The Number One Cause of Chronic Disease

processed food aisle

The Western world, along with an increasing fraction of the rest of the world, is facing a health crisis. With a combined overweight and obesity rate of 80%, epidemics of diabetes and depression, and heart disease and cancer as the most important causes of death, understanding the roots of our problem is critical. To avoid becoming a health statistic, understand the number one cause of chronic disease.

Diseases of Civilization

The diseases of civilization are those that people living in civilization get, and that people living a primitive or hunter-gatherer lifestyle do not get. They include:

  • coronary heart disease
  • obesity
  • hypertension
  • type 2 diabetes
  • cancer
  • autoimmune disease
  • osteoporosis

These diseases are “rare or virtually absent in hunter–gatherers and other non-westernized populations”.

We could add a few others to that list:

  • depression
  • sarcopenia
  • ADHD
  • male hypogonadism (low testosterone and erectile dysfunction).

A huge fraction of Americans live with chronic disease

The diseases of civilization are chronic diseases, and a large number of Americans have them.

According to the Center for Disease Control (CDC), 78% of Americans 55 years and older have chronic diseases.

These diseases include arthritis, asthma, cancer, cardiovascular disease, COPD, and diabetes.

For Americans age 55 to 64, the percentage that have a chronic disease is 70%.

For Americans 65 and over, the percentage is 86%.

Much of this is avoidable.

Much of this is correctable too.

The top 1% have no chronic disease

A small fraction of people age 85 and up have no chronic diseases. Zero.

These people have been called super seniors. They represent the top 1% in health for their age.

While 1% is a low number, it shows what’s possible. You can get older without falling victim to chronic disease.

Or, you can be like almost everyone else and look forward to a great deal of pain and suffering.

The number one cause of chronic disease

What’s the mysterious factor that leads to chronic diseases in the developed world, but leaves hunter-gatherers alone?

Processed food. Specifically, foods that contain hefty amounts of seed oils, sugar, and refined grains. (See these links for citations.)

Humans are not genetically adapted to eating modern, ultra-processed foods. We’ve been around for hundreds of thousands of years, and our predecessors for millions. Yet agriculture began only about 10,000 years ago, and we began to eat ultra-processed food in large quantities only in the past few decades.

The diseases of civilization are better called the diseases of processed food.

When people living a traditional lifestyle begin to eat processed foods, their health declines and they get chronic diseases. This phenomenon has been seen over and over.

The rise of cheap fast food and other ultra-processed foods in the past few decades is arguably responsible for the obesity epidemic.

Despite what conventional health wisdom claims, animal foods have nothing to do with chronic diseases, including obesity. The main offenders are all plant-based foods: seed oils, sugar, and refined grains.

Americans ate huge amounts of meat in the 19th century and before, and didn’t have chronic diseases. So did many other people in many other nations.

“Heart-healthy” isn’t

Ever since the dawn of the cholesterol hypothesis of heart disease, animal products have been demonized.

They urged us to replace animal products with “healthy whole grains” and “heart-healthy” oils like corn oil.

As a consequence, obesity rates exploded.

They started an uncontrolled experiment on the American people, who never gave their consent. Even when they began, there were many dissenting voices, but of course they were ignored, or had their careers ruined.

Mainstream health authorities are being dragged, kicking and screaming, away from their dogma, but most will never admit that they’ve been wrong. If they do, it would mean taking responsibility for the horrible state of health of most Americans.

Another consequence is that most people now consider processed foods as healthy, or at least benign.

Processed foods now make up 70% of the American diet. The answer is staring us in the face.

If someone sees a doctor about a chronic illness, in all likelihood the doctor won’t advise lifestyle changes. Some do, but most don’t know what the right changes are.,

Instead, the doctor will prescribe drugs, which are often toxic or at best ineffective.

To reliably produce obesity, metabolic syndrome, and fatty liver in lab animals, just feed them processed food.

Other lifestyle factors

Certainly, other lifestyle factors are involved in chronic disease. Among the most important are:

  • exercise
  • sunshine
  • circadian rhythms
  • sleep
  • social connection.

It’s difficult if not impossible to assign ranks of importance or the degree to which these things are responsible.

But I do argue that processed food is a huge factor, and if you stop eating it, you could make huge gains in health.

Eat whole, minimally processed food.

Share this post with your friends

Want to look and feel great in your 40s, 50s, 70s and beyond?

Discover how to avoid chronic disease, excess body fat, and enjoy limitless energy


  1. Rob says:

    What you write is no doubt true. However, the likelihood that most Westerners will remove all processed foods from their diet and switch to a 100% whole-food based diet is basically zero. There are several reasons for this, among them: 1) there is way too much money to be made by the companies selling processed foods (and also the big drug companies, who make drugs to treat people made sick from processed food), for them to ever give it up; 2) most of what you can buy at the grocery store these days is processed food; and 3) most people are hooked on the taste and convenience of processed food (the big food companies work very hard to come up with flavors/textures that people basically get addicted to). So, a lot of this comes down to money, and the huge profits companies make from selling people unhealthy products that they can’t stop eating. Some people (like those who read your blog, PD) are able to break free (at least to some extent) of these factors and actually consume a mostly whole-foods diet, but we are definitely a very small minority, and will probably continue to be so.
    One other comment I would make on your article – when you say that “animal foods” have nothing to do with obesity, I would agree with you if you are talking about unprocessed meats from animals that are fed a natural diet. Lunchmeats and other highly processed meat products (hot dogs, etc), on the other hand, probably due contribute to chronic disease.

    • P. D. Mangan says:

      No argument from me there, although I’m not totally convinced about processed meat. Is it the hot dog, or the bun and soda that go with it?

      • Morgana says:

        I’m also not convinced about processed meat, at least not the traditional ones, like hung-dried Serrano ham, or high quality bacon. Sure, the crappy ones that are full of fillers like soy and sugar are probably not good…..and I agree that it’s most likely the bun, the corn-syrup laden ketchup and the soda that make processed meat “bad” in epidemiological studies. Also, not all of the scientists were in agreement with the WHO report anyway- (according to what I’ve read).

  2. Morgana says:

    You hit the nail on the head; this is exactly what I believe is our main problem- (though it’s rare for our so-called health authorities, or even anyone really, to admit it). Thanks for posting this.

    Oh, except I think you mean “heart-healthy” corn oil rather than “heat-healthy”- (corn oil is not exactly “heat healthy”, ha ha……nor is it “heart healthy” either, which I guess is the point you were trying to make).

  3. peter connor says:

    Notice the curious fact that women have more of these conditions than men in all age groups, yet women live much longer than men in the US….Are women over-reporting (likely) and/or more durable? This is an important question.

  4. Paul Rivas MD says:

    Chronic inflammation is at the root of most chronic illnesses. It is such an important part of the initiating process of Alzheimer’s disease that daily ibuprofen in high risk groups will prevent the disease. So at all costs avoid those foods that are highly inflammatory.

  5. Scott Smith says:

    Excellent as usual.

  6. Herman Rutner says:

    Hi PD, hate to be contrarian about any high meat/ fat diet as your fix of modern diseases caused largely by inflammation, not only from processed or mass produced by Big Meat. Recent studies reported by MacDougall on civilizations dating back more than 4000 y, e.g .done on mummified Egyptians, especially among meat eating royals showed similar Western style diseases. In contrast the Biblical controlled 3 y diet study involving 3 Jewish captives versus local kids in Daniel, chapter 1 showed superiority of a vegan kosher diet to the royal meat diet, which was noticeable within 10 days by superior complexions and 3 y later as superior intellect. Dr Mac Dougall is a strong advocate of “ starch” or vegan based diets in his book advocating diets devoid of animal derived food. His diet is similar to the diets of millions of Chinese in the huge epidemiological comparison of diseases of poverty versus affluence reported in the China Study by Dr Campbell. Food for thought and further review if not done already. But disregard the hatchet job of a stooge hired by Big Meat critiquing trivial errors that do not affect Campbell’s conclusion.

    • Stephania says:

      The China Study was thoroughly debunked.

    • Morgana says:

      Except for the fact that Paleolithic hunter-gatherers thrived on meat…..we humans have been eating meat for most of our existence. The fossil records clearly show that our health dwindled, and the diseases of civilization only started to appear when we switched to grain eating. And Egypt was one of the early “grain” civilizations. The Royals who were supposedly eating meat- (?- not sure we know how much of it they were really eating)- were still living longer than the poor people, who’s average lifespan was about 35. So they would have lived long enough to get these degenerative diseases. And they were all eating grain; the rich people ate wheat, the poor people ate barley.

  7. I agree, exercise (including resistance/weight training) is important, but you can’t outrun a bad diet of processed foods! I was blessed to be raised by a mother who was way ahead of her time in her interest in nutrition. She knew instinctively not to jump on the “heart healthy” bandwagon with margarine and “vegetable” oil and all that. Whether one eats paleo, keto, Mediterranean, carbs/no carbs, I think it’s vital that the food consumed be organic, non-GMO, pastured, as close to “whole” as possible.

    • Herman Rutner says:

      I agree, Jean. Strenuous work or rec exercise are essential and type of diet may be less important. I came from a family of hard working farmers in former East Prussia working during daylight hours ( without indoor plumbing, electricity or telephones) taking care of animals and fields and eating wholesome food of home cooked rye bread, butter, potatoes, eggs, etc. they often ate a high calorie “farmers breakfast” of eggs, potatoes and bacon or ham) and cabbage stews with occasional meat. They commonly lived into their 80s without medical and dental care unavailable in their isolated communities. Ailments in humans and animals were treated with traditional herbal concoctions. Such a non GMO grandparents diet may still applicable to the current generation but caloric intake must match calories spent in either strenuous work or exercise.

  8. Chuks says:

    Being from Nigeria, I am starting to see the negative effect of these ultra processed foods. More and more young people are becoming obese. Our grandparents were fit than our parents at the same age and our parents were fitter than us when they were our age. Makes you wonder. Thanks for the continuous knowledge.

Leave a Reply

Your email address will not be published. Required fields are marked *