Recently I read an article by Ray Peat describing the almost limitless negative effects of lactic acid on the human body: http://raypeat.com/articles/aging/altitude-mortality.shtml
Peat does not consume any fermented foods except cheese for this reason. Although he provides tons of references supporting his statements about lactic acid in the human body and it all makes sense to me, I have two problems with his recommendation to avoid all fermented foods except cheese: 1 - just about every single culture throughout the recorded history of humanity (HG or agrarian) has consumed at least one fermented food or beverage in their diet, including the longest living cultures like the Okinawans; 2 - I recently started making water kefir and although I have not noticed any significant effects on my health from it yet, I really don't want to give it up because of how cheap and superior in both quantity and variety of species it is compared to probiotic supplements.
Can someone reconcile the negative effects of lactic acid described in the above article by Peat with the known health benefits of consuming fermented foods and beverages daily? Could there be some property of the fermented foods and beverages that offsets the putative negative effects of the lactic acid? Is this a perfect example of the limitations of science in explaining human health and disease or is there validity to Peat's argument? Any facts or ideas about this subject will be greatly appreciated.
If anyone has any evidence showing positive effects of lactic acid on the body I would be interested in that also.
Yeah lactic acid is a primary energy source so I dunno what he's smoking. It's like someone saying pyruvate is toxic.
Jon, the links below refer to research conducted in animals but they're probably relevant to why we seem to benefit from water kefir, yogurt, etc. And I think we need to distinguish between lactic acid and probiotic lactic acid bacteria.
In one study, probiotic lactic acid bacteria inhibited growth of Salmonella in young chickens.
In another, perhaps more relevant, I found this quote:
"Lactic acid bacteria also inhibit the growth of harmful putrefactive microorganisms through other metabolic products such as hydrogen peroxide, carbon dioxide and diacetyl."
A third document says, "Probiotic micro-organisms including lactic acid bacteria (LAB) positively influence the composition of the gut microflora; they stimulate the production of secretory IgA; they affect the targeted transportation of the luminal antigens to Peyer’s patches and they increase the production of IFN-γ. LAB stimulate the activity of non-specific and specific immune cells. ese properties of the LAB depend on the particular species or strain of bacteria. ese singularities are probably determined by differences in the cell wall composition. LAB belong to a group of beneficially acting bacteria and they are able to eliminate damage to the gut microenvironment; they stimulate local and systemic immune responses and they maintain the integrity of the gut wall."
It is possible that cultures used it as a mechanism to reduce metabolism in order to make do with less food and less nutrition. Another confounder is the fact that continuing the fermentation will make alcohol, that is pretty sought after.
On a personal note, it feels wrong to eat yogurt and eggs at the same meal.
His recommendations are more about not burning glucose in a oxygen deprived state which produces lactic acid, this is where most of the damage from lactic acid occurs.
People get pretty hyped on the fermented food thing because traditional cultures did it but they forget they did it because it was a necessity they would die without. Would they be healthier with out it?? Maybe, maybe not. Not a very good argument though imo.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3043458/ "Cerebral lactic acid, a product of ischemic anaerobic glycolysis, may directly contribute to ischemic brain damage in vivo."
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