Iron status of middle-aged women in five counties of rural China

Abstract

Objective: To determine the relationships of dietary iron sources, other dietary factors, and lifestyle to iron status among premenopausal and recently postmenopausal Chinese women with widely varying regional dietary patterns. Design: Cross-sectional. Subjects were interviewed, blood samples were drawn, and dietary intakes were measured by a 3-day dietary survey for subjects in the ®ve survey counties. Setting: Rural China Subjects: About 80 randomly selected subjects per county among women aged 32 ± 66 y. Main outcome measures: Blood hemoglobin, plasma ferritin, and plasma iron. Results: Total iron intake was relatively high (15 ± 29 mgad) compared to developed counties. Heme iron intake was negligible in two of the study counties. Overall levels of iron de®ciency anemia were relatively low in these generally iron-stressed women. There was no clear statistical relationship between iron intake and physiological iron status. Although several measures of dietary intake (heme iron, dietary calcium, animal protein) were correlated with several measures of iron status before adjusting for survey county, only dietary animal protein was signi®cantly positively correlated with plasma ferritin after adjusting for the possibly confounding factor of the survey county (r 0.15, P 0.009). Intakes of potential inhibitors of iron absorption, such as tea, even in very high amounts, were not correlated to iron status. Plasma ferritin was positively correlated with plasma retinol (P 0.024) and cholesterol (P 0.007). Systemic in¯ammatory response, as indicated by high plasma Creactive protein levels, was shown to be raised in a group of subjects with apparently contradictory high levels of ferritin and low levels of hemoglobin (P 0.03). Conclusions: Iron nutriture in these areas of rural China seemed more related to physiological factors such as in¯ammatory response, menses, plasma vitamin A and cholesterol, than to dietary factors.

Tea consumption and iron status

“…Table 2 summarises studies that investigated the association between tea consumption and iron status in women. No significant associations between high tea consumption and low iron status parameters were found in a European study (Van de Vijver et al, 1999) and in a Chinese study (Root et al, 1999) with a low percentage of iron deficient women. The cross-sectional study (Van de Vijver et al, 1999) among European girls (n ¼ 1080; mean 13.5 y) and young women (n ¼ 524; mean 22.0 y) from six countries focused on the association between calcium intake and iron status.…”

“…Tea and coffee consumption was not significantly associated with serum ferritin. The Chinese study (Root et al, 1999) showed that women can adapt successfully to a wide range of iron intakes and bioavailability. Root et al, (1999) examined the iron status of middle-aged Chinese women (n ¼ 400; 32 -66 y old) randomly selected from five counties in rural China.…”

“…The conclusions are mainly based on cross-sectional studies determining tea consumption on the one and iron status on the other hand. Most studies addressed the effects of a variety of dietary factors, among them tea, that could affect iron status and calculated correlation factors between tea consumed and serum ferritin (Doyle et al, 1999;Galan et al, 1985;Gibson, 1999;Pate et al, 1993;Root et al, 1999;Soustre et al, 1986;Van de Vijver et al, 1999). These analyses were carried out with (Doyle et al, 1999;Pate et al, 1993;Root et al, 1999;Soustre et al, 1986) or without (Galan et al, 1985;Gibson, 1999;Van de Vijver et al, 1999) adjusting for other iron bioavailability factors.…”

“…Most studies addressed the effects of a variety of dietary factors, among them tea, that could affect iron status and calculated correlation factors between tea consumed and serum ferritin (Doyle et al, 1999;Galan et al, 1985;Gibson, 1999;Pate et al, 1993;Root et al, 1999;Soustre et al, 1986;Van de Vijver et al, 1999). These analyses were carried out with (Doyle et al, 1999;Pate et al, 1993;Root et al, 1999;Soustre et al, 1986) or without (Galan et al, 1985;Gibson, 1999;Van de Vijver et al, 1999) adjusting for other iron bioavailability factors. Other case -control studies (Kuvibidila et al, 1992;Mehta et al, 1992;Merhav et al, 1985;Razagui et al, 1991;Roebothan & Chandra, 1996) compared iron deficient (or anaemic) cases with non-iron deficient (and=or non-anaemic) controls with respect to tea consumption and other dietary habits.…”

Special postpartum dietary practices of Hong Kong Chinese women

“…No data, to the best of our knowledge, on postnatal iron intake for rural Chinese postpartum women are available from the literature. Previous studies have showed that the daily total iron intake of rural Chinese women is around 20 ± 30 mgaday, of which non-haem iron is the main iron source (Root et al 1999;Ge et al, 1995). Although the consumption of the special dish is common for Guangdong postpartum women, the increased consumption of other haem iron sources eg poultry, meat and eggs, during the early postpartum period is commonly practised by the rural Chinese women of other provinces, eg Chongqing (Chen et al, 1997).…”