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Nutrition Past and Future

TPNS 66-67: Animal Food Odds and Ends

Primitive Nutrition 66:
Animal Food Odds and Ends, Part I


There seems to be a belief among many that there must be a diet out there that perfectly supplies every last nutrient.  I consider this belief to be a byproduct of the design fallacy.  Only a perfect and coherent organism would require a perfect and coherent diet.  Yet our evolution should make it plain that we did not arise out of perfect and consistent circumstances.  Abandoning the expectation of finding a perfect diet might be liberating.  I have no requirement for a perfect diet.  I only want the best possible diet for my priorities. 

My nutrional requirements, like yours, all arise from biochemistry.  How those requirements are met is of secondary importance to me.  If I need to supplement B12, for example, what is the downside to that?  I'm not going to abandon a diet that provides perhaps thousands of important nutrients just because of one that it lacks.  A whole food vegan diet supplies me with the greatest nutrient density possible.  With that as my caveat, I'm going to run through a few of the claims you might read to support the belief in a requirement for animal-sourced foods.

First up, the omega-3 fatty acids that supposedly make fish and grass-fed beef so good for you.  Even the website for American Grass Fed Beef makes it clear that these fatty acids are not produced by animals.  Instead, they get into the animals through the plants they eat.

These fatty acids are in such low concentrations in grass fed beef it is not a significant source for them.

And yet people are willing to spend a lot more money for the perceived health benefits of grass fed.  Plant sources of omega-3s are inexpensive.

The meat industry is finding that the nutritional value of beef is enhanced by the addition of flaxseed flour.  It seems more efficient to me just to eat the flax seed directly.

Fish can't make omega-3's, either.  They get theirs from microalgae. Here you see these algae are fed to farm-raised fish to make them more nutritious.  Fish also get these fats from eating other fish.

Because of the over-exploitation of our fisheries, it is increasingly recognized that feeding fish to fish to feed to us doesn't make as much sense as it used to.  Soy is being fed to fish instead now.  Once again, why not just eat the soy directly?

It is a fact that no animal naturally produces omega-3 fatty acids.  Animals are being genetically modified now so that they can.  This is hardly primitive nutrition.

Omega-3s are one of those nutrients that are caught up in evolutionary speculation.  Here it is hypothesized that they explain why fish must have have been a key component in the human diet, as though fish were the only place to find them.  Maybe that is what happened, but I'm not sure why that matters for our diets today.

That article set off a debate.  The gentleman disagrees.

And it went back and forth a bit.  These interpretations of evolution strike me as speculative and not particularly useful for planning your diet.

In any case, there are more modern concerns with seafood.  Mercury is a potent neurotoxicant.

It is responsible for a loss of intelligence in our children.  The consumption of contaminated fish is the primary mode of exposure for us.

Environmental pollution is probably why the consumption of crustaceans and canned tuna were significantly associated with undersized babies in this study.

As for the omega-3's themselves, when they are sourced from seafood, they are associated with the development of diabetes.  From plant-based sources they are not.

A huge review of the literature on omega-3's found little benefit for total mortality, cardiovascular events, or cancer, so this is not much of a reason to eat fish or grass fed beef.

To the extent that they might help for reducing heart disease, plant-based sources seem just as good.

Often opinions are expressed based on articles like this.  Humans cannot convert their alpha linolenic acid to EPA and DHA.

But this doesn't seem to be such a problem for vegans.

You may have noticed a previous slide said that background omega-6 fatty acid consumption has little effect on the benefits of omega-3's.  This undercuts a big issue among the Paleo people.  There is supposed to be a proper ratio for these fats that we used to achieve but no longer do.

I'll just run through a few slides here to show you this is not a view that is universally shared.  These authors find it quite oversimplifies our understanding of fats and distracts from where our focus should be.

This researcher finds the idea has little value and is not supported by observations in humans.

This researcher concurs.

The UK Food Standards Agency has concluded this ratio is not a useful concept.

Here's a strange one.  Loren Cordain says the information on arachidonic acid is equivocal, which a charitable way to put it.  He wants you to think his diet, loaded with arachidonic acid, is good for you.

I wonder why he thinks the National Cancer Institute wants you to know what foods have the most if you are monitoring your risk factors.  You see chicken is on top.

There has been research into trying to lower arachidonic acid concentrations in chickens.  I guess Cordain would disapprove of these efforts.

The arachidonic acid you eat definitely affects the arachidonic acid in your blood.

Cordain seems so interested in helping people with autoimmune disease.  He should spread the word that lowering arachidonic acid in the diet helps people with rheumatoid arthritis.

More arachidonic acid in the diet makes you more vulnerable to ulcerative colitis, an autoimmune disease.

This was recently affirmed in a cohort study.

Your body does need some arachidonic acid, but you can make it without eating it.  Vegetarians moms have no problem with this.

On a side note, vegan and vegetarian moms-to-be can have very healthy pregnancies with a little planning.  I have a few more odds and ends for you in Part II.


Primitive Nutrition 67:
Animal Food Odds and Ends, Part II


I'll run through just a few more of these minor nutritional concerns now before I start wrapping up.

You have no doubt heard that trans fats are bad for you.  You may not have heard that animal foods have them naturally.  One of them, conjugated linoleic acid is often touted as a selling point for grass fed beef and milk.  Mark Sisson wants you to know grass fed dairy has a lot more than conventional dairy.

I wonder why this is supposed to be good.  CLA doesn't help your cholesterol, so that must not be why.

In fact, CLA is bad for your lipids, just like industrial trans fats.

CLA won't help you lose weight, either.

Same finding here.

These researchers were surprised to see CLA causes insulin insensitivity and raises blood glucose and cholesterol concentrations.

The reason some animal food promoters thought CLA might be good for you is because they saw some studies in animals and jumped to conclusions about what CLA does for people.

It turns out it is not good for people and is therefore not recommended for supplementation.

Here's an issue that is often overlooked.    A natural fatty acid called phytanic acid is more present in grass fed animals and their milk because of the chlorophyll they consume.  It makes its way into dairy fats people eat.

Dairy fat consumption determines blood concentration.  Vegans have way less in their blood.  They are better off for it.

Phytanic acid has gotten more attention recently because it is suspected of contributing to cancer development.  These researchers say it is a significant risk factor.

The lack of dairy consumption in vegans and some vegetarians doesn't seem to be a problem for their bones.

This is the most recent study I’ve seen on this issue.

Here's an issue I hadn't heard much about.  Natural toxins in plants that humans don't eat can get into us through the animals that do eat them.

This is considered to be a severe problem by these authors.  Some milk has been shown to contain this toxicant.

The best-known such toxicant in history is white snakeroot, which caused a condition called milk sickness.  In the 19th century it killed up to 50% of the people in some parts of the United States.  One of the victims was President Lincoln's mother.

For those who insist on searching for a magic nutrient that will end veganism, I'll just say that humans manage to do well on lots of different diets.  The health problems caused by diet, through deficiencies, imbalances, and overconsumption, are well-established at this point.  We're better off focusing on the issues that are clearly harming human health rather than searching for an "X-Factor" silver bullet to protect our fragile belief systems.

The exaggerated and imaginary nutritional concerns harped upon to discourage plant based diets are mostly just distractions from some very important issues.  In the last section of the Primitive Nutrition Series, I will try to show you what the big issues are. Some are quite distressing, but if we face them, they also give us the chance to do something truly positive.

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