You probably don’t think much about the health of your food itself, but this is an important factor to consider when choosing what to eat.
There are many different reasons why eating food that wasn’t healthy while it was on the vine, in the ground, or running through the woods, is potentially hazardous, and why the healthier your food…the more likely it is to be nourishing to you.
What makes things sick? What makes them healthy? For starters, deficiencies of nutrients are deadly to any organism. These deficiencies often lead to infections with everything from parasites to viruses. Likewise, exposures to toxins can also cripple the immune system and lead to infections. Overwhelming exposures to bacteria, viruses, or parasites are likewise lethal, however, most animals are wired to avoid such exposures. This comes down to situations in which food is either improperly nourished or is poisoned in some way. There is also concern that as foods have been bred selectively, the properties that made them healthy have been bred out of them. This is one potential explanation for the rise in allergies to foods like wheat, which were once critical sources of nutrition. There are many links between the health of the food we eat and our own health, but you won’t see scientific studies with titles like, “healthy food shown to make healthy humans.” I’ll explain this using some examples from plant and animal sources of food.
Think of the perfect apple. It’s probably big, colorful, firm, round, juicy, and its skin is perfect. Why does that make it perfect? Why aren’t we attracted to asymmetric, pale, soft, shriveled, and pock-marked apples? The differences between these two different versions of an apple have to do with the health of the apple, the tree it came from, the soil that the tree grew in, the tree’s total environment (including pests, air quality, water availability – to name a few), and how the apple was preserved between the farm and your table. The color of the apple is due to antioxidants that protect it from free-radical damage. The apple is symmetric because symmetry is a sign of health, whether in animals, fruits, or plants (for a wide variety of reasons), and this attracts animals that will eat the apples and spread their seeds. The firmness of the apple is a sign that it is intact inside, rather than riddled with disease. The larger the apple, the stronger the tree and the more resources it had go into creating it, including water, minerals, and vitamins. The apple’s skin can be affected by diseases just like human skin can be, which ruin its symmetry and color. The health benefits of the apple are entirely due to these visible, tangible markers of health. The colorful antioxidants in the skin prevent free radical damage and have powerful benefits for our immune systems. Vitamins and nutrients are necessary to keep the fruit free of blemishes from diseases. They’re also necessary for the growth of the tree and the production of fruit at all. These are just some of the examples of how your brain knows what healthy food is – both in the sense that the food is healthy and that it will be a healthy food for you.
These principles hold true for animals as well. A healthy animal is strong, fast, stands tall, and has healthy skin or fur. When you butcher these animals, their bones and sinews are strong, their meat is perfectly red, and they have ample body fat. Compare that with an animal that has been subject to disease, whether cancer, infection, or toxic exposures. Those animals are thin, weak, slow, and often have mange (loss of fur due to disease) or other diseases of their skin or fur. Microbes from animals can infect humans who eat or consume the milk of infected animals. Many of these diseases are spread by insects like ticks or mosquitoes. This is why animals (including humans!) spend so much time grooming each other – all kinds of animals will pick ticks or other ectoparasites (parasites that grow on the skin) off of each other. Even when an animal is exposed to a parasite or bacteria, its immune system may keep it in check, or even eradicate it. This will reduce the likelihood of transmitting that disease to humans or other predators that end up eating that animal. The health of the animal’s immune system depends entirely on its environment – the availability of food and its nutritional value. When the animal has a nutritious diet, its immune system is stronger, and its health is therefore better. Toxic exposures, as mentioned before, can poison the animals many different organ systems, both worsening infections and impairing the animal’s ability to compete for nutritious food or escape predators.
These differences are not limited to sight and touch. You know the difference in taste or smell between a rancid piece of food and a fresh piece of food instantly. Your taste buds are excellent at figuring out what foods are spoiled, whether that means they are infected with dangerous microbes or have lost all their vitamin content.
While your senses can be a powerful tool in determining what food to eat or not, they can also be tricked. Food manufacturers have figured out a million ways to do this. Artificial dyes are used to create the illusion of healthy antioxidants. Artificial preservatives are used to prevent fats from going rancid. Artificial flavorings are used to mimic the tastes of healthy foods like seaweed and bone broth. Understanding how your senses work is the first step in using them wisely, which includes knowing when to distrust them.
The mechanisms by which your brain makes decisions about what to eat are awesomely complex and entirely integrated. Again, you won’t see studies on this. Much of this is just common sense. Yet we are daily being told that everything from factory-farmed beef to irradiated almonds are “no different” from their alternatives. Once you understand the principles behind how your brain immediately recognizes, “healthy food,” you can begin to understand the science behind them and use them to your advantage to sort out which innovations in food safety are likely working for you, or against you.