One of the most frequent questions I get, whether in the clinic or at a dinner party, is “What’s the best diet to prevent a heart attack?” “What food is good for the heart?” And this isn’t surprising, given how much misinformation abounds about what constitutes the best heart healthy diet.

Research has demonstrated that 80% of chronic disease is preventable. And at the cornerstone of this is hands down - diet. Suboptimal diet is estimated to be responsible for an astonishing 1 in 5 deaths worldwide. You simply cannot out-run or out-meditate a bad diet. And by the way, I don’t mean diet, like “I’m going on a diet,” but instead nourishment. Selecting a dietary pattern or way of eating that fuels our bodies so they can live longer, be healthier, and perform better. We are after healthspan, not looking a certain way. 

There is SO much misinformation out there, so let’s try to break it down - what we know, what we don’t know, and what we should do.

First, what isn’t a heart healthy diet?

Unfortunately, that’s what most Americans (and now everyone across the globe) consume - the aptly named Standard American Diet (SAD for short, who said scientists don’t have a sense of humor?). I’m sure you can already guess what this consists of - highly processed foods, refined grains, fried foods, sugar sweetened beverages, and way too much meat (often treated with hormones, antibiotics, and fed totally unnatural foods). We are sicker than ever, fatter than ever, and feel awful.

We also know that the oft-preached, over-simplistic “low-fat” diet doesn’t work.

To understand why, all you need to do is take a peak in a kitchen from the 1990s - with “low-fat” Snackwell cookies and “sugar-free” cereal. We have loads of data, including the Women’s Health Initiative and PREDIMED which compared “low-fat” diets to either a control diet or a Mediterranean diet, and in both cases the low-fat diet group did not improve health outcomes (in fact, the higher in fat Mediterranean group actually reduced cardiovascular events compared to the low-fat group). Unfortunately, our past demonization of the specific macros of “fat” left room for food companies to market highly processed low-fat items as health foods, which made their way into our kitchens by the bucketload. Also lost within the over-simplified “low-fat” paradigm is the very important distinction between fats, namely polyunsaturated or monounsaturated fats (mostly found in plant foods and fish), trans fats, and saturated fats. It also further neglects the source of these fats as well as the context in which they are consumed.

We also know that processed junk food, refined grains, and sugar sweetened beverages are totally devoid of things that nourish our body and contain tons of things that are not so good for our body such as trans fats, sugar, and other toxic compounds. Working toward reducing these things in our diet is uncontroversially important. It’s also probably the hardest thing to eliminate because they are designed to taste good (or in food industry parlance, “highly palatable”). Ugh.

Intake of processed meats (ie hamburgers, hotdogs, deli meats) has been consistently demonstrated to increase the risk of heart disease quite robustly, while the intake of unprocessed red meat shows a similar, but less profound, association. Replacing red meat with plant-based sources (but NOT refined carbohydrates!) is associated with lower risk of heart disease. Beyond the fact that animal products tend to be high in saturated fat (which increases LDL cholesterol and LDL particles typically) and sodium, they also contain other bioactive molecules that may be detrimental to our health including heme iron, nitrates, and carnitine.

Best food for heart health

We know from all kinds of evidence (mechanistic and animal studies, prospective cohorts, epidemiological analyses, randomized controlled trials) that eating more plants - vegetables, fruits, legumes (beans), nuts, and seeds - reduces our risk of heart attack and stroke. Everyone can stand to increase their intake of plants because they contain tons of fiber (vital for our gut health and blood sugar control) as well as vitamins, minerals, micronutrients, polyphenols, and antioxidants you just can’t get anywhere else.

Is a plant-based diet good for your heart?

A whole food, plant based (WFPB) diet is one that is exclusively or almost exclusively comprised of vegetables, fruits, legumes, whole grains, nuts, and seeds.

It completely eliminates (or is very low in) both processed foods and animal products (red meat, poultry, fish, dairy products, and eggs).

This is in contrast to a vegan diet, which simply specifies for the elimination of animal products. This is an important distinction because a plant based diet high in less-healthy plant foods (ie a junk food vegan diet) was found in one study to be associated with an increased risk of heart disease. All this means is what you probably already suspected - Oreos (despite being vegan) aren’t so good for you. Lots of observational and prospective data points to lower rates of high blood pressure, cholesterol issues, obesity, inflammation, and heart disease in those following a whole food, plant based diet.

Why is there so much confusion about the best heart healthy diet?

First of all, it’s so difficult to study.  It’s very difficult to study diet because you must always ask - instead of what. For instance, you can have a study where you have participants substitute lollypops for red meat, eggs, and cheese and you probably won’t see them get better - in fact you will likely see them get worse. And just like that, red meat isn’t bad for you! However, if you instead have the participants replace processed meat with vegetables, you would see a very different result. Unlike studying a drug or supplement, in which you can have one group take a pill and other a placebo, with nutritional research the food you ask one group to eliminate must always be substituted for something else. In this case, context is paramount.

Secondly, there probably isn’t a single best diet for the entire human population. We are increasingly understanding that how one diet affects one person, may be a totally different experience for another person. Recent studies have found large variations from person to person in response to carbohydrates as well as fats. Genetics and the microbiome likely play central roles, as does environmental exposures and a whole host of other factors we probably haven’t even thought to study yet. Personalized dietary plans that take into account dietary preferences and our unique risk factors is key to success.

Lastly, what we eat and how we eat is so complex. It’s heavily influenced by our culture, our family and traditions, values, preferences, and cravings. Eating chocolate cake is not particularly good for me from a nutritional biochemistry perspective, but does it make me happy? Absolutely. Is that important too? Of course. What about the impact on the environment? We certainly can’t have personal health without planetary health, so that matters too.

The best heart healthy diet - back to the basics

So what in the world should we eat? All of these nuances make it very confusing. And while the diet wars rage on, Americans are left perplexed and paralyzed.

Here’s the short of it - we have robust, high quality evidence that eating more antioxidant-rich fruits, leafy green vegetables, legumes, whole grains, nuts, and seeds are very important for our overall health, and more specifically our cardiovascular health. We also have high quality evidence that whenever possible, we should be limiting our intake of highly processed foods, sugar sweetened beverages, processed meats, and refined grains. Plant centered, flexitarian, pesco-Mediterranean, plant predominant, or totally plant based - I think there is room for all of these healthful eating patterns in the prevention of cardiovascular disease depending on your risk factors and preferences. Beyond that, it can be very helpful to work closely with a registered dietician or nutritionally focused doctor to help fine-tune and optimize the best nutritional eating pattern for you.