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Benefit and risk assessment of breastmilk for infant health in Norway
Report no: 2013: 44
Breastmilk covers all the nutritional needs of the infant the first months of life, with the exception of vitamin D. In addition, breastmilk has a number of protective properties. However, as humans are exposed to polluting chemicals through food, air, water and skin contact, breastmilk also contains contaminants. Taking the present-day levels of contaminants in Norwegian breastmilk and the long duration of breastfeeding (12 months) in Norway into account, the Norwegian Scientific Committee for Food Safety concludes that contaminants poses a low risk to Norwegian infants, and that the benefits of breastmilk to Norwegian infants clearly outweigh the risk presented by contaminants.
The present benefit and risk assessment of breastmilk and contaminants in breastmilk has been undertaken by the Norwegian Scientific Committee for Food Safety at its own initiative. The assessment is based on a comprehensive assessment of systematic reviews, meta-analyses and single studies as well as occurrence data for contaminants in Norwegian breastmilk.
Norwegian health authorities recommend that infants are exclusively breastfed for 6 months with a total duration of at least 12 months. However, few Norwegian mothers breastfeed exclusively for the recommended 6 months, although almost half of the infants are still breastfed at 12 months of age.
Beneficial and protective components in breastmilk
The positive health effects of breastmilk relates to nutritious as well as immunological properties. An infant who is exclusively breastfed for the first 6 months of life has, provided adequate nutrition of the mother, all the nutritional needs covered with the exception of vitamin D.
In addition to nutrients, breastmilk contains a number of specialised components, including factors with anti-microbial and anti-inflammatory properties as well as constituents stimulating the maturation of the infant’s immune system.
There is convincing evidence that breastmilk supports and strengthens the development of the nervous- and immune systems of the child. There is also convincing evidence that breastmilk reduces the risk of childhood overweight and obesity. There is probable evidence for a protective effect of breastmilk on the development of diabetes and high blood pressure.
There are indications that breastmilk might also protect against coeliac disease, childhood cancer, Crohn’s disease, ulcerative colitis and cot death.
The Norwegian Scientific committee for Food Safety finds that the evidence for a protective effect of breastmilk on asthma, allergies, wheezing and cardiovascular diseases is too limited to draw conclusions.
Children benefit from the protective properties of breastmilk in childhood and most likely also later in life.
Levels of contaminants in Norwegian breastmilk
Due to national and international restrictions and bans on use, the levels of many well-known contaminants such as dioxins, PCBs, DDTs and HCBs have declined substantially in the environment and in humans the last three decades.
The concentration of PBDEs in breastmilk in Norway increased until approximately year 2000, after which a decline has been observed. The fluorinated surfactants PFOS and PFOA have shown a similar time trend as the PBDEs.
The Norwegian Scientific Committee for Food Safety has identified high quality studies regarding PCB, DDT and HCB, and mercury in breastmilk and their effect on infant health. Occurrence data for contaminants in Norwegian breastmilk were available for PCB-153, dioxins and dioxin-like PCBs, DDE and HCB.
Studies investigating associations between these contaminants in breastmilk and health addressed child growth and indicators of neuro- and immune development.
Levels of contaminants in infant formula
The present benefit and risk assessment of breastmilk and contaminants in breastmilk does not provide an extensive review of infant formula.
Infant formula fulfils the infant´s established nutritional needs, but does not provide maternal antibodies and innate defence factors or immunity-promoting components.
The main difference between the contaminants in breastmilk and those provided by infant formula is that breastmilk generally contains higher levels of persistent organic pollutants, while most of the unwanted substances imposed by infant formula and bottle-feeding have a shorter half-life.
Following a comprehensive assessment of scientific literature on the positive health effects of breastmilk and concentrations in breastmilk of compounds representing possible health hazards, and given current knowledge about concentrations of contaminants in Norwegian breastmilk and breastfeeding duration in Norway, the Norwegian Scientific Committee for Food Safety concludes that the benefits associated with breastmilk clearly outweigh the risk presented by current levels of contaminants in breastmilk.
This conclusion is valid whether a child is exclusively or partially breastfed up to the age of 6 months and partially breastfed up to 12 months of age.