Tobacco smoke led to accumulation of heavy metals in breast milk
Maternal smoking during pregnancy or lactation, both active and passive, increased the content of toxic substances in breast milk. A study by Iranian scientists has shown this.
Tobacco smoke contains thousands of harmful compounds, including heavy metals and carcinogens. Its direct or indirect impact (as in passive smoking) negatively affects a person and increases the risk of various diseases. It is especially dangerous for pregnant and lactating women, because the health of their babies depends on the quality of their milk. According to numerous studies, breast milk plays an important role in the growth and intellectual development of infants, helps to form a healthy intestinal microflora and immunity.
From previous work, we know that babies who are fed by mothers who smoke have a higher risk of colic, sleep disorders, upper respiratory infections, allergies, heart rhythm disorders and even sudden infant death syndrome. Scientists also know that the effects of inhaling other people's cigarette smoke are comparable to the harms of smoking.
However, the direct effects of tobacco smoke on breast milk quality have not been studied enough, so scientists from several research centers and medical schools in Iran decided to fill the gap. They compared how the levels of potentially toxic substances in the milk of nonsmoking mothers and those who smoked or were exposed to other people's tobacco smoke during pregnancy and lactation differed.
For the cross-sectional analysis, the results of which were published in the journal Scientific Reports, 100 breastfeeding mothers who were observed at health centers in the city of Kermanshah in western Iran were selected. All women were healthy, had no pregnancy complications, and had given birth to and nursed their first child. Mothers with many children, women with chronic diseases, and those who lived in areas with high levels of environmental pollution were excluded from the study.
The women were divided into three groups: nonsmokers, active smokers, and passive smokers. Based on the data collected on the participants, there were significant differences in occupation, education, age, use of cosmetics and fruit consumption. However, there were no major differences in terms of salt, milk, vegetable, fast food, potato and oil consumption.
Breast milk samples were collected from the women, which were then analyzed using inductively coupled plasma mass spectrometry to measure concentrations of manganese, magnesium, cobalt, iron, zinc, copper, arsenic, chromium, cadmium, nickel, mercury and lead.
As a result, the scientists found elevated levels of mercury, cadmium, lead and arsenic in breast milk samples from active and passive smokers compared to nonsmokers. At the same time, manganese and magnesium concentrations in milk from passive smokers were higher than those from actively smoking mothers.
The study confirmed that inhalation of tobacco smoke in any form contributes to an increase in the level of heavy metals in breast milk. The absorption of these substances is higher in breastfed infants, probably due to binding to easily digestible milk proteins.
Increased concentrations of heavy metals in breast milk may lead to disorders in the development and growth of children. Additional research is needed to assess the toxic effects of these substances on newborns, the experts concluded.