Debby Padilla-Hudson wrote:

>Todd, I would love to share this study with my mother,
>who is diabetic and is always debating with me about
>the healthfulness of low carb and asking for a proper
>study.
>
>Problem is, I don't I would share this study with her
>because of the poor results with lean muscle and
>homocysteine (marker for heart disease).  
>  
>

Wildtrout has already posted the criticism of the lean muscle loss 
measurements, which should allay concerns on that score.  In addition, I 
think you can find other studies that demonstrate that lowcarb diets do 
not cause excessive muscle loss.  But they do cause diuresis, which is 
apparently what threw off the lean tissue measurements.

>Maybe homocysteine is not a good marker for heart
>disease after all?  Perhaps bad levels of various
>things in the body raise temporarily while the body
>heals itself?
>  
>
No, I think homocysteine is probably an independent risk factor for 
heart disease.  I recall other research indicating somewhat elevated 
homocysteine levels in people on very lowcarb diets.  I believe, for 
example, that studies of the Samburu in Africa showed that they tended 
to have elevated homocysteine levels.  Homocysteine, of course, is a 
metabolite of the amino acid methionine, which is abundant in meats.  
Folic acid and vitamins B6 and B12 are needed in abundance to keep 
homocysteine levels low.  It's not especially easy to get a lot of folic 
acid on a paleo diet.  It's found in liver, for example, at about 260 
mcg per 100g of cooked beef liver.  The RDA for folic acid is 400 mcg, 
and if you're eating enough meat to elevate homocysteine in the first 
place, you'd probably want more.  In vegetables, the best sources tend 
to be legumes, but they are off-limits on paleo.  Next best would be 
spinach and turnip greens, at just under 200 mcg per 100g.  So if you 
eat a lot of greens and/or liver each day, you might get enough to 
control homocysteine.  Personally, I can't get used to the taste of 
liver.  I take some dessicated liver, but I don't know if that is 
sufficient.  Since going paleo, I have found that I don't digest large 
quantities of leafy greens very well.  The occasional salad is fine, but 
a steady intake of greens seems to irritate my gut, causing bloating, 
discomfort, and other unpleasantness.  I have no idea why.  So...I 
supplement with one of the commercially available anti-homocysteine 
products.  That's not a paleo solution, I know, but I am simply 
unwilling to stuff myself with liver and greens every day.


>I've seen cholesterol raise early on in LC diets which
>some people think is a healing reaction - cholesterol
>being used to repair the body.  Perhaps it's the same
>with homocysteine?
>  
>

I don't think so.  Liberal intake of saturated fat tends to raise LDL 
cholesterol by a well-known mechanism, which is the downregulation of 
LDL receptors in the liver.  Although many people see LDL go down when 
they follow a lowcarb diet, not all do.  I think this is because there 
are two independent mechanisms at work: the rate of LDL reuptake by the 
liver, which is affected by saturated fat; and the rate of LDL 
production, which is affected by insulin.  A lowcarb diet that includes 
a liberal amount of saturated fat would tend to lower both reuptake and 
production, but not necessarily by the same amount.  There are probably 
large individual differences here, so some will see a net decline in 
LDL, while others will see a net increase.  Moreover, 8 weeks isn't 
enough time to draw any firm conclusions--although to see an increase in 
HDL in so short a time is certainly striking.  HDL is one of those 
numbers that's usually pretty hard to budge.

Todd Moody
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