In briefBMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d1338 (Published 01 March 2011) Cite this as: BMJ 2011;342:d1338
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The recent Scientific Advisory Committee on Nutrition (SACN) report
on Iron and Health recommends reducing red and processed meat consumption
due to links with colorectal cancer incidence . The report states that
a reduction to 70 mg cooked meat/day would have little impact on the
proportion of the adult population with low iron intakes. The above
recommendation is largely based on evidence from prospective studies of
diet and colorectal cancer in middle-aged participants. The biggest
prospective study showing a significant increase in risk of colorectal
cancer with red meat consumption included around 440,000 participants aged
50-71 years at baseline . A pooled analysis of around 61,566 younger
participants from the EIPC-Oxford cohort aged 35-69 years at baseline
observed no significant difference in colorectal cancer incidence between
meat eaters and vegetarians .
In the SACN report, women of reproductive age are indentified as
being at particular risk of iron deficiency anaemia. Around 25% of women
of reproductive age in Western societies are estimated to have iron
deficiency anaemia . Iron deficiency anaemia during the first half of
pregnancy increases the risk for preterm birth, low birthweight, infant
mortality, and infant iron deficiency . We know that dietary iron
intake in these women is lower than other population groups. Around 41% of
women aged < 34 years had daily dietary iron intakes less than the
Lower Reference Nutrient Intake (LRNI) of 8 mg/day according to the 2001
National Diet and Nutrition Survey (NDNS) in Great Britain . The mean
iron intake was 10 mg for women aged 19-64 years. This is lower than
levels of intake in other developed countries such as the United States
(15 mg/day in pregnant women) . We have shown that around one in four
pregnant women in a prospective study of around 1300 participants in
Leeds, UK had iron intake less than the LRNI, and total iron intake during
early pregnancy was positively linked to birthweight .
The SACN report does not recommend any changes to the current
National Institute for Clinical Excellence (NICE) antenatal guidelines in
relation to iron. NICE recommends that haemoglobin levels less than 11
g/100 ml in the first trimester and 10.5 g/100 ml at 28 weeks are
investigated and iron supplementation considered if indicated .
However, the problem arises when supplements are not well-tolerated and
therefore abandoned by iron-deficient pregnant women because of common
side effects such as nausea and constipation. There is no focus in current
UK antenatal care on providing specific dietary advice to maximize iron
intake from food during pregnancy. A public health approach to providing
antenatal advice of how to ensure adequate iron intake during pregnancy is
needed. Recommending meat as the source of haem, the readily-absorbed form
of iron, during the limited span of pregnancy is unlikely to have adverse
effects in relation to lifetime risk of colorectal cancer given the
available research evidence.
With the relatively high prevalence of inadequate dietary iron intake
in women of child-bearing age in the UK, changes to the current antenatal
policy in relation to iron intake may be warranted. Public health messages
about increasing dietary iron intake during early pregnancy and possible
ways to optimise iron absorption from non-haem sources, whether from diet
or supplements, need to be promoted.
We recommend considering iron intake during pregnancy separately from
lifelong recommendations for red meat intake.
1. Scientific Advisory Committee on Nutrition (SACN). Iron and Health.
2011; Available from:
2. Cross, A.J., et al., A prospective study of red and processed meat
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3. Key, T.J., et al., Cancer incidence in vegetarians: results from the
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Oxford). The American Journal of Clinical Nutrition, 2009. 89(5): p. 1620S
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Hematology, 2008. 87(12): p. 949-959.
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2003, Food Standards Agency: London.
7. National Center for Health Statistics, Plan and Operation of the Third
National Health and Nutrition Examination Survey, 1988-94, 1994, U.S.
Dept. of Health and Human Services, Public Health Service, Centers for
Disease Control and Prevention: Washington, DC.
8. Alwan, N.A., et al., Dietary iron intake during early pregnancy and
birth outcomes in a cohort of British women. Human Reproduction, 2011.
9. NICE, Antenatal care: Routine care for the healthy pregnant woman,
2008, National Institute for Clinical Excellence London.
Competing interests: No competing interests