New Research Finds Low-Carb Keto Diet May Not Increase Cardiovascular Disease Risk

High cholesterol has often been criticized for its association with poor heart health. However, a recent study presents evidence that the low-carb ketogenic diet may not be linked to an increased risk of cardiovascular disease.

The research, spearheaded by The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, involved collaboration from various research institutions. It examined 100 participants adhering to a long-term keto diet who exhibited elevated levels of LDL cholesterol, frequently referred to as the ‘bad’ cholesterol.

Participants demonstrated metabolic health despite their raised cholesterol levels, and they maintained adherence to the ketogenic diet for an average of five years, as indicated in a press release dated April 7.

All subjects qualified as lean mass hyper-responders, a designation referring to individuals who undertake a carbohydrate-restricted diet and experience a significant spike in cholesterol levels.

Utilizing advanced cardiac imaging techniques, researchers discovered that standard cholesterol markers, including ApoB and LDL-C, bore no correlation with changes in plaque levels within the coronary arteries or with baseline heart disease over a year-long observation period.

Interestingly, the pre-existing levels of plaque appeared to serve as a more reliable indicator for predicting future plaque buildup.

Dr. Bret Scher, medical director at Baszucki Group, which funded the study, stated that individuals classified as metabolically healthy with elevated LDL due to ketosis do not show an automatically increased cardiac risk solely based on their LDL levels.

He emphasized the necessity to pivot away from LDL and ApoB metrics in favor of vascular imaging techniques, such as coronary artery calcium screening or computed tomography angiography, for improved risk assessment in heart health.

The findings were published in the Journal of the American College of Cardiology: Advances, reinforcing previous research suggesting that lean mass hyper-responders maintained coronary plaque levels comparable to those with normal LDL cholesterol levels. This highlights the possibility that LDL increases resulting from ketogenic diets may not signify a higher coronary plaque risk.

Dr. Nick Norwitz, an independent researcher at the University of Oxford and one of the study’s leaders, emphasized that this is the first study to isolate extremely high LDL and ApoB levels as potential heart disease risk factors, contrasting previous studies that included populations with metabolic dysfunction or genetic causes of elevated LDL.

Norwitz expressed that while the findings challenge prevailing assumptions held by many clinicians, they do not necessarily repudiate the established understanding of cholesterol. They suggest, however, that existing models might have overlooked some critical areas.

He pointed out that using cardiac imaging, particularly the coronary artery calcium score, provides more insightful data than traditional cholesterol levels when predicting plaque development.

Scher acknowledged that while ketogenic therapy can be an effective approach for addressing specific metabolic conditions, many individuals grappling with high cholesterol hesitate to continue the keto diet. He stated that this study encourages people to collaborate with their healthcare teams to develop tailored cardiac evaluations rather than feeling compelled to abandon their dietary approach.

In addition, Dr. Ken Berry, a family physician and diabetes specialist in Tennessee who was not directly involved in the research, acknowledged its groundbreaking nature. He remarked that the study did not find any connection between LDL-C and ApoB with the progression of coronary plaque over a one-year period using high-resolution CT angiography.

Berry highlighted that the most significant predictor of plaque progression was pre-existing plaque rather than cholesterol levels, leading researchers to conclude that existing plaque leads to more plaque formation, while ApoB alone does not.

This study is described as the first prospective trial of its kind involving a demographic often labeled as ‘high-risk’ according to traditional health guidelines. It raises crucial questions regarding the assessment of cardiovascular risk in the context of low-carb, high-fat diets.

Moreover, Berry questioned whether high ApoB levels are a valid predictor of heart attack risk across various demographics, implying that it may simply be the latest lab test fueling unnecessary dietary fears.

Dr. Bradley Serwer, a cardiologist and chief medical officer at VitalSolution, reviewed the study and identified some limitations. He suggested that the narrow focus of the study, involving a low-risk group over a brief duration, makes it challenging to apply the conclusions to a broader and more vulnerable population.

Although the study aims to hypothesize regarding dietary cholesterol’s role, Serwer noted that it does not present conclusive evidence asserting its effects.

He concurs with the authors when they advocate for better risk stratification tools to identify individuals at higher risk of coronary artery disease.

Michelle Routhenstein, a registered dietitian in New York City specializing in heart health, pointed out that the progression of plaque formation is a lengthy process influenced by several factors. She highlighted that the study excluded individuals with high blood pressure, a subgroup more prone to arterial damage conducive to plaque formation.

Routhenstein stated that while high LDL and ApoB levels can be concerning, especially if one is not metabolically healthy and has pre-existing plaque, the impact of these levels on individuals without existing arterial plaque may be minimal over a year.

She cautioned that many individuals on a ketogenic diet may not be aware of underlying, soft plaque development, and ignoring LDL and ApoB levels could be detrimental.

Dr. Serwer and others with medical expertise hope this study ignites future research to explore cardiovascular risks in diverse populations, focusing on the mechanisms behind the lean mass hyper-responder phenotype.

To wrap up, this research highlights the need for individualized assessments and encourages a fresh perspective on the health implications of the ketogenic diet.