Why some of the most nutrient-dense parts of an animal disappeared from the American diet.
We hear the phrase, “Eat healthy.”
What does that mean?
Most of us inherited a picture of healthy eating: Vegetables are good. Processed foods are bad. Lean meat is better than fatty meat. We eat chicken breasts, steaks, hamburger, and fish. If our diets don't provide everything we need, we can take vitamins and supplements.
Consider, there's something strange about the way we eat animals. We consume mostly their muscle. We avoid, or don't have access to, liver, heart, kidney, spleen, pancreas, and other organs. Many of those organs are among the most nutrient-dense parts of the animal. That raises a question:
If organ meats are nutritionally valuable, why did we stop eating them?
Perhaps a more interesting one:
Did we stop because of nutrition or as our culture changed what we consider food?
We Don't Eat the Most Nutritious Parts
When most Americans think of beef, we think of steak, hamburger, or roast. Those are primarily muscle meats. Organ meats occupy a different place in our food culture. Liver is occasionally available. Heart and kidney are less common. Spleen and pancreas are invisible to the average grocery shopper.
It's might be assumed that's because those parts don't have much nutritional value.
That's not the case.
Different organs have different nutritional profiles. Collectively they can provide high concentrations of nutrients including vitamin B12, iron, vitamin A, folate, copper, and other micronutrients. Heart contains compounds such as CoQ10 and taurine.
Muscle meat contains valuable nutrients too. The point isn't that steak is nutritionally worthless and liver is nutritionally superior.
The question is:
Which nutrients does a particular food contain, in what amounts, and how much would we have to eat to obtain them?
That's a more meaningful question than asking whether something is "healthy."
Why Did Organ Meat Disappear?
Our eating habits weren't necessarily created by nutritional science. History, economics, transportation, food processing, availability, social status, and culture all helped determine what ended up on our plates.
Organ meats were once a ordinary part of the American diet. During World War II, Americans were encouraged to eat them, while conventional cuts of meat were needed elsewhere.
Organs present practical problems. Many are highly perishable. Muscle meat is easier to process, package, transport, store, and sell through a centralized food system.
At the same time, increasing prosperity changed the social meaning of meat. Steaks and roasts became desirable. Organs became associated with inexpensive food, older generations, or something people ate because they had to.
Then something interesting happened.
People stop buying organ meat. Stores stop carrying it. Parents stop cooking it. Children don't grow up eating it. Restaurants don't serve it. Eventually an entire generation encounters liver or heart not as food, rather as something strange. Strange becomes gross.
Is "Gross" Evidence?
Consider the reaction people have to eating heart. A steak came from the same cow. So did hamburger. Why does one seem normal while the other can trigger disgust?
Much of it is learned. People in cultures where organs remain part of ordinary cuisine may have no such reaction. Foods that seem bizarre to one culture can be everyday meals or delicacies in another.
How often do we mistake familiarity for evidence?
Something we've encountered our entire lives feels safe and normal. Something unfamiliar feels questionable. Neithertells us about nutritional value. Our aversion to organ meat may tell us more about our culture than about the food.
What About Toxins?
There is an intuitive objection to eating certain organs, particularly liver. As the liver filters toxins, wouldn't eating liver mean consuming all the toxins the animal filtered?
Notice what's happened.
We started with a fact about what the liver does, and created a mental model for how it does it.
The liver becomes something like the filter in an air purifier. Dirty material passes through it, contaminants get trapped, and the filter becomes full of them. If that's how the liver worked, eating it wouldn't sound very appealing.
Biological detoxification is more complicated. The liver processes and transforms substances so they can be eliminated from the body. It isn't simply a disposable filter accumulating everything that passes through it.
That doesn't mean the conditions in which an animal was raised are irrelevant. What an animal eats, what it encounters, how it is raised, and how meat is handled are legitimate questions.
Does Eating an Animal's Organ Help the Same Organ in Our Body?
There is a longstanding idea sometimes summarized as "like supports like."
Eat heart to support the heart.
Eat liver to support the liver.
Eat brain to support the brain.
This can sound as folk medicine. Some organs do contain high concentrations of nutrients and compounds relevant to the functions associated with those organs. Heart, for example, contains CoQ10, a compound involved in cellular energy production and associated with cardiovascular health. It also contains taurine.
There are two propositions:
Heart contains nutrients relevant to cardiovascular function.
and
Eating heart improves your heart because it came from a heart.
Evidence for the first doesn't prove the second. That logic can disappear when an interesting observation becomes a health claim. Instead of accepting or dismissing the idea, we might ask:
What compounds are actually present in each organ?
How much survives digestion and becomes biologically available?
Do people who consume the organ experience measurable differences?
Are those differences greater than consuming the same nutrients from other foods?
Can the effect be reproduced?
Food Isn't the Same as a Pill
Suppose liver contains a nutrient I need. Why not simply take that nutrient as a supplement?
Food and supplements aren't interchangeable systems. Eating involves taste, smell, texture, chewing, digestion, appetite, and satiety. Those processes provide biological feedback that swallowing a capsule bypasses.
That raises a question:
How much nutritional information is contained in our appetite and sensory experience of food?
Feeling like eating something doesn't prove the body has precisely identified a particular nutritional deficiency. Modern food complicates the relationship. For most of history, flavor was connected to the food producing it.
Today we can manufacture flavor independently of nutrition. A product can taste like strawberry while containing little or no strawberry. Sweetness can exist with little sugar. Richness, saltiness, texture, aroma, and mouthfeel can be engineered.
We've become good at creating the sensory experience of food. What isn't clear is whether we've fully considered what happens when sensory signals and nutritional content become separated.
What Does "Nutrient Dense" Mean?
This brings us back to the phrase healthy eating. Healthy for what?
Weight loss?
Protein intake?
Iron?
Vitamin B12?
Fiber?
Blood glucose?
Cardiovascular health?
Correcting a specific nutritional deficiency?
Those aren't the same objective. A food can be an excellent source of one nutrient while being a poor choice for another purpose. The question, "Is this food healthy?" isn't specific. A better question is:
What nutritional problem are we trying to solve?
Once that has been defined, we can compare foods based on what they provide. That changes healthy eating from a collection of cultural labels into something we can investigate.
A Systems Problem
There's another side to organ meat that has little to do with whether you want liver for dinner: What happens to the parts of animals we don't eat?
Modern meat production is built around the cuts consumers want to buy. If consumers don't want particular organs, processors have less incentive to collect, package, distribute, and market them for human consumption. Some can be used for pet food or other products. Some may have little economic value. And some can become waste.
We raise an entire animal. We devote land, water, feed, energy, transportation, labor, and infrastructure to doing so. Then we preferentially consume certain parts of it.
At the same time, people buy manufactured supplements to obtain nutrients that occur naturally in some of the parts we've decided aren't food. Whether eating more organ meat is the answer or not, that's an interesting systems problem. It changes the sustainability question.
Instead of asking:
How many animals should we raise?
we might ask:
How much useful nutrition are we obtaining from every animal we raise?
Reducing waste sometimes means recognizing value in something we're throwing away.
What We Can and Can't Conclude
The case for reconsidering organ meat is stronger than the case for making claims about it. We have good reason to recognize that organ meats can be extraordinarily nutrient dense.
We have reason to question whether their disappearance from the American diet reflects nutritional inferiority. Economics, food distribution, culture, familiarity, and changing preferences provide plausible alternative explanations.
That doesn't establish that everyone should eat organ meat. Nutrient density does not prove that eating a particular organ will improve the corresponding organ in your body.
Those are separate questions requiring separate evidence.
Maybe We Should Re-think"Healthy Eating"
The interesting thing about organ meat isn't what's in liver or heart. It's what our reaction to those foods reveals about how we decide what is healthy. We assume foods prominently displayed in grocery stores are there because they're the foods we're supposed to eat.
We assume foods our culture abandoned must have been abandoned for good reasons.
We assume something that disgusts us probably shouldn't be eaten.
We assume a vitamin in a capsule can substitute for obtaining that nutrient through food.
Some of those assumptions may turn out to be correct.
Instead of starting with the question: What foods are considered healthy?
Start by asking:
What does the body actually need, and what is the best way to provide it?
If we begin there, some of the parts of the animal we've learned to ignore may deserve another look.
About This Article
This article is based on my conversation with James Barry, founder of Pluck, an all-purpose seasoning made from grass-fed, pasture-raised beef organ meats. Rather than asking people to change the way they eat, James started with a different question:
How can you make nutrient-dense foods practical for everyday life?
That question led us into a discussion about organ meats, nutrition, cultural attitudes toward food, supplements, sustainability, and what we mean when we call something “healthy.”
The article above is my exploration of the ideas and questions that emerged from that conversation.
This article is based on my podcast interview with James Barry. The structure, emphasis, and commentary are my own. Any errors or interpretations should be attributed to me, not to James Barry.
Listen to the podcast episode:
About the Author
Daniel Stih is an aerospace engineer, software engineer, indoor environmental consultant, and author of 12 books. Through engineering, investigations, and interdisciplinary research, he explores how people define problems, interpret evidence, and make conclusions when there's uncertainty. Learn more in Why I Think This Way.