We are a civilization of terrible teeth. I say this with some personal knowledge, because with the exception of the four front teeth on the top and bottom, every tooth in my head has cavities and every last one deep fillings (albeit white ones).

The state of my teeth has everything to do with the diet I was brought up with. My parents, part of the “better living through chemistry” generation in America and buoyed by the postwar optimism of the time, placed their faith in the extraordinary progress that processed food represented: freedom from the hours that my Italian grandmother had spent in front of a hot stove.

In the main, besides meat, if it didn’t come in a box, my family didn’t eat it—except for Sunday night, when we ate TV dinners (in aluminum foil containers). Sugar-laden cereals, ‘pre-cooked’ white rice, frozen vegetables, even mashed potatoes came in a box. Just add water, and those precooked white flakes magically turned into some approximation of the real thing.

This regime, abetted by Coca-Cola, white bread (bologna sandwiches!) and chewing gum, helped to produce all the decay in my mouth. In fact, it’s probably the one abiding regret I have in my life: that I didn’t know what I know now to take better care of my teeth.

But decay is not the only issue with the standard American and British diets.

The soft diet of ultra processing—even cooking itself—has also produced generations of maloccluded teeth, according to a father and son team of British orthodontists, Dr John Mew and his son Dr Mike Mew.

These two dentists began their renegade journey by asking a simple question: why do people have such terribly misaligned and crowded teeth? At last count, half of American children will get braces and at least half of all Americans will require a wisdom tooth pulled by age 25 (I’ve lost two of mine), three-quarters of them by age 60.

Many of those children who get braces also get a tooth pulled in the process, as do many people whose teeth don’t fit in their mouths. According to most dentists, this has simply to do with a bad genetic roll of the dice—teeth that simply grow too big for your mouth.

The fact remains that only a third of Americans and probably the same number of Europeans have well-aligned teeth.

But this wasn’t always the way. Skulls from early civilizations, such as the Paleolithic periods, invariably have perfectly aligned teeth, as do the approximately 5,000 species of animals.

This all changed in humans two centuries ago, when skulls showed evidence of jaws that seemed too small for their teeth. So what happened to create this tsunami of crooked teeth?

The simple answer is cooked food, claims the elder Dr Mew in his textbook The Cause and Cure of Malocclusion. Our Stone Age ancestors would have eaten uncooked food, which would have required hard grinding and chewing of raw food from a young age. This in turn would have created strong jaw muscles and larger oral cavities.

But with the advent of cooking, food got softer, chewing was reduced, babies were given pureed food and formula milk replaced much breastfeeding. Even bottle-feeding reduced the sucking a baby ordinarily has perform to extract milk from his mother. Small wonder that jaws became poorly developed in children.

And this isn’t just speculation by the Mews. Increasing scientific studies, even with monkeys and rats, show that soft food produces a shrunken and misaligned jaw too small to house the teeth. On the other hand, introducing hard food earlier and maintaining a diet with a good amount of raw food can improve the size and alignment of the jaw.

Blocked noses from allergies, causing mouth-breathing, also lead to jaw misalignment. All this, in turn, leads to TMJ pain and poorly developed faces, so that many of us just aren’t as handsome as we were meant to be.

What is the solution? According to the Mews, and to hundreds of orthodontic dentists who follow their practices, it’s orthotropics.

Instead of forcing the teeth into place, orthotropics attempts to change the posture of the mouth, muscle function and the balance of the lips and tongue. This in turn improves the development of the face and alignment of the jaw so that the teeth naturally fall into place.

The Mews have developed some simple mouth exercises and appliances to encourage alignment and proper facial structure..

But, of course, another aspect of good dental health is the food we put into our mouths, which doesn’t just create beautifully aligned teeth but also leads to a healthy life.

That Italian grandmother of mine lived to 96 and simply went to sleep one night and never woke up. My mother, on her diet of processed food, died from cancer at an age nearly 20 years younger than her mother.

It’s too late for my teeth, although thankfully, I never needed braces—nor did our children. But there is something else that will help keep our mouths aligned even in later life: consuming raw food.

And this puts that old wives’ exhortation into some sort of context. As my grandmother would likely have told us: just chew your food.