Monday, June 09, 2008

Dr. Westman: Yet Another Possible Explanation

After reading the findings comparing the Masai, and the rural and urban Bantu in Tanzania, Dr. Eric Westman penned a reply to the British Journal of Sports Medicine:

Yet another possible explanation
Eric C Westman, researcher Duke University

Thank you for this contemporary assessment of dietary intake among the Masai pastoralists. Through the paradigm-shifting lens of a recent comprehensive summary of the lack of science to implicate saturated fat as a cause for heart disease [1], and new studies which suggest carbohydrate to be more worrisome than saturated fat for atherogenesis [2-4], there is a simple explanation for why the Masai do not develop atherosclerosis despite consuming a high-fat diet that the authors did not consider: high-fat diets (not containing man-made fats) are not atherogenic.

1. Taubes G. Good Calories, Bad Calories. Knopf Publishing, 2007.
2. Krauss RM et al. Separate effects of reduced carbohydrate intake and weight loss on atherogenic dyslipidemia. Am J Clin Nutr 2006;83:1025-31.
3. Mozaffarian D et al. Dietary fats, carbohydrate, and progression of coronary atherosclerosis in postmenopausal women. Am J Clin Nutr 2004;60:1102-3.
4.Volek JS et al. Dietary carbohydrate restriction induces a unique metabolic state positively affecting atherogenic dyslipidemia, fatty acid partitioning, and metabolic syndrome. Prog Lipid Res 2008;Mar 15 (Epub ahead of print]


  1. Yep.

    Thanks, Regina.

  2. I'm interested in this because I've been low-carbing for the last ten months and my LDL cholesterol has increased from 140 to 153 since then. I was expecting an improvement in my numbers and was really surprised it was so high.

    Has anyone else experienced something like this? The only fats I eat are butter, olive oil, and fats from meat and whole dairy--no soy, canola, corn oil or other man-made stuff.

    Thank you for your blog, Regina. I've learned a lot from it.

  3. Thank you, Dr. Westman!

    Of course, it couldn't POSSIBLY be THAT simple now, could it? [/sarcasm]

  4. Nina,
    The important number is the ratio between triglycerides and HDL (triglycerides/HDL.) Lowering triglycerides and raising HDL is an improvement because it reflects a change in LDL particle size. The small, dense lipoprotein particles are the ones that are arthrogenic, they also carry less cholesterol than the large, fluffy, more benign lipoprotein particles.

  5. Anonymous11:34 PM

    Hi Regina and thank you for the lab data and analysis!

    However, tha abstract made me ponder about the reported data on energies.

    In Tanzania hunting and cattle herding is man-duty but farming seems largely to rely on female work power. Furthermore, farming can be hard work too.

    The report included both sexes. I have trouble believing that maasai ladies should need that much more energy than their bantu colleagus. How about you?

    (And, as a non-reseach fact to side with these wonderings, I'm livin largely on dairy and pork fat without much excerciseat all... and my lab values are ok, too.)

    Regards from LeenaS, Finland
    (been on LC since 2000)

  6. Anonymous10:49 AM


    Yes I saw my LDL increase by10% on LC. But it is not a problem. The increase in LDL comes in the form of the less dense, fluffier, sub-type of LDL. The other subtype, the smaller, denser sub-type is the atherogenic kind. On LC, typically HDL goes up, Triglycerides plummet, TC goes down for most, and LDL goes down for most. HDL going up and TG going down are the parameters of concern.

  7. LDL particles are what carries cholesterol (they are not cholesterol themselves) out to your organs. Since your brain and heart are made up of large amounts of cholesterol, that's kind of important--the cholesterol on LDL particles must be used at least in part to maintain the brain and the heart.

    So if you've got more LDL going on then you've got more maintenance going on.

    HDL is the particle that carries cholesterol back to the liver. If your HDL increases as well as your LDL then that would say to me your body doesn't need all that cholesterol for specifically maintenance and rebuilding needs, so it's sending the excess back to the liver, which is fine too.

    It's when you're sending out more cholesterol than you're getting back when you're going to see a problem. Obviously something is going on that the body needs to fix more than usual, I would think.

  8. During weight loss from fatty tissue, you're liberating lipoproteins along with lipids. There's no way around this. Unfortunately, the specific LDL particles released are likely to be small and dense, which might worry you unless you were expecting this to happen.

    Wait for at least a month or two after your weight stabilizes before you look for serious improvements in either LDL/HDL ratios or in LDL particle size. All will improve, but it will take some time.

    Be patient, you're on the right track.