- New research suggests not all plant-based diets are healthy.
- Some plant-based diets may be bad for heart health.
- Experts suggest focusing on certain elements when eating a plant-based diet.
Many medical organizations recommend following a plant-forward diet, but new research points out that all plant-based foods are not created equal. In fact, some may even be bad for your heart health.
The study, which was published in the American Journal of Preventive Cardiology, found a clear link between eating an unhealthy plant-based diet and a key biomarker linked to having a heart attack. For the study, researchers analyzed data from more than 7,700 people who participated in the 1999-2004 National Health and Nutrition Examination Survey (NHANES). (Yes, that’s data from more than 20 years ago—but experts say the findings still apply.) All of the participants were at least 20 years old and had no history of heart disease at the start of the study.
During the study period, the participants reported what they ate over a 24-hour period and gave blood samples to allow the researchers to look for biomarkers of heart disease. The researchers discovered that people who followed a healthy plant-based diet had a 49% lower risk of having higher levels of cardiac troponin I. (Cardiac troponin I is a sign of cardiac muscle damage and is linked to heart attack risk.)
Meet the experts: Scott Keatley, R.D., is co-owner of Keatley Medical Nutrition Therapy; Hosam Hmoud, M.D., cardiology fellow at Northwell’s Lenox Hill Hospital; Dena Champion, R.D., a dietitian at The Ohio State University Wexner Medical Center; Jennifer Wong, M.D., a cardiologist and medical director of Non-Invasive Cardiology at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA.
But people who followed an unhealthy plant-based diet had a 65% higher risk of having elevated levels of cardiac troponin I, meaning they had a greater heart attack risk. “Supporting access to and adoption of healthy plant-based diets may be a useful strategy for promoting population-level cardiovascular health,” the researchers wrote in the conclusion.
The study raises a lot of questions about what qualifies as a “healthy” or “unhealthy” plant-based diet, plus the potential impact on your heart. Here’s what cardiologists and dietitians want you to know.
Why are certain plant-based foods bad for your heart?
It’s easy to confuse “plant-based” with “healthy,” but they’re not the same thing, points out Dena Champion, R.D., a dietitian at The Ohio State University Wexner Medical Center. “The term ‘plant-based’ lacks a universal definition, which creates confusion for consumers,” she says. “Many food manufacturers and restaurants use ‘plant-based’ simply to indicate their products contain no animal ingredients.”
Having a lack of animal products doesn’t automatically make a food healthy, Champion points out. Scott Keatley, R.D., co-owner of Keatley Medical Nutrition Therapy, agrees. “Not all plant-based foods are created equal,” he says. “A diet heavy in refined grains, fried foods, sugary beverages, and ultra-processed snacks may technically be ‘plant-based,’ but it lacks the protective compounds that whole fruits, vegetables, legumes, and intact grains provide.”
These unhealthy plant foods can spike your blood sugar, contribute to bodily inflammation, contain trans fats, and deliver excess calories without important nutrients, raising the risk of heart disease and other health issues, Keatley says.
“It’s important to point out that a vegan or vegetarian diet can absolutely be a heart-healthy diet, but eliminating animal products alone does not make a diet healthy,” Champion says.
How to tell when plant-based foods are unhealthy
There are a few different ways to tell if a plant-based food is unhealthy, according to Keatley: the level of processing and the amount of sodium and additives.
“The further a food is from its natural state, the more likely it has lost beneficial nutrients while gaining added sugars, unhealthy fats, or refined starches,” Keatley explains. “Packaged plant-based meals, snacks, or meat alternatives often carry sodium levels comparable to processed meats and may include stabilizers and oils that don’t support cardiovascular health.”
Champion also recommends being on the lookout for higher amounts of saturated fat, and making sure to read the nutrition label carefully. “The label ‘plant-based’ does not necessarily indicate anything about the healthiness of a food,” she stresses.
How to follow a heart-healthy diet
In general, whole foods—not packaged products—are best for your heart health, according to Jennifer Wong, M.D., a cardiologist and medical director of Non-Invasive Cardiology at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA. “I recommend the DASH Diet,” she says. “It’s low in salt, high in fruits and vegetables, whole grains, and legumes. It focuses on healthier fats like olive oil and avocado rather than animal fats.”
But the Mediterranean diet is also helpful for heart health, says Hosam Hmoud, M.D., cardiology fellow at Northwell’s Lenox Hill Hospital. “I encourage all of my patients to follow a Mediterranean-style diet which consists of whole grains, legumes, fruits, vegetables, and lean meats,” he says.
Ultimately, Keatley suggests filling your plate with whole foods first and building out your diet from there. “Most people already consume a plant-based diet if you look closely—grains, fruits, vegetables, and even snack foods all come from plants,” he points out. “The real distinction isn’t whether something is plant-based or not, but whether it’s minimally processed and nutrient-dense.”