Edited video of Dr. Noakes' Testimony is available from the Noakes Foundation.
The following is my commentary, a reconstruction, written from my own notes, and may not be entirely as accurate as I (or Dr Noakes) would like.
Weaning in Mammals
Carnivores have the advantage in terms of reproductive capacity to wean earlier, and to have shorter inter-birth periods. That's possible because carnivores eat a better quality diet. Suckling can stop when the brain is fully developed.
In humans, the rapid growth of the brain continues for a long time, so while it's possible to wean children at six months or younger that's not advisable. In fact continuing to breast feed until the child is 24 months of older is to be encouraged.
Click to enlarge |
---|
Before 1853 children were weaned onto whatever food was available. Since food supply for adults was uncertain, the ability of the mother to supply some milk was important. In 1862 the first commercial baby foods were marketed. After that the manufacturers of those foods encouraged their use at younger and younger ages. In industrial towns this had numerous advantages for women, but severe disadvantages for the children.
Click to enlarge |
---|
Amy Bentley in "Inventing Baby Foods" writes about the development of canned baby foods by Gerber Foods in the 1930's. By 1950, some companies were recommending that weaning should begin at one month. We now know that this advice is completely wrong, and current recommendations are to begin weaning at six months, but only onto complementary foods. Breast feeding should continue for as long as the child wants the milk.
In "The Englishman's Food" by T.C. Drummond and A Wilbraham, they write that infant foods contained mostly flour, starch, malted flour and similar cheap materials. On this diet children appear to flourish, especially if mothers milk or full cream milk is available. But the children by the age of two or three became overweight and flabby. We now know that this diet was deficient in proteins, vitamins and minerals. Many children developed either rickets or undiagnosed rickets, and later, poor quality adult teeth.
Click to enlarge |
---|
Amy Bentley explains that commercial companies presented doctors and other "baby experts" to build the assumption that these were "modern" prepared foods that were superior for baby's health. They were also efficient and time saving for mothers. An advertisement form the 1930's presents baby food as pure, wholesome, convenient, modern, and scientific. Using commercial baby foods made mothers feel confident and modern. It also made it possible for many of them to take on extra employment.
Click to enlarge |
---|
Bentley also explains that when we feed children low density foods, like breads, cereals and starches, we "fill them up" but we didn't feed them quality nutriments. As a result the demand for breast milk which is nutritious may be reduced, a double loss.
One of the innovations of the 1940's was the idea of introducing one food at a time, beginning with white rice. Some there was a special order for introducing new foods, white rice, apple sauce, mashed banana, pureed vegetables, and lastly meats. By the end of WWII, in the USA, white rice was firmly established as the ideal first food for weaning babies.
Click to enlarge |
---|
This reinforces a theme that I've seen often. Industry sets the agenda, and tells us what's good for us. We now know that this diet was entirely inadequate, especially if suckling was reduced.
Lessons from Modern Hunter Gatherers
A paper from 1962, about the Hadza Tribe for Northern Tanzania is interesting. They wean their children onto Zebra fat and bone marrow, both raw and cooked. Breast feeding is prolonged. As children develop teeth, mothers pre-chew meat for the children to gnaw on.
Click to enlarge |
---|
Mild Ketosis in the Fetus and Young Children
Both glucose and ketones from the mother can cross the placenta, but insulin from the mother cannot. If the mother is producing excess glucose, (mother may be diabetic) the baby has to protect itself by producing it's own insulin.
Click to enlarge |
---|
At the beginning of this video the study under discussion was looking for cancer forming (teratogenesis) problems in exposing rat fetus's different concentrations of glucose or ketones. The study shows that both excessive glucose and excessive ketones can produce teratogenesis, but only in extreme cases. Normally the fetus is very well protected, the availability of nutriment is controlled, and there is no possibility of the mild ketosis, that is normal for a fetus, would cause any problem. In this case ketones are likely to be 0.5mmol/l to 1mmol/l. Something extraordinary might produce 2mmol/l. In this study damage began to occur at 8mmol/l.
With Glucose, a normal level is 1.2 mg/ml, with a diabetic mother this might be a little higher, but damage begins at 9 mg/ml, which is far out of range.
Click to enlarge |
---|
Exclusively breast fed babies will be in mild ketosis. Ketones will be 0.5mmol/l to 1mmol/l. This is ideal for the best rate of brain growth. Feeding infant formula is likely to stop ketosis, and is not recommended. In the same way feeding the weaning child carbohydrates, or adding sugar to the diet. will kill ketosis. The later this happens the better.
When we look at blood profiles for people using their glucose metabolism, glucose is normal at 5mg/ml, and ketones hardly exist at levels like 0.2 mmol/l. Babies have much higher ketone production, usually between 0.5mmol/l and 2mmol/l, occasionally a little higher. They are in mild ketosis, but this is entirely under control. Breast fed babies have slightly higher ketone levels.
Click to enlarge |
---|
This chart shows the level of both glucose and ketones in the blood during the first week after birth. In the first few hours things are a little unstable. Then glucose levels quickly settle at a level just below 5mg/ml. That means there is no demand for extra insulin, so insulin levels are low. That enables fat burning, the fat from mothers milk being the fuel. Hence the fat is used to produce ketones, at good levels above 0.5mmol/l up to about 2mmol/l, these ketones doing two important tasks, giving the brain energy and providing building blocks for making cholesterol, and building the physical brain.
Click to enlarge |
---|
This graph shows ketones on the vertical axis and glucose on the horizontal axis. Note that the breast fed babies have slightly higher ketone levels and slightly lower glucose levels. Since this "natural environment" of mild ketosis is desirable for the best development of the child's brain, we should think carefully about what foods we give the child if breast feeding is reduced or stopped. We need to keep the child in ketosis for as long as possible. Feeding the child carbohydrates, or worse sugar, of excess fruit is likely to switch the child's metabolism from lipid burning to glucose burning. That's not ideal.
"Baby Foods" to Avoid
Click to enlarge |
---|
Fruit juices, and flour based foods like rusks, or cereals and bread, contain "energy" but very little nutriment. Porridge is filling, but it's not a quality food. Adding butter, cream, or chopped bacon to it would help increase the nutriment density.
Added sugar should be eliminated from the diet of children. Porridge or Weet-bix with sugar is a double bad.
Grain Based Foods are Insufficient
Click to enlarge |
---|
Because of poverty most children in South Africa are weaned onto soft maize meal porridge, a bulky food but with low nutriment density. It's insufficient in protein and fats, vitamin A, iron, zinc and calcium. In South Africa less that 20% of infants are given meat based foods, and only 20% get dairy products regularly.
The South African Dietary Guidelines for Weaning recommend that children are fed chicken, fish, meat, dairy foods and eggs every day, so children will grow taller. They will also develop larger brains. Unfortunately, chicken, fish, meat, dairy foods and eggs are expensive. In South Africa their daily inclusion in the diet of infants is a challenge.
Click to enlarge |
---|
The science is very clear - to build a strong nation we have to feed our children well. The South African Dietary Guidelines for Weaning are a fabulous resource, but they admit that many families cannot afford the best diet, so the guidelines cannot be followed. The solution is to for government to make better quality food available to families with young children. We shouldn't accept poor diet as normal in our society.