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Can a plant-based diet reverse atherosclerosis? It is a big question, and one that lands differently when heart disease feels personal. In a recent video, Simon Hill, the Australian nutritionist, physiotherapist, and host of The Proof podcast, digs into six major clinical trials to see what the best available evidence actually shows about plaque buildup, diet, and long-term heart health.
For Hill, this is not just an abstract science discussion. He says his father had a heart attack at 41, which shaped his interest in the silent, slow-moving disease process that can sit unnoticed for years before changing life in an instant.
Read more: Plant-Based Diets Could Help Prevent And Reverse CMD Heart Disease, Says Study
What is atherosclerosis and why it matters
Atherosclerosis is a chronic disease in which plaque builds up inside the arteries. This plaque is made from cholesterol, immune cells, calcium, and fibrous tissue. Over time, it can narrow blood vessels and restrict blood flow.
Hill explains that the disease develops gradually and often silently. “Atherosclerosis is not an inevitable part of aging,” he says. Instead, it is strongly influenced by genetics, environment, and lifestyle choices.
Plaque can take different forms. Soft plaque is considered the most dangerous because it is more likely to rupture and trigger a clot that blocks blood flow. Calcified plaque is more stable but still signals long-term damage in the artery wall.
Because the condition progresses slowly, Hill emphasizes that measuring plaque and cardiovascular risk markers can be important. Doctors may use tools such as coronary artery calcium scans, carotid artery ultrasound, CT angiography, or invasive angiography to assess plaque and artery health.
The Ornish Lifestyle Heart Trial
One of the earliest and most influential studies Hill reviews is the Lifestyle Heart Trial led by Dr. Dean Ornish. Published in 1990, the study included patients with moderate to severe coronary artery disease.
Participants in the intervention group followed an intensive lifestyle program. This included a whole foods vegetarian diet very low in fat, regular aerobic exercise, stress management practices like meditation and yoga, group support sessions, and smoking cessation.
After one year, artery narrowing improved slightly in the lifestyle group but worsened in the control group. LDL cholesterol dropped by roughly 40% in those following the lifestyle program.
Five-year follow-up data showed a larger difference. The lifestyle group continued to improve, while the control group experienced a significant progression of artery narrowing. Participants who followed the program most closely saw the greatest improvements.
Hill notes that the program combined several lifestyle factors, so the study does not isolate diet alone. However, the results suggest that comprehensive lifestyle changes can slow and potentially reverse aspects of atherosclerosis.
STARS and SCRIP: Diet and risk-factor management
Next, Hill highlights two studies from the early 1990s: the STARS trial and the SCRIP trial.
The STARS study tested whether lowering cholesterol through diet or diet combined with medication could reverse coronary artery disease. Participants followed a diet that emphasized fruits, vegetables, grains, and fish while reducing red meat, eggs, and full-fat dairy.
Researchers found that many participants following the diet experienced regression or stabilization of artery disease. Those combining diet with medication saw even greater improvements.
The SCRIP study took a broader approach. Participants were given a comprehensive risk-reduction program including diet changes, exercise guidance, smoking cessation support, and lipid-lowering medications when necessary.
After four years, artery narrowing progressed far more slowly in the lifestyle intervention group. Hospitalizations for cardiac events were also significantly lower.
These findings suggest that combining multiple risk-reduction strategies may offer stronger protection than standard medical care alone.
The Mediterranean diet trials changed the conversation
A major shift in Hill’s analysis comes with PREDIMED and CORDIOPREV, two Spanish trials that move away from very low-fat prescriptions and toward higher-quality fat sources. These studies are central to his conclusion because they challenge the old assumption that low-fat automatically means heart-healthy.
PREDIMED enrolled more than 7,000 people at high cardiovascular risk and compared a Mediterranean diet supplemented with extra virgin olive oil or nuts against a low-fat control diet. Hill says both Mediterranean groups had about a 30% lower risk of major cardiovascular events than the control group. In a smaller imaging substudy, the nuts group showed regression in artery wall measurements, while the olive oil group showed stabilization rather than worsening.
Hill is cautious here, too. He does not say nuts “won” over olive oil, because the substudy was small and not designed to make that comparison. But he does point out that nuts offer fiber, plant sterols, and arginine, all of which could plausibly support better artery health.
CORDIOPREV then tested a Mediterranean diet rich in extra virgin olive oil in people who already had coronary heart disease. Hill says this is especially important because it looked at secondary prevention, not just prevention before a first event. The Mediterranean diet group showed significant decreases in carotid IMT, plaque height, and plaque burden over time, along with fewer cardiovascular events. Event risk was reduced by about 25% to 28% compared with the low-fat group.
This is where Hill makes one of his clearest points. “Quality matters more than macronutrients,” he says. In other words, the total amount of fat may be less important than the kind of fat people are eating. Diets rich in extra virgin olive oil, nuts, seeds, and fiber performed better than low-fat diets that often ended up pushing people toward more refined carbohydrates. For readers wondering if a plant-based diet can reverse atherosclerosis, this part of the evidence suggests that plant-rich eating patterns can help, but that the details matter a lot.
A newer look at plaque: the DISCO CT trial
The most recent study Hill reviews is the DISCO CT trial. Unlike older studies, this research used modern CT imaging and artificial intelligence analysis to measure plaque composition in detail.
Participants already had early coronary artery disease and were receiving standard medical therapy. The intervention group added an intensive lifestyle program centered around a DASH-style eating pattern and regular exercise.
After just over a year, total plaque levels did not differ significantly between groups. However, the lifestyle group showed a meaningful reduction in non-calcified plaque, the softer type that is considered more dangerous.
Hill highlights this finding because it suggests diet and lifestyle may help change the type of plaque in arteries, potentially making it more stable and less likely to rupture.
What the evidence suggests about diet and heart disease
Looking across the six trials, Hill concludes that diet and lifestyle changes can influence atherosclerosis in meaningful ways.
The research suggests that dietary patterns rich in plant foods can slow plaque progression and sometimes lead to modest regression. More importantly, these patterns consistently reduce cardiovascular events.
Across the studies, several dietary themes appear repeatedly. Successful interventions typically reduce saturated fat while increasing fiber-rich foods such as whole grains, fruits, vegetables, legumes, nuts, and seeds. Many also include higher levels of unsaturated fats.
These changes help improve several key risk factors linked to heart disease, including cholesterol levels, inflammation, blood pressure, and endothelial function.
Three key takeaways for heart health
Hill ends the discussion with three major takeaways.
First, prevention should start early. The earlier people improve their diet and lifestyle habits, the more years they spend protecting their arteries.
Second, diet quality matters more than simply reducing fat intake. Foods rich in unsaturated fats and fiber appear to support cardiovascular health more effectively than low-fat diets that rely heavily on refined carbohydrates.
Finally, Hill emphasizes combining lifestyle changes with medical care when necessary. “If your doctor recommends a statin or another lipid-lowering therapy, don’t see this as an alternative to lifestyle,” he says. “See it as an addition.”
In other words, the most effective strategy may involve multiple tools working together: diet, physical activity, medical treatment when appropriate, and long-term lifestyle change.
So can a plant-based diet reverse atherosclerosis? The current evidence suggests the answer is complex but encouraging. Diet alone may sometimes lead to modest plaque regression, but the strongest and most consistent benefit appears to be stabilizing disease and significantly lowering the risk of heart attacks and strokes.
For more science-based content exploring health and nutrition, check out Hill’s YouTube channel and website.
Read more: Ultra-processed Plant-Based Foods May Be Better For Your Heart Than Unprocessed Meat And Dairy
