply ample evidence that the pitfalls of high glycemic load along with high inflammation can be avoided with a vegan diet, even if it includes substantial starch and natural sugars in fruits.

Vegans that combine the sufficient amounts of sweets and vegetable oils, and avoid the anti-inflammatory nutrients in fruits and vegetables could easily become sick, with the usual inflammatory response issues, not the least of which is type 2 diabetes.

One key point that both paleo and vegan advocates typically can agree on, especially after checking the science, is that highly inflammatory diets are not good for you, and if most of your calories come from high glycemic index foods combined with ample saturated fat, you are much more likely to get health problems than if you eat a predominantly anti-inflammatory diet.

Neither vegans nor paleo diets include dairy, so no differences to discuss in this category.

Now lets look at the elephant in the room: starch vs. meat.

Commonly I read and hear that starch is bad and meat is required for the protein and the omega 3's. However, whereas fats are not all the same, neither are starches, nor the context in which they are consumed. Take for instance a relatively recent survey of studies on refined grains and health outcomes. I'm not an advocate for refined grains as a staple of diet, but it's interesting that:

"The totality of evidence shows that consumption of up to 50% of all grain foods as refined-grain foods (without high levels of added fat, sugar, or sodium) is not associated with any increased disease risk." [1]

As for protein, conventional wisedom has shifted over the years from thinking protein in plants was incomplete to being unavailable as bioactive because of protease inhibitors and other anti-nutrients, to being in too small a quantity if not from legumes, to just simply not being adequate. However, I have found no studies to support any of this as being true across plant sources. It is true that there exist protease inhibitors in many plants that interfere with our abiltity to digest the accompanying protein. However, most are destroyed readily with traditional food preparation, such as cooking. [2] Young and Pellett suggest in passing that legumes or meat might be used for a lysine source in cases where lysine intake might otherwise not be adequate for those living off of wheat as their main sources of calories [3], but otherwise found no issues with plant protein in general. However, a quick check lysine per calorie of many seeds and other plant food sources reveals that legumes are not the only option.

Omega 3's and 6's are found in ample quantities per calorie in many plant sources, including a number of seeds (including flax and hemp seeds) and green leafy vegetables.

As for meat, while grass-fed animals might have less saturated fat than other animals, there is a great deal of evidence that meats have health risks:

Generally even lean and grass-feed animals still contain some saturated fat and cholesterol. Plants contain only trace amounts of cholesterol, so low that nearly (perhaps all) references report 0 as the amount per measured sample.
The CDC's list of top food-borne diseases are:
- Campylobacter: comes from animals to people via animal based food.
- E. coli: comes from animals to people via animal based food.
- Listeria: comes from animals to people via animal based food.
- Salmonella: comes from animals (esp. poultry) to people via animal based food.
- Vibrio: comes from animals (esp. shellfish) to people via shellfish based food.
- Mad cow (Variant Creutzfeldt-Jakobs) disease only has animal hosts (cow, pigs, dear, etc.).
Plants that come in contact with infected animals may carry these diseases, typically from animal feces somehow getting in contact with the plants. Simply washing fresh produce well is generally sufficient to mitigate disease risk. Note that plants are not viable hosts for human infectious diseases, but animals generally are. Often the bacteria infecting the meat has come from feces and soaked in some bath prior to packaging. For ground meat, it is not practicle to wash it, so the feces is eaten along with the meat. Cooking sufficiently may prevent infection, but the infected (with no killed bacteria) feces is eaten along with the meat.

And as for meat being a part of the general human population prior to grains, consider a few facts:

Both grain and meat typically require cooking before being eaten. Both have exceptions to this such as corn and other fresh grass seed and sushi on the non-plant side.
Both grain and meat are availble in the wild without cultivation or domestication, respectively. Yet it's generally easier to collect the seeds of wild grasses when available, than to hunt most prey, for example.
Ancient remains have been found with starch granules on the teeth more than once.
For the hundreds of olfactory receptors in our noses, there are many more aromatic chemicals produced by plants that we perceive as enticing to eat, while animals generally do not give off aromas that stimulate our appetites until they have been cooked to the point of undergoing significant chemical reactions causing thousands of new chemicals to form. It's the chemicals that form after cooking that are aesthetically pleasing to most people, usually not the raw form, and usually not the live animal. This seems to suggest that prior to using fire, we evolved without animals as part of our diets. There still may be some debate over how long after the widespread use of fire in food preparation boiling may have become common. However, even if grains where not eaten until after boiling, other than oil seeds, the vast majorit of calories from plants comes in the form of starch, so starch would have been the primary source of calories prior to us eating animals.

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Refs:

[1]  Peter G Williams,  "Evaluation of the evidence between consumption of refined grains and health outcomes," Nutrition Reviews, Volume 70, Issue 2, pages 80–99, February 2012

[2]  Timothy Johns, "The Origins of Human Diet and Medicine," University of Arizona Press (September 1, 1996).

[3]  Vernon R Young and Peter L. Pellett, "Plant proteins in relation to human protein and amino acid nutrition,"
Am J Clin Nutr, 1994:59: pp. 1203S-1212S.