synaesthesia

synaesthesia

all of us can may have had the memory of, and taste a favourite food conjured up by the mentioning of the food.
Synaethesia is a rare condition involving the crossing of the senses , some people will have synaesthetic tastes produced by words the names of a food, lexical- gustatory synaesthesia. They taste the taste even before the word is said. That is on the tip of the tongue.
This is a genuine neurological phenomenon , and is one component of the complex reresentation of the meaning of words.
Everyone has this phenomenon but those with true synaesthesia have a more exagerated response.
Simner J and Ward J Nature 2006 , 444, 438

Folic acid, homocysteine and cardiovascular disease

Folic acid, homocysteine and cardiovascular diseaseBMJ 2006, 333, 114-7

Wald and his colleagues have published a meta analysis of Folic acid, homocysteine and cardiovascular disease, judging causality in the face of inconclusive trial evidence.
Meta ananysis of cohort studies show significant positive associations betwen serum homocysteine concentrations and ischaemic heart events and stroke. A 3 umol decrease in serum homocysteine ( achievable with 0.8 mg/day folic acid lowers the risk of myocardial infarct by 15% and stroke by 24 %.
Moderate raised homocysteine occurs as a result of a mutaiton in the methylenetetrofolate reductase gene.
The size of studies are small and there may be a publication bias, benefit publish , don't benefit, forget it.
However Wald and his colleagues looked at the meta analysis studies, genetic polymorphism studies and randomised trials and tok the view that the evidence was now sufficient to justify lowering the serum homocysteine concnetration.

The normal human genome

Understanding the human genome is essential for nutritionists.
1. Because the genome is biologically important
2. The genome is the basis for an individual person's metabolism
3. The exciting innovations in nutrition will be throughan undersanding of the interplay between
dietary intake and genome constitution
Of importance are two articles in Nature 23rd November 2006.
Pages 428-429 ; 444-454
The human genome contains many forms of genetic variation. The most plentiful are the millions of single base-pair changes in the DNA code . This single nucleotide polymorphism (SNPs) distinguish any two unrelated copies of the genome. This forms the neutral forms of widespread genetic variation marking diversity between individuals in a species.
There are however variations in copy number of sequence elements that is in the number of deleted or duplicated versions or segments of the genome that result in a range of the number of copies among normal members of the population. These are called copy number variants ( CNVs). In a large study of various apparently normal individuals nearly 1500 variable regions involving nearly 12% of the human genome and including hundreds of genes and the copy number were shown to differ quite significantly.
This implies that genetic diversity lies not in the millions of SNPs but in larger segments of the genome.
The deletions or duplications might be expected to influence the protein production from that gene. Hence variation in proteins eg Haemoglobin.
Only when there is a full atlas of CNV variation and the consequences in terms of individual susceptibility to disease or nutritional metabilism will these variations have any meaning.

Obesity and WHO 2006

The threat to Public Health the widespread prevalance of obestiy was recognised in a meeting of WHO in Istanbul of the 53 states in the WHO region. One fifth of the population is obese in this area.
A Charter, the European Charter on Counteracting Obesity was written which calls for preventitive measures to be initiated including promoting breastfeeding, cutting sugar, salt, and fat in foods and increasing physical activity and better nutrition in schools.
BMJ 2006 vol 333 p 1081

omega-3 fats

The recently published book The Queen of fats:why omega 3s were removed from the western diet and what we can do to replace them. Susan Allport

University of Californai Press 2006

is a very interesting account of these important fats.

The nutritional qualities of these fats are well outlined. The only misgivings are
1. The rapid depletion of fish form our seas means that serious thought has to be given to alternative sources eg algae
2. That sources of omega 3 may be contaminated with lipid soluble toxins eg dioxins and polychlorinated biphenyls

3. and too much of a good thing can occureg bleeding tendencies.

read the review in Nature 2006, vol 444 p 425 by Asim Duttaroy

Book recommendation

A good general book on practical nutrition

What to eat: an Aisle to Aisle guide to savvy food choices and good eating.
North Point Press 2006 624 pp $30

Malthus revisited

Thomas Malthus ( 1766-1835 ) argued that population growth was increasing faster than the means of providing food. Improved agriculture and means of providing food have proved that his argument was not correct.
However Akio Shibata of the Marubeni Research Institute in Japan suggests that Japan faces a potential food crisis that could lead to austere food patterns in the future. As countries become more afluent, the number of people working the land grows less, and the population requires adequate food. Millions of people are leaving their villages in China and India lured by the hope of a better life. As happened in Britan in the Victorian period. This stretches the urban provisions, houses, water, fuel, sewage, power to new limits.
The USA which is a net exporter of wheat is experiencing substantial population growth and hence is using more of its home grown grain. Less being available for Japan and other food importing countries. The answer in part is self sufficiency, in all countries. In 1965 Japan was almost able to supply all its requirements of vegetabls, meat, fish and fruit, now lit is less than 50 %.
London Times June 6th 2006, p 53

Pollution, and children's development

Industrial pollution has an important effect on children's development. Pollutants may lower the IQ of growing and developing children. Over a thousand chemicals are neurotoxic, various uses, few of which are tested for neurotoxicity. Quite reasonably if the use is far removed from the nursery.
Important chemicals are lead, methyl mercury, arsenic, polychlorinated biphenyls, solvents including ethanol, turpentine, toluene, and pesticides.
London Times Nov 8th 2006, p 33

Pesticide Poisoning

Pesticides are widely used in agriculture and hence have an impact on our diet and nutrtion. One and half million tonnes of pesticide are produced a year at a cost of 30 billion US dollars. The use of pesticides has resulted in increased crop yields, opening up of new agricultural grounds and reducion in vecto-transmitted disease. But pesticide resistance is increasing.
Most pesticides are toxic to human beings. In parts of the developing world pesticide poisoning kills more people than infections. Much of these by suicide, over 750,000 world wide, over 500,000 from self harm in Southeast Asia, especially in young women.
WHO estimated that there are three million pesticide poisoning cases each year.
Clearly less poisonous pesticides used with greater care and availability are needed.
Eddleston et al Lancet 2002, 1163-67, vol 360

Childhood obesity

The BMJ of 18th November 2006 has a leader and an article devoted to this very real problem. Local programmes and changes in policy have not had a substantial influence on reducing the number of obese children.
In a large study in Glasgow nurseries, Reilly and his colleagues (BMJ 2006, vol 333, pp 1041-3) studied in a cluster randomised controlled single blinded trial over 12 months whether physical activity reduced body mass index in young children. Modifications of one element of the problem ( exercise or diet ) have been more beneficial than changing both. There was no reduction in BMI at 6 months or 12 months in the increased acivity group. However the Leader commenting on this study suggests that BMI in young chjildren may not be a good index of obesity. Possibly insufficient exercise was added. Chilren can be extremely active, far more than adults can envisage.

Water in India

The Brahmaputra river in northern India provides water for 185 million people in northwest India and Bangladesh as well as sustaining wild life and hydro- electric schemes. . The Indians have have plan to develop 6,000 kilometeres of water way from the Tibetan border to the southern tip of India. This would link the Brahmaputra , the Ganges and other rivers.
However the Chines may have a plan to develop the Western Route Diversion Project which would divert the Brahmputra river to China as the river passes through the worlds deepest canyon before entering India. A net work of dams, canals, tunnels and aqueducts would divert 2oo million cubic metres of water annualy to the Yellow River and this would have a dramatic benefitial effect on the water supply to China.
Another problem is that the proposed dam would be in a territory which has regular earthquakes. Endangering the dam system.
This river engineering could have very considrable consequences.
Similar problems are affecting the Jordan river in the Middle east and the Nile in North Afrias
The nutritional effects of such moves on populations could be enormous.

Short Chain Fatty acids and colonic cancer

Burkitt and Trowell observed and then suggested that the African population was free of colonic cancer because of the protective action of dietary fibre. There has been much debate as to whether or not this is fact or fantasy. Epidemiological studies have been both supportive and dismissive of the fibre story. They preached that wheat bran was the fibre of choice.
Roediger wrote a series of papers suggesting short chain fatty acids, in particular butyrate generated in the colon by the fermentation of fibre were important in the metabolism and health of colonic cells . Butyrate was shown to inhibit DNA synthesis.
Another important observation was that acetyl salicylic acid ingestion was protective against the development of colonic polyps which are the precursors of colonic cancer.
With this background thee is a very interesting paper in the British Journal of Nutrition , vol 96, 2006, pp803-810. The authors, J. Kiefer, G Beyer-Sehlmeyer and BL Pool-Zobel show that short chain fatty acids modulated acetylaition in human HT29 colonic cancer cells. Acetylation of histones in the DNA of cancer cells has been associated with the reactivation or silencing of genes critical to cancer progression, differentiation and apoptosis. The activation of genes by inhibiting histone deacetylators ( HDAC) may be an important factor mediated by exogenous factors. It is also of interest that aspirin is an acetylator of cyclo-oxygenase. There maybe other enzymes and proteins that aspirin is involved in with acetylation of the protein and enzyme .
Such studies are so exciting in the development of nutrition. Proper experiments not conjecture.

Human Survival without food

The ability of individuals to survive without food is well demonstrated by the awful experiences in Concentration Camps and more recently by the Irish Hunger strikers. Women appear to last longer than men and over all the body mass at the outset is a predictor of length of survival. The amount of water available is also a factor.
In the London Times August 17th 2006 p 13 there is a remarkable account of fishermen being rescued after nine months adrift on the Pacific Ocean. The fishermen left El Limon in Mexico on a three week fishing trip, the engine ran out of petrol and they drifted westerly away from the land . They lived on raw fish, sea birds and rain water. They kept their spirits going with readings from the Bible. They went for long periods up to 15 days without food. They saw ships but no one saw them. They were rescued by a Taiwanese tuna boat. The initial and rescued weights are not mentioned
Other such mishaps include last year three fishermen adrift in the Pacific for seven weeks .
A ship sank in 1820 after being rammed by a whale. The 20 survivors escaped in three boats , they travelled 200 miles. Only 8 survived and cannabilism was practised.
During the battle of the Atlantic a tanker was sunk by a submarine. The submarin gave the survivors water and bread. The 26 men sailed in a lifeboat 1000 miles 28 days to Antigua.

In Franklin D Roosevelt’s inaugural address on being elected President of the USA in January 1941, he expounded basic truths of freedom
One has nothing to fear but fear itself

He said the freedoms were
Freedom of speech and expression
Freedom of everyone to worship God in his own way
Freedom from want
Freedom from fear
All of these are interdependent. . These are by and large all present in the economically well off countries. In the poor countries this is not the case. It is not unreasonable to think that the basic need is freedom from poverty. From this comes all the other loss of freedoms. A poverty stricken population struggles for survival and this is so often accompanied by other deprivations, nutrition being an important case. The culture of poverty is the greatest problem for the human race and yet must be resolved without ruined the delicate and precarious state of the ecology of the planet.
See also the writings of JK Galbraith in the 1980s and 90s.

Epidemiological studies and conclusions for nutrition

Epidemiological research has been one of the mainstays of our understanding of nutrition.
There is a real worry thqt epidemiology can and may well bring our science into redicule. Valid statistically identified risk factors are pumped up into "well known facts". So often one will hear a nutritionist being interviewed on the media and say, "my study shows that an excess of ********** , is a real aetiological factor in the development of a condition". Maybe. What are the probabilities or risk. Equal to smokig and cancer of the lung or sufficiently modest for most people to make a note and ignore with no health consequences.
There are three objectives for epidemiology:
• to describe the distribution and extent of disease problems in human populations
• to elucidate the aetiology of diseases
• to provide the information necessary to manage and plan services for the prevention, control and treatment of disease
What is being studied must be carefully defined and the interpretation of the results of the study be within the framework of the original definition.
Nutritional epidemiology, in addition to the study of the nutritional determinants of disease, measures nutritional status in relation to environment and dietary intake. Most clinical measurements of nutritional status are used to identify deficiencies in overall intake or intake of individual nutrients.
The great nutritional studies of the 19th and early part of the 20th century led to the discovery of dietary deficiencies in the form of beri-beri, goitre, pellagra, rickets, scurvy and xerophthalmia. These spectacular discoveries led to the concept of single dietary factors in the aetiology of disease. There is an understandable desire to identify simple and singular causes of contemporary diseases. However, it is now apparent that the system is complex, with groups vulnerable to multiple other predisposing factors in addition to nutritional factors, for example infection, activity levels and individual genetic variation. Furthermore, only a proportion of individuals who are at risk develop the particular nutritional problems under study.
Reaching rapid conclusions on the basis of epidemiological associations all too frequently mars the reputation of nutrition as a science, and delays identification of processes. Many recorded associations may not be causative of the condition ; instead, they are markers for the net effect of many variables that influence morbidity and mortality ( post hoc, non ergo propter hoc : after this, not therefore on account of this, the tendency to confuse sequence with consequences)

Bradford Hill suggested nine points which may suggest causality:
1. strength of association
2. consistency
3. specificity
4. relationship in time
5. biological gradient
6. biological plausibility
7. coherence of evidence
8. experimental evidence
9. analogy
He set out the conditions which had to be met before it could be concluded that an association observed, in a case-controlled study could be interpreted as indicating cause and effect:
• there should be no bias in the selection of subjects and controls, in the way that subjects and controls reported their histories or in the way that interviewers recorded data
• that there is an appropriate time interval between exposure to the suspected agent and the development of the disease
• the lack of any other distinction between the affected subjects and their controls that could account for the observed association or of any common factor that could lead both to the specific exposure and the development of the disease.
The proof of the pudding must be confirmation by clinical trials. The observation that protection from cancer was given by fruit and vegetables lead to large scale clinical trials using fibre, vitamin and trace element supplements. The benefits were negligible if at all. This still leaves the evidence that fruit and vegetables are helpful and why has still to be explained.

Man made toxins in food WWF report

Man made toxins have been detected in foods including such and eggs in analyses funded by WWF, formerly World Wide Fund for Nature. Furthermore these toxins are to be found in blood samples from a large number of people tested, however the concentrations are low, and may well be of not importance for health.
The risks posed by these contaminants are unknown. .Unwarranted speculation on the possible side effects of these is unhelpful until proven in carefully controlled studies.
The toxins found include
Organochorines
Polychlorinated biphenyls
Perfluoronated chemicals
Phthalaltes
Artificial musks
Alkylphenols
Organootins
Reported in the London Times September 21 2006, p11

Climate change and nutrition

Climate change and Global warning

Whilst there is debate as to the nature and possible causes of Global warming, and whether or not this is a threat, there is a growing belief that throughout the world the ambient temperature is climbing. There is a body of opinion that would have us believe that this is due to the green house gases especially CO2. Another group believes that the changes, are part of a cycle in our climate and are to be welcomed.
Whatever, a report published, on October 10th , 2006, by Sir Nicholas Stern a former Chief eEonomist at the World Bank predicts a rise in temperature by 2050 of about 5 degrees Celsius.
If this were to happen the prime result would be on water, drought , flooding and rainstorms depending on local condition,.
The consequences would be profound , especially on Nutrition . The disturbances of such changes on available water could be far reaching. .As nutritionists we must try to prevent such an occurrence and also have contingency plans for preventing or minimising the effect. On a local level how are people to sustain life in wide spread torrid conditions?
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