Health Beliefs Science Has Quietly Updated

Here’s a little secret about medicine:

It changes its mind.

And thank goodness it does.

Not because doctors were foolish 30 years ago. Not because researchers were incompetent. And certainly not because your grandmother was trying to lead you astray when she insisted that whatever she was recommending had “been proven.”

We simply don’t know what we don’t know.

Medical advice is generally based on the best evidence available at the time. Then larger studies are conducted. People are followed for decades instead of five years. Researchers discover confounding variables they hadn’t considered. Technology improves. We learn more about genetics, metabolism, and individual differences.

And sometimes the advice changes.

That isn’t a failure of science.

That is science doing exactly what it is supposed to do.

So consider this a friendly, judgment-free tour through seven health beliefs that many of us—including physicians—spent years believing.

And if after reading this you still choose to have a lovely glass of wine with friends, eat an omelet, take your multivitamin, or use hormone therapy because you and your physician have decided it makes sense for you, wonderful.

This isn't about achieving some mythical state of perfect health behavior.

It’s simply about knowing what the newer map says so we can make our own informed choices.

And, really, where would the fun be in living forever if we weren't allowed to enjoy brunch?

1. “A little alcohol—especially red wine—is good for your heart.”

Oh, how we loved this one.

For decades we heard about the French paradox, resveratrol, and the supposedly heart-protective glass of red wine with dinner.

Study after study seemed to show that moderate drinkers were healthier than nondrinkers.

It was perhaps the most enthusiastically embraced health recommendation in history.

Doctor’s orders. Pour the Bordeaux.

Unfortunately, the story became considerably more complicated as researchers got better at asking who was being compared with whom.

Moderate drinkers in observational studies often differed from nondrinkers in all sorts of ways. They could have higher incomes, better diets, more exercise, better access to healthcare, and stronger social lives.

Meanwhile, some people classified as nondrinkers had stopped drinking because they were already ill—the wonderfully named “sick quitter” effect.

As researchers became better at untangling these variables, much of alcohol’s apparent cardiovascular magic weakened.

We also know something with much greater certainty today: alcohol increases the risk of several cancers, and risk generally rises with greater consumption.

That doesn't mean your glass of Champagne at your loved one's wedding suddenly becomes a moral failing.

It means we should stop drinking alcohol because we think it is medicine.

If you enjoy a glass of wine with dinner or cocktails with friends, that pleasure and social connection may have value to you. Just call it what it is:

Something you enjoy.

Not a heart supplement served in a pretty stemmed glass.

And there is encouraging news here too: health isn't all-or-nothing. Drinking less reduces exposure and therefore risk. You don't have to live perfectly to make healthier choices.

Old thinking: A nightly glass of wine may help you live longer.

Current thinking: Don't start drinking for your health. If you enjoy alcohol, think of it as a pleasure rather than preventive medicine—and generally, less is better.

2. “Every healthy adult should take a daily multivitamin to live longer.”

This one is fascinating because an entire cultural habit was built around the idea of

nutritional insurance.

Perhaps I didn't eat perfectly today, but no worries.

I took my vitamin.

Then researchers followed hundreds of thousands of generally healthy adults for decades and found no convincing evidence that taking a daily multivitamin makes healthy people live longer.

That doesn't mean vitamins are useless.

Far from it.

Someone with iron deficiency, low B12, malabsorption, pregnancy-related nutritional needs, certain restrictive diets, or another specific indication may genuinely need supplementation.

That is medicine.

It's simply different from:

“I'm already well nourished, but this pill will add years to my life.”

For that sweeping promise, the evidence isn't particularly convincing.

And because science apparently enjoys keeping us humble, there is an interesting wrinkle:

several randomized studies have suggested that daily multivitamins may offer modest cognitive benefits in some older adults.

So we shouldn't throw the vitamin bottle dramatically into the trash either.

The better lesson is that supplements should supplement something.

Preferably an actual need.

Old thinking: Everyone should take a multivitamin as nutritional insurance.

Current thinking: Correct deficiencies and supplement when there's a good reason. A multivitamin isn't a substitute for nutritious food, and we shouldn't assume it extends life simply because it contains an impressive alphabet.

3. “A baby aspirin a day keeps the heart attack away.”

This may be one of the best examples of medicine discovering that preventing one problem can occasionally create another.

Millions of otherwise healthy adults were once encouraged to take low-dose aspirin every day to prevent a first heart attack or stroke.

And the reasoning wasn't silly.

Aspirin reduces clot formation.

Clots cause heart attacks and strokes.

Therefore: aspirin prevents heart attacks and strokes.

Perfectly sensible.

Except biology has an annoying habit of refusing to be quite that simple.

The same mechanism that makes aspirin reduce clotting also makes bleeding easier—including gastrointestinal bleeding and, more rarely, bleeding in the brain.

When modern trials weighed those benefits and harms together, the advantage for many people without established cardiovascular disease turned out to be considerably smaller than previously believed.

Today, starting aspirin for primary prevention is much more individualized, and routinely beginning it in older healthy adults is generally no longer recommended.

But there is an enormous asterisk here:

If you have already had a heart attack, stroke, stent or another cardiovascular condition for which aspirin has been prescribed, that is a completely different conversation.

Please do not read a blog post and ceremoniously throw your aspirin into the garbage disposal.

Talk with your physician.

Old thinking: Most middle-aged and older adults should consider daily aspirin.

Current thinking: Aspirin is a real medication with real benefits and real risks. For primary prevention, whether to use it depends on the individual.

4. “Eating low-fat is the path to a healthy heart.”

If you were alive during the 1980s and 1990s, you probably remember this era.

Fat disappeared from yogurt.

Fat disappeared from salad dressing.

Fat disappeared from cookies.

And food manufacturers frequently replaced it with refined starches and sugar.

We somehow managed to create cookies that weren't particularly satisfying while simultaneously convincing ourselves they were health food.

Fat-free cookies may have been one of marketing's greatest achievements.

Eventually we learned that “fat” was far too broad a nutritional category.

The more useful question isn't simply:

How much fat are you eating?

It is:

What kind of fat are you eating—and what are you eating instead?

Replacing saturated fat with refined carbohydrates doesn't appear to offer the cardiovascular benefit people once expected.

Replacing some saturated fats with unsaturated fats or high-quality carbohydrates such as whole grains is a different story.

Olive oil, nuts, seeds, avocado and fish are simply not metabolically interchangeable with butter, processed meats and trans fats because they all happen to contain fat.

And while we're updating nutritional beliefs, the internet has helpfully supplied us with a brand-new extreme:

Seed oils are poison!

The evidence doesn't support that sweeping claim either.

So perhaps we can retire both the butter panic and the canola-oil panic and return to the much less exciting—but considerably more useful—concept of eating mostly minimally processed foods in sensible proportions.

Nutrition desperately wants to be dramatic.

Human physiology usually prefers nuance.

Old thinking: Low fat = healthy.

Current thinking: Food quality, dietary pattern, and the type of fat matter much more than simply trying to eliminate fat.

5. “Hormone therapy keeps women healthier as they age by preventing disease.”

This one deserves more nuance than almost anything else on this list.

There was once enormous enthusiasm for prescribing menopausal hormone therapy not simply to treat symptoms, but as long-term preventive medicine—particularly to protect women from cardiovascular disease.

Large randomized trials challenged that broad prevention strategy, and hormone therapy is no longer recommended simply as a universal way to prevent chronic disease in postmenopausal women.

Unfortunately, what happened next illustrates another problem we occasionally have in medicine.

The pendulum swung.

Suddenly many women became frightened of hormone therapy altogether.

And that's not quite the right lesson either.

Hormone therapy remains the most effective treatment for bothersome menopausal symptoms such as hot flashes and night sweats and can be an entirely reasonable option for appropriately selected women.

Timing matters.

Age matters.

The type and dose of hormone matter.

Personal and family medical history matters.

And the reason you're taking it matters.

I have a particular appreciation for this distinction because I went through menopause a little earlier than nature might otherwise have planned after having my ovaries prophylactically removed because of a BRCA2 mutation.

Before then, I had heard the phrase “vaginal dryness” plenty of times.

And, frankly, I thought I understood it.

I did not.

I assumed it basically meant you might want to become comfortable purchasing AstroGlide.

After all, lubrication certainly has a meaningful place in sexual pleasure and intimacy.

Menopausal vaginal dryness, I discovered, can be something entirely different.

My best description?

Imagine having sandpaper between your legs.

Suddenly you're thinking about your vagina all day long.

And really, who has time for that?

For me, carefully individualized low-dose estrogen made an enormous difference. A higher dose wasn't better for me—it caused edema and other problems. Working with my physician to find the lowest dose that controlled my symptoms was the sweet spot.

And that experience perfectly illustrates the newer thinking.

The question isn't:

Are hormones good or bad?

It's:

For whom? For what purpose? At what age? At what dose? And with what individual risks and benefits?

Old thinking: Postmenopausal women should take hormones to prevent chronic disease.

Current thinking: Hormone therapy shouldn't be prescribed universally as chronic-disease prevention, but it can be extremely valuable individualized treatment for menopausal symptoms.

6. “Eggs and dietary cholesterol are terrible for your heart.”

Poor eggs.

For decades, they were practically public enemy number one at breakfast.

The logic seemed airtight:

Eggs contain cholesterol.

High blood cholesterol contributes to atherosclerosis.

Therefore eggs must clog your arteries.

A generation dutifully ordered egg-white omelets and felt very virtuous about it.

Then nutrition science became considerably more interesting.

It turns out that for most people, the relationship between the cholesterol we eat and the cholesterol circulating in our blood is more complicated than we once believed.

Saturated and trans fats, overall dietary pattern, genetics, metabolic health, and other factors matter enormously.

That's one reason rigid dietary-cholesterol limits eventually disappeared from major guidelines.

But here's where we shouldn't make the same mistake in the opposite direction.

This does not mean:

Excellent news! Twelve eggs for breakfast!

Studies examining eggs and cardiovascular outcomes aren't perfectly uniform, and some populations—particularly people with certain lipid disorders or metabolic conditions—may have reasons to be more cautious.

Perhaps the most useful realization is that eggs don't generally arrive at breakfast alone.

They often travel with friends.

Bacon.

Sausage.

Butter.

Biscuits.

Hash browns.

The egg may have spent decades taking the blame for the entire breakfast party.

Old thinking: Eggs and dietary cholesterol should be kept as low as possible.

Current thinking: Moderate egg consumption can fit comfortably into a healthy diet for many people. Your overall dietary pattern and individual cardiovascular risk matter far more than whether you ate an egg Tuesday morning.

7. “Everyone should take fish oil for a healthy heart.”

This story splits rather neatly into two categories:

Fish.

And:

Fish-oil pills.

The fish story has held up rather nicely.

Eating fish—particularly oily fish such as salmon, sardines and mackerel—fits beautifully within heart-healthy dietary patterns, and major guidelines continue to recommend it.

The little golden capsule has had a more complicated career.

Large randomized trials of routine omega-3 supplements in generally healthy populations haven't produced the dramatic cardiovascular protection many people expected.

That doesn't mean omega-3s are useless.

Certain prescription-strength omega-3 preparations have important roles in selected high-risk patients, particularly in specific lipid-management situations.

But that's very different from:

“I'm healthy, so I'll grab a giant bottle of fish oil at Costco because everyone needs it.”

And more isn't automatically better. High-dose omega-3 supplementation can carry risks, including a small increase in atrial fibrillation in some studies.

This is another lovely example of why food and supplements aren't necessarily interchangeable.

A salmon fillet comes packaged with protein, selenium, vitamin D and other nutrients.

Nature apparently neglected to put those things inside the gel capsule.

Old thinking: Everyone should take fish oil for heart protection.

Current thinking: Eat the fish. Routine fish-oil supplements offer much less benefit for healthy people than we once hoped, while prescription formulations have specific medical uses.

The Bigger—and More Fascinating—Story

Look at what these seven examples have in common.

Again and again, we confused:

• association with causation

• biological plausibility with proven outcomes

• a better lab number with a healthier human being

• “this helps some people” with “everyone should do this”

And perhaps most importantly:

We occasionally confused “this makes sense” with “we've actually proved this.”

Modern preventive medicine increasingly asks a harder question.

Not merely:

Does this lower cholesterol?

Does it thin the blood?

Does it contain antioxidants?

Does it improve a biomarker?

But:

Does doing this actually reduce heart attacks, cancer, dementia, disability, or premature death—and does it accomplish that without creating an equally important harm somewhere else?

That's a much higher bar.

There are plenty of other health “sacred cows” wobbling under that bar right now: routine vitamin D supplementation for people who aren't deficient, calcium pills for universal fracture prevention, antioxidant supplements for longevity, and the old assumption that pharmacologically raising HDL automatically protects the heart.

And ten years from now?

I suspect we'll discover that we're wrong—or at least incomplete—about a few things we feel remarkably confident about today.

I hope we do.

Because science changing its mind isn't a bug.

It's the whole point.

Nobody was foolish for following yesterday's recommendations.

Physicians weren't foolish for giving them. Patients aren't foolish if, after understanding today's evidence, they still make slightly different choices based on their own priorities.

We were all simply working with the best map we had.

Today the map is a little better.

Someday it will be better still.

And in the meantime, perhaps one of the healthiest habits we can develop has nothing to do with food, supplements, medications, or exercise.

It's remaining curious enough to change our minds when the evidence changes—while giving a little grace to ourselves and everyone who was doing the best they could with what we knew before.

And if that conversation happens over an occasional glass of wine with someone you love?

Well.

Life was never meant to be a laboratory.

It was meant to be lived.

Stay curious. Change your mind when the evidence changes. And occasionally order dessert anyway.

🍯 Honey 🐝

Before starting or stopping a medication, hormone, or supplement—particularly aspirin or hormone therapy—talk with your own healthcare professional about your individual risks, benefits, and goals.