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Showing posts from July, 2012

Fibre, farts and faeces

Some 2,500 years ago, Hippocrates declared that: “Wholemeal bread cleans out the gut and passes through as excrement. White bread is more nutritious as it makes less feces”.For a long time fibre was regarded as a non-nutrient and of no importance. Thomas Richard Allinson[1] was a medical doctor who advocated vegetarianism and wholemeal bread and in 1892 he was struck off the medical register in the UK for his non-establishment views. In 1936 the American Medical Association formally condemned the use of bran, a view which would dominate for the next three decades. Fibre was of course of enormous importance in animal nutrition, a science that was far more developed than human nutrition. To understand why, its best to first consider fibre from the botanical viewpoint. When a seedling finally gets to the sunshine of boundless photosynthetic energy, it is green and very leafy. As it grows, its stem moves from a predominantly photosynthesizing function to the dual function of physical suppo…

Iodine - now a problem in developed countries

When we think of hunger, we think of the gaunt and emaciated children in sub-Saharan Africa. There is another form of hunger known as “hidden hunger” which requires the services of a biochemist to detect deficiency symptoms in blood or urine and the three main nutrients of hunger are iron, leading to anaemia, vitamin A leading to blindness and iodine, leading to goiter. Today’s blog focuses on the latter[1]. Iodine is required as an element within the molecular structure of the thyroid hormone and this hormone plays an essential role in every cell where it regulates metabolic rate. Iodine also has a major role in brain development during pregnancy and the very early years of life.  If iodine intakes are inadequate, a condition known as goiter emerges in which the thyroid gland in the neck swells as it seeks to extract every last drop of iodine in blood for thyroid hormone synthesis. Most importantly, iodine deficiency in pregnancy will lead to impaired cognitive ability and if severe …

Nature, nurture and the control of food intake

Some weeks ago, my blog was entitled: “Ever seen a fat fox”, the gist of which was that whereas biology can tell us a lot about the control of food intake in animals, in man, with a large pre-frontal cortex, living in a highly social existence, social aspects may be far more important than the biology. I return to this theme today in light of some intriguing research jointly carried out by researchers at the Universities of Washington and Toronto[1]. The research centers around the phenomenon of restrained eating, so let me first explain what this means. As I have previously pointed out, overweight and obesity are not usually the outcome of any conscious decision to get fat (Sumo wrestlers excluded). Restrained eating, on the other hand, is a very conscious decision to do, as the name implies, to consciously count calories in order not to gain weight or to maintain weight loss. Restrained eaters frequently have experienced some weight gain and have then made the lifetime commitment to…

Calorie counting on menus ~ The US experience

The Minister for Health here in Ireland wants to introduce calorie counts on menus and has given the industry 6 months to implement the proposal or, if they fail to  do so, legislation will be introduced. All packaged food requires full nutrition labeling, so it would seem quite reasonable to require the food service sector to follow suit. Calorie counts on menus were first introduced into New York in 2008 and, in 2010, the US Congress passed an act which required menu labeling for all restaurants with 20 or more locations. Researchers at the University of North Carolina conducted a systematic review of the impact of this legislation on actual average caloric intake in the US food service sector. A systematic review sets out very clearly, the criteria that a published paper must meet in order to be considered by the reviewers. In this case the studies had to have an experimental or quasi-experimental design comparing a calorie labeled menu with a menu without any caloric data. The rev…

Fructose - challenging the myths

In the past, the sugar component of most sweetened beverages was obtained either from sugar beet or cane sugar. For both sugar cane and sugar beet, the sugar found is called sucrose and it is one molecule of glucose linked to one molecule of fructose. In the late 1960s, an alternative to sugar was developed which was cheaper to use and less prone to the volatility of the global sugar market in terms of price and volume. This alternative is known as High Fructose Corn Syrup (HFCS) and it is produced in two stages. Ordinary cornstarch is first broken down to its basic constituent glucose and the glucose is then treated with a natural enzyme that converts it to fructose. The two sugars, glucose and fructose can now be blended yielding mixes with varying ratios. For the soft drinks industry, the ratio is 55% fructose and 45% glucose.
For some time now, various “experts” have come down heavily on fructose for its deleterious effects on health. Google the word ‘fructose and within the top t…