Aurelio Rojas, cardiologist and health expert: "There are people who have a genetic disorder that prevents the liver from removing LDL cholesterol from the blood."

High cholesterol is n't always related to a poor diet . Although for years it has been blamed exclusively on dietary fat, studies and clinical experience reveal that there are much more complex internal mechanisms behind this disorder, such as inflammation, sugar metabolism, and genetics. This is explained by Dr. Aurelio Rojas , a cardiologist and expert in cardiovascular health, who has detailed the main reasons why cholesterol levels can skyrocket even in people with healthy habits.

"Why do I have high cholesterol even though I don't eat fat? This is a question my patients ask me every day," says Rojas. The specialist clarifies that more than 70% of total cholesterol in the blood is produced by the liver itself . This occurs largely through an enzyme known as hydroxymethyl glutaryl-CoA reductase, especially when fat intake is low.

Paradoxically, a low-fat diet can induce the liver to increase its own cholesterol production as a compensatory mechanism. This process, which can be altered in the presence of chronic inflammation or oxidative stress , is one of the most common causes of dyslipidemia in patients with a balanced diet.

But it's not just fat that's a factor: excessive consumption of sugars , refined flours, and ultra-processed foods also activates a metabolic pathway called hepatic de novo lipogenesis, through which the liver transforms excess glucose into fatty acids. These are incorporated into cholesterol- and triglyceride-rich particles, raising levels of total cholesterol and small, dense LDL cholesterol, considered the most harmful to arteries.

"There are people who have a genetic disorder that prevents the liver from removing LDL cholesterol from the blood," explains Dr. Rojas, who emphasizes the importance of early diagnosis in these cases. Mutations in genes such as LDLR, APOB, or PCSK9 can alter the body's ability to remove cholesterol from the bloodstream, causing high levels to accumulate even without a high-fat diet.

In these genetic profiles, diet has a much smaller impact on cholesterol levels, and it's essential to identify the cause early, especially if there's a family history of cardiovascular disease. The cardiologist insists that the importance of regular cholesterol monitoring should not be underestimated, even when lifestyle habits are seemingly healthy.