Tuesday, August 31, 2010

More on Protein Quality

Dear friends,

Thank you for your so many compliments on my previous article. Maybe I was just too harsh to prescribe laws on what is good, and what is nutritionally inadvisable.

I was just trying to tell you nutritional truth about collagen and gelatin as its by-products on hydrolysis after boiling and cooking

Perhaps I may have given the wrong message by giving the impression that chicken, duck’s and pig trotters should not be eaten because of their poor protein biological value of zero or almost zero compared to reference protein from whole eggs and milk with a score of 100 which is the maximum biological and chemical score. Thus whole egg is used as a reference to compare the quality of all other proteins

These are scores nutritionists use to evaluate the quality of proteins by their limiting amino acids. In order to have a high score, all the essential amino acids must be there, else if one is missing or are present only small amounts – what we call ‘limiting amino-acids’ then the body is incapable of retaining it for growth, repair and development. If a particular amino acid is missing or not present in sufficient quantity, then its biological value and chemical score goes down from 100 (maximum) to zero as in the case of collagen and gelatin.

Limiting Amino Acids:

The measurement of protein quality is a very highly technical subject, and also very difficult to understand for those are not trained in nutritional medicine, nutritional biochemistry or clinical physiology. But I shall try to make it very simple to understand for the lay person using the analogy of a wooden water barrel made of wooden ribs sealing it from top to bottom.

Imagine this barrel is complete with all the ribs complete and intact. Such a barrel can contain water, wine or oil right to the brim. Imagine there are 9 ribs, each representing an essential amino acid to make the barrel complete (complete protein like whole egg protein). Suppose one of the ribs is broken somewhere at the top, say 10 % from the top with 90 % still intact from the bottom.

In that case, no matter how perfect the remaining 8 ribs are, it can only hold water up to 90 % of its maximum capacity. You can even pour the entire Pacific Ocean into that barrel; still it can only remain 90 % full at maximum. The rest of the water just leached out from 10 % of the broken rib. The lower the broken rib, the less water it can contain. Thus the ‘limiting amino acid’ to measure the quality of the protein to retain nitrogen in the body, is the ‘limiting level of the rib’ to hold water in that barrel. This measures the quality of that water barrel.

The meaning of ‘limiting amino acids’:

Please note that in a protein, it does not mean that all the amino acids in there are all complete (all the ribs in perfect condition), except with one amino-acid missing or partly complete. This is not true. In a protein all the amino acids may be there, or may not be there. They may be present in different levels as if they are the barrel ribs broken or partly complete at different levels. But the amino acid that has the lowest content among the rest, is the one that limits the value of that particular protein. That specific amino acid with the lowest content among all of them, or is completely absent in the protein, is called the limiting amino acid. In short, it is liken a water barrel with several incomplete ribs, but it is the rib that is the lowest that limits the barrel to contain water only up to that level. That is the meaning of ‘limiting’.

The brains of the Jews:

It is as simple to understand as that. Unfortunately when I was a postgraduate student in London, this was taught to us in a highly technical manner with so many mathematical and biological models to grabble in the calculations. It was really complex and highly intricate, and we have to strain our brains to the maximum capacity to understand and how to calculate both the quality and quantity of protein values, their absorption, retention and their metabolic utilization. It gave us all students a lot of headache trying to understand this world expert on protein utilization by humans and by animals. All my course mates at London University were already highly qualified doctors and research scientists coming from various countries, but this Jewish professor’s brain who taught us, beat us all to it with his highly complex research on proteins.

The Jews who literally heads all the university departments are a highly intelligent race. They won almost all the Nobel Prizes in Science, Medicine or Physiology, Literature, Economics and Peace. They are exceptionally brilliant, and powerful. Einstein was a Jew, as an example. The Bible says they are God’s chosen people. With God protection over them, no wonder no country can defeat them whether they are settled in Israel, Middle East or even in the United States. They are such a powerful and intelligent race.

Quality more important…

This means that no matter how much protein you eat, similar to pouring the entire Pacific Ocean into that barrel, the body just cannot retain them for growth, development and repair if only one of the 8 + 2 essential amino acids out of 20 + 2 in a protein is incomplete or totally missing. The body can hold as much protein as the ‘limiting amino acids’ in the protein it prescribes and limits.

In the case of collagen, two very important essential amino-acids called lysine and tryptophan are missing even though it is rich in glycine and proline which account for about 50% of the amino acids present in collagen. But because these two very important body building amino acids are missing in collagen, it is like having a water barrel with two of its ribs completely missing. How can this barrel store any water in the same way as how the body can retain the amino acids from collagen when these two very important amino acids almost completely missing. The body has no choice but to throw it out like any sensible person will throw away a water barrel with even just one of its ribs missing or almost all missing?

Thus it is not just how much protein-rich foods you eat that is important for health, but also the type and quality of protein you choose. Hence you may eat the entire Pacific Ocean of proteins on this planet, but the body will still throw all of them away if only one of the 9 essential amino acids is completely missing. An egg or a glass of milk is far better because of their protein quality. The body will keep all of them. It is as simple to understand as that.

Hence it is not the quantity of protein foods, but also the quality as well, with whole eggs and milk right on the top. These two foods are specially designed by Mother Nature for babies and young animals that depended solely on their mother’s milk, and the protein inside an egg for the un-hatch chicken or other egg-laying animals for their growth and development. No other protein-rich foods can beat these two for their protein quality. You can clearly see how logical Mother Nature gave us for our survival immediately after birth.

This analogy I give here is 10 million times easier to understand than the complexities of protein nutrition we have to crack our brains day and night to understand with endless discussions among ourselves as postgraduate students. Thank God, we all passed with a Postgraduate Diploma in Nutrition as Internal Students from the University of London in 1966.

Net Protein Utilization:

There is another measure to evaluate the quality of protein. This is called the net protein utilization (NPU). It is measured by the ratio of amino acid converted to proteins to the ratio of amino acids supplied, but this is affected by the amount of limiting amino acids present. We will not go into that, as it is meant for nutritionists only and not for ordinary housewives and consumers to understand.

The reason why I extended this article from the previous one is that I do not want you all to think that eating collagen or gelatin is completely useless for our health and should not be eaten. The reason is because as Alice in Wonderland (Lewis Carroll) asks 'do we eat to live or live to eat'.

Severe protein deficiency is not a problem in Malaysia:

My answer to this question is very simple: both. In situations like Malaysia there is really no shortage of food and proteins these days. Unlike in some deprived communities like in some countries in Africa, people, especially the children are very deprived of valuable good protein so important for their growth, development, and against diseases. The children before they even reach one year old they were already deprived of their mother’s milk (which is the best protein) when the mother gets pregnant again before the first child can be properly nourished and brought up. They suffer severely from a protein-deficiency disorder called kwashiorkor, and often from energy-deficient as well leading to another condition called marasmus.

More often than not, they are severely malnourished on both, leading the child with marasmic-kwashiokor (protein-energy malnutrition). This leads to very high infantile mortality. These children need very high protein diet which is not available to them when the mother took them off breast milk, and feed them on dilute solutions or porridge of cereal grains of cassava or maize with hardly any protein or very poor quality protein as in maize / corn. The child simply dies or fails to thrive. This is a very serious health problem.

Over-nutrition is the problem:

But in Malaysia the situation is almost the opposite these days. In the 1950s and earlier, to the 1970s health and nutrition status in the rural areas, especially in Kelantan were almost like those in African countries, albeit not as bad. Malnutrition due to protein, energy, iron and vitamin deficiencies were quite common in the rural areas, especially among the Malays and Indians in the estates, although the Chinese in similar areas are better off. This was due to rural poverty among the Malays and Indians living in the rubber estates and oil palm plantations in the rural villages respectively. But with the overall economic improvement in the country since the 1980s the situation changes quite dramatically in recent years. Instead of suffering from various deficiency diseases as in World War II, the people in this country are now eating far too much to the extent they suffer from diseases of over-nutrition and nutritional excesses.

Hardly anyone in Malaysia suffers from any of the protein and energy deficiencies anymore. In fact they are obese due to far too much food available to them that is beyond their physiological needs.

Fair ‘to live to eat’:

It is this group of people that eating collagen-rich foods will not compromise their daily nutritional needs for adequate protein. They have excess of proteins in their diet of meat, fish, chicken, eggs, soy-beans, legumes and eggs. They do not require extra proteins. By eating chicken and duck’s legs, joints and ligaments of beef, mutton and pork, albeit has little nutritional benefits except for taste.

Thus, consumption of these foods is not going to compromise their needs for extra quality proteins. Food consumption surveys showed most Malaysians, especially in the cities and urban areas, and especially among the Chinese who have a very rich diet of fish, pork and chicken, eating collagen-rich foods is not going to make any difference to their daily protein requirements. They already have enough from other sources, and pig’s totters are just for fun eating and enjoyment and nothing more.

Holistic and Psychological health:

Just as Alice in Wonderland asks 'do we eat to live or live to eat' the answer has to be holistic to our health. It is important to realize that psychological health is just as important as physical health and health and enjoyment is part and parcel of physical, mental and social well-being. Humans are not laboratory rats and animals that can thrive well with adequate synthetic diets and water. Rats reared in the laboratory for medical, drug, toxicological testing etc can easily thrive and reproduce when kept in cages, but given adequate food in the form of synthetic nutrients and water. But man eat food, not nutrients for the sense of enjoyment, psychological and social well-being besides ‘eat to live’

There is a big difference between synthetic nutrients for rats and complete and nice-tasting foods for humans. Laboratory animals can be kept alive throughout their natural life-spans by just artificial nutrients and water, but no similar trials has been done on humans, because humans are not rats. They demand food, not nutrients.

Once again, nutritionists need to remind themselves that man eat food, not nutrients.

jb lim

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On Sun, Jul 25, 2010 at 11:51 AM, Tan Seng Khoon ++ wrote:

Dear Dr. Lim JB,

Fantastic piece of Medical thesis. Brilliant. Absolutely brilliant, intelligent and deep are your scientific knowledge

I absolutely, completely and fully agree with you on all your views. No holes for any spear to go through. So David, your spears tak laku again.

Thank you for sharing your thoughts.

Now that the nutrition law will come into effect, you will be higher in demand in the market for your services.

This is very very good news. I think one table for all. Pig trotter a must I suppose. Ha..ha..ha...

Rgds,

khoon.

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