Low-carbohydrate diet — does it raise cholesterol, and is that dangerous?

Aim of the study: Numerous studies have examined the effects of ketogenic diets (KD) on health-related outcomes through meta-analyses. However, the presence of biases may compromise the reliability of conclusions.

Results: In addition, KD was associated with seizure reduction in children, which can be explained by the ketosis state as induced by the diet. Furthermore, KD demonstrated a better alleviation effect in refractory childhood epilepsy, in terms of median effective rates for seizure reduction of ≥50%, ≥90%, and seizure freedom. However, the strength of evidence supporting the aforementioned associations was generally weak, thereby challenging their credibility. Consequently, future studies should prioritize stringent research protocols to ascertain whether KD interventions with longer intervention periods hold promise as a viable treatment option for various diseases.

Aim of the study: Objective: to evaluate the lipid metabolism of patients with type 2 diabetes mellitus (T2DM) after very low-carbohydrate ketogenic (VLCK) diet treatment, so as to provide an evidence-based basis for better dietary management and comprehensive treatment of diabetic patients.

Results: Triglyceride levels decreased after VLCK diet compared with control (SMD = -0.49, 95 % CI: -0.82 to -0.17, p = 0.003). A marked reduction of triglyceride levels was identified after 3 months of VLCK diet treatment (SMD = -0.69, 95 % CI: -1.00 to -0.38), without significant difference after 6 and 12 months. Conclusion: T2DM patients who receive a VLCK diet to lower blood glucose are not associated with increased levels of total cholesterol and LDL, and decreased levels of HDL. Additionally, this diet can achieve a short-term reduction of triglyceride levels.

Aim of the study: Although there is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss and in the management of type 2 diabetes, concerns have been raised that the LCD may increase cardiovascular disease (CVD) risk by increasing the level of low-density lipoprotein cholesterol (LDL-C). We have assessed the value of LDL-C as a CVD risk factor, as well as effects of the LCD on other CVD risk factors.

Results: Multiple longitudinal trials have demonstrated the safety and effectiveness of the LCD, while also providing evidence of improvements in the most reliable CVD risk factors. Recent findings have also confirmed how ineffective LDL-C is in predicting CVD risk.

Aim of the study: Low-carbohydrate diets are popular for weight loss, but their cardiovascular effects have not been well-studied, particularly in diverse populations. To examine the effects of a low-carbohydrate diet compared with a low-fat diet on body weight and cardiovascular risk factors.

Results: Sixty participants (82%) in the low-fat group and 59 (79%) in the low-carbohydrate group completed the intervention. At 12 months, participants on the low-carbohydrate diet had greater decreases in weight (mean difference in change, -3.5 kg [95% CI, -5.6 to -1.4 kg]; P = 0.002), fat mass (mean difference in change, -1.5% [CI, -2.6% to -0.4%]; P = 0.011), ratio of total-high-density lipoprotein (HDL) cholesterol (mean difference in change, -0.44 [CI, -0.71 to -0.16]; P = 0.002), and triglyceride level (mean difference in change, -0.16 mmol/L [-14.1 mg/dL] [CI, -0.31 to -0.01 mmol/L {-27.4 to -0.8 mg/dL}]; P = 0.038) and greater increases in HDL cholesterol level (mean difference in change, 0.18 mmol/L [7.0 mg/dL] [CI, 0.08 to 0.28 mmol/L {3.0 to 11.0 mg/dL}]; P < 0.001) than those on the low-fat diet. The low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet.

Aim of the study: Diet ranks among the most modifiable determinants of cardiovascular disease risk, yet the evidence base is vast, conflicting, and burdened by observational confounding. This narrative review synthesizes evidence on controversial dietary components and established heart-healthy dietary patterns.

Results: Low-carbohydrate and ketogenic diets improve select metabolic parameters but raise concern for sustained LDL-C and apolipoprotein B elevation, particularly with animal-derived macronutrient substitution. Omega-3 supplementation reduces coronary heart disease and myocardial infarction risk dose-dependently; atrial fibrillation risk is confined to high-dose formulations in high-risk populations. The Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets carry the most robust evidence for cardiovascular risk reduction; the Portfolio diet provides effective non-pharmacologic lipid lowering. Overall dietary pattern quality predicts cardiovascular risk more reliably than any single food or nutrient.