A study published this week in the British Medical Journal has analysed the relationship between breast-feeding and subsequent intelligence. Breast-feeding was associated with enhanced intelligence, but this study found that this benefit was associated not with the breast-feeding itself, but by other factors including the mother’s intelligence. No doubt, the results of this study will do the rounds, and may even help to persuade some parents that there’s really not very much difference between breast and bottle-feeding.
I must admit, I don’t find it easy writing about breast-feeding, mainly because I have never done it and will never need to either. Also, there is often a lot of feeling of guilt and inadequacy around the feeding of children, and I certainly would not want to add to any of those feelings. However, despite today’s research findings, breast-feeding does seem to have significant advantages over bottle-feeing, that I do feel parents and members of the medical profession should be aware of. To this end, I summarised the benefits below.
Personally, I would like to see mothers keen to breast-feed given more support. And I’d also like to see our rather Victorian attitude to the practice of breast-feeding in public relaxed a bit. There’s a major opportunity here for a celebrity or two to lead the way!
The Benefits of Breast-feeding
Breast milk has been crucial to the survival and evolution of our species over millions of years. Analysis of human milk reveals that it contains a veritable cornucopia of nutrients and other elements that not only help to ensure the very best raw materials for a baby’s development, but also appear to protect against a range of conditions and health issues.
What’s in breast milk?
Breast milk contains proteins, carbohydrates, fats and a range of nutrients, including vitamins and minerals, that play important roles in the growth and well-being of a baby. It is, in essence, designed to give the right amounts of nutrients important for the early development of a human infant’s body and brain. One critical difference between human milk and cow’s milk is that it is relatively rich in fats (such as the omega-3 fat docosahexaenoic acid) that are believed to have many important functions including supporting the development of the brain and visual function. In contrast, cow’s milk (on which most formula-feeds are based) is pretty bereft of these crucial fats, and is generally richer in nutrients such as calcium and phosphorus. These minerals are important for bone-building which has obvious significance for calves who are up on their hooves within a few minutes of being born. However, they have much more limited usefulness in human babies who generally won’t be taking their first tentative steps for a year or more.
Another fundamental difference between human milk and cow’s milk is the types of protein that they contain. Some children may have difficulty digesting cow’s milk protein, and bottle-feeding is therefore more likely to give rise to problems often related to something called food sensitivity. Common manifestations of this include colic and eczema.
Crucially, breast milk is a ‘live’ food. Unprocessed in any way, it comes from the breast in a form which preserves all of its health-giving properties. In contrast, formula feeds are pasteurised and dried ” processing techniques that can deplete the milk of many of its nourishing elements. Substances found in human breast milk that are not present in conventional formula feeds include enzymes, antibodies, immune cells, growth factors, hormones and substances that feed beneficial bacteria in a baby’s gut (1). With all this going for it, it’s perhaps no surprise that feeding a child with breast milk has been found to be associated with so many benefits.
The emotional angle
Before we look at the health benefits of breast milk, let us not forget that the act of breast feeding can have important emotional elements too. Many women find breast-feeding an intensely enjoyable experience, and it seems that many babies get a lot from it too. The regular intimate contact it affords is generally believed to help cement the relationship between a mother and child in the first few weeks and months of life. During breast-feeding, mothers release a hormone called oxytocin which some scientists believe actually promotes emotional attachment and bonding.
Oxytocin has some physical benefits too, as it seems to reduce the bleeding directly after the birth, and helps the recovery of the womb (2). If you are planning to breast-feed, then putting your new baby your breast as soon as is practically possible after the birth makes good sense. Studies shows that mothers who breast-feed in the first hours of life, choose to keep their infants longer in their rooms than mothers who have later contact. In addition, mothers who breast-feed are generally found to be less prone to anxiety and low mood after the birth (3).
Breast-feeding and bowel bacteria
Breast milk contains elements that feed healthy bacteria in the gut of the new-born and infant. Also, it has been shown that the bacteria in the faeces of breast-fed babies is quite different to those fed on formula (4), and this may have important consequences for digestive and general health. One effect of having good amounts of the right sorts of organisms in the gut is a greater resistance to unwanted gastrointestinal infection. Studies show, for instance, that babies breastfed for three or more months have a much lower risk of gastroenteritis compared to bottle-fed infants (5).
Breast-feeding and the immune system
A baby’s immune system is not fully developed at birth, and will get added protection from antibodies and immune cells present in breast milk. The immune boost provided by breast-feeding helps to prevent a variety of different infections including diarrhoea, respiratory tract infections, ear infections, urinary tract infections (cystitis and kidney infections) and septicaemia (infection of the blood) (6). What is more, this added protection last for years after breast-feeding has stopped, and therefore has longer-term health benefits for your child.
Breast-feeding and allergic conditions
There is evidence that asthma, and other allergies, can be prevented or at least partially protected against through breast-feeding (7,8). This protective effect may be related to the fact that allergic conditions in children are often related to food sensitivity, and breast-feeding helps prevent this problem through a variety of mechanisms. In particular, delaying the introduction of cow’s milk proteins (in the form of formula) seems to reduce the risk that a child will develop a sensitivity to milk and perhaps other diary products. Breast-feeding also helps to ensure the right amount of healthy bacteria in the gut ” something that will help improve digestion and reduce the risk of undigested food ‘leaking’ through the gut wall.
Breast feeding and obesity
There is some evidence that breast-feeding lowers the risk of childhood obesity and may also protect against obesity in later life (9). Why this should be is not clear, though it is important bearing in mind the epidemic of childhood obesity we’re seeing in the West.
Breast feeding and protection against other diseases
Many studies have found that breast-feeding appears to protect against other conditions too, including:
� Sudden infant death syndrome (cot death) (10-12).
� Insulin-dependent (Type 1) diabetes (13).
� Crohn’s disease (14-15).
� Ulcerative colitis (15).
While breast-feeding seems to have clear advantages over bottle-feeding for a child’s health, the benefits do not end there: studies suggest that it may have important implications for the mother too.
Breast-feeding and maternal health
As we have already mentioned, breast feeding after birth increases levels of the hormone oxytocin in the mother, which seems to reduce blood loss and enhance recovery (16). During breast feeding, a woman’s periods are unlikely to return. Pregnancy can be a quite a drain on a woman’s body, and this is not help any by menstruation. By holding off menstruation, breast-feeding help to preserve some nutrients (for example iron) in a woman’s body. Also, breast feeding is a natural contraceptive, which helps gives women a natural ‘breather’ between pregnancies (17, 18).
Many women are keen to lose weight that they might have put on during pregnancy. Research shows that women who breast-feed tend to return to their pre-pregnant weight earlier than those who don’t (19). Looking at the longer term, it has been found that women who breast-feed are also at a reduced risk of osteoporosis (20, 21), and cancer of the ovary and breast (22).
1. British Nutrition Foundation BNF briefing paper Nutrition in Infancy 1997
2. Chua S, et al. Influence of breastfeeding and nipple stimulation on postpartum uterine activity. Br J Obstet Gynaecol. 1994;101:804-805).
3. Mezzacappa ES, Katlin ES. Breast-feeding is associated with reduced perceived stress and negative mood in mothers. Health Psychol. 2002 21(2):187-193).
4. Balmer SE, et al. Diet and faecal flora in the newborn. Archives of diseases in children 1991 66:1390-1394
5. Howie PW, et al. Protective effect of breast feeding against infection. Brit Med J 1990 300:11-16).
6. Hanson LA, et al. Breastfeeding provides passive and likely long-lasting active immunity. 1998 Annals of Allergy Asthma and Immunology. 81: 523-537).
7. Lucas A, et al. Early diet of preterm infants and development of allergic or atopic disease: randomised prospective study. Br Med J. 1990 300:837-840
8. Saarinen UM, Kajosaari M. Breastfeeding as prophylaxis against atopic disease: prospective follow-up study until 17 years old. Lancet 1995 346:1065-1069).
9. Armstrong J, et al. Breastfeeding and lowering the risk of childhood obesity. Lancet 2002 359:2003-4
10. Ford RPK, et al. Breastfeeding and the risk of sudden infant death syndrome. Int J
11. Mitchell EA, et al. Four modifiable and other major risk factors for cot death: the New
Zealand study. J Paediatr Child Health. 1992;28:3-8
12. Scragg LK, et al. Evaluation of the cot death prevention programme in South Auckland.
N Z Med J. 1993;106:8-10).
13. Gerstein HC. Cow’s milk exposure and type 1 diabetes mellitus. Diabetes Care.
14. Koletzko S, et al. Role of infant feeding practices in development of Crohn’s disease in
childhood. Br Med J 1989;298:1617-1618
15. Rigas A, et al. Breast-feeding and maternal smoking in the etiology of Crohn’s disease
and ulcerative colitis in childhood. Ann Epidemiol. 1993 3:387-392
16. Chua S, et al. Influence of breastfeeding and nipple stimulation on postpartum uterine activity. Br J Obstet Gynaecol. 1994;101:804-805
17. Kennedy KI, Visness CM. Contraceptive efficacy of lactational amenorrhoea. Lancet. 1992;339:227-230
18. Gray RH, et al. Risk of ovulation during lactation. Lancet. 1990;335:25-29
19. Dewey KG, et al. Maternal weight-loss patterns during prolonged lactation. Am J Clin Nutr 1993 58:162-166
20. Melton LJ, et al. Influence of breastfeeding and other reproductive factors on bone mass later in life. Osteoporos Int. 1993 3:76-83
21. Cumming RG, Klineberg RJ. Breastfeeding and other reproductive factors and the risk of hip fractures in elderly woman. Int J Epidemiol 1993 22:684-691
22. Newcomb PA, et al. Lactation and a reduced risk of premenopausal breast cancer. N Engl J Med. 1994 330:81-87