Debby Padilla-Hudson wrote:

>>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.
>>    
>>
>
>OK, so are you saying that low carb can be bad for the
>heart, especially because it is usually low in B
>vitamins in normal practice?
>  
>

I think "bad for the heart" is too strong a statement.  But  a diet that 
is high in meat protein and low in folic acid, B12 and B6 *will* lead to 
elevated homocysteine levels, and this is believed to make artery walls 
"stickier".  As I said in the previous message, this need not be the 
case, since one can get ample folic acid and other B vitamins in liver, 
for example, and certain greens (remember that "folic" refers to 
foliage).  But it's a question of making certain choices.  I just don't 
enjoy liver.  I never ate it as a kid, and as an adult I've found it 
impossible to acquire a taste for it.  So I choose to supplement and not 
worry about it.


>>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.
>>    
>>
>
>OK, so does this mean that in the long run low carb is
>good for your cholesterol, or that having low
>cholesterol doesn't matter?  Sorry I'm just trying to
>get the direct answers to my question, as it seems
>that your answers gave a lot of
>speculation/observation/hypothesis but no conclusions.
>  
>

That's because I'm an academic, so I wrap my statements in qualifiers, 
disclaimers, and cautions, so to speak, as it were, if you will, as a 
rule, generally, notwithstanding.

Seriously, this is one of the most controverted issues in nutrition.  We 
each have to look at the evidence and work out what we think about the 
cholesterol issue.  For what it's worth, here's what I think.

1.  For many people, including myself, increased intake of saturated fat 
raises LDL cholesterol.  The reason for this is that the saturates 
downregulate the LDL receptors in the liver, decreasing LDL reuptake.  A 
Nobel Prize was awarded for the discovery of this mechanism not too long 
ago.

2.  At the same time, reducing carbs should cause the liver to produce 
less cholesterol, by reducing insulin levels, since insulin signals the 
liver to make the stuff.

3.  In a person with significant insulin resistance (IR), it's likely to 
take a while to get control of insulin levels, so the process in (1) is 
likely to outrun the process in (2) at first.  The result would be an 
initial increase in LDL on a lowcarb diet that is also high in saturates.

4.  A lowcarb diet that is rather high in protein won't achieve good 
insulin control, because of the need to convert a lot of that protein to 
glucose.

5.  What matters is not the absolute amount of LDL cholesterol, but the 
percentage of it that is small-dense particles.  This is not usually 
measured in routine lab work, but is strongly correlated with 
triglycerides.  So if triglycerides are low, the small-dense LDL 
fraction is likely to be small as well.

6.  Lowcarb diets are the best way to reduce triglycerides and 
small-dense LDL.

7.  A lowcarb diet that doesn't avoid saturated fat is the best dietary 
way to raise HDL.

That's pretty much where I stand on the cholesterol question, for now.

Todd Moody
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