Excerpt

Breast milk from a healthy mother provides adequate nutrients and calories to the baby for the first 6 months after birth. Beyond six months, however, the energy value of breast milk is not enough to support a baby who is becoming more active. Therefore weaning should be planned for this period. A weaning diet should be nourishing without burdening the baby with excess calories. Most babies, especially those in urban centers, are already on cow’s milk or formula at this point. A good weaning diet should keep the baby thriving for the next 2-3 years, during which he will gradually be introduced to the family diet. Throughout this period cow’s milk will form part of the weaning diet. The weaning period is a vulnerable period for many children, especially in sub-Saharan Africa. This is because, since the dietary staple is maize, it is common for maize porridge to be a weaning food. The porridge is often enriched with milk. A maize-staple diet is one of the reasons kwashiorkor and marasmic kwashiorkor are endemic across SSA. Cow’s milk, as we have already seen, worsens this protein malnutrition.

Milk is a complete food. It has its own unique digestive enzymes. Rennin digests the protein in milk whereas lactase digests the milk sugar, lactose. Both enzymes are most active at birth but decline gradually. The activity of lactase decreases gradually for most people; so that by age 3-4 years, lactase activity is absent or minimum. Affected people are unable to digest milk effectively; many black people fall in this category. The decline in lactase activity does not occur drastically in certain select population groups, typified by most Europeans, the Maasai, the Tutsi and the Fulani (2b, 36). It was thought that, in these communities, the law of natural selection had over generations ensured that only the fittest survived. Emerging evidence, however, supports the view that heritable malnutrition helps determine the level of lactase activity. An example is given of the Maasai who only a few decades ago were good digesters of milk. Today, however, after settling down to maize agriculture, many have lost this capacity and have succumbed to the same milk-related problems as many other communities in East Africa, and SSA in general (37).

Before their induction into a maize diet the Maasai were able to drink a lot of milk without getting digestive problems like bloating, abdominal pain/ distension, diarrhea and vomiting. Indeed, Maasai children were rarely noted to have malnutrition or to even develop diarrhea despite their socioeconomic circumstances. In recent decades, the endemicity of maize on the African continent has increased the prevalence of lactose intolerance (and other symptoms of pellagra). Untreated pellagra tends to run in maize-eating communities as heritable malnutrition. The capacity to treat such malnutrition (including attendant micronutrient deficiencies like deficiencies in iron, zinc and vitamin B12, all known to be endemic in the community) can decrease the morbidity from lactose intolerance by improving digestive capacity. Increasingly, therefore, the use of supplements is redefining the prevalence of lactose intolerance (and malnutrition in general). This is discussed in greater detail in The Heritage of Maize is Killing Africans: the Kenyan Story, which is available on www.nutritionafrica.com.

Rennin activity, like lactase activity, is maximal at birth and thereafter declines slowly, so that by the age of 3- 4 years, its activity is low in the majority of the population. In “primitive” communities breastfeeding is usually allowed to last its natural life. This tends to coincide with the life of maximum enzyme activity i.e. 3-4 years. So it looks like, for a majority of people, nature’s plan intended that milk be utilized during the first few years of life. Like lactase activity, rennin activity can be improved through successful treatment of malnutrition. Overall improvement in digestive capacity improves the uptake of micronutrients from the diet and, by extension, the child’s general well-being.

Since the immunity of the baby’s digestive system is not fully developed at birth, the baby should not be exposed to alien (non-human) protein if disease is to be avoided. Studies have shown that if one delays introducing alien proteins like eggs, cow’s milk, meats and so on, the frequency of allergies goes down (21, 9). Breastfeeding during the first year of life allows the immune system to mature. However, this only happens when the breastfeeding mother is healthy. If the mother has iron deficiency anemia, pellagra (niacin deficiency) or some other micronutrient deficiency, the baby’s system will gradually weaken. Then weaning will become problematic, with frequent illnesses. This is why it is advised that infants get a thorough health check-up at the end of their first year. It is important because any emerging problems can be detected early and treated. If this is not done, then any problem is likely to worsen even faster as the baby switches to formula or other forms of non-human milk.

Cow’s milk has more protein than breast milk, which makes it more difficult to digest. It also has lower carbohydrate levels than breast milk. Its iron levels are also much lower. Not surprisingly, iron deficiency anemia is more common in bottle-fed infants than in breastfed infants. Cow’s milk is an ideal food for calves because grass readily provides them with enough iron. To ‘humanize’ cow’s milk, it is common practice for mothers to dilute it with water, and then add some sugar. Most infant formula manufactures, on the other hand, add iron and other micronutrients to the milk. If one must use cow’s milk, then it makes sense to use infant formulae as these are considered superior to sweetened and diluted cow’s milk in digestibility and nutrient content. For babies who are completely intolerant to cow’s milk in any form, there are other substitutes available on the market. Lactose-free formulae (e.g. soy-based milks) are an example. However, the nutritional superiority of a healthy mothers’ milk cannot be duplicated by infant formulae (2, 6).