"The Safety of Heme vs. Non-Heme Iron"
It is commonly thought that those who eat plant-based diets
may be more prone to iron deficiency,
but it turns out that they’re no more likely to suffer
from iron deficiency anemia than anybody else.
This may be because not only do those eating meat-free diets
tend to get more fiber, and magnesium,
and vitamins A, C, and E,
but they also get more iron.
But the iron found in plants is non-heme iron.
Those eating meat-free diets don’t get much of heme iron
found in blood and muscle, which may be a GOOD thing.
The avoidance of heme iron may be one of the key elements
of plant-based protection against metabolic syndrome,
and may also be beneficial in lowering heart disease risk.
The link between iron intake and coronary heart disease
has been contentiously debated,
but the inconsistency of the evidence may be because
the majority of total dietary iron comes mostly from plants
and so total iron intake is associated with lower heart disease risk.
But if you just look at iron intake from meat,
it’s associated with significantly higher risk for heart disease.
This is thought to be because iron can act as a pro-oxidant
contributing to the development of atherosclerosis
by oxidizing cholesterol with free radicals.
The risk has been quantified as a 27% increase
in coronary heart disease risk
for every 1 milligram of heme iron consumed daily.
The same has been found for stroke risk.
The studies on iron intake and stroke have had conflicting results,
but may be because they never separated out
heme from non-heme iron, until…
...this study, which found that the intake of meat iron,
but NOT plant iron,
was associated with an increased risk of stroke,
as well as diabetes.
Higher animal iron intake significantly associated
with greater risk for type 2 diabetes,
but not total or plant iron.
16% increase in risk for every daily milligram
of heme iron consumed.
And the same for cancer, with up to 12% increased risk
for every milligram of daily heme iron exposure.
In fact, you can actually tell how much meat
someone is eating by looking at their tumors.
To characterize the mechanisms underlying
meat-related lung cancer development,
they ask lung cancer patients how much meat they ate
and examined the gene expression patterns in their tumors,
and identified a signature pattern
of heme-related gene expression.
Though they just looked at lung cancer
they expect these meat-related gene expression changes
may occur in other cancers as well.
We do need to get enough iron,
but only about 3% of premenopausal white women
have iron deficiency anemia these days,
however, the rates are worse for African and Mexican Americans.
Taking our leading killers into account—
heart disease, cancer, diabetes—
the healthiest source of iron appears to be non-heme iron,
found naturally in abundance in whole grains, beans,
split peas, chickpeas, and lentils, dark green leafy vegetables,
dried fruits, and nuts, and seeds.
But how much money can be made on beans?
So the industry came up with a blood-based crisp bread,
made out of rye and cattle and pig blood,
one of the most concentrated sources of heme iron,
about 2/3 more than chicken blood.
Now, if blood-based crackers don’t sound particularly appetizing,
no worries, there’s also cow blood cookies and blood-filled biscuits.
The filling ends up a dark-colored, chocolate flavored paste
with a very pleasant taste.
Dark-colored because spray-dried pig blood
can have a darkening effect on the food product’s color,
but the worry is not the color or taste,
it’s the heme iron,
which because of it’s potential cancer risk,
is not considered safe to add to foods
intended for the general population.