This is looking at HDL3 levels and clearly one can see that low levels are bad, while 2nd quartile and above it is kind of a wash. In the conclusion:
Currently, low HDL3 concentrations are not targeted for intervention. Niacin effectively increases HDL-C, but this does not appear to involve HDL3. Specifically, niacin increases HDL2b and reduces HDL3c and HDL3b without significantly affecting HDL2a or 3a.[36] Fenofibrate is reported to increase HDL3-C and apo A-II while decreasing HDL2-C,[37] which may not be the change desired. Lifestyle approaches to raising HDL, such as physical activity and weight loss, primarily raise HDL2 mass concentrations and not HDL3 mass concentrations.[26] It has been reported that higher HDL3 mass concentrations are associated with greater alcohol intake and lower carbohydrate intake[38] and subsequently shown that, in moderate drinkers randomized to an abstention group or a control drinking group (n = 12), HDL-C and HDL3-mass decreased significantly in abstainers but not in drinkers and that resumption of drinking increased HDL-C levels and HDL3 mass without affecting HDL2 mass.[39] Another study confirmed that replacing dietary carbohydrates with fat significantly increased HDL3 mass concentrations.[40]
So get those monounsaturated fats into your diet and replace those non-fiber carbohydrates. Ensure a variety of non-soluble, soluble fibers (e.g. psyllium, pectin, bran).
References
01. J Am Geriatr Soc. 2012 Feb 13. doi: 10.1111/j.1532-5415.2011.03851.x. [Epub ahead of print]Low High-Density Lipoprotein 3 Reduces the Odds of Men Surviving to Age 85 During 53-Year Follow-Up.Williams PT.
