## New Research Challenges Conventional Wisdom on Cholesterol and Ketogenic Diets
For years, high cholesterol has been widely linked to an increased risk of heart disease. However, recent research suggests that the popular ketogenic diet might not pose the cardiovascular threat previously assumed. A new study indicates that elevated LDL cholesterol – often termed “bad” cholesterol – observed in individuals following a long-term ketogenic diet may not necessarily translate to heightened cardiac risk.
The study, conducted by The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center and collaborators across multiple institutions, analyzed 100 participants who had been adhering to a ketogenic diet for an average of five years and exhibiting elevated LDL cholesterol levels. All participants were deemed “metabolically healthy” and classified as LMHRs – lean mass hyper-responders—individuals who experience a significant rise in cholesterol when adopting a carbohydrate-restricted diet.
Using advanced cardiac imaging, researchers found no correlation between traditional cholesterol markers (ApoB and LDL-C) and changes in plaque levels within the arteries or with pre-existing heart disease over a one-year observation period. Instead, the amount of existing plaque appeared to be a better predictor of future plaque accumulation.
“This population—metabolically healthy individuals experiencing elevated LDL due to ketosis—are not automatically at increased cardiac risk simply because their LDL is high,” explained Bret Scher, MD, medical director of Baszucki Group and study funder. “We should likely shift our focus from solely relying on LDL and ApoB measurements towards vascular imaging techniques like CAC or CTA for more accurate risk prediction and treatment guidance.”
The findings challenge established beliefs within the medical community. Dr. Nick Norwitz, a lead researcher at the University of Oxford, emphasized that this is the first study to isolate very high LDL and ApoB levels as potential risk factors while accounting for other variables.
“All prior human studies have either included individuals with metabolic dysfunction or those with genetic predispositions to high LDL,” he noted. “This research suggests a significant gap in our understanding of cardiovascular health.”
The study’s implications are far-reaching, particularly concerning the use of ketogenic therapy for certain metabolic conditions. Dr. Ken Berry, a family physician and diabetes specialist, described the findings as “groundbreaking,” stating that researchers found no association between LDL-C, ApoB, and plaque progression over one year using high-resolution CT angiography.
“Instead, pre-existing plaque was the strongest predictor of further plaque buildup – leading to the conclusion that ‘plaque begets plaque, ApoB does not,’” Berry explained. He questioned whether elevated ApoB is truly a reliable indicator of heart attack risk or simply a widely used test that can unnecessarily frighten people away from beneficial dietary practices.
While acknowledging potential limitations—the study’s relatively short duration and focus on a low-risk population—Dr. Bradley Serwer, a cardiologist, agrees with the authors’ call for improved risk stratification tools. He stressed the importance of individual patient assessment and shared decision-making in developing long-term care plans.
Michelle Routhenstein, a registered dietitian specializing in heart disease, highlighted the complexity of plaque formation, emphasizing that it’s a multi-step process influenced by factors beyond cholesterol levels, such as high blood pressure or endothelial damage. She cautioned against dismissing elevated LDL and ApoB entirely, particularly if an individual exhibits other risk factors like inflammation or insulin resistance.
Looking ahead, researchers hope to expand their study to broader populations and further investigate the LMHR phenotype. Scher expressed optimism that this research will encourage physicians to treat individuals on ketogenic diets differently, recognizing their unique physiological state and potential metabolic benefits.
The team hopes to further investigate the mechanisms of the lean mass hyper-responder (LMHR) phenomenon.
