What You Need To Know About Bioavailability and Nutrient Dense Foods

It's an Orwellian world where some nutrients are more equal than others

There is a pervasive theme in the media that the way to solve our environmental problems is for the world to turn vegan and eat only plants. While I agree that the environmentally disastrous CAFOs (Confined Animal Feeding Operations) have to go, the idea that we could produce enough nutrient dense foods to feed the world without animal inputs is a biological and environmental non-starter. I’ll save this last sentence for a post all its own on another day. Today, I want to focus on bioavailability and nutrient density in our diets and the different relative values of animal and plant foods that can affect our health.

Previously I have written about “bliss point” foods and how these scientifically tuned ultra-processed foods trigger our brains to release dopamine even though their nutrient content is poor. Essentially these foods lie to us through their color, taste, smell and texture which have been enhanced (manipulated) to make us want them (crave them), but their nutritional value is low. We eat more and more of these ‘junk’ foods because they lack the cues that tell us to stop eating, and thus it is easier than ever to become overweight and yet still be nutrient deficient. (You can read more about Bliss Point Foods here).

Bioavailability and nutrient density are two key concepts that can help you make better food choices. Plant and animal foods differ in what they can provide our bodies and this knowledge can help you make better food choices.

What is bioavailability?

We often hear the phrase ‘you are what you eat’. That’s because you eat food that consists of once-living things, and your body breaks down that food and reassembles it as your human body.

To use the food we eat, it goes through digestion (which begins in the mouth), absorption (in the gut), availability (movement through the body) and finally utilization (at the cellular level).

Nutrients are “bioavailable” if they can be broken down via digestion, absorbed in the gut, travel through the body and then enter and get used by cells.

You can imagine that many things affect your ability to use the food you eat. Your current nutritional and health status has a lot of influence over what you need to eat and absorb today.

If your system is already saturated with a nutrient, your body isn’t going to absorb more just because you eat it. The most visible example of this is water-soluble Vitamin B2 (riboflavin). Once your system is saturated with B2, your kidneys flush out the excess resulting in bright yellow urine. It doesn’t matter how much more B2 you consume, it is literally going down the drain once the saturation point has been reached.

So even though you need a wide array of nutrients to be healthy, and even if you consume highly bioavailable foods all the time, that doesn’t mean your body is going to absorb and use everything you take in. This is one of the reasons why human nutritional studies are so challenging to create -there is a LOT of noise in the system that is hard to control for.

Plant vs Animal Sources of Key Nutrients

There is no one-size-fits-all diet that every person on the planet should be consuming to be healthy. Everyone has different starting points, nutrient deficiencies, preferences, and cultural influences.

One of the most uplifting messages from the Blue Zone studies (places with high proportions of people living over 100 years), is that a wide variety of culturally and regionally specific foods can support health and longevity.

Biologically, humans evolved as omnivores, eating both plants and animals. When we look at the bioavailability of certain key nutrients, it is easy to see why. Some nutrients are most readily available in plants and others in animals. It’s easy to see why a mixed diets easily supports human health. Sure many cultures have found work-arounds that create whole proteins with all 9 essential amino acids from plants, and which can improve absorption rates, but this is where the Orwellian concept kicks in.

George Orwell famously wrote in his book Animal Farm, “All animals are created equal, but some are more equal than others”. While Orwell was talking about the hypocrisy of the ruling class, I’m calling out the idea that it doesn’t matter whether you get your nutrients from plants or animals.

Yes, many important nutrients are found in both plants and animals, but they are not necessarily the same once they hit your gut. Some nutrient sources absorb better and faster, meaning you can eat MUCH less to obtain what you need for good health. Your body also has to work less hard to obtain those nutrients.

You can make up the difference of low bioavailability by eating more plants in some cases, or by carefully combining plants to improve absorption. And animal foods lack key vitamins like Vitamin C and Vitamin K, which are essential to our immune system and repair functions. Again, there is just no one-size-fits all. You do you.

The bioavailability of key nutrients from plant and animal sources is the focus of this 2023 article in the journal Critical Reviews in Food Science and Nutrition. The authors found that overall absorption of key nutrients from animal sources tended to be higher than from plants, but there are certain nutrients only available from one or the other food system. I’ve summarized those in the table below.

Data source: Critical Reviews in Food Science and Nutrition

Nutrient Dense Foods

Nutrient dense foods are those that are rich in the life-enhancing proteins, fats, vitamins, minerals and phytonutrients essential to living a long and healthy life. The best examples of these foods are whole foods with minimal processing like eggs, nuts, dark green leafy vegetables, brightly colored vegetables and fruits, lean meat, fish, etc.

Adding to the complexity of this discussion is the fact that not all animal or plant foods are created equal. Beef produced in a CAFO does not have the same nutrient profile as regenerative, grass-fed beef. Plants grown on nutrient poor soil and bolstered by chemical fertilizers do not have the same nutritional profile as plants grown on thriving healthy soil, rich in organic materials and with complex soil microbiomes.

Soil health, cultivar, harvesting, handling, processing, storage, transportation and preparation all impact the results you would expect to see if you further refined the above bioavailability table by taking a deeper dive into what is really going on.

So what can you do?

Eat as much whole foods sourced from local small-scale and regenerative farms. Why?

Because above all else, shortening your food supply chain as much as possible gives you the best chance of eating high quality food that can flood your body with the best building blocks for good health. Time to the table matters from a nutrient quality perspective:

Regardless of your preferred eating orientation, make sure you understand the potential limitations on key nutrients that you need for health so that you can find solutions.

One of the best things you can do is grow at least some of your food yourself. Whether that is sprouts in your kitchen, pots of herbs, a garden, or a small farm, connecting to your food by growing some of your own and experiencing what fresh, unadulterated, nutrient dense food looks, smells, feels and taste like gives you perspective on choosing the rest of your diet from other other sources.

You’ll find a lot of support and useful food growing information here at the Naturalized Human. Let’s change our relationship to food together, and cut through the noise of diets, trends, and misinformation.

So I have written about the bliss point

and about how what we really need to connect to our food again.

Part of that connection is eating nutrient dense foods.

• ultra-processed foods lie to us about what they contain - the have been treated with colors to make them visually more vibrant - they have salt, fat and sugar added to make them taste as if they contain more nutrients than they actually do. .. . . . but the problem is they only lie to our eyes, mouths and to our brains via those sources . ..they don’t lie to our gut though - that is bombarded with this crap and has to deal with it.

think about this some - what does nutrient density mean and how do we get there?

I eat a chocolate bar and want MORE.

I eat a nutrient dense homemade chocolate snack and I am satisfied for hours

https://foodlies.substack.com/p/its-not-hyperpalatable-its-nutrient/comments

Brian Sanders - I am reading this post - and he says the lack of nutrition keeps us eating - but in theory if we ate something that had no nutrient value - paper or cardboard - our brains would tell us to stop wasting our time. . .but we don’t stop eating the junk food, we just keep eating more and more of it - so the dopamine hit is key in my mind . . .except then he backs up his point of view with the protein theory where mice keep eating to obtain the same amount of protein