On Protein Quality, Health & Nutrition

The Blogger is honoured to be invited by Dr JB Lim to post the following article as Part 2 to his previous one (see earlier post) as he wishes not to mislead readers "into thinking that collagen, gelatin and all those ligaments, joints, connective tissues from feet, web, and trotters from animals cannot be eaten because they have no nutritive values":
Date received: Wednesday, 28 July, 2010 7:30 PM

Dear friends,

Thank you for your numerous compliments on my previous article. It was for educational value, not for compliments.

Maybe I should elaborate Part 1 of my article a little in order not to misdirect my Gentle Readers. Maybe I was just too harsh in prescribing laws on what is good, and what is nutritionally inadvisable.

Back to the Protein Score again:

I was just trying to tell you nutritional truth about collagen and gelatin is produced as its by-product when collagen is hydrolyzed by 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 that have a score of 100 and almost 100. This is the maximum biological and chemical score of a protein. This is used as a reference 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 and complete to the maximum. If one is of them is missing or are present only small amounts we call it the ‘limiting amino-acids’. This means that 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 or almost zero as in the case of collagen and gelatin.

The Analogy of a Water Barrel:

The measurement of protein quality is a highly technical subject. It is 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 by using the analogy of a water barrel made of wooden ribs sealing it from top to bottom.

Imagine a water barrel is complete when all the ribs are there, complete and intact from the top to the bottom of the barrel. Such a barrel can contain water, wine or oil right to the top without any of its liquid content spilling out.

Imagine there are 9 to 10 ribs needed to make up the whole and complete barrel. Each rib represents an essential amino acid as in the case of a complete protein like whole egg protein. Suppose one of the ribs is broken somewhere at the top. Let us say 10 % of its rib is missing from the top with 90 % of it still intact from the bottom. In that case, no matter how perfect the remaining ribs are, it can only hold water up to 90 % of its maximum capacity.

This means even if you pour the entire Pacific Ocean into that barrel; still it can only contain 90 % of its full capacity. Water can never reach up to the top, and even if it does temporary, the water will still leach out until it sinks to the top 10 % of the broken rib.

The lower the broken rib, the less water it can contain. Thus the ‘limiting rib’ of the barrel is similar to the ‘limiting amino acid’ of a protein. In short, the quality protein to retain nitrogen in the body, is governed by its ‘limiting amino acids’ similar to the ‘limiting rib’ to hold water in that barrel. This measures the quality of a water barrel the same way we measure the quality of a protein.

Simple, but unfortunately…

It is as simple to understand as that. Unfortunately this was not taught that way to us as postgraduate students at the University of London. It was taught to us in a highly complicated and technical manner with so many mathematical and biological models to grabble in the calculations. It was made 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 at the same time. We have also to consider their absorption, retention and their metabolic utilization.
Headaches:

It gave us students a lot of headaches trying to understand our professor who was a world expert on protein nutrition. He lectured to us on protein utilization by humans and animals in such great depth and in such a technical details expected of us until my course mates were not able to understand fully. All my course mates and class-mates were already highly qualified doctors and research scientists from their respective countries including female students from Britain when we decided to specialize in nutrition at London University. We thought it would be easy. But this Jewish professor beat us all to it with his fantastic knowledge on the subject, and the understanding of his complex research. He was a highly intelligent and a very brilliant professor. After receiving all the headaches, I now make it so very, very simple to my gentle readers.

The Nobel Prize Winning Jews:

The Jews literally heads almost all the university departments in the United Kingdom. They won almost all the Nobel Prizes in Science, Medicine or Physiology, Literature, Economics and Peace. They are exceptionally brilliant and very powerful at the same time. They are truly a highly intelligent race.

It marvels me that the Bible says they are God’s chosen people. With God protection over them it is little wonder why no country surrounding the Jewish state of Israel can defeat them. Actually all the countries are surrounding tiny Israel sitting at the edge of the Mediterranean Sea. They can easily push that country into the Mediterranean Sea, but are unable.
I think there this Divine protection from above in the war in Israel, Middle East and even in United States. I knew the Jews are a very brilliant race, but I sometimes wonder why they are also militarily ‘powerful’ at the same time. I believe an unseen Hand above is hovering over this race. This has been God’s promise to them even since the time of Moses when God lead them out of Egypt in the Promised Land.

It is Quality, not just Quantity:

Back to our discussion on protein nutrition, this means that no matter how much protein we eat, but if their biological is zero, the body just cannot retain the invaluable nitrogen in the protein to support growth.

The body just cannot retain them for growth, development and repair even if only one of the 8 + 2 out of 20 + 2 amino acids in a protein is incomplete or totally missing. The body can hold as much protein as the amount of ‘limiting amino acids’ it provides. This is similar to pouring the entire Pacific Ocean into a water barrel with one of it ribs missing.
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 praline. Collagen accounts for about 50% of the amino acids present in collagen. But because these two very important amino acids are missing in collagen, it is like having a water barrel with two of its ribs completely missing. The body has no choice but to throw it out like any sensible person would throw away a water barrel even if just one of its ribs is missing or incomplete. It cannot hold anything.

Thus it is not just how much protein-rich foods you eat that is important for health, especially for the vital growth and development of a young child. It is also the type and quality of protein you choose in a diet.

Eggs and Milk the Best: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 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.
Mother Nature knows best. She made whole eggs and milk to be 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 has to be the best 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 when we were postgraduate students, and paid hefty tuition fees for this. Thank God, we all passed. Now I give this knowledge to my gentle readers for free.

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 ordinary consumers to understand.

The wrong message:
The reason why I extended this article from the previous one is that I do not want my readers 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?' My answer to this question is very simple. It is both. In situations like Malaysia there is really no shortage of food and proteins these days. It is readily available to even the hard-core poor. So take advantage of the abundance of food in Malaysia, but never go overboard and indulgence.

Never depend on clutches:

Always take a holistic approach in the practice of nutrition and medicine. Never live on a ‘health-protective’ mono-diet just to live. Alice in Wonderland was in a dilemma asking that.
Neither just depend on your doctor’s pharmacological clutches in a vain attempt to regain health if your lifestyle is the real root causes, and totally to be blamed. Drugs can never replace healthy lifestyle. Blame the nutritionist and the doctor if they are not able to educate you. It is preventive medicine, and not curative medicine that is far more important. The sense on well-being and enjoyment and good health depends on the choice of a wide variety of foods, and we eat to live just as important that we live to eat for total well-being.

Protein-energy Malnutrition:
Unlike in some deprived communities in countries like Africa, people, especially the children are very deprived of valuable good protein so vital 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 contains the best protein) when the mother gets pregnant again before the first child can be properly nourished and brought up.

They are taken off breast milk so that the mother can reserve them for the second child. Thus the first child suffers 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, these infants are severely malnourished on both, leading the child with marasmic-kwashiokor (protein-energy malnutrition). This leads to very high infantile mortality in some of the communities. 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 porridge of cassava or maize with hardly any protein inside. The quality and quantity of protein as in maize / corn is extremely low. The child simply dies or fails to thrive. This is a very serious health problem.

Situations in Malaysia:

In Malaysia the situation is almost the opposite these days. Back 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 these rural areas, especially among the Malays and Indians in the estates, although the Chinese in similar areas were better off.

This was due to rural poverty among the Malays and Indians living in the rubber estates and oil palm plantations in rural Malaya. But with the overall economic improvement in the country since the 1980s the situation changes quite dramatically and in recent years Malaysians are suffering from the other end of health problems due to excess of food and over-eating.

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. This is malnutrition at the other end. A lot of people think that the word ‘malnutrition’ means under-nutrition. The word ‘mal’ or ‘malapert’ is actually a loan word from French meaning ‘bad’ So ‘malnutrition’ actually applies to both under-nutrition and over-nutriition. It is bad for health either way.

Low incidence:

The incidence of anyone in Malaysia suffering from any of the protein and energy deficiencies is low. There are still cases we see in hospitals, or picked up during a health survey. It is not completely absent. Even in advanced countries like United States and Britain malnutrition is still there. In Malaysia most of the cases are among the Orang Asli and those in deprived rural villages away from good transportation. We have picked up quite a number of significant cases of deficiency conditions in our nation-wide surveys.

But in the urban rich, people are obese and overweight due to far too much food available to them beyond their physiological needs.

Eat collagen-rich foods:

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 daily diet of meat, fish, chicken, eggs, soya-beans, legumes and eggs. They do not require extra proteins especially after puberty. By eating chicken and duck’s legs, joints and ligaments of beef, mutton and pork, albeit has little nutritional benefits will not compromise their nutritional needs for extra proteins.

The 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 have a very rich diet of fish, pork and chicken. Consumption of 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 one that is 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 eats food, not nutrients for the sense of enjoyment, psychological and social well-being. They also live to eat, and not just eat to live.
Difference between humans and animals:

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 on just artificial nutrients and water, but no similar trials has been done on humans, because humans are not rats. They demand food, not nutrients.

This means, despite bones, ligaments, joints, being low in nutritional values, they nevertheless are delicious if skillfully prepared by a good cook. With proper spices, and various sauces, the soft jelly-like substances (gelatin) made from collagen is a delight to a discerning taste-bud. Personally, I have enjoyed beef joints and ligaments cooked in curry powder, and various spices.

But not advisable for…:
However, I would not advise any mother with very young babies and children to feed their young children on a diet of gelatin and collagen products for obvious reasons that protein from these sources are not going to help with their physical and mental development during their formative years. Do not compromise their health and development with low quality proteins just because soft collagen properly prepared taste nice. Do not be foolish. Young children need proper nourishment, not good taste.

My recommendation:

I should recommend a diet rich in good quality proteins derived from milk, eggs, fish, chicken, meat, and soya beans. These would be the best diet for a baby after his weaning period from six months onwards. Wean off from milk slowly with a soft- boiled egg daily, and grade on to boneless fish (be careful with fish bones), soya products and then at one year start off with chicken and tender meat, legumes. A child should be brought up with adequate supply of not just proteins, but also a diet rich in calcium, phosphorus, iron, all the various vitamins and trace minerals as well.
Give a child a wide range of all foods, including lots of fruits and vegetables. This will ensure adequate nourishment to meet all his / her physiological and psychological needs. But an ample supply of good quality proteins for at least up to 5 years is mandatory, but preferably for at least for another 2-3 years after reaching puberty to cater for individual nutritional needs and biological variations. This is a safety net.

If these foods are introduced, there is no harm giving a young child an occasional feed of soft chicken and duck feet, or pork trotters, or any collagen preparations. After all, humans are designed with taste buds to enjoy a variety of foods and food preparations provided adequate nutritional needs of all the nutrients have been met.

Health risks after puberty:

A few years after puberty has been achieved, food intake needs to be restricted to minimize risk of childhood obesity, and diseases of overweight as in adults. Never pamper young children with a fast-food culture if we care and love them. An occasional treat is beautiful. It is part of life. It is meant to be enjoyable. There is no harm.

The conclusion:
Hence food is meant to nourish and at the same time, to be enjoyed. The dilemma of Alice in Wonderland in asking ‘should we eat to live or live to eat’ can easily be answered with both answers.

Health is to be taken holistically. It is just as important to attain a sense of psychological well-being as physical health. The trinity of physical, mental and social health is what makes us humans different from laboratory experimental rats and other animals. Collectively, they make up a healthy individual, a family, a community, and ultimately a happy and harmonious nation. It is far from we eat to live which is the objective of the animal kingdom.

Once again I echo what my eminent professors in nutrition at the University of London and at Cambridge taught us. ‘Man eats food, not nutrients’.

jb lim

Lim Ju Boo BSc (Physiol & Chem) Postgrad Dip Nutr MSc (Food QC) MD PhD (Med) FRSPH FRSM

Special Medical & Science Adviser
Head of the Technical Advisory Board
Dynapharm Int’l Pharmaceutical Group
Malaysia

Formerly:
Research Nutritionist & Toxicologist
MIT

Senior Researcher
Institute for Medical Research
Malaysia