A randomized controlled trial on the effects of jujube fruit on the concentrations of some toxic trace elements in human milk

BACKGROUND: This study aims to investigate the concentrations of lead, cadmium, and arsenic in the human milk, and to assess the effect of jujube fruit consumption by lactating mothers in reducing the concentration of these heavy metals in their milk. MATERIALS AND METHODS: This randomized controlled trial was conducted in 2014 among forty postpartum mothers in Isfahan, the second largest and polluted city in Iran. Mothers were randomized into two groups; the intervention group received 15 g/day of fresh jujube fruit, and the controls received routine care for 8 weeks. RESULTS: In the beginning, the concentrations of lead, cadmium, and arsenic were high, without significant difference between groups. The mean (standard deviation) concentrations of lead, cadmium, and arsenic were 29.49 (16.6), 4.65 (3.51), and 1.23 (0.63) μg/L, respectively. The smoothed empirical distribution of environmental pollutants showed that in both groups the mean values and variance of toxic metals decreased after 8 weeks, with a sharper decline in the intervention group. Quantile regression analysis showed that in the intervention group, lead concentration decreased by 2.54 μg/L at the 90(th) quintile, and cadmium decreased by 0.19 μg/Lat 75(th) quintile; without significant change in arsenic level. The corresponding figures were not significant in the control group. CONCLUSION: The concentrations of heavy metals were high in human milk, and the consumption of jujube fruit had some beneficial effects in reducing these harmful elements. Pregnant and lactating mothers should be advised to reduce their exposure to environmental pollutants, and consumption of some natural medicinal foods can be useful in reducing the concentration of pollutants in human milk. Because of numerous benefits of breast milk, in spite of the existence of some toxic trace elements, breastfeeding must be encouraged because such contaminants are also found in water and formula. The impact of the current findings on the primary prevention of chronic disease should be determined in future longitudinal studies.