- A recent study indicates that the quality of food is more crucial for heart health than merely cutting fats or carbs.
- Relying solely on a low-carb, low-fat diet could lead to deficiencies in heart-helping nutrients.
- A well-balanced diet rich in high-quality, unprocessed foods is better for your heart.
When it comes to maintaining a healthy heart, the food quality you choose may hold more weight than just eliminating carbs or fats.
According to a new study, instead of narrowly focusing on macronutrient counts, prioritizing whole, minimally processed, and plant-based foods—while reducing refined grains, added sugars, and animal products—could significantly lower the risk of coronary heart disease.
This research points to the need for a shift towards more individualized dietary advice when it comes to cardiovascular health.
For years, advice to switch to low-carb or low-fat diets has dominated discussions about health, weight management, and the prevention of chronic conditions like heart disease.
However, there’s been ongoing debate about how effective these diets are at actually protecting heart health, especially given the wide variability in food quality within these dietary patterns.
Researchers from Harvard T.H. Chan School of Public Health aimed to clarify this question, ultimately concluding that the quality of food is equally, if not more, important than simply limiting carbs or fats.
The study tracked dietary habits and heart disease outcomes for 25 years, using detailed food frequency questionnaires to evaluate the healthfulness of foods consumed on low-carb and low-fat diets.
Results showed a clear link between diets low in carbs and fats that included high-quality foods (like whole grains, fruits, vegetables, nuts, and legumes) with a roughly 15% lower risk of developing coronary heart disease.
In contrast, low-carb or low-fat diets that included unhealthy options, such as refined grains, sugary snacks, processed meats, and animal fats, were found to have a higher risk of heart disease.
“Healthier iterations of these diets, which are abundant in plant-based foods and whole grains, were connected to improved heart health and metabolic function. Conversely, low-carb and low-fat diets focused on unhealthy options raised the risk of heart disease,” said Zhiyuan Wu, PhD, the study’s lead author, in a release.
This suggests that cutting carbs or fats without considering the source and quality can actually be counterproductive.
To gain deeper insights, the research team also analyzed blood metabolites—biological markers related to metabolism—from a subset of over 10,000 participants.
This analysis provided valuable information about how different diet qualities impacted metabolic regulation and lipid profiles in the body. The study found that versions of low-carb and low-fat diets distinctly influenced plasma lipid species and other metabolites linked to cardiovascular health.
Interestingly, they made distinctions between types of low-carb and low-fat diets. For instance, animal-based low-carb diets, which generally have more saturated fats and animal proteins, were associated with a heightened heart disease risk.
On the flip side, plant-centric low-carb diets showed better health outcomes.
Likewise, unhealthy low-fat diets packed with refined carbohydrates and added sugars also raised risk, whereas healthier low-fat diets emphasizing whole foods were beneficial.
Yaa Boakye, a registered dietitian nutritionist—not involved in the study—offered a perspective on food quality, likening it to a grading rubric for your body.
“Think about it: if you asked a student to write a report without a rubric, they might finish it, but could miss the essential criteria,” she remarked.
Boakye emphasized that food quality is like this rubric, guiding your body in interpreting what you consume.
“It’s not enough to simply tick a box for ‘low carb’ or ‘low fat’—we need to focus on what’s really in the food: fiber, added sugars, sodium, micronutrients, and compounds that may be either anti-inflammatory or pro-inflammatory,” she explained, adding that carbohydrates, fats, and proteins are broad categories.
“For instance, a carbohydrate could be a sugary white roll or a fiber-rich lentil; a fat could be a trans fat or high-quality olive oil,” she noted. “Looking at food quality helps us clarify these differences.”
Boakye pointed out that individuals often overlook critical nutrients by strictly adhering to low-fat or low-carb diets without these distinctions.
“High levels of sodium, added sugars, a lack of fiber, and insufficient antioxidants are all issues that may go unnoticed,” she cautioned, adding that you might be achieving your macro targets but still consume a diet that contributes to hypertension and poor cholesterol profiles.
“A low-fat diet missing key nutrients like magnesium, potassium, and omega-3s could be counterproductive, while a low-carb plan that doesn’t include prebiotic-rich plants or vibrant fruits may compromise gut health, ultimately stressing the cardiovascular system,” she added.
She recommended following a plate model: fill half your plate with fruits and vegetables, a quarter with lean proteins (like meat, fish, beans, or lower-fat cheese), and a quarter with whole grains.
“This method naturally reduces the amount of carbs and fats by cutting out excess fats typically found in high-fat foods,” she said.
Smart added that fruits and vegetables provide fiber, keeping you satisfied and less likely to snack unnecessarily.
They also offer essential nutrients—vitamins, minerals, and antioxidants—critical for heart and vascular health. According to Smart, whole grains also contribute fiber and B vitamins.
“All this fiber helps in stabilizing blood sugar,” she stated. “Poor blood sugar management can damage blood vessels, so maintaining better control helps reduce heart disease risk.”
Furthermore, consuming lean proteins, such as lean meats, beans, and legumes, helps keep your saturated fat intake in check.
Smart added that a high-quality food diet tends to include fewer highly processed foods, subsequently lowering sodium, saturated fat, and excess calories.
“Reducing processed food intake can help safeguard your cardiovascular health by managing blood pressure and diminishing the risk of atherosclerosis (hardening of the arteries), all while preventing unnecessary weight gain,” she concluded.
