When my book gets done, I can save you all a ton of time now. Only two things you need to know: eat whole foods and exercise.

Conventional wisdom. A big disappointment (for me), I am not going to be able to offer any new or different advice that will revolutionize our health. You see, an Everest of research has gone into our human system. And what we get out of this mountain of data is that we need to eat whole foods and exercise. There is no “one weird trick” that will change our system.

Conventional wisdom wins. Perhaps that’s why it’s stuck around for so many years. We don’t need to necessarily understand exactly the why (which is what research has spent a bajillion dollars attempting to find out) in order to effect a change.

But the why can be pretty cool.

A story about conventional wisdom: being in the cold gives you the cold. Researchers have demonstrated that to an extent this saying is true. The common cold is usually caused by the rhinovirus (get it? rhino = nose). Rhinovirus replicates (i.e. hijacks the cellular machinery of the host cell to make more viruses) in infected cells best at body temperature. Unfortunately, our immune cells also function very well at body temperature which prevents the rhinovirus from being effective at infection. If the virus can’t get into cells, who cares how well it replicates. So, at 98.6 degrees Fahrenheit, the war between our immune cells and cells turned zombie slaves of the rhinovirus is pretty even. The virus needs an advantage. So it evolved to infect better at cooler temperatures like those found in the upper respiratory tract. At cooler temperatures, our immune cells don’t function quite as well. The rhinovirus confined its effective infection niche to colder areas of the upper respiratory tract so that it would have more of an advantage in replication. Therefore, when you breathe cold air, you are slowing down your immune cells and giving the virus more of a chance to infect new host cells. Being in the cold doesn’t give you the cold, but it does aid its spread in your cells (Papadopoulos N, Sanderson G, Hunter J, Johnston S. Rhinoviruses replicate effectively at lower airway temperatures. J Med Virol 1999;58:100–104).

But of course nothing is ever so neat and tidy that we can say a set rule like conventional wisdom always wins–especially when dealing with complex systems of which we can only see parts. And sometimes, science can work super hard and develop elaborate why’s that explain conventional wisdom yet are absolutely wrong. Think about the dance of the sun and earth. Conventional wisdom held that the sun revolved around the earth (duh, can’t you see that with your eyes?), and many scientists devoted their lives to formulas and theories that supported this wisdom. Until Galileo. He changed our conventional wisdom about celestial bodies.

This change in conventional wisdom is called a paradigm shift. A paradigm is the template we use to make sense of the world. Most paradigms are collective on some scale. There are large paradigms like germs spread illness (called germ theory) that most of the educated world embraces, and there are smaller paradigms like religious ones that only a sect of people follow.

Paradigms are so much a part of what we are as a social species that we don’t even really notice that they shape how we think about things and act on a day to day basis. They are like breathing in that we engage them without thinking, yet they are social constructs. Even when we can’t imagine something different, paradigms are not absolute and perhaps can even be a poor template for real use in the world.

The goal of a scientist is to acknowledge the current paradigms, work within them, yet also be open to evidence that could challenge conventional wisdom. The scientist (like the artist) strives to truly see things as they are rather than as we are conditioned to see them. This is hard. Many scientists have spent their lives refusing to acknowledge that what they see is actually just a construct of conventional wisdom. They have built their careers around that.

A story about a paradigm: the stomach is so acidic that it is sterile. Conventional wisdom said that ulcers and stomach cancer were caused solely by stress. The “cure” for extreme cases of ulcers was to cut out the offending part of the stomach and reattach it to the intestines. A drastic procedure that left people, as Barry Marshall called them, “gastric cripples.” Barry Marshall noticed that in his patients, he was finding the presence of a microbe called H. pylori in their stomach samples. No one else had noticed this microbe because it grew so slowly that the usual two days of culture time, showed nothing (H. pylori needed almost two weeks). The medical community laughed at him. They stuck to the paradigm that no germ could survive in such an acidic environment, that ulcers were psychosomatic. They built treatments and entire hospitals around this paradigm. Marshall got more and more frustrated as he saw people who weren’t his patients suffering from ulcers and ultimately having their stomachs removed. Finally, he took a sample of H. pylori from one of his patients, mixed it in a broth, and drank it to the aghast of his wife. Within days, he had all the symptoms of an ulcer. Symptoms that went away with a simple treatment of antibiotics. Barry Marshall changed our paradigm of how we develop ulcers and what can be in the stomach.

[remember, no story is simple. H. pylori does not cause ulcers in every stomach, and some ulcers are not from a bacterial infection.]

But still, Barry Marshall was operating in the paradigm that germs are pathogens.

So back to my book. The why of eat whole foods and exercise is proving to be a tangle thread of many organisms that make up a human ecosystem. All germs aren’t pathogens and all viruses aren’t out to take over our cells. We live quite well with billions of germs and billions upon billions of viruses going through their life cycles on our bodies.

The scientific community is looking to effect another paradigm shift on society: humans are comprised of a myriad of ecosystems containing a multitude of species. This ecosystem is being called the holobiont.