The Safety of Heme vs. Nonheme Iron

The Safety of Heme vs. Nonheme Iron

September 17, 2019 45 By Bertrand Dibbert


“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.