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Fermented dairy, lactic acid, and CLA

I consume a lot of full fat dairy. A good half of it—probably more—is fermented in some bacterial cocktail. In some places there has been resurgence in the idea of drinking lots of milk. I think anything coming from a cow is healthy. But some people believe that the lactic acid in fermented bacterial cocktails is harmful.

As well, people talk about how much milk the Maasai drank. Now the Maasai and other dairy herding cultures are healthy. Thriving off of cows and their milk and the products produced from their milk no doubt is a high saturated fat diet. I think dairy, as far as food sources go, is probably the best and safest food source. I think the rest of the cow is good, too. But with how bad fermented foods are supposed to be and limiting yourself to maybe two tablespoons of yogurt, well that sounds rather…

Thriving off of cows and their dairy is like extended breast feeding

Babies seem healthy to me and they seem to like breast milk. How dare a mother poison her baby with lactic acid producing bacteria (Martín et al., 2003).

I’m a big believer that a theory should—if it has any ounce of credibility—reflect what we see in reality. Most of the milk drank by the Maasai was fermented. There is a problem there. Given their good health and the fact they smoke a lot gives us a couple of angles to work from. No science required, just a little logic and common sense. First, the traditional Maasai were healthy. Second they smoked a lot. In modern culture we view smoking and/or nicotine as unhealthy, so if the Maasai have an unhealthy lifestyle factor then they must be protected by something in their diet (or some other factor). But we’ll avoid the complexity of those other factors for now and focus on the diet. So the Maasai smoked, and according to those who believe that lactic acid is harmful, that is also another risk factor for disaster.

The real question is: if lactic acid is harmful despite the fact that the lactic acid producing bacteria modulate endotoxin (Schiffrin, Rochat, Link-Amster, Aeschlimann, & Donnet-Hughes, 1995), and if smoking is harmful despite the fact that nicotine modulates endotoxin (Wittebole et al., 2007), well then…we have a big problem considering that most of the calories in the traditional Maasai diet are coming from fermented milk. These guys, according to some paradigms, are literally waiting to burst giant lactic acid secreting tumors out of their eye sockets, earholes and rectums. But they don’t. Of course, we could forever go down the road of different arguments, but really the simplest answer, and an answer that agrees with other traditional healthy cultures that ate fermented dairy, is simple: lactic acid is not harmful. Much like people who eat more saturated fat tend to be healthier. Yes, people who eat butter are healthier, faster, and stronger.

Of course, what is more interesting about fermented dairy is some of the special properties those bacteria provide us with. For example, Lactobacillus plantarum found in some fermented dairy products (but mostly in fermented plant concoctions) converts linoleic acid to CLA (Kishino, Ogawa, Yokozeki, & Shimizu, 2009; Ogawa et al., 2005). Of course, CLA is useful (Belury, 2002).

I don’t know. If you are eating a low PUFA diet and you are worried about PUFA, I kind of like the idea of a little flora mopping up what I can’t humanly avoid and turning it into something useful and probably healthful.


Belury, M. A. (2002). Inhibition of Carcinogenesis by Conjugated Linoleic Acid: Potential Mechanisms of Action. J. Nutr.132(10), 2995–2998. Retrieved from http://jn.nutrition.org/content/132/10/2995.full

Kishino, S., Ogawa, J., Yokozeki, K., & Shimizu, S. (2009). Metabolic diversity in biohydrogenation of polyunsaturated fatty acids by lactic acid bacteria involving conjugated fatty acid production. Applied Microbiology and Biotechnology84(1), 87–97. doi:10.1007/s00253-009-1949-0

Martín, R., Langa, S., Reviriego, C., Jimínez, E., Marín, M. L., Xaus, J., … Rodríguez, J. M. (2003). Human milk is a source of lactic acid bacteria for the infant gut. The Journal of Pediatrics143(6), 754–8. doi:10.1016/j.jpeds.2003.09.028

Ogawa, J., Kishino, S., Ando, A., Sugimoto, S., Mihara, K., & Shimizu, S. (2005). Production of conjugated fatty acids by lactic acid bacteria. Journal of Bioscience and Bioengineering100(4), 355–64. doi:10.1263/jbb.100.355

Schiffrin, E. J., Rochat, F., Link-Amster, H., Aeschlimann, J. M., & Donnet-Hughes, a. (1995). Immunomodulation of human blood cells following the ingestion of lactic acid bacteria. Journal of Dairy Science78(3), 491–7. doi:10.3168/jds.S0022-0302(95)76659-0

Wittebole, X., Hahm, S., Coyle, S. M., Kumar, A., Calvano, S. E., & Lowry, S. F. (2007). Nicotine exposure alters in vivo human responses to endotoxin. Clinical and Experimental Immunology147(1), 28–34. doi:10.1111/j.1365-2249.2006.03248.x

3 comments… add one
  • James 28/03/2014, 1:54 pm

    I’m a bit skeptic about inferring that a habit or food is good based upon the apparent health of a population. You mentioned that there could be protecting factors, for example. But also, how do you know that the population is healthy? A population could be healthier than average, yet still unhealthy and could still benefit from adopting different habits.

    That said, I’m not saying that you are wrong in your conclusion. Generally I think its possible that you are correct in your opinions even when they contradict others (on tobacco, lactic acid, fat,…), because I find it plausible that there are several optimums – for someone healthy, there could exist different diets that lead to about the same outcome, continued health.

    For diet and fat however, I would make an exception for the situation of someone being in poor health and trying to recover – I find the case for emphasizing sugar convincing. But Ray Peat seems to think carb (esp. sugar – but let’s leave alone the debate on starch and endotoxin for now) is needed for good thyroid even once in good health – do you disagree and if so why? Again, I find it plausible that a high sat fat diet could be as good for someone healthy, but I wonder if you’d agree about high sugar being good.

  • John Eels 31/05/2014, 1:07 pm

    I see you linked to Shant’s blog that Seth put in the spotlight. If I recall correctly Shant pointed out that heart disease associated with smoking was related to a change of bacterial composition in the large intestine. That’s as far as I understand his hypothesis. Oh, here I’ve found the article: http://mrheisenbug.wordpress.com/2013/12/26/is-this-why-smoking-is-the-number-one-predictor-of-heart-disease/ A quote from it:

    “Profound shifts in the microbial composition after smoking cessation were observed with an increase of Firmicutes and Actinobacteria and a lower proportion of Bacteroidetes and Proteobacteria on the phylum level. In addition, after smoking cessation there was an increase in microbial diversity.”

    It looks like smoking is a two edged sword. It seems to modulate LPS exposure in favorable ways as you pointed out. On the other hand it seems to reduce bacterial diversity. So maybe the Masaii compensate for the lost diversity of bacterial composition with drinking fermented milk. Anyway, I wonder about the different role of bacteria in different parts of the intestine. You don’t want much bacteria in the small intestine. It’s supposed to be fairly sterile (I think Ray Peat has even gone as far as to say that many mental diseases are related to bacterial over population in the small intestine and proposed antibiotics as treatment for schizophrenia for example). The large intestine is different. That’s where you find the highest density of bacteria and I think Shant always talks about the bacterial composition in the large intestine.

    So, what’s preferred? Do you make the large intestine happy or the small intestine? Ray Peat’s dieatary advice to eat easily digested foods stems from the idea to keep the small intestine sterile (stomach acid kills most pathogens and is an important defensive). When Shant looks at bacteria he talks about the large intestine. I think that’s where the very opposing views stem from.

  • James 05/06/2014, 3:24 pm

    Ray talked about caffeine being protective against tobacco smoke in some animal experiments. It seems like the Maasai might be getting caffeine from tea, which they consumed with meat.

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