Is Higher Consumption of Animal Flesh Foods Associated with Better Iron Status among Adults in Developed Countries? A Systematic Review

Abstract

Iron deficiency (ID) is the most prevalent nutrient deficiency within the developed world. This is of concern as ID has been shown to affect immunity, thermoregulation, work performance and cognition. Animal flesh foods provide the richest and most bioavailable source of dietary (haem) iron, however, it is unclear whether low animal flesh diets contribute to ID. This systematic review aimed to investigate whether a higher consumption of animal flesh foods is associated with better iron status in adults. CINAHL, Cochrane, EMBASE and MEDLINE were searched for published studies that included adults (≥18 years) from developed countries and measured flesh intakes in relation to iron status indices. Eight experimental and 41 observational studies met the inclusion criteria. Generally, studies varied in population and study designs and results were conflicting. Of the seven high quality studies, five showed a positive association between animal flesh intake (85–300 g/day) and iron status. However, the optimum quantity or frequency of flesh intake required to maintain or achieve a healthy iron status remains unclear. Results show a promising relationship between animal flesh intake and iron status, however, additional longitudinal and experimental studies are required to confirm this relationship and determine optimal intakes to reduce ID development.

Diet quality and 10‐year healthcare costs by BMI categories in the mid‐age cohort of the Australian Longitudinal Study on Women's Health

“…Meat is the richest dietary source of high biologically available iron (haem-iron) and is considered to have a major role in the prevention of iron deficiency (37) . For every 1 point increase in the meat subscale score, obese women made 6.2 fewer claims cumulatively over 10 years.…”

“…For every 1 point increase in the meat subscale score, obese women made 6.2 fewer claims cumulatively over 10 years. Meat is the richest dietary source of high biologically available iron (haem-iron) and is considered to have a major role in the prevention of iron deficiency (37) . Although iron deficiency is most common among young women, iron deficiency is relatively prevalent across the life cycle of women and is associated with poor immunity, reduced capacity for physical activity, increased fatigue and reduced cognitive function (38,39) .…”

Meat consumption, health, and the environment

“…It is possible to obtain a sufficient intake of these nutrients without eating meat if a wide variety of other foods is available and consumed (22,23). However, in some low-income countries access to alternative nutrient-dense foods may be limited; therefore, diets low in meat may have negative health impacts (24,25). Approximately 35% of people in India are vegetarians, but the impact of vegetarianism is not well documented, although there is some evidence that Indian vegetarians have a slightly more favorable cardiovascular risk profile than that of nonvegetarians (26).…”

Iron status in the elderly: A review of recent evidence

“…It was concluded that diet could potentially be used as means to change iron status. Jackson et al (Jackson et al, 2016) undertook a meta-analysis on the effect of increased consumption of meat on iron status in adults from industrialized countries. A total of 49 studies met the criteria, out of which 10 included people over 65 years.…”