Keto, Cholesterol & Heart Health
What does the research show about ketogenic diets and cholesterol, and what are the cardiovascular risks?
Copper Keto Companion gathers the research on keto and cardiovascular markers here — including the adverse findings. The lipid picture on keto is genuinely mixed: triglycerides and HDL typically improve, LDL typically rises, and whether that LDL rise translates to cardiovascular events is contested and depends on how LDL is measured and in whom.
Contents — 5 entries
- 📄 Ketogenic Diet and Cardiovascular Disease Risk Factors (Meta-Analysis of 27 RCTs)
- 📄 Low-Carbohydrate Ketogenic Diet and LDL Particle Subclasses (RCT)
- 📄 Low-Carbohydrate High-Fat Diet, LDL, ApoB, and MACE Risk (UK Biobank Cohort)
- 📄 Low-Carbohydrate Diet and Cardiovascular and All-Cause Mortality (Meta-Analysis of Cohorts)
- 📄 Ketogenic Diet and LDL Rise in Lean Healthy Women (Controlled-Feeding RCT)
📄 Ketogenic Diet and Cardiovascular Disease Risk Factors (Meta-Analysis of 27 RCTs)
Wang Z, et al. — American Journal of Clinical Nutrition, 2024 · Am J Clin Nutr, 2024
Copper Keto Companion research surfaced this report because it covers how a ketogenic diet shifts the main cardiovascular lipid markers. Pooling 27 randomized trials and 1,278 participants, the 2024 meta-analysis found triglycerides fell about 0.20 mmol/L and HDL rose about 0.16 mmol/L, while LDL cholesterol rose about 0.35 mmol/L and total cholesterol rose about 0.36 mmol/L. The authors describe the LDL and total cholesterol rise as a reason for a cautious approach, and note these are lipid-risk markers rather than long-term cardiovascular outcomes.
What it examines: pooled RCT data on how a ketogenic diet shifts triglycerides, HDL, LDL, and total cholesterol. Why it's in the Copper Keto Companion research index: a meta-analysis of how a ketogenic diet shifts the main cardiovascular lipid markers across randomized trials.
📄 Low-Carbohydrate Ketogenic Diet and LDL Particle Subclasses (RCT)
Westman EC, et al. — International Journal of Cardiology, 2006 · Int J Cardiol, 2006
Copper Keto Companion research surfaced this report because it covers how a ketogenic diet changes not just LDL quantity but LDL particle type. In a randomized trial of 119 participants, a low-carbohydrate ketogenic diet reduced small dense LDL by about 78% and increased large buoyant LDL by about 54% (p=0.004 for large LDL change). Small dense LDL particles are more strongly associated with cardiovascular disease than large buoyant ones, though whether this particle-type shift meaningfully changes outcome risk is not settled in long-term trials. The study is from 2006 and does not include cardiovascular outcome data.
What it examines: a randomized trial of how a low-carbohydrate ketogenic diet changes LDL particle size subclasses. Why it's in the Copper Keto Companion research index: a randomized trial of how keto changes LDL particle types — a nuance the standard LDL-cholesterol number misses.
📄 Low-Carbohydrate High-Fat Diet, LDL, ApoB, and MACE Risk (UK Biobank Cohort)
Iatan I, et al. — JACC: Advances, 2024 · JACC Adv, 2024
Copper Keto Companion research surfaced this report because it covers a cardiovascular outcome signal associated with a low-carbohydrate high-fat diet. In a UK Biobank analysis of 305 participants identified as following a low-carbohydrate high-fat diet (matched to 1,220 standard-diet controls), major adverse cardiovascular events occurred in 9.8% vs 4.3% over 11.8 years (unadjusted HR 2.18, 95% CI 1.39–3.43). LDL-C and apolipoprotein B were significantly higher in the low-carbohydrate group. The study's key limitation is that diet was assessed from a single 24-hour dietary recall, which is a poor measure of habitual intake; the 305-person dietary group is small, and the design is observational.
What it examines: a UK Biobank cohort analysis of cardiovascular events in people self-reporting a low-carbohydrate high-fat diet. Why it's in the Copper Keto Companion research index: an observational cohort study linking a low-carbohydrate high-fat diet to elevated LDL, apoB, and major cardiovascular events.
📄 Low-Carbohydrate Diet and Cardiovascular and All-Cause Mortality (Meta-Analysis of Cohorts)
Qin P, et al. — Food & Function, 2023 · Food Funct, 2023
Copper Keto Companion research surfaced this report because it covers the association between low-carbohydrate diets and mortality at population scale. Pooling 38 cohort studies and up to 771,609 participants, the 2023 meta-analysis found the risk of coronary heart disease was significantly elevated at RR 1.43 (95% CI 1.18–1.72), while all-cause mortality (RR 1.03) and cardiovascular mortality (RR 1.09) were not statistically significant. Heterogeneity across studies was substantial (I² up to 86.6%), limiting the reliability of the pooled estimates, and the analysis cannot establish causation.
What it examines: a meta-analysis of cohort studies linking low-carbohydrate diets to coronary heart disease and mortality. Why it's in the Copper Keto Companion research index: a large meta-analysis of cohort studies examining the association between low-carbohydrate diets and cardiovascular and all-cause mortality.
📄 Ketogenic Diet and LDL Rise in Lean Healthy Women (Controlled-Feeding RCT)
Burén J, et al. — Nutrients, 2021 · Nutrients, 2021
Copper Keto Companion research surfaced this report because it covers who tends to see the largest LDL rise on a ketogenic diet. In a controlled-feeding crossover of 17 healthy lean women, four weeks of a ketogenic diet raised LDL cholesterol by 1.82 mmol/L, with both large buoyant and small dense LDL increasing. The sample was small and lean and the diet was fully supplied, so it shows a clear signal in one specific group rather than a population average; lean, metabolically healthy individuals appear to show a larger LDL response than those with obesity or type 2 diabetes.
What it examines: a controlled-feeding trial of the LDL response to keto specifically in lean healthy women. Why it's in the Copper Keto Companion research index: a controlled-feeding trial showing that lean, healthy individuals may see a larger LDL rise on keto than higher-weight populations.
All 5 sources last verified June 2026.
Frequently Asked Questions
Does keto raise cholesterol?
It depends on which marker. A 2024 meta-analysis of 27 RCTs (Wang) found keto lowers triglycerides and raises HDL — both favorable — while LDL and total cholesterol rose. The LDL rise is highly variable: lean individuals tend to see larger increases than those with obesity or type 2 diabetes. This summarizes research and is not medical advice; discuss your lipids with a clinician.
Is the LDL that rises on keto dangerous?
Contested. A 2006 RCT (Westman) found keto shifted LDL toward larger, less-dense particles, which are less strongly associated with cardiovascular risk. But observational data — a UK Biobank study (Iatan, 2024) and a cohort meta-analysis (Qin, 2023) — find associations between low-carb high-fat diets and elevated cardiovascular event risk. Neither RCT data nor observational studies provide definitive long-term outcome evidence. Talk to your doctor if you have existing cardiovascular risk.
Does keto improve HDL and triglycerides?
Yes, consistently in randomized trials. The 2024 meta-analysis (Wang, 27 RCTs) found triglycerides fell about 0.20 mmol/L and HDL rose about 0.16 mmol/L — favorable changes for cardiovascular risk markers, though they co-occur with LDL rises.
Should I monitor my cholesterol on keto?
Yes. The research shows meaningful LDL rises in some people, particularly lean individuals. If you have existing cardiovascular risk factors — elevated LDL, family history of heart disease, diabetes — discuss keto with your doctor before starting and get lipids checked after four to eight weeks. This is general information, not medical advice.
More in Keto Research
Educational information only — not medical advice, and not a recommendation to start, stop, or change any diet, supplement, or treatment. Talk to a qualified healthcare professional before making changes. Copper Keto Companion and Copper Sun Content and Creative, LLC are not medical providers.