Our final, non-duplicate study in S-T and K's meta-analysis is another study of strokes out of Japan. The Adult Health Study (apparently rated R), looked at a single category of cerebral infarction in Japanese from Hiroshima and Nagasaki.
The answer to the question you have in your mind right now is, "Yes, they were all exposed to the atomic bombs." So this is not your typical run-of-the-mill nutritional epidemiological study. What it's doing in this analysis is really hard to justify IMO. stroke.ahajournals.org/content/35/7/1…
The infarction is a single category, with no breakout between hemorrhagic stroke and ischemic stroke. Does radiation exposure materially effect the risk of hemorrhagic stroke? One study suggests the possibility but I have seen no high quality research. bmj.com/content/340/bm…
It's not hard to imagine radiation weakening the blood vessels, and there are case reports of this taking place. In this one, a woman received radiation for lymphoma and had a severe hemorrhagic stroke 3 months later. onlinelibrary.wiley.com/doi/10.1002/10…
In any case, nobody could argue that this population could be safely grouped with the others looked at in this meta-analyis. Again, because there was no distinction in this study between hemorrhagic and ischemic stroke, we don't know what was being protected.
So again, this study showed a protective effect of SFA and animal protein in this population. And it is likely that if the prevalence of hemorrhagic strokes was high, this effect could be real. I agree that SFA likely protects against hemorrhagic stroke in some patients.
It is likely NOT protective, however of overall stroke risk, since only about 1/10 of strokes are hemorrhagic, and it is also of limited benefit in normotensive patients who do not consume alcohol regularly, these are the big risk factors for this type of stroke.
So this is the final study we will examine in this series. Tomorrow, I'll add some closing thoughts on this overall study and discuss meta-analysis and its pitfalls.
