Consumption of a low-carbohydrate, high-fat diet, dubbed a “keto-like” diet, was associated with an increase in LDL levels and a twofold increase in the risk for future cardiovascular events, in a new observational study.
“To our knowledge this is the first study to demonstrate an association between a carbohydrate-restricted dietary platform and greater risk of atherosclerotic cardiovascular disease,” said study investigator Iulia Iatan, MD, PhD, University of British Columbia, Vancouver, Canada.
“Hypercholesterolemia occurring during a low-carb, high-fat diet should not be assumed to be benign,” she concluded.
Iatan presented the study March 5 at the American College of Cardiology (ACC) Scientific Session/World Congress of Cardiology (WCC) 2023.
The presentation received much media attention, with headlines implying a causal relationship with cardiac events based on these observational results. But lipid expert Steven Nissen, MD, Cleveland Clinic, Cleveland, Ohio, warned against paying much attention to the headlines or to the study’s conclusions.
To the heart.org | Medscape Cardiology, Nissen pointed out that the LDL increase in the “keto-like” diet group was relatively small and “certainly not enough to produce a doubling in cardiovascular risk.”
“The people who were on the ‘keto-like’ diet in this study were different to those who were on the standard diet,” he commented. “Those on the ‘keto-like’ diet were on it for a reason — they were more overweight, they had a higher incidence of diabetes, so their risk profile was completely different. Even though the researchers tried to adjust for other cardiovascular risk factors, there will be unmeasured confounding in a study like this.”
He said he doesn’t think this study “answers any significant questions in a way that we want to have them answered. I’m not a big fan of this type of diet, but I don’t think it doubles the risk of adverse cardiovascular events, and I don’t think this study tells us one way or another.”
For the study, Iatan and colleagues defined a low-carbohydrate, high-fat diet as…