You Have to Do More Than Eat Your Veggies to Prevent Heart Disease

Eating plenty of veggies often tops the list of dietary advice for a heart-healthy diet because they’re a rich and varied source of nutrients. They’re also naturally low in sodium and saturated fat—two diet components that are linked to heart disease risk.

However, a new study published in Frontiers in Nutrition has raised questions about whether eating your veggies plays a major role in promoting—or protecting—your heart health.

The Study

The researchers looked at the effects of vegetable intake on heart disease risk and outcomes. Specifically, they wanted to see if there would be different effects from eating raw veggies compared to cooked veggies.

Who Was Included?

Using data from the UK Biobank cohort, the researchers looked at almost 400,000 people who did not have cardiovascular disease at the start of the study.

The participants answered a dietary questionnaire that asked them about their intake of raw and cooked vegetables.

The researchers analyzed the data to see if there was a link between participants’ vegetable intake and being diagnosed with heart disease and/or dying from the disease.

What Did the Findings Show?

During 12 years of follow-up, the researchers noted that eating more raw vegetables was linked to a reduced risk of getting heart disease or dying from it. They did not see the same link with cooked vegetables.

However, vegetable intake wasn’t the only thing that set the people with higher and lower heart disease risk apart.

The people who ate more vegetables were also more likely to have other factors that could have affected their risk for heart disease. For example, the participants were more likely to:

• Be female
• Have more education
• Live in more affluent areas
• Have a lower body mass index (BMI)
• Participate in more physical activity

When the researchers looked at the data more closely, they factored in socioeconomic and lifestyle variables—like smoking, supplement use, and exercising—that can affect heart disease risk.

They concluded that these factors appeared to have a bigger effect on a person’s heart disease risk than their vegetable intake.

Don’t Count Veggies Out Yet

The study might make it sound like eating your veggies isn’t as important to your heart health as you’ve been told—but don’t count them out just yet.

The research had some limitations that are important to understand.

Study Limitations

One of the main limitations to the research was readily acknowledged by the authors: The study used self-reported data.

Getting data this way is not always reliable. People might misremember details or omit information—either on purpose or by accident.

Taylor C. Wallace, PhD, CFS, FACN, the chief food and nutrition scientist at Produce for Better Health Foundation, told Verywell that there were some other “watch outs” to consider when looking at the study’s data.

Variables

Wallace, who was not involved in the research, questioned whether some of the variables in the study were important.

While the study adjusted for far more variables than he deems normal, Wallace pointed out that “an issue with nutrition epidemiology, in general, is that you can easily ‘over-correct,’ which leads to null findings.”

Looking at All the Data

In the supplementary material provided by the researchers, Wallace flagged some important information.

In the basic model that arranged participants by age, gender, ethnicity, and region, cooked vegetable intake showed similar effects as raw vegetables.

However, that detail was not included study’s abstract.

Wallace said that if you look at all the data, the “adjustment for all these covariates didn’t make a difference in regard to all-cause mortality.” That suggests that there is “still a large protective effect of cooked and raw vegetables.”

Therefore, Wallace said that the reported findings don’t really tell the full story.

Timing

Wallace pointed out that the participants’ vegetable intake was only assessed at the start of the study, “which makes the study a very weak and ill-designed prospective cohort study that has limited utility.”

Research that Wallace has been part of showing the benefits of veggies on heart health took a different approach.

His team used validated food frequency questionnaires that participants answered more than once over time. According to Wallace, this matters because a person’s dietary patterns often change.

Cooking Method

Finally, Wallace highlighted that “the study couldn’t account for the cooking method" used by participants when they consumed veggies.

Potatoes are one example. Fried potatoes may have a negative effect on heart health, but baked or boiled potatoes may have positive—or at least neutral—effects.

“Not accounting for factors like this is equivalent to throwing dice down a roulette table and then claiming the game is impossible to win at because you lost,” said Wallace.

Bottom line? Given the study’s limitations and conflicting results highlighted in other studies, people shouldn’t quit veggies because they think it won’t matter to their heart health.

A Heart-Healthy Diet

Even if vegetables aren’t the key player, your dietary choices still have a profound and lasting effect on the wellness of your whole body—your heart included.

Melissa Azzaro, RDN, LD, a registered dietitian and podcast host at Hormonally Yours, told Verywell that “following the Mediterranean diet, the DASH diet, and the TLC diet have all been shown to support heart health.”

Azzaro said that “while all of these diets have some differences among the guidelines, they all emphasize vegetables as a part of a suggested dietary pattern.”

Ultimately, Azzaro said that "eating a nutrient-dense, whole-foods based diet that is high in fiber, antioxidants, and healthy fats while being mindful of refined carbohydrates and added sugars appear to be your best bet when trying to support heart health.”