Excess Protein Diets their effect on the mother & the unborn

When we talk of high protein we are talking of a protein intake above requirements.

I will state first that I believe high to excess protein diets are the biggest silent killer in society today

Experiences: Over the years I have been in the field of soil, plant and animal nutrition, dealing with laboratories in the USA, Adelaide and China. In China

The lack of understanding of basic nutrition in humans is a constant frustration to me. Every week we hear of some new discovery re nutrition in humans and most times it is something that we have known or have been dealing with in animals for many years and is often something I learnt in my agriculture studies over 50 years ago. Eg Research shows in humans that high protein diets reduce appetite, yet in dairy cows we have known for 40 years that high protein diets acidify the stomach reducing appetite and production.

My real concern is the promotion of high protein diets for general health but as yet few have considered the long term adverse effects on our liver and kidneys,


I say few as there is now research showing that we need to be concerned. This research is looking at the ability of our liver and kidneys to sustain the nutritional abuse from the continuous intake of high protein, especially women that consume high protein to keep their weight down.  Every year in Australia thousands of animals die from protein overload or toxicity which normally this occurs when stock are grazing lush or drought recovery pastures. The problem is that under these circumstances, consumption of fresh green grass, they are actually suffering a significant energy deficiency as high protein negates energy. Apart from sudden deaths in young stock there are other issues in pregnant sheep and cattle that can be compared to humans.

  1. Animals can abort when consuming high protein diets
  2. Calves/lambs can be still born when mothers consume high levels of protein just prior to giving birth, this is vegetable protein
  3. Young can be born ahead of time with little chance of survival
  4. Following birth young animals can be weak and suffer respiratory problems or they may suddenly die up to 14 days following birth.

All of these issues must be related to the present problems being experienced in mothers. I believe that still births are on the increase and I heard recently that children that were at risk of being still born are more at risk of SIDS. So there maybe some similarity, this is a challenge for the medical field

So what is happening here? Sure high protein diets result in weight loss, so lets look at why and what happens in the body and then relate it to unborn child.

Protein is the element nitrogen multiplied by 6.25, this gives us actually the crude protein (CP) percentage of a food. So in fact protein is nitrogen and it is important to understand that nitrogen in a food source comes in different forms, some toxic and some good. If nitrogen is converted quickly by the plant to amino acids then great but in the real world of today this doesn’t happen, why due to the high levels of nitrogenous fertiliser and WE CONSUME THEM BEFORE THEY HAVE MATURED. We recently analysed a lettuce plant that showed that nearly 30% of the protein was toxic protein, more later.

This means that the CP of a food is a recording of the nitrogen percentage. High protein means that which is in excess to requirements, young animals/humans require 14 to 16% protein and adults 10 to 12% protein. Our diets are normally 40% plus. It is a fact that the longest living and healthiest people have high carb lower protein diet

What happens in the body when high protein is ingested? Remember protein is Nitrogen X 6.25. (Here I related the same issues I see in animals)

  1. It creates an energy deficit as dietary energy is used to convert the excess nitrogen (protein) to ammonia. So high protein diets can make you tired as you are energy deficient
  2. The ammonia goes to the blood so we have high blood nitrogen
  3. High blood nitrogen inhibits the transfer of oxygen from the blood to your muscles and the transfer of C02 back to your blood
  4. The liver converts this ammonia to urea by using body fat as an energy source and so you lose weight. Body fat is being mobilized to combine with ammonia to produce urea by your liver and then it is discharged in the urine through your kidneys. You have all seen urine scalds on the lawn from a dog well it is exactly the same process. When see these urine scalds the dog is asking for help as your feeding program is slowly killing it.
  5. As long as you have surplus body fat then this process is doing little harm in the short term apart from stressing your liver and kidneys
  6. Once your surplus body fat is gone then the problems really start. Your liver becomes really stressed and in severe cases the liver cells will fuse and death can occur. There have been recorded deaths in Australia. It is important that you maintain some body fat as it is essential to stored fat soluble vitamins especially.

The mother and unborn child (Related to problems I see in livestock)

  1. Firstly high levels of ammonia (nitrogen) in the blood can lead to mental instability in the mother so high protein diets are not suitable when pregnant
  2. Reduce fertility. Work in the USA showed that high protein diets reduced conception, a high carb diet increased conception
  3. High Blood pressure. A recent trial in England where pregnant women were put on a high protein diet showed that all participants developed high blood pressure which is particularly dangerous for the un born child
  4. Dangers for the unborn child are as a result of the high blood ammonia reducing oxygen supply to the feotus
  5. The cotyledons on the placenta connecting the baby to the mothers blood supply become inflamed and inhibit the supply of oxygen to the unborn child.
  6. Stress is created and then in severe cases the baby can be aborted or born ahead of time or be still born
  7. Or can be born weak with respiratory problems
  8. In animals high levels of blood ammonia can lead to mis-mothering, this is where the mother refuses to recognise their own off spring. I am told that this can also be problem with young mothers, the question, is it related to the above issues? I suspect yes
  9. High blood ammonia also reduces the quality of the colostrum (First milk) by inhibiting the formation of antibodies in the colostrum. This is a major issue as many mothers consume high protein diets both prior and immediately following birth without realising the adverse effect it is having on their milk quality. Ensuring good colostrum quality is essential for the early health and development of their baby.


Trials conducted in WA in sheep showed that feeding a high carbohydrate low protein diet in the last 10 days prior to birth significantly increased both the survival rate and health of the new boron. So what are the issues here for humans, shouldn’t we be just following the same program.

Earlier trials in South Africa in cattle, showed a significant increase in the antibody level of the colostrum where a high carbohydrate diet was fed in the last week before birth. This must surely apply to humans as well. Many dairy farmers know to reduce pasture and legume hay, higher protein, and feed lower quality products to cows just prior to calving which reduces likely calving issues. I personally have consulted on cases where the colostrum of pregnant cows, that were drinking nitrogen contaminated water, was completely void of antibodies. In this case the new born calves all died within a week due to the poor quality colostrum which failed to give them natural protection. In another case a farmer in Northern NSW called me stating that every cow in his herd was having a still born calf. A few over the phone questions establish he was calving on regrowth lucerne, being very high in protein. A simple diet change and all following calves were born alive, the problem being excess dietary protein

High carb low protein died pre giving birth

In humans, eating a high carbohydrate low protein diet would mean eating, eg a cereal/pasta/apple diet for the last 10 days before giving birth.

It is also important to understand the sources of protein as many think that protein only comes from meat. Nitrogen is essential for all life, animal and vegetable. A fast growing vegetable will contain up to 6% nitrogen, now multiply that by 6.25 and we have 37.5% protein. Green leafy vegetables normally contain 30 to 35% protein and yes they do contain a high percentage of water and normally you wouldn’t eat them on their own but many women do, it keeps the weight down you know, doesn’t really matter that they are destroying their liver and kidneys.

But remember these leafy vegetables can also contain high levels of toxic proteins. The worst ones identified are spinach, rocket and lettuce that are commercially grown. Now don’t stop eating them as they do have many other benefits just don’t consume them on their own. Always add a portion of a high carbohydrate (energy) food to the meal which will help to negate the effect of the high protein eg pasta, noodles, rice can also be used but note it is lower in calcium. As vegetables mature, we normally see a decrease in the protein level. Coarser and brightly coloured vegetables are generally lower in protein so always include some in your salads, if you are pregnant stay away from too many leafy ones.

Some other protein levels are: approximately. Beef 30%, Pork 45%, Chicken 16%, Fish 16%, Pasta 6 to 10%, Legumes 20 to 30%, Corn 6 to 9%, Oats 5 to 7%, Wheat 10 to 14%, Cheese 40 to 50%, apples 3%, avocados 1.5%. Once we know the percentage of protein in a food then it’s a matter of doing what many farmers already do with their stock, they mix and match to form an ideal diet.

Mineral Dilution

Another serious issue that has developed with our vegetables, especially the leafy ones, is the lower mineral content. This has been identified by the USA FDA, they have reported that our vegetables contain 30% less nutrients than they did 30 years ago. And it is not due to soil degradation but due to two other issues [1] Plant breeders have produced plants that grow quicker and have neglected the mineral content in the new varieties. [2] Growers apply nitrogen fertiliser to increase growth, the end result is that the amount of mineral concentrate in the plant is significantly reduced.

So when we look at the adverse effects that high protein has in our livestock industry, what are the repercussions in humans? There must be similarities and work needs to be undertaken to fully investigate these issues to help reduce the many associated issues especially the family devastation that results from a still birth.

Bryan L McLeod proagcon@ozemail.com.au





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