Whole Foods Fad

QUESTION FOR AI: I have a question about processed food, and food fads in general. I have been around a long time and have seen my share of food fads. The Atkins diet, SlimFast, DASH diet, the no gluten fad, the no carbs fad, the current protein-maxxing fad...I could go on. Humans are prone to fads and mindlessly accepting things with almost no research, just glancing at a few headlines or listening to their friends.

The current "whole foods" fad is what I want to ask about. That is, you should only shop the perimeter of the grocery store and buy whole foods such as meat, fruit, and vegetables. By the way, even the "shop the perimeter" notion is stupid: the perimeter of every grocery store has a bakery with cakes and donuts and lots of unhealthy foods, highly-processed meats in the meat department such as sausage and hot dogs, and dairy with its many processed foods.

Processed foods are one of the reasons developed countries like the U.S. are able to feed large populations. Go back to the depression and the Dust Bowl and you will see why food preservatives were invented. They fed millions of people and prevented starvation.

My question is this: are there any peer-reviewed, double-blind clinical studies that conclusively prove that preservatives added to foods shorten lives? I mean bulletproof evidence like twins who live in the same community and have the same level of work stress and exercise and same level of other habits? And what good are studies anyway? Like the studies that “prove” diet soda causes obesity. News flash: overweight people drink diet soda to try to lose weight. Diet soda does not cause obesity.

I tried the whole foods fad. I bought a whole fresh turkey and cooked it myself, cut it up and separated it into sandwich size portions and froze them. I had a sandwich or two - not really my favorite. Boring. A waste of time and money. Maybe with mayonnaise and a few slices of bacon on a hoagie roll it would be good.

Here is the problem with the whole food fad: it is almost impossible to execute. You want a salad? You're going to need salad dressing. The good kind that comes out of a bottle, not some crappy vinegar and oil nonsense. You want a potato? You're going to need butter. Want an egg? You're going to need cheese to scramble in with it to make it edible. Eventually so many processed foods sneak in around the edges that you realize it is almost impossible and not worth the effort.

STATS: USA, 64 years old, PSA 11.6, unfavorable intermediate risk, Gleason 4+3=7, 6/13 cores positive, 42 ml prostate, Decipher 0.61, locally contained. Pre-ADT testosterone 323. Treatment: 5 sessions SBRT + 6 months ADT. Countermeasures: Daily strength training and 3-mile walk, Cialis, Curcumin, Calcium supplements.

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AI RESPONSE: This is a good question, and I think it gets muddled because several different claims get lumped together under the label "processed food."

There are really three separate questions:

1. Are food preservatives themselves proven to shorten human life?
2. Are people who eat a lot of ultra-processed foods less healthy?
3. If so, is it because of the processing or because of everything else that comes with those foods?

Those are very different questions.

The short answer to your main question is:

No, there is no bulletproof evidence that food preservatives, by themselves, have been shown to shorten human lifespan in humans.

In fact, it would be almost impossible to generate the kind of evidence you're asking for.

Why we don't have that kind of study

Suppose you wanted to prove sodium benzoate, potassium sorbate, or some other preservative reduced lifespan.

The ideal study would require:

• tens of thousands of identical people
• randomly assigned to preservative vs. no preservative
• identical diets except for that one ingredient
• identical exercise
• identical genetics
• identical income
• identical healthcare
• followed for 50 years

That study simply isn't feasible.

Nutrition science almost never gets evidence that clean.

Double-blind studies

Double-blind randomized controlled trials are the gold standard for drugs.

For nutrition?

They're usually only practical for:

• a few weeks
• maybe several months
• cholesterol
• blood pressure
• blood sugar
• inflammatory markers

Not lifespan.

Nobody can realistically randomize people to eat preservatives for 40 years while ensuring they don't cheat.

What we actually have

Most evidence comes from observational cohort studies.

Researchers follow 50,000–200,000 people for decades.

They record:

• smoking
• alcohol
• BMI
• income
• exercise
• education
• medications
• diet

Then they statistically adjust for those factors.

This is useful.

It is not proof.

And you're absolutely right to point out the diet soda example.

That's a classic problem called reverse causation.

People don't become obese because they drink diet soda.

Many obese people choose diet soda because they're already obese.

Good researchers know this and try to adjust for it, but adjustment is never perfect.

Processed food is an awful definition

The public discussion is terrible because "processed" includes things that have almost nothing in common.

Examples:

Frozen peas.

Frozen peas are processed.

So are canned tomatoes.

Whole wheat bread.

Pasteurized milk.

Yogurt.

Peanut butter.

Olive oil.

All processed.

Nobody seriously believes frozen broccoli is unhealthy because it was frozen.

Even washing, cutting, freezing, or pasteurizing technically counts as processing.

Ultra-processed is different

Researchers increasingly focus on ultra-processed foods, which are things like:

• packaged snack cakes
• sugary cereals
• soda
• candy
• chips
• instant noodles
• frozen pizza
• processed meats
• fast food

Notice these foods share much more than preservatives.

They also tend to have:

• lots of sugar
• refined starch
• lots of sodium
• low fiber
• low potassium
• low vitamins
• high calories
• engineered to encourage overeating

So if someone eating mostly these foods develops diabetes...

What caused it?

The preservative?

The sugar?

The calories?

The lack of fiber?

The obesity?

It's very difficult to separate.

What about preservatives specifically?

Food preservatives undergo extensive toxicology testing before approval.

That doesn't mean they're perfect.

But for common preservatives, regulators establish acceptable daily intake levels that include large safety margins.

If preservatives were dramatically increasing cancer or causing people to die younger, we'd likely have seen a strong signal by now given how widely they're consumed.

Instead, most concern centers around a few specific categories:

• nitrites/nitrates in processed meats
• excessive sodium
• certain contaminants formed during processing (not the preservatives themselves)

Even then, the evidence is often about the food as a whole, not one additive in isolation.

Processed meat is one of the stronger exceptions

Processed meats like bacon, hot dogs, sausage, and deli meats consistently show associations with colorectal cancer and cardiovascular disease.

Again, it's difficult to know whether the culprit is:

• nitrites
• salt
• heme iron
• smoking
• cooking methods
• combinations of these

But this is one of the more consistent findings in nutrition research.

I also agree with one of your criticisms

The phrase

"Shop the perimeter."

has always struck me as more of a catchy slogan than a scientific principle.

As you noted, the perimeter also contains:

• donuts
• cakes
• ice cream
• bacon
• sausage
• processed cheese
• sugary yogurt
• butter

Meanwhile, the center aisles contain:

• beans
• oatmeal
• canned tuna
• frozen vegetables
• brown rice
• whole wheat pasta
• olive oil
• nuts

Many of those are nutritious foods.

The practical problem

You also identified something real:

Eating 100% minimally processed food is difficult.

Most people don't actually do it.

Salad dressing.

Cheese.

Bread.

Pasta.

Peanut butter.

Tomato sauce.

Yogurt.

Frozen vegetables.

Canned beans.

They're all processed to varying degrees.

If someone insists on avoiding every processed ingredient, life becomes unnecessarily complicated for most people.

Where I think the evidence is strongest

If I had to summarize decades of nutrition research, I'd say the evidence is strongest for a few broad patterns rather than rigid rules:

• Eating plenty of fruits and vegetables is consistently associated with better health.
• Whole grains generally outperform refined grains.
• Beans, nuts, and fish are consistently favorable.
• Limiting sugar-sweetened beverages is one of the clearest wins.
• Excess calories leading to obesity are a major driver of disease.
• Heavy consumption of processed meats is associated with worse long-term health outcomes.

Notice that none of those require someone to reject all processed foods.

From what you've shared in earlier conversations, you've already made many changes that fit these evidence-based patterns: you've cut back on sugary drinks and highly processed snack foods, increased fruits and vegetables, switched to more whole-grain products, and maintained regular walking and weight training. Those changes are supported by much stronger evidence than trying to eliminate every bottled salad dressing or slice of cheese.

In other words, I don't think the evidence supports the idea that a turkey sandwich becomes unhealthy because you added mustard or that a salad becomes unhealthy because it has bottled dressing. Nutrition is much more about the overall dietary pattern than whether every ingredient is technically "processed."