Lactate and brain

Discussion in 'Articles & Scientific Studies' started by jyb, Apr 29, 2013.

  1. jyb

    jyb Member

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    Just thought it's interesting how, in contradiction with what one can learn from RP, it is sometimes written in more mainstream media that brain uses lactic acid as preferred source of energy, and are quoted studies such as

    http://www.ncbi.nlm.nih.gov/pubmed/21593331

     
  2. pboy

    pboy Member

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    I bet its more of a prioritization thing rather than a 'preferred' source...like for example, if you drink alcohol the cells will preferentially use it for energy over glucose until the alcohol is exhausted...because it is less stable, and potentially more inflammatory than glucose, so your body would rather process and get rid of it before it utilizes the less potentially inflammatory glucose. I'd assume this same concept applies to lactic acid. One thing that's good though about this study is that it is good to know that even if you were to eat an abundance of glucose, inefficiently metabolize it, thereby producing lactic acid, the brain can still utilize this lactic acid for energy and therefore not much overall ATP/energy is wasted.
     
  3. Edward

    Edward Member

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    The lactate shuttle theory has been for around for several decades and it has especially received a lot of attention in the low-carbohydrate community, this is because lactate tends to elevate during low-carbohydrate dieting which is a consequence of limited glucose. People who have seizures have elevated lactate levels from malfunctioning glucose pathways, the only away around those pathways is ketones or fructose, both of which are documented in the literature for stopping seizures in rats. If you flood an epileptic with glucose during seizure the seizure will usually worsen because the inefficient use of glucose is flooding the brain with lactate.

    In a healthy person this is not an issue, there are times that glucose is converted into lactate when glucose or fructose or ketones need to be prioritized somewhere else. Typically this occurs as you a approach a glycogen depleted state.

    Still the lactate "pathway" exists but the fundamental flaw with the theory is that it is somehow a desirable state to be in. Sometimes people on low-carbohydrate diets will experience feelings where it feels like their body is separated from them, a detached feeling, etc. This is typically the result, besides electrolyte imbalances, of approaching lactic acidosis. The feeling can be either fearful or pleasant; it depends on a lot of different variables. The body maintains tight control over blood pH and usually as lactic acid increases it is buffered. But during a stressful situation this sometimes becomes impossible.

    However, lactic acid does have a protective effect in healthy people under certain situations. Lactic acid can also be converted into glucose via the Cori cycle. Like so many of the other stress compounds released in the body, it is protective in the short term, and harmful in the long term.

    I've attached a full paper from my hard drive that gives a good historical overview and current thinking, it's interesting, at points in the paper you can detect whiffs of desperation. I also attached the paper on the anticonvulsant activity of fructose.
     
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