Nutrition alone won't save you
The 90% Prevention Myth and What Mark Hyman Gets Wrong About Nutrition
It’s a powerful statement.
It’s also wrong.
I’m a physician. I’m also certified in culinary medicine. I believe in the power of nutrition—especially the Mediterranean diet. But if we’re going to talk about prevention, let’s talk about what the data actually shows.
The Best Evidence We Have
If nutrition alone could prevent 90% of chronic disease, we’d have seen it by now. So let’s look at the best cohort studies and clinical trials on this topic.
The PREDIMED Study
NEJM, 2013: PREDIMED Study Link
Mediterranean diet reduced major cardiovascular events by 30%, not 90%.
The Finnish Diabetes Prevention Study
Diabetes Care, 2003: Finnish Study Link
Lifestyle & nutrition reduced type 2 diabetes risk by 58%.
The Look AHEAD Trial
Lancet , 2016: Look AHEAD Trial Link
Despite weight loss, no significant reduction in heart attacks or strokes.
Why Medicine Still Matters
Nutrition is vital—but it’s not a cure-all.
If you want to prevent heart disease and strokes, we have proven tools beyond diet:
Statins and other drugs : Reduce cholesterol and cardiovascular risks.
JAMA 2018 Link to study
Anti-hypertensives: Control blood pressure to prevent strokes.
Lancet 2021 Link to study
Modern diabetes medications: Protect both the heart and kidneys.
Diabetes Care 2022 Link to study
Doctors are trained to use these tools effectively. That’s why you want your physician skilled in medicine first.
I am an advocate for nutrition in managing health, and we have some good examples.
The Lyon Diet Heart Study and Secondary Heart Disease
We also have the Lyon Diet Heart Study, a landmark trial that showed the power of the Mediterranean diet in secondary prevention—that is, preventing further heart issues in people already with cardiovascular disease. Link
Participants who followed a Mediterranean-style diet had a 72% reduction in major cardiac events compared to those on a standard Western diet. This wasn't just about avoiding salt or cutting carbs—it was about a balanced pattern of eating rich in fruits, vegetables, whole grains, fish, and healthy fats like olive oil.
Even then, these patients still needed medications like statins, aspirin, and blood pressure control. The diet helped reduce risk, but it didn’t replace medicine.
So when people like Mark Hyman suggest that nutrition alone is the solution, they ignore the evidence that the best outcomes come from combining nutrition with proven medical treatments.
DASH and hypertension
While the DASH trial (Link) showed that a low-sodium diet rich in fruits and vegetables can lower blood pressure by an amount similar to one antihypertensive pill, this doesn’t mean we can prevent or cure advanced disease.
In other words, nutrition is powerful—but it has its limits.
For people with established cardiovascular disease, diabetes, or kidney disease, medication remains essential. Nutrition helps manage these conditions, but it's not a substitute for the precision of medical treatment.
That's why we need both: good nutrition for prevention and support, and modern medicine for effective treatment.
It’s also worth noting that what Mark Hyman often advocates isn’t the DASH diet. Instead, he promotes his own brand of supplements paired with a low-carb lifestyle. That’s not the same as following a proven dietary pattern like DASH or the Mediterranean diet—both of which have decades of evidence backing them.
Supplements and carb-restriction can have a place, but they’re no substitute for a well-rounded, evidence-based approach to health that includes both nutrition and medicine.
Nutrition Education? Start in Schools
Where should nutrition be taught? In schools.
We should integrate nutrition education from K-12, so the foundations of health are laid early.
By the time you see a doctor, it's often too late for prevention alone.
As I often say:
Doctors are here for absolution, not repentance.
When you’re sick, you need more than Kale—you need care.
Bottom Line
I’ll always promote evidence-based nutrition. I’ll always champion the Mediterranean diet and lifestyle changes. But claiming we can prevent 90% of chronic disease with nutrition alone is a soundbite, not science.
We need data-driven medicine, real public health education, and yes—a plate of vegetables. But let’s not pretend one replaces the other. And let’s not pretend you go to your doctor to get a salad recipe.
Much like an orthopedic surgeon sends his patients to physical therapy, we can send you to a Registered Dietician for more intense information about the Mediterranean or DASH for your lifestyle.
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Dr. Terry Simpson, MD, FACS
Board-Certified Physician | Culinary Medicine Certified