Friday, July 11, 2008

Fat and the sexes

Of all the hubris, bad science, politics, hand-wringing, strident talk of saving lives and etc that went into demonizing saturated fat and cholesterol in the name of reducing the risk of heart disease, the one that gets me the most is this:

All the studies until 1987 were of men.

When we finally looked at women (through the emerging data at the framingham heart study and several that followed) we found that none of the correlations of men (higher CHD rates and lower overall mortality) of a high fat diet were apparent for women.  Women seem to have a much higher tolerance for blood cholesterol then men.  

Now, the evidence also started mounting that a low-fat diet was associated with higher rates of cancer and stroke.  In fact, from the very start we have found both in tests in which we followed groups (framingham) and in randomized control experiments, that the mortality rate of a high fat diet (>30%) is lower then a low fat diet.  Additionally, test after test has found higher rates of cancer the lower the fat content becomes.

So, we have been recommending to women for nearly 60 years that they significantly lower their Saturated Fat content in their diets (Milk, cheese, red-meat, coconut oil, butter) in order to prevent heart disease.   All along we were finding only that a higher saturated fat diet had a slightly higher association with CHD in MEN.  Additionally we were finding that the low fat diet also had a higher overall mortality rate.  And we never tested women.

A good friend of mine keeps telling me that the medical establishment is filled to the brim with well-meaning, intelligent, caring, incremental thinkers, who are not pushed around by fads and poor data.  

I just don't believe her anymore.  We must look more closely at everything we have come to believe.  

That is just what I did - I looked at the latest framingham data from their website.  Here are some bits:

Probabilities Pts 2-yr - Men, ages 35-74, chance of CHD event (heart attack or stroke)

0 0% 14 1% 28 17%
2 0% 16 2% 30 24%
4 0% 18 3% 32 32%
6 0% 20 4% 34 43%
8 0% 22 6%
10 1% 24 9%
12 1% 26 12%

The chart for women is quite similar, but is separated into menopause groups and non-menopause groups, so I have left it out.  The point system works this way:  Points are assigned to risk factors (high cholesterol, HBP, smoking, etc.)  

What this chart shows us, according the the point assignments on the 2-year risk factor page is that a man or women needs a score of 10 or more to be at risk of a CHD event.  For a 50 year old non-smoking woman, according to framingham, to be at risk she must have a cholesterol level of 290 or above and a systolic BP of 180 or more.  And that would give her an increased risk of 1%.  

{Note:  Doctors will usually medicate a cholesterol of >200 and a systolic of >130}

Look over the figures yourself, those I refer to can be found here.

Be Well.

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