Professor Michael Crawford is one of the world’s most eminent researchers into brain function and nutrition, with over 300 publications. He is one of the most engaging presenters you will ever hear and is always in demand for speaking roles.
Michael comments on “The protein myth”, a subject dear to his heart.
Over the years I have heard several speakers referred to the importance of fish and sea food for protein. This is a common misconception.
The value of fish and or sea foods does not lie in protein. Protein is readily obtainable. A cow, horse and rhinoceros eat all the protein they need from the simplest food namely grass. Human milk has the least amount of protein compared to any other large mammal. Protein is good for body growth. Indeed at a meeting on the plight of the oceans of international donors at FAO in Rome several years ago I heard the representative of the World Bank declare that he was not as worried about the sustainability of fish as protein could be obtained from other sources!
What we forget is the human developmental biology is about brain growth and the brain is largely made of fat (60%). Human milk contains long chain essential fats that are critically important for brain growth and function. The Omega 3 DHA for example, is present at over 10 times that found in cow’s milk whilst cow’s milk has some 4 times the amount of protein.
We are not a fast growing animal like a cow or horse. Homo sapiens is characterized by extraordinary brain growth. The brain requires essential fats of which fish and sea food are the richest source.
It is an interesting and relevant fact that the brain evolved in the sea some 500-600 million years ago. Despite genomic changes from dynoflagelates to cephalopods, to fish, to amphibians, to reptiles, to birds, mammals and ourselves, the use of omega 3 DHA (an essential fatty acid) has been strictly conserved for the construction and function of the photo-receptor, the synapse and neurons, as well as for the instruction of gene expression on how to serve the brain, throughout that whole period of animal evolution.
There is abundant evidence in animals and humans on the need for DHA for the brain. The international expert consultation on the role of dietary fatty acids, jointly of FAO and WHO, accorded the highest level of confidence to the evidence for the requirement of DHA for the infant retina and brain development (FAO nutrition report no 91, 2010). Of all the essential fatty acids needed by the brain DHA is the most limiting in availability.
Land foods are relatively poor in DHA which comes largely from eggs and small mammals and poultry. Unfortunately intensive poultry has substantially depressed their value as a source . As you have seen in my presentation, Roy, all land mammals evolved faster body growth based on protein so their brain shrank relative to their body size. It was different for the marine mammals. For example a Dolphin has a 1.8 Kg brain compared to about 350g for a land mammal with a similar body weight such as a zebra.
It is most likely that human evolution was coastal to ensure a rich DHA supply for the mothers and so secure the epigenetic cerebral enhancement from embryogenesis to fetal and infant development from one generation after another. There is now good fossil and biological evidence for cerebral expansion at the coast , . There is also human evidence of substantial cognitive and behavioral advantages for children at 8 years of age when women eat fish and/or sea food during pregnancy from the ALSPAC study in the Avon District of West England. This study followed up the children born to over 14,000 pregnancies with a straight line incrementing performance assessed in the 8 year olds with the fish and sea food omega 3 eaten in the pregnancy.
The importance of detaching fish and sea foods from protein also includes the value of sea foods as a source of iodine and other trace elements. There are today some 2 billion people at risk to iodine deficiency which induces mental impairment. Additionally there are many other minerals and vitamins which are important in seafood – if there was ever a complete meal it would be an entrée of freshly shucked Oysters followed by a grilled oily fish fillet!
In 2008 the Declaration of Muscat, Oman called for a realignment of the approach to human nutrition focusing on maternal health, nutrition and brain development as well as the development of novel methods for marine agriculture.
In 2009 11 representatives of Ministries from the Far Eastern Countries agreed on a Declaration of Manila in which addressing marine and fresh water pollution was given high priority. We have not even begun to think about it in Europe toying mostly with ideas on controlling fish catches and burning boats.
In 2010 at the Conference you organised in Melbourne, Roy, we were not able to get the politicians to come and listen and debate this with us. Politicians and Department bureaucrats are avoiding the issue in my opinion.
There needs to be a radical re-thinking of the funding into the fisheries and oceans in many places around the world and especially in the EU. Apart from the logic voiced at the meetings, there is a vital subject not so far discussed; the subject of mental ill health.
The EU commissioned an audit on the health costs for the 25 member states. The result was that at 2004 prices mental ill health had overtaken all other burdens of ill health at Euros 386 billion . Questions were asked in the House of Lords. In 2007 Dr Jo Nurse of the Dept of Health did the sums for the UK. The answer was a cost of £77 billion, greater than cancer and heart disease combined. She re-assessed the numbers in 2010 which came out at £105 billion.
At several scientific conferences over the last 18 months including at NOAA; Beijing; the International Sea Food and Health Conference, Melbourne; Salt Lake City (GOED) and the Omega 3 Summit in Bruges, this subject has been aired and questions asked as to whether there is enough fish to meet the requirements recommended by FAO and WHO.
At the moment there is a disproportion fish and sea food use with the Far East consuming the most. Interestingly they have the least mental ill health, least heart disease and least Western cancers with Japan having the best longevity of any industrialized nation. The mental health issue as predicted in the 1970s is a Western problem but tragically, like much else it is being globalised.
This scenario raises important issues if we are to arrest the climb in mental ill health. It requires a multi-factorial attack ranging from education through to water quality and aquaculture and the food system. However, one key issue that stands above all is that the wild catch has been stagnant for several decades. Although aquaculture has expanded rapidly (again unsurprisingly in Far East & Asia), it will have its challenges in the developed world as we are more inclined to want development along the coast than growing seafood.
Astonishing as it may seem, the use of the oceans today is Neanderthal. We are still hunting and gathering. Some 10,000 years ago, people recognized that hunting and gathering on land was not sustainable and invented agriculture and animal husbandry. They did not need expert committees established by governments. The rivers, lakes and seas had an abundant harvest at that time and indeed until very recently. We need to re-visit those days.
The only real solution to providing adequate fish and sea food is to do the same in the oceans. We need to develop marine agriculture and husbandry. This is now happening in Japan and the Far East. Take a simple example: we all know about cows on green pastures. Starting in 1991, Dr Takehiro Tanaka who is Director of Fisheries Division, Department of Agriculture, Forest and Fisheries, Okayama Prefectural Government has been developing the same in the sea. They are using Zostera marina (sea grass) to make ocean bed pastures for fish. Cows graze festuca pratensis – fish graze Zostera marina a mind blowing simple and effective approach. They have developed an extensive area of sea bed with a variety of ecological techniques to encourage the primary productivity using sunlight as the main energy source, and with it, the productivity of fish and sea food has grown.
I hope I have made the case that fish and sea foods are not necessarily of major value for protein but are for their essential fats and trace elements needed for the brain. They also happen to be needed for the heart, vascular and immune systems but that is another story. The rise in mental ill health is the greatest health threat facing us today. Its continued escalation is predictable which is also unthinkable. The brain evolved in the sea 500-600 million years ago using marine fats and trace elements. It still uses the same today. Addressing this issue is the greatest challenge we face as humans. The need cannot be met from existing wild fish stocks. Marine agriculture and husbandry and using the Oceans in an environmentally sustainable fashion IS THE SOLUTION.