The Mediterranean diet has the strongest evidence for preventing heart disease, with a landmark trial of over 7,400 people showing it reduced major cardiovascular events by 30% compared to a low-fat diet over five years. But “best” depends on your specific risk factors. If high blood pressure is your primary concern, the DASH diet may be more targeted. If high cholesterol is the issue, a plant-heavy approach called the Portfolio diet has shown impressive results. All three share a common foundation: more plants, more fiber, more healthy fats, and far less processed food.
The Mediterranean Diet
The Mediterranean diet is built around vegetables, fruits, whole grains, legumes, nuts, olive oil, and fish, with moderate amounts of poultry and dairy and very little red meat. It doesn’t restrict calories or fat. Instead, it shifts the type of fat you eat, replacing butter and processed oils with extra-virgin olive oil and nuts.
The PREDIMED trial, published in the New England Journal of Medicine, tested this approach in people at high cardiovascular risk who hadn’t yet had a heart attack or stroke. One group supplemented with extra-virgin olive oil, another with mixed nuts, and a control group was advised to reduce dietary fat. Both Mediterranean diet groups saw roughly 30% fewer heart attacks, strokes, and cardiovascular deaths over five years. That’s a meaningful reduction from a change in eating pattern alone, with no calorie counting required.
What makes this diet practical is its flexibility. There’s no rigid meal plan. A typical day might include eggs with tomatoes and olive oil for breakfast, a grain bowl with chickpeas and roasted vegetables for lunch, and grilled fish with a side salad for dinner. Snacking on nuts, fruit, or hummus fits naturally into the pattern.
The DASH Diet for Blood Pressure
If you have high blood pressure or are trending in that direction, the DASH diet (Dietary Approaches to Stop Hypertension) is specifically designed to bring those numbers down. It emphasizes fruits, vegetables, whole grains, lean protein, and low-fat dairy while sharply limiting sodium, red meat, and sweets.
The results are striking. In clinical trials, people with hypertension who followed DASH and reduced sodium saw their systolic blood pressure (the top number) drop by about 11.5 mmHg. A meta-analysis of multiple trials found average reductions of 6.74 mmHg systolic and 3.54 mmHg diastolic. Those numbers may sound modest, but even a 5 mmHg systolic reduction significantly lowers your risk of stroke and heart attack over time.
DASH overlaps heavily with the Mediterranean diet in its emphasis on whole foods, but it’s more structured. It specifies daily servings of each food group and puts a harder ceiling on sodium and saturated fat. For people who prefer clear guidelines over general principles, that structure can be helpful.
The Portfolio Diet for Cholesterol
The Portfolio diet takes a more targeted approach, combining specific foods known to lower LDL cholesterol (the type that builds up in artery walls). It centers on four categories: plant protein from legumes and soy, viscous fiber from oats, barley, apples, and citrus, nuts and seeds, and plant-based unsaturated fats from sources like avocado and olive oil.
A systematic review of trials found the Portfolio diet lowered LDL cholesterol by 17% compared to a standard low-saturated-fat diet, without significant weight loss. It also reduced a key marker of inflammation by 32%. Those cholesterol reductions approach what some people achieve with medication, making this diet particularly worth considering if your doctor has flagged your LDL levels but you’d like to try dietary changes first.
The Foods That Matter Most
Fiber
Fiber is one of the most consistently protective nutrients for heart health, yet most people fall well short of recommended intake. Research tracking U.S. adults over nearly two decades found that getting enough fiber was associated with a 39% reduction in cardiovascular mortality, comparable to or greater than the effect of some cholesterol-lowering medications. The benefit was most pronounced as people moved from low intake up to around 20 to 25 grams per day, where the protective effect plateaued. Good sources include beans, lentils, oats, whole grains, berries, and vegetables.
Fish and Omega-3 Fats
The American Heart Association recommends eating fish rich in omega-3 fatty acids at least twice a week. Fatty fish like salmon, mackerel, sardines, and trout are the best sources. Regular fish consumption appears to lower the risk of heart disease, particularly sudden cardiac death. If you don’t eat fish, walnuts, flaxseed, and chia seeds provide a plant-based form of omega-3, though the conversion to the most active forms in your body is less efficient.
Nuts
Nuts appear in nearly every heart-healthy eating pattern for good reason. They provide unsaturated fats, fiber, and plant sterols that help manage cholesterol. In the PREDIMED trial, the group supplementing with about a handful of mixed nuts daily (walnuts, almonds, and hazelnuts) saw the same cardiovascular benefit as the olive oil group. A small daily portion is enough.
What to Cut Back On
Added Sugar
A CDC-linked study found that adults who got 10% to 25% of their daily calories from added sugar had a 30% higher risk of dying from cardiovascular disease compared to those who stayed under 10%. At 25% or more of calories from sugar, the risk nearly tripled. For someone eating 2,000 calories a day, 10% is about 50 grams, or roughly the amount in one large sweetened coffee drink and a flavored yogurt. Sugary beverages, desserts, candy, and sweetened cereals are the biggest contributors.
Sodium
The average American consumes over 3,300 mg of sodium per day. Federal guidelines recommend staying under 2,300 mg. Most of that excess doesn’t come from the salt shaker. It comes from restaurant meals, packaged foods, bread, deli meats, canned soups, and condiments. Reading nutrition labels and cooking more meals at home are the two most effective ways to reduce sodium without obsessing over every milligram.
Ultra-Processed Foods
A meta-analysis of 22 prospective studies found that people with the highest intake of ultra-processed foods had a 17% higher risk of cardiovascular disease and a 23% higher risk of coronary heart disease compared to those who ate the least. Ultra-processed foods include things like packaged snacks, instant noodles, hot dogs, frozen meals, and soft drinks. These foods tend to be high in sodium, added sugar, and refined oils while being low in fiber, potassium, and other protective nutrients. Reducing them addresses multiple risk factors at once.
How These Diets Compare
- Mediterranean diet: Best overall evidence for preventing heart attacks and strokes. Flexible, enjoyable, and sustainable long-term. Emphasizes healthy fats and doesn’t restrict calories.
- DASH diet: Most effective for lowering blood pressure specifically. More structured with defined daily servings. Particularly useful if hypertension is your main concern.
- Portfolio diet: Best targeted approach for lowering LDL cholesterol through food. Can be layered on top of either the Mediterranean or DASH pattern.
These diets aren’t mutually exclusive. They share about 80% of their recommendations: eat more vegetables, fruits, whole grains, legumes, nuts, and fish. Eat less processed meat, refined grains, added sugar, and packaged food. The differences are mostly in emphasis. Many cardiologists now recommend a hybrid approach, sometimes called the “Mediterranean-DASH” pattern, that pulls the strongest elements from each.
Making It Practical
The best diet for your heart is one you’ll actually follow. Research consistently shows that adherence matters more than perfection. A few high-impact starting points: replace butter and cooking oils with extra-virgin olive oil, add a handful of nuts to your daily routine, eat beans or lentils several times a week, and swap one or two red meat meals for fish. These changes alone move you meaningfully closer to every heart-healthy eating pattern.
Gradual shifts tend to stick better than dramatic overhauls. If your current diet is heavy on processed food, even moving halfway toward a Mediterranean pattern over a few months can produce measurable improvements in blood pressure, cholesterol, and inflammation markers.