9.10: summary:
. vegans seem more prone to bleeding;
Sears's zone diet research suggests
that there is greater risk of bleeding
when taking high-dose fish oil,
because the omega-3 oil EPA
greatly exceeds the balancing effects of
arachidonic acid (AA) omega-6 oil.
. it is quite likely that the converse is true,
those with very low levels of AA,
are going to have a bloody EPA/AA ratio
even if their EPA is not high.
. one of the richest sources of AA is egg yolk,
and AA may be why a 2018 study showed
Chinese eating one yolk daily can
reduce their risk of bleeding death.
. a great vegan source for both protein
and the omega-6 that may be converted to AA,
is chickpeas (1.1g omega-6 per 100g);
of course, nuts and seeds
are the richest source of omega-6
other than processed oils.
. chia seeds and walnuts are balanced:
chia: 5.8g omega-6, 17.5g omega-3.
walnuts: 38g omega-6, 9g omega-3;
walnuts are rich in polyphenols too.
Arachidonic acid
is not considered an essential fatty acids;
however, it does become essential if a
deficiency in essential linoleic acid exists
or if there is an inability to do
any of the following conversions:
linoleic acid to GLA to dihomo-GLA
to arachidonic acid.
Since little or no arachidonic acid
is found in common plants,
such persons are obligate carnivores
[non-vegetarians].
Brenda Davis, RD, 1998:
Eicosanoids formed from arachidonic acid (AA)
have the potential to increase platelet aggregation, ...
[that stops bleeding]
Those formed from eicosapentaenoic acid
(EPA)(omega-3 family) have opposing affects.
[ Lee, K., Oilce Y., and Kanazawa T., eds
The Third International on Nutrition in Cardiovascular Diseases.
Annals NY Acad Sci Vol 676, 1993.
Chow, CK ed, Fatty Acids in Foods and their Health Implications.
New York, Marcel Dekker Inc., 1993.]
Heart, 2018:
daily egg consumers (up to one egg/day)
in China where there is more
haemorrhagic stroke [HS, bleeding in the brain]
than in high-income countries,
had a 26% lower risk of HS,
and a 28% lower risk of HS death.
. also there was an 18% lower risk of
CVD [coronary vascular disease] death.
9.6: a confusing story:
. vegans get more stroke?
it's confusing to hear they get
less heart disease but more stroke
because stroke is a major form of heart disease
but there's clotting vs bleeding.
. it's just an epidemiological study
not real science with a
randomized intervention study;
so it could be simply showing that
the sort of person who goes vegan
happens to also have risk factors for bleeding
that is unrelated to veganism.
. however, later it would occur to me
that from what I knew about bleeding from fish oil,
the same thing could also apply to vegans:
. fish oil users get bleeding
when their EPA omega-3 far exceeds
the AA omega-6 they get from animal products,
and apparently this can happen either from
getting too much EPA,
or getting too little AA.
. most of our AA comes from animal fat
so vegans can get it only when
they can convert vegetable oil to it
-- apparently not alway easy to do,
and made worse by a low fat diet.
source:
CNN Nina Avramova, September 4:
Vegetarians might have
higher risk of stroke than meat eaters:
. BMJ research explained by Dr.Tong
found that vegetarians had up to a
20% higher risk of bleeding stroke
than eaters of mammal or fish,
particularly hemorrhagic stroke.
This translates to 3 more cases of stroke
per 1,000 people over 10 years.
. compared to mammal eaters,
Vegetarians had a 22% lower risk
of coronary heart disease,
whereas fish eaters had only a
13% lower risk.
that story comes from this BMJ article:
BMJ 2019;366:l4897
Risks of ischaemic heart disease and stroke
in meat eaters, fish eaters, and vegetarians
over 18 years of follow-up:
results from the prospective EPIC-Oxford study
. the study authors assume that
LDL cholesterol is associated with
more bleeding because of statin trials;
but statins don't just control cholesterol,
they also are anti-inflammatories
according to Dr.Sears,
and that is what fish oil does too:
both are diluting the effects of AA.
the risk change for certain diseases
relative to the risk for mammal meat eaters;
but due to wide 95% confidence intervals,
here is what the table actually says:
. for ischaemic heart disease,
clearly it happens less often
in fish-only eaters and vegans,
and possibly veganism is the most helpful.
. for ischaemic strokes,
they have no statistical significance:
no idea whether veganism or fish-only
does better or worse than mammal eaters.
. for hemorrhagic stroke:
clearly vegetarianism is less safe
than eating mammal meat,
whereas the fish-only results were not clear:
it could either be safer than mammal,
or even riskier than veganism: non-sense.
. I'm glad they added the word
heterogeneity (of p) to the table
because it helped me find this
students4bestevidence page
which mentioned that the sort of graph they use
is called a forest plot
and that forest plot page, I think,
confirmed the hunch I had,
that they really had no idea
(no statistical significance):
students4bestevidence`forest-plot:
"( The horizontal line and whether it
crosses the “line of null effect”
[or in our case the line of
being better or worse than mammal diet]
is particularly important.
. the basic definition of the
95% confidence interval is:
“The range of values within which you can be
95% certain the true value lies.”
If the horizontal line crosses the line of null effect
what that is effectively saying is that
the null value lies within your confidence interval
and hence could be the true value.
simplest explanation:
“any study line which crosses the line of null effect
does not illustrate a statistically significant result.”
).
No comments:
Post a Comment