It is not clear if collagen
supplements affect cholesterol levels. A study of 32 healthy Japanese adults (average age 54) showed that taking 8 grams of collagen twice daily for 6 months modestly increased high-density lipoprotein (HDL or "good") cholesterol by 3.9 mg/dL compared to baseline. The collagen supplement also reduced artery stiffness, as well as the ratio of low-density lipoprotein (LDL or "bad") cholesterol to HDL cholesterol in people with a baseline ratio greater than 2.5, which is linked with increased risk of atherosclerosis. On the other hand, taking collagen also increased triglycerides by 11.5 mg/dL, and levels of total cholesterol and LDL cholesterol rose slightly, although not to a statistically significant extent (Tomosugi, J Atheroscler Thromb 2017
). Because this study did not include a control group, the reliability of the results is questionable.
You can learn more about the other effects of collagen supplements, such as on the skin and joints, in our Collagen Supplements Review
, which includes our Top Picks for collagen
Collagen is essentially a form of animal protein derived from skin, joint cartilage, and bones. Another animal protein, whey protein, which is from milk, seems to modestly lower triglycerides, but the effects on cholesterol have been inconsistent (Zhang, Eur J Clin Nutr 2016
). However, casein (also from milk) doesn't seem to significantly improve triglyceride or cholesterol levels (Crouse, Arch Intern Med 1999
; Koury, J Physiol Biochem 2014
). (For more about these proteins, see our Protein Powders Review
, which includes our Top Picks for protein powder
To learn about supplements with stronger evidence for improving cholesterol levels, see our answer to the question Which supplements can help lower cholesterol and keep my heart healthy?