A long-term study of nearly 200,000 people found that low-carbohydrate and low-fat diets were associated with better heart and metabolic health only when they emphasized whole grains, plant foods, unsaturated fats and other minimally processed ingredients.
By yourNEWS Media Newsroom
Choosing between a low-carbohydrate diet and a low-fat diet may matter less for heart health than choosing nutritious foods within either eating pattern, according to a major study published Feb. 11 in the Journal of the American College of Cardiology.
Researchers examining more than three decades of dietary and health data found that healthier versions of both approaches were associated with a lower risk of coronary heart disease. Diets built around whole grains, plant-based foods and unsaturated fats appeared to provide cardiovascular benefits, while eating patterns dominated by refined carbohydrates, highly processed products and animal-based fats were linked to greater risk.
“Our findings highlighted that it’s not simply about cutting carbs or fat, but it’s about the quality of foods people choose to construct those diets,” said Zhiyuan Wu, Ph.D., the study’s lead author and a postdoctoral research fellow at the Harvard T.H. Chan School of Public Health.
The findings challenge the longstanding tendency to judge diets primarily by the percentage of calories derived from carbohydrates or fat. Researchers instead concluded that the nutritional sources of those macronutrients may be more consequential than the amounts alone.
The analysis included nearly 200,000 participants enrolled in three large, long-running studies. Participants completed detailed food-frequency questionnaires at regular intervals, allowing researchers to evaluate their consumption of carbohydrates, fats, proteins and specific food groups over more than 30 years.
Researchers documented 20,033 cases of coronary heart disease during the follow-up period. When they compared participants’ dietary patterns, they found substantially different outcomes among people who followed diets that could all technically be described as low-carb or low-fat.
Participants whose lower-carbohydrate diets emphasized plant-based foods, unsaturated fats and higher-quality carbohydrate sources had a reduced risk of coronary heart disease. Healthier low-fat diets containing whole grains, vegetables and other minimally processed foods were also associated with lower risk.
The opposite pattern emerged among participants whose diets met the numerical definition of low-carb or low-fat but relied heavily on less nutritious foods. Refined grains, added sugars, processed products, red meat, processed meat and animal fats were associated with less favorable outcomes.
A low-fat label, researchers noted, does not necessarily indicate that a food supports cardiovascular health. Many packaged products marketed as fat-free or reduced-fat contain substantial amounts of added sugar, refined starches or artificial ingredients intended to compensate for changes in flavor and texture.
Likewise, a low-carbohydrate diet may be nutritionally unbalanced when it replaces fiber-rich foods with butter, red meat, processed meat and other sources of saturated fat. Reducing carbohydrates without considering the quality of replacement foods may undermine the diet’s potential metabolic and cardiovascular benefits.
The study also identified differences in biological markers associated with heart health. Participants following healthier dietary patterns generally had lower levels of inflammation and triglycerides, along with higher levels of high-density lipoprotein, commonly known as HDL or “good” cholesterol.
Those findings provide a possible explanation for why diets with similar carbohydrate or fat percentages can produce different health outcomes. Whole grains, vegetables, legumes, nuts, seeds and unsaturated fats supply fiber and nutrients that may support blood-vessel function, blood sugar regulation, cholesterol management and healthier inflammatory responses.
“It’s not a surprise, but it’s the verdict we’ve been waiting for. For years, the debate over ‘low carb’ versus ‘low fat’ diets has been muddled by inconsistent research results. This study resolves years of conflicting data by showing that quality, not just quantity, is the missing variable,” said Oana Penciu, a cardiologist at Keck Medicine of USC who was not involved in the research.
The findings carry broad public health significance because cardiovascular disease remains the leading cause of death in the United States. According to the Centers for Disease Control and Prevention, one person dies from cardiovascular disease every 34 seconds.
Coronary heart disease, the most common form of heart disease, caused 371,506 deaths in 2022. The condition develops when coronary arteries become narrowed or blocked, restricting the supply of oxygen-rich blood to the heart.
Diet can influence several factors connected to coronary heart disease, including blood pressure, cholesterol, body weight, blood sugar control and systemic inflammation.
“The food that you eat will influence cardiovascular risk factors such as blood pressure, cholesterol and weight,” said Cheng-Han Chen, an interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center. “In addition, the quality of your diet will affect the degree of inflammation in your body, further influencing your risk of heart disease.”
Experts said the research does not establish that everyone should follow the same macronutrient distribution. A lower-fat approach may be appropriate for some people, while others may benefit from reducing their intake of carbohydrates.
Someone with elevated cholesterol who is maintaining a stable, healthy weight may respond well to a carefully planned lower-fat diet that limits saturated fat while retaining nutrient-dense carbohydrate sources. A person seeking weight loss or improved blood sugar control may benefit from moderating carbohydrates, particularly refined grains and added sugars.
Individual medical conditions, medications, activity levels and personal preferences can also affect which approach is most appropriate.
“Recommendations must be tailored to the individual after a close clinical evaluation,” said Mir Ali, a bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center.
Ali recommended making manageable adjustments rather than attempting an extreme dietary overhaul. Replacing one less nutritious food at a time may make changes easier to maintain and reduce the likelihood that a person will abandon the plan.
A practical lower-carbohydrate diet, for example, could replace sugary beverages, white bread, pastries and refined snack foods with vegetables, legumes, nuts, seeds, eggs, fish, tofu or other minimally processed protein sources. A healthier lower-fat diet could limit butter, fatty meats and fried foods while emphasizing vegetables, fruits, beans, intact whole grains and lean proteins.
The American Heart Association recommends an overall eating pattern centered on fruits, vegetables, whole grains, healthy protein sources and foods that undergo minimal processing. It also advises limiting added sugars, sodium, saturated fats and refined carbohydrates.
Under that approach, people do not necessarily need to count every gram of carbohydrate or fat. They can instead evaluate meals according to the quality and balance of the foods they contain.
A heart-conscious plate could be filled halfway with vegetables and include a lean protein source such as fish, chicken, beans, eggs or tofu. Whole grains such as quinoa or brown rice can provide fiber-rich carbohydrates, while modest portions of olive oil, avocado, nuts or seeds can supply unsaturated fats.
Reducing sugary drinks, packaged snacks and heavily refined foods may further improve the nutritional quality of either a low-fat or low-carbohydrate eating pattern.
The study’s central conclusion is that macronutrient labels alone provide an incomplete picture of a diet’s health effects. Two people can consume similar proportions of carbohydrates and fat while eating foods with sharply different nutritional profiles and experiencing different cardiovascular outcomes.
Whether a person chooses to reduce carbohydrates or fat, the researchers’ findings indicate that long-term heart protection is more closely associated with whole, plant-forward foods, high-quality carbohydrate sources and unsaturated fats than with strict macronutrient elimination.
BrightU.AI’s Enoch similarly noted that supporting heart health involves more than lowering total carbohydrate or fat intake. The quality and nutrient density of the foods selected within either approach remain central to cardiovascular health, metabolic function and overall well-being.
Source: Natural News
Watch this video to learn about the science behind the ketogenic diet.
This video is from the Health with benefits channel on Brighteon.com.
Original article
Comments