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Monday, April 30, 2012

Organic food and agricultural romanticism

A seed has three main parts: an outer husk to protect it until germination (bran), a reserve of energy (endosperm) and the cells that have the DNA to kick start growth (germ). After planting into the earth with sufficient moisture to break down the bran, the process of growth starts. The germ cells use the nutrient reserve in the endosperm to get started in making fledgling leaves and roots and eventually, the seedling breaks through to the infinite energy of photosynthesis from sunlight. The roots develop and start to move water from the soil through the plant to be evaporated from the leaves and in so doing, the water brings the minerals the plant needs to grow, of which one is nitrogen. 
Nitrogen is absorbed from the soil as either ammonium (NH4+) or as nitrate (NO2-). Both are released from commercial fertilizers and both are released from farmyard manure. The ammonium and the nitrate ions of both commercial fertilizers and manure are absolutely identical and there is simply no way a plant can differentiate between the two. The same is true of all the other minerals which plants absorb from soil such as sulphates and phosphates. The minerals absorbed are used for all sorts of functions but most of the nitrogen and sulphur ends up in plant amino acids and proteins. Some will end up in the vitamins that the plant makes and also the phytochemicals which give plants their colour, texture, smell, taste and so forth. The plant assemble all of these compounds according to its DNA. Unlike animals, plants do not have any nervous system and thus cannot make choices. Thus they are hardwired to do exactly what their genes tell them to do. Thus a carrot seed becomes a carrot and not a parsnip and vice-versa. Those who espouse organic farming harbour the view that the plant grows differently in the presence of organically derived minerals as compared to those that are industrially derived. This is utter nonsense. Michael Pollan, for example, argues that synthetic fertilizers force plants to grow at a faster than average rate and that in so doing, the plants get things wrong. Rubbish!!!
Plant growth, like animal growth, is determined by growth hormones which are genetically controlled but which also respond to climate. These hormones determine the rate of growth and thus the demand for minerals from soil and it doesn’t matter one iota if the minerals are from manure or “chemical” fertilizers. This has an analogy in human growth. Athletes can eat as much protein as they like but that will not drive muscle growth. Hormones drive muscle growth and athletes can take hormones illegally or they can increase their natural levels by training and conditioning. 
Let us now turn to the idea promoted by organic enthusiasts that organic food is tastier and more nutritious. Firstly, theory would say that that is not possible as explained above but the proof of the pudding is in the eating. Research published in the American Journal of Clinical Nutrition and FUNDED by the Danish organic farming movement, categorically failed to find any difference in the nutritional value of plants grown under organic or conventional farming conditions. Equally, researchers at the University of Kansas found that consumer panels could not distinguish between the taste of organically grown fruit and vegetables and those grown using industrially produced fertilizers. Endless reviews by eminent scientists and funded by governmental bodies reach similar conclusions. For example, the UK Food Standards Agency commissioned a review of all the literature relating to the nutritional quality of organic food. The review concluded: ‘On the basis of a systematic review of studies of satisfactory quality, there is no evidence of a difference in nutrient quality between organic and conventionally produced foodstuffs’. The taste and flavour of plants are determined to some extent by microclimate and the variation in these qualities between growing seasons or between different parts of the same field exceeds any variation between crops grown under either conditions.
The organic movement also suggest that foods grown under organic conditions are better for the environment. A report commissioned by the UK Department of Food, Environment and Rural Affairs
 concluded: “There is insufficient evidence available to state that organic agriculture overall would have less of an environmental impact than conventional agriculture. In particular, from the data we have identified, organic agriculture poses its own environmental problems in the production of some foods, either in terms of nutrient release to water or in terms of climate-change burdens. There is no clear-cut answer to the question: which ‘trolley’ has a lower environmental impact - the organic one or the conventional one?”. 
Finally, we turn to pesticide residues. By definition, organic food should not contain residues of synthetic pesticides. However, studies repeatedly show that about 15% of organic crops will contain some minute level of pesticide residues which is explained by “drift” ~ farmers upstream from the wind direction spraying their crops with downward drift of some spray. By definition, conventional crops will contain pesticide residues and as with organic crops, the levels are minute. In neither case do these residues contain a shred of threat to health since they are present at  ultra-low levels, and well below the agreed residue levels in legislation. Of course there have been cases of neglect or accident where pesticide levels above this threshold have been found and even some very rare cases of sickness arising from these high levels. But these are accidents or neglect and they can also occur in organic agriculture where contamination with E. Coli on organic food has led to food poisoning.
As I pointed out in a previous blog, all the scientific arguments in the world will not change the views of the agricultural romanticists. Theirs is a view based on emotion and not science, or a distorted view of science. But if such arguments help the very many who haven’t the resources to pay for organic food to feel better about conventionally produced foods, then it is very worthwhile making the case. 

Monday, April 23, 2012

Michael Pollan's "In defense of food" - a critique

Michael Pollan’s book “In Defense of Food’ has been a global best seller within the genre of books on food and health. It appears to be extremely popular among journalists since it bashes conventional wisdom on food. Twice, correspondents for the Irish Times chose to feature this book and marvel at its wisdom. Pollan’s book is peppered with half-truths, circular arguments and highly selective supporting material. His fundamental point is that we should focus our dietary choice on foods and not bother too much, if at all, with all of this nutritional advice that abounds today.

Pollen’s belief that health is the driver of food choice in the modern era is a cornerstone of his argument. Take for example the statement he makes: “That eating should be foremost about bodily health is a relatively new, and I think, destructive idea”.  As I pointed out in my blog of April 2nd, the interest in healthy eating is as old as civilisation and this obsession is the pursuit of a relatively minor section of society[1]. The vast majority chooses food that they plan to enjoy and, in making those choices, take care to get some level of balance as regards to their personal health. Every study that has examined the drivers of food choice have come away with the conclusion that the “go – no go” part of food choice is whether the consumer likes the food.  Pollan’s assumption that it is the pursuit of health that drives food choice is an opinion based his personal reflections and observations. However, our own research, published in peer-reviewed journals shows the opposite. In a survey of over 14,000 consumers across the EU, some 71% either ‘agreed strongly’ or ‘agreed’ with the statement: “I do not need to make changes to my diet as my diet is already healthy enough”.  Figure that Mr Pollan!

The putative obsession with food and health of modern consumers that Pollan puts forward arises from the dogmatism and doctrine, which he calls “nutritionism”. He argues that nutrition has reduced the food and health issue to nutrients. In his view, nutritionists see foods solely as purveyors of nutrients and summarises their view thus: “Foods are essentially the sum of their nutrient parts”.  He quotes his fellow food saviour and author Marion Nestle who says of nutrition: “…it takes the nutrient out of the food, the food out of the diet and the diet out of the lifestyle”. Eloquent, but utter baloney! This needs to rebutted along several lines. In 1996, I chaired a joint WHO-FAO committee that issued a report entitled “Preparation and use of food-based dietary guidelines”. The notion behind this was that many developing countries did not have detailed data on the nutrient content of their food supply, that they didn’t have nutritional surveys and that we should encourage the development of healthy eating advice in terms that consumers can understand. Indeed, statistical techniques such as cluster analysis are widely used to study food intake patterns and moreover, there are many examples of systems that score food choice for their nutritional quality. To write a book based on the impression that nutritionist see foods solely in terms of nutrients is simply daft.
Let me go a little further with this. Take the disease spina bifida, which is one of several forms of neural tube defects (NTD) that occur early in pregnancy. Extensive human intervention studies have shown that an increased intake of the B vitamin, folic acid, will significantly reduce the re-occurrence of an NTD birth in women who have previously had a child with this condition. This research has led to a threshold value of folic acid in blood above which this reduction occurs and the research shows that in human intervention studies, it is not possible to attain this threshold with normal foods, naturally rich in folate. Such folate has a rather low bioavailability and the threshold can only be reached if the volunteers consumed foods fortified with synthetic folic acid. This has led to the mandatory fortification of flour in the US with folic acid leading to a dramatic reduction in the incidence of new cases of spina bifida.
What is laughable about Pollan’s approach is that he himself engages in his so-called reductionism because he devotes at least almost 11 pages to the argument for and against the polyunsaturated fats from plants (omega-6 variety) and the polyunsaturated fats from fish (omega-3 variety), ultimately favouring the latter and then ends up with the statement: ”Could it be that the problem with the Western diet is a gross deficiency in this nutrient?” Now Michael you can’t have it both ways. You can’t decry nutritionists for studying individual nutrients in relation to health and then proceed to do so yourself! And remarkably, this champion of foods over nutrients goes on to argue that older persons should take multivitamins. Don’t take a bow Michael. Just stop doing summersaults.

The final piece in his jigsaw is to dismiss the modern processed food as though bread, cheese, yogurt, pasta, wine, chocolate, coffee and the like are not processed. Their processing details were worked out long ago and so they don’t qualify for the derogatory tag of “processed”. As I pointed out in a recent blog, the first sugar refinery was built in Crete in 1000 AD and that the Arabic name for Crete, Qandi, gave rise to what we today call “candy”. This process requires the sugar can to be pulped in water, the water filtered through muslin and the water evaporated in the searing heat of the Crete sunshine, which is why Crete was chosen and not Cork. And he makes the inevitable mistake of the agricultural romanticist that organic food is nutritionally superior to conventionally farmed food, which is palpably untrue but let that be next week’s blog.

[1] Sex, obesity and the seven deadly sins

Monday, April 16, 2012

Even fat people can go hungry

Any word association involving obesity will quickly throw up the word ‘America’. It was in the US where obesity was first seen in epidemic proportions and it was in the US that fast food, Coca Cola and super-sizing originated.  It is the gold standard of an obesogenic environment with a cheap and abundant food supply and, of course, most of its urban sprawls actively promote the car over shank’s mare. The concern over obesity begins with the First Lady herself and embraces all elements of US health policy. But within that obesogenic environment lies hunger and lots of it. Even the obese can be hungry.

The story of hunger in modern US can be traced back to 1967 when the US Senate Select Committee on Employment, Manpower and Poverty moved its hearings from Washington to a heartland of unemployment in Jackson, Mississippi, in April, 1967. The testimony that they received was dominated by stories of hunger and starvation and the stories told were so unbelievable as to persuade the young Senator Robert Kennedy to travel to the countryside to see for himself the truth or otherwise. The story is told in the book: “Toward an end to hunger in America” by Peter Eisinger. The young Senator was shocked.

Robert Kennedy, sitting beside a seriously undernourished child was reported as saying: “My God. I didn’t know this sort of thing existed. How can a country like this allow it? Maybe they just don’t know”. A journalist George Lapides who accompanied the Senator Journalist described the scene thus: “And I saw Senator Kennedy, who was dressed in a beautiful pinstripe, charcoal-gray suit, sitting on a dirt floor with a child about 18-months old with a distended stomach. Senator Kennedy had him sitting on his lap and tears were coming down Senator Kennedy’s eyes.” The Senator wrote to the White House in frank language: “….. conditions of malnutrition and hunger that can only be described as shocking”. This prompted a delegation of medical experts to visit the region funded by the Field Foundation who reported back on a serious problem of hunger and malnutrition in terms such as: “…..listless children who lived on nothing but grits, bread and Kool-aid”. Shortly after, The Citizens Board of Inquiry into Hunger and Malnutrition, issued a report “Hunger in the US”. Ultimately it was the new powerful medium of television which brought this to the full gaze of the US through a CBS documentary “Hunger in America. This led the US Senate to establish a “Select Committee on Nutrition and Human Needs” chaired by Senator George McGovern who would lose a presidential race to Richard Nixon but who with Senator John Dole would receive the World Food Prize for their contribution to the fight against global hunger and malnutrition.
  The Senate Select Committee’s work eventually led to a raft of food and nutrition aid programmes in the US, which persist today, programmes such as WIC, the Women, Infants and Children Scheme of food aid or the Summer Food Service Programme and many other intervention programmes[1].  It also led Washington to establish an annual survey of food security, which is defined by the UN as ”When all people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life”. It’s most recent report[2], issued just six months ago estimates that in 2010, some 15% of US households were food insecure meaning that at some stage, food on the table was not a given. For some, 5%, food on the table was a very unpredictable event. The USDA uses income as a means of determining food insecurity but in 2010, the NGO Feeding America took a more in-depth approach, which matched food expenditure with food prices and income. Feeding America[3] undertook the Map the Meal Gap project, with the generous support of the Howard G. Buffett Foundation and The Nielsen Company, to learn more about the face of hunger at the local community level. “The results indicate that no county is free from food insecurity. Counties ranged from a low of 5% of the population that experienced food insecurity in 2009 to a high of 38%”. In California the county of Los Angeles had 1.7 million hungry homes (17.4%) while between them,  5 boroughs of New York had 1.3 million hungry houses (16.2%). Thus in 2 of the most iconic of US cities, one in six families suffers from the uncertainty of the next meal.
Without question, obesity remains a massive public health programme with considerable social and economic costs. But so too is hunger and it never hits the headlines because it is a blight, a national shame. Lest any reader outside the US cast their eyes to heaven at yet another injustice in the US, ask yourself if in your country there is an active programme to actually document hunger and to fight it. At least the US does, thanks in no small way to Robert F Kennedy.

[2] Program Household Food Security in the United States in 2010

Tuesday, April 10, 2012

Sleep, obesity and the rhythm of life

We make ourselves and break ourselves day-by-day, hour-by-hour and minute-by-minute. The only time this stops is when we pop our clogs and die. The molecules that make up the chemicals that give form and function to your liver today will not be there next week. Some (Carbon & Oxygen) will leave the body to the atmosphere and some (Nitrogen & Hydrogen) will vanish down the loo. Next weeks liver will be today’s salami and tomorrows mushroom soup. This constant synthesis and degradation of all human organs has one enormous survival advantage. In times when food is short, the body can prioritise which organs are more precious than others such that they get priority for re-synthesis. Usually, the brain, the gut and the immune system get priority over muscle, fat and bone because they perform more vital functions. Why look like Arnold Schwarzenegger when your immune system is in trouble.

The constant making and breaking of the human body is cyclical and almost all biological systems operate in cycles and in rhythms. The most important is the circadian cycle, which is regulated by a part of the brain called the supra-chiasmatic-nucleus (SCN), which connects to the pineal gland, which in turn secretes melatonin into the blood stream.  Daylight is detected by photosensitive cells in the retina, providing a signal to the pineal gland to suppress melatonin secretion. As daylight fades and night time falls, melatonin levels in the blood begin to rise and we begin to wind down in preparation for sleep. No one really knows why we sleep but every living creature does so and among the popular theories of why we sleep is the repair of faulty wiring of nerves in the brain that occur as we process information throughout the day.

Once upon a time it was New York that boasted it was the “city that never sleeps” but today that is a global urban phenomenon. Light abounds and night time is getting busier. Moreover, we are spending a decreasing proportion of night time asleep. In the US, sleep duration was 8-9 hours in the 1960s. This fell to 7 hours in 1995 and to just 6 hours in 2005.  Whereas jet lag can temporarily disrupt our circadian cycles, the growth of urban light, the increasing proportion of the population engaged in shift work and shorter sleeping habits, all have long-term effects on our circadian cycles with a particular emphasis on obesity and its related disorders.
About 15% of our entire genome is involved in circadian cycles and this can go up to 25% in some tissues including fat.  Thus the gene for leptin, a protein that is centrally involved in feeding, peaks at night in humans. In contrast, two other hormones secreted by our fat tissues (adiponectin and lipocalin 2) show a trough at night time at about 04.00 hours and the scale of the trough is substantial (40% fall from the peak daytime value). Animal studies that either insert or delete genes that have a circadian rhythm also reveal major changes in energy metabolism involving both glucose and fat and also body temperature. Shift workers show higher levels of obesity, diabetes and cardiovascular abnormalities when compared to those who work by day and these studies corrected for all the relevant confounding factors of age, gender and social class. Whereas light is the main factor in driving the circadian rhythm, there is considerable interest in the role that meal patterns might have on these events. However, those few human studies that have been completed under strict experimental conditions fail to show any major difference in the circadian cycles of eating-related hormones (adiponectin and lipocalin 2) in the fed or the fasted state. Of course, the act of eating sets off a cyclic events which is characterised by transport of nutrients into tissues in the immediate postprandial phase followed by the transport of nutrients out of tissues such as adipose tissue in the later postprandial phase but these diet induced metabolic cycles do not drive the main biological clock in the SCN.
Interestingly, a group of researchers at Oxford measured the rate of flow of fats into and out of human abdominal fat when the subjects were fully fasted. The expected direction of traffic would be out of adipose tissue because they are in the fasted state. They measured these events every 2 minutes over an hour. Was the outflow steady over time?  It wasn’t. The researchers noted 7 peaks in the exit of fats, effectively indicating cycles of net inflow and net outflow, each lasting about 8 minutes. This isn’t surprising since the making and breaking genes are always switched on with one dominating over the other in cycles. However, what is fascinating is how these genes are switched up and down with such regularity.

Changing sleep patterns are beginning to attract great interest in obesity. Bring back the siesta, I say. 

Monday, April 2, 2012

Sex, obesity and the seven deadly sins

In 2003, The Economist carried a major article on obesity and featured the topic on its front cover, which has become a PowerPoint icon in obesity lectures.  The images imply that throughout time, our ancestors were lean and fit and that obesity is a modern phenomenon, arising from today’s food industry, as witnessed by the use of a McDonalds package in the illustration of modern obese man. ‘Not so’, says Louise Foxcroft in her recent book “Calories and Corsets” which documents the history of obesity and dieting and which forms the basis of this blog.
 The Venus of Berekhat from the Golan Heights is believed to date from 500,000 BC, prior to Homo Sapiens and in the Era of Homo Erectus. Like later figures such as the Hohle Fels Venus from 35,000 BC, females are portrayed as being grossly obese with pendulous breasts and multiple folds of fat. It is of course impossible to say whether these were based on real cases or are merely symbolic of the recognised need of a minimal amount of body fat for female fertility, grossly exaggerated in these cases (see blog of  February 20th 2012).  However, the very fact that folds of fat are depicted implies some existing cases on which to draw inspiration. Hippocrates, Socrates and most notably, Galen, the father of medicine for a millennium, all espoused diet and physical activity as central to health and in all of their writings they titrate their advice on caloric restrictions to the need for physical activity.  Vomiting was also raised to an art form by the Greeks.
The interest in food and obesity of the early Greeks continued on through the era of the Roman Empire and the advent of printing was to reveal just how passionate the world was with diet and obesity. Luigi Cornado (1464-1566) published his book “The art of living long” in 1558 (he was then 94 years old!) in many editions and in many languages. Louise Foxcroft quotes Milton from Paradise Lost: “If thou well observe the rule of ‘Not Too Much’ by temperance taught in thou eat’st what drink’st, seeking from thence due nourishment, not gluttonous delight, till many years over thy head returns”. One could return to the issue that these were concerns for jus a few and that obesity was about as common as murder. However, the writings of the day say otherwise. Cornado wrote that gluttony “kills every great a number as would perish during the time of a most dreadful pestilence, or by the sword or fire of many bloody wars”. This was echoed by the English parliamentarian John Hales who, in the 16 century believed that obesity claimed more lives than the sword or plague. Only after the industrial revolution did we start to collect the relevant statistics on diet and health and by 1908, enough data had been gathered by the New York Life Insurance company to declare that obesity in those aged 35 years or more was seriously disadvantageous from a mortality point of view. The more widespread morbidities of obesity, diabetes and hypertension, would not have been counted at that time. For actuarialists in 1908 to reach this conclusion meant that there were data stretching back some time into the 19th century on height and weight and that obesity was a public health issue over two centuries ago. Independent data from the US military bear this out. Not only has the human race lived with obesity since time immemorial, but we have also lived with the stigmatization of the obese. As Louise Foxcroft writes:” The insults that are often used against fat people........also have ancient roots. The old disease of polysarcia, the pathological condition of too much flesh was thought to indicate a lazy, phlegmatic, stupid person who just could not control themselves”.

This brings us to the moral stance of society on obesity. There are seven deadly sins in certain Christian faiths of which two might be regarded as “cerebral” (Pride and Envy) with five involving what we call today “lifestyle choices”: Gluttony and Greed associated with diet, Sloth associated with a sedentary lifestyle and of course Lust associated with sex. Food was the perfect illustration of the need to balance pleasure and sin and so great was the former and so dire the latter in its consequences that the concept of ascetism evolved with hermits living lives of great self sacrifice effectively, taking total control of their body in terms of food, exercise and sex, so that their body (effectively detached from “them”) could not get on the way of the pursuit of the moral ideal.  Gluttony was by far the most visible of the seven deadly sins and it was gluttony that attracted most attention from those seeking the afterlife. As ever, the organised churches had very profound views on gluttony, none more so than Pope Gregory the Great who managed to define 6 levels of gluttony: “nimis (eating too much), ardenter (eating with unbecoming eagerness), forente (eating wildly), praepropere (not waiting until decent mealtimes), laute (enjoying food that is too expensive) and studiose (being too picky)”.

Now it could be argued that this is all very interesting but that it has nothing to do with the modern epidemic of obesity. “Not so” say I. The high priests of obesity apparently know the cause of this putatively modern epidemic. It is a food chain that is low cost, engineered to pamper our hedonism and convenient to suit our sedentary lifestyle. Once we know the problem, we can now organise the solution, which means policing, taxing, labeling, restricting, banning and whatever. Louise Foxcroft in her book quotes the anthropologist Meyer Fortes: ”It is not so much that food is good but that it is good to forbid”.  If just for a moment, the hierarchy of obesity were to look at this issue historically, then they would see the present issue as one of scale rather than uniqueness.  Just as we have always had sexually transmitted disease, we have simply far more of it today than ever before. By recognising that obesity has always been with us and at a scale of measurable concern for at least two centuries, we would immediately have to accept that simple solutions drawn from societal experience in the last half century will just distort a true vision of the solution. Obesity will be around for centuries to come. Either we tackle this long term from the food chain to the built environment or we just fool ourselves. Careers are built on the latter. Dreams are built on the former.