The debate appears to be continuing. Those that promote low-fat diets for heart health claim that a low-carb, high-fat diet is bad for your heart. On the surface, it appears that this is correct. Is that true, though?
A newly published clinical experiment led by a doctor and researcher who specializes in heart and metabolic health came to some fascinating and unexpected discoveries. The participants were randomly assigned to one of three groups for this study. For 20 weeks, they followed the diets that had been allocated to them. Each of the three diets contained 20% protein but differed in carbohydrate and fat content.
Participants in the study were given fully cooked, tailored meals to consume in the cafeteria or take home. As a result, there was no guesswork involved in determining whether they consumed the recommended macronutrient levels.
The following is a breakdown of the diets:
- Low-carb: 20% carbohydrate, 21% fat
- Moderate-carb: 40% carbohydrate, 14% fat
- High-carb: 60% carbohydrate, 7% fat
The astonishing results were disclosed at the end of the 20 weeks:
A low-carbohydrate diet, high in saturated fat, improved insulin-resistant dyslipoproteinemia and lipoprotein(a), without adverse effects on LDL cholesterol. Carbohydrate restriction might lower CVD (cardiovascular disease) risk independently of body weight, a possibility that warrants study in major multi-centered trials powered on hard outcomes.
In plain English, the researchers discovered that people who followed a low-carb, high-fat diet improved their triglycerides, adiponectin (a fat-derived hormone that appears to play a crucial role in protecting against insulin resistance/diabetes and atherosclerosis), blood pressure, and lipoprotein(a) more than those who followed a moderate or high-carb diet. Lipoprotein(a) is a type of protein that transports cholesterol in the bloodstream and can induce LDL cholesterol to build plaques on blood vessel walls, causing blood vessels to constrict or block arteries to stiffen. The high levels of saturated fat had no effect on cholesterol or cardiovascular indicators.
That contradicts everything we've been told for years. It always boils down to the quality of the food and where the fat originates from, in my opinion. We've been warned for a long time that saturated fat is a harmful substance. My personal opinion is that it depends on the source of the fat and how saturated fat affects your metabolic profile.