Does Minimizing Saturated Fats Consumption Lower Blood Cholesterol levels?

Familial hypercholesterolemia is a genetic disorder in which people’s blood cholesterol levels are elevated to about 2-4 times higher than that of the average individual. Health officials have always instructed that individuals diagnosed with this condition cut down foods like meat, eggs, cheese, and more importantly, coconut oil. For more than 8 decades now, people diagnosed with this genetic condition have been advised to lower their blood cholesterol levels with a low saturated fat diet.

Familial hypercholesterolemia affects nearly 40 million people worldwide and the global prevalence of this condition is very much underestimated. When left untreated, familial hypercholesterolemia can lead to life-threatening complications including premature coronary artery disease. Indians are 2-3 times more likely to acquire premature coronary artery disease compared to others. 

For several decades now, individuals diagnosed with familial hypercholesterolemia have been advised to minimize their consumption of saturated fats to lower their blood cholesterol levels to reduce their risks of heart diseases. 

But recent research found no evidence to support such claims and the researchers said that they couldn’t find any justifications for recommendations against saturated fats. The study demonstrated that a ‘heart-healthy’ diet was one that was low in sugar and carbohydrates and not low in saturated fats. 

In the study, an international team of researchers led by David M Diamond evaluated dietary recommendations for individuals diagnosed with familial hypercholesterolemia. They analyzed the recommendation that postulated that eating foods rich in saturated fats elevated their serum cholesterol levels, which in turn elevated their risk of heart diseases. 

Historical perspective:

In 1939, during the first documentation of premature heart diseases in individuals diagnosed with familial hypercholesterolemia, it was recommended that these patients consumed a diet which was poor in saturated fats without any egg yolk, butter, cream, fat milk, or any other sort of fat that was of animal origin. Although such a dietary recommendation for FH patients was praised, it failed to address the concerns that the presumed benefits of the low-fat diet hadn’t been confirmed via any randomized controlled trial.  

And the 2018 AHA cholesterol guidelines also recommended that FH patients should continue to follow an LDL-cholesterol-lowering heart-healthy diet that limits animal and vegetable sources of saturated fats. Historical perspective only illustrated the absence of an evidence-basis for such a dietary recommendation for FH patients. 

The researchers opined that the emphasis on a low-fat diet might in fact result in the consumption of a carbohydrate-dense diet which might exacerbate an insulin-resistant phenotype and thereby put them at a greater risk of developing heart diseases. 

Contemporary research:

Since LDL-cholesterol appears to be elevated in individuals with FH, a diet-induced reduction of the bad cholesterol has been assumed to be effective at improving cardiovascular health. However, it is believed that LDL-C in isolation is a poor marker of coronary heart diseases in both people with FH as well as in the general population. And a comprehensive review of several studies revealed that people above the age of 60 with the highest LDL-cholesterol levels lived as long, or even longer than those with low LDL-C. Therefore, it is very important to identify biomarkers other than LDL-C which are closely related to coronary heart diseases and more importantly, are affected by dietary interventions that may benefit FH patients. 

About a century ago, the fact that certain individuals with FH developed premature coronary heart diseases has led to the assumption that elevated total cholesterol and LDL-C elevated their susceptibility to developing CHD. 

A low-carb diet lowers CHD risk in FH patients

Several clinical trials have reported that a low-carb diet resulted in significant and substantial reductions in blood pressure, hyperglycemia, as well as, hyperinsulinemia. 

In their systematic review and meta-analysis on low carb diet and coronary heart diseases revealed that carbohydrate restriction seemed highly effective in improving lipid markers when compared with low-fat diets. Therefore, the researchers opine that dietary guidelines should consider carbohydrate restriction as an alternative dietary strategy for both preventions as well as managing dyslipidemia among those with elevated cardiometabolic risk. 

The researchers emphasized that adhering to a low-carb diet is highly effective for individuals at an elevated risk of cardiovascular diseases including those who are overweight/obese, hypertensive, and/or diabetic.  

Bottomline

Familial hypercholesterolemia- the genetic condition characteristic of elevated blood cholesterol levels is highly underestimated. Moreover, there hasn’t been any evidence to support the age-old dietary recommendation for FH patients which has restricted saturated fats. The new research pointed out that a low-carb diet is more effective in cutting down heart disease risk among FH patients compared to a low-fat diet. The researchers highlighted that foods that raise blood sugar like bread, potatoes, and sweets should be minimized rather than tropical oils and other animal-based foods.