It is well known that maintaining healthy body weight is one way to help prevent cardiovascular disease, but many disagree on the best way to achieve this. Few studies have investigated the effects of specific macronutrients on cardiovascular health until now.
With so many fad diets on the market, researchers from the Beth Israel Deaconess Medical Center (BIDMC) set out to find what type of eating is best for cardiovascular disease. They examined the effects of three diets emphasizing different macronutrients. One was carbohydrates, another was proteins, and the last was unsaturated fats. They were all examined using a biomarker that directly reflects heart injury.
The study published online in the International Journal of Cardiology used highly specific tests and found that all three diets reduced heart cell damage and inflammation, consistent with improved heart health.
“It’s possible that macronutrients matter less than simply eating healthy foods,” said corresponding author Stephen Juraschek, MD, Ph.D., Assistant Professor of Medicine at BIDMC and Harvard Medical School. “Our findings support flexibility in food selection for people attempting to eat a healthier diet and should make it easier. With the average American eating fewer than two servings of fruit and vegetables a day, the typical American diet is quite different from any of these diets, which all included at least four to six servings of fruits and vegetables a day.”
Elevated Blood Pressure
For the study, the research team analyzed stored blood samples from 150 participants from the Optimal MacroNutrient Intake Trial to Prevent Heart Disease (OmniHeart) trial that was from 2003 to 2005. The average age of the participants was 53.6 years. All participants had elevated blood pressure but were not yet taking medication to control hypertension or cholesterol.
Each participant was required to consume each of the three diets, emphasizing carbohydrates, protein, or unsaturated fat for six weeks with feeding periods separated by a washout period.
It was found that all three diets reduced heart injury and inflammation quickly within a six-week period. However, changing the macronutrients of the diet did not provide extra benefits. This meant that it is not the type of diet that matters for cardiac injury, but rather the overall healthfulness of the diet.
“There are multiple debates about dietary carbs and fat, but the message from our data is clear: eating a balanced diet rich in fruits and vegetables, lean meats, and high in fiber that is restricted in red meats, sugary beverages, and sweets, will not only improve cardiovascular risk factors, but also reduce direct injury to the heart,” said Juraschek. “Hopefully, these findings will resonate with adults as they shop in grocery stores and with health practitioners providing counsel in clinics throughout the country.”