Daily Dose: Keto Diet and Cardiovascular Health

Patient Care brings primary care clinicians a lot of medical news every day—it’s easy to miss an important study. The Daily Dose provides a concise summary of one of the website's leading stories you may not have seen.

On March 8, 2023, we reported on a study abstract presented at the American College of Cardiology’s (ACC) 2023 Annual Scientific Session Together with the World Congress of Cardiology that examined the association between a low carbohydrate, high-fat (LCHF) diet and lipids as well as incident major adverse cardiovascular events (MACE).

The study

Researchers tapped the UK Biobank database to identify adults aged 40 to 69 years recruited between 2006 and 2010. Based on responses to a 24-hour dietary intake questionnaire completed by participants upon biobank enrollment, the investigators identified those whose diet met the study's definition of LCHF: daily intake of carbohydrates <100 g and/or <25% of total daily energy intake and fat >45% of total daily energy intake. A standard diet, for comparison, was defined as one that did not meet the LCHF criteria. A total of 305 participants were identified as following the keto dietary regimen.

Compared with participants consuming a standard diet, those following the LCHF pattern had significantly elevated levels of some lipids and ketone bodies:

• LDL cholesterol (3.8 vs 3.64 mmol/L; P=.004)

• ApoB (1.09 vs 1.04 g/L; P<.001)

• Total cholesterol (6.08 vs 5.85 mmol/L; P=.002)

• 3-hydroxybutyrate (0.14 vs 0.06 mmol/L; P<.001)

• Acetone (0.02 vs 0.01 mmol/L; P<.001)

• Acetoacetate (0.02 vs 0.01 mmol/L; P<.001)

In contrast, the researchers reported lower levels of lipoprotein(a) (39.43 vs. 46.13 nmol/L; P=.041) and triglycerides (1.34 vs. 1.53 mmol/L; P=.001) in the keto-diet group vs the standard diet group. After a mean follow-up period of 11.8 years, analysis of data for the secondary composite outcome, incident MACE, found the rate more than 2 times higher among those following the LCHF vs the standard diet (9.8% vs. 4.3%; adjusted HR, 2.18; 95% CI, 1.39–3.43; P<.001); this analysis was completed after multivariable adjustment for presence of diabetes, hypertension, smoking, and BMI.

Note from authors

“Our findings suggest that people who are considering going on an LCHF diet should be aware that doing so could lead to an increase in their levels of LDL cholesterol. Before starting this dietary pattern, they should consult a health care provider. While on the diet, it is recommended they have their cholesterol levels monitored and should try to address other risk factors for heart disease or stroke, such as diabetes, high blood pressure, physical inactivity, and smoking.”

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