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Sunday, July 27, 2014

Celebrating 100,000 views of Gibneyonfood

“The media is today awash with articles on all aspects of food and health and some are so non-sensical that I thought I'd start my own blog to provide an alternative medium through which an informed view on food and health can be delivered. The blog will be a weekly event coming live every Monday morning, beginning on Monday November the 8th and will cover a wide range of topics”.

So began my first blog on November the 1st, 2011.  Now, 80 posts later, the blog has passed 100,000 page views giving an average of 1,251 views per post and an average of over 3,000 views per month. At first I welcomed comments on individual blogs but stopped that facility when people abused it to advertise their health food rubbish. A typical comment might be: “What a fantastic blog and all antioxidants are not the same. Try[1] for best results”. Another reason to block comments was the advent of porn tags. One day you’d look at the Google Analytics and see an enormous rise in views from some quite unlikely country. When I sought out the most popular referral site, I hit an XXX site. The advice from  Google was to let it pass and never open a referral site you don’t know about. My own book “ Something to chew on ~ challenging controversies in food and health” was the most viewed which is great. I’m currently working on another with the tentative title: “Ever seen a fat fox - the science of human obesity”. After that the rankings are as follows: “Oh Sugar! Wrong about fructose”, “Dolly Parton and the art of dieting”, “Sugar taxes and weight loss prediction”, “Michael Pollan’s in defense of food – a critical appraisal”, “Dietary advice with a grain of salt, “Dietary supplements: useless or useful”, “Sex, obesity and the seven deadly sins”, “Fructose – challenging the myths” and “Sorry Dr Lustig: A calorie is still a calorie”.

 As regards countries,, averaging the last 33 months the country top-ten rankings for views are: US, Ireland, UK, Spain, France, Germany, Romania, Canada, China, Australia.  However, that varies by time. For example taking today (defined by Google analytics as the most recent 24 hours), the rankings now include the Ukraine (life goes on there), Sweden and Russia. Many EU states, Gulf States. Middle East and South American countries also view the site but their contribution is outside the top 10. I have very few views from sub-Saharan Africa so if any readers want to pass on the URL to colleagues in SSA, I’d be very grateful.

I’ve enjoyed blogging and ranting and iconoclasting and I hope you continue to enjoy the product. Thanks for taking a look. Next blog will be on school lunches.

[1] At the time of writing, no URL exists for ,which is entirely fictitious! 

Tuesday, July 22, 2014

Super-foods, super-diets and pseudo science

From time to time, certain  “super-foods” and “super-diets” emerge to dominate the menus of fashionable restaurants and chique delicatessens. The most recent super-food has been quinoa (pronounced KEEN-wah). Apparently, it will treat hypertension, diabetes is a natural appetite suppressor and is anti ageing[1]. In fact, the UN Food and Agricultural Organization deemed 2013 to be “The Year of Quinoa”[2]. The Director General of FAO stated that “…quinoa can play an important role in eradicating hunger, malnutrition and poverty”. The facts are however somewhat at variance with this view of quinoa as a super-food. Firstly, it is stated that its protein quality is unique in the plant world in that it is complete in all the 8 essential amino acids. This leaves the non-expert think that some plant foods therefore lack one or more essential amino acids. Not so. All plant proteins contain all amino acids but they vary in the relative amount of each. To rank the quality of a protein, its “protein digestibility corrected amino acid” (PDCAA) score is calculated. Three proteins gain a perfect score of 1.0: two of animal source, egg and whey protein and one of plant origin, soy protein. According to an entry in Wikipedia (most Internet listings for quinoa are from advocacy groups), quinoa, along with amaranth, buckwheat, hempseed, and spirulina fall below 1.0 but they are still called complete proteins because they contain sufficient of all the nine essential amino acids to meet the dietary needs of man[3]. So, quinoa is hardly unique despite its hype. If we turn to protein levels, we find that the following are the levels of protein in average servings of some plant food: amaranth, 3.8; rice, 4.0; beans, 15.0; lentils, 18.0 and soybeans 29.0[4]. Again, this hardly qualifies quinoa as a super-food. Quinoa is putatively “packed” with dietary fibre. An average serving of quinoa has the same amount of fibre as amaranth (5g) which does not compare well with other plant foods: lentils with 16g per serving and both beans and soybeans with 30g. Quinoa is also a truly marvelous source of antioxidants but most of these are simply natural bioactives and not nutrients and there is no serious data linking such plant bioactives to the incidence of chronic disease or risk factors for chronic disease. The hype on quinoa has caught the interest of researchers. Thus in the 20 year period from 1991 to 2011, PubMed lists 20 studies published on quinoa. In the last 2.5 years, a further 20 were added to the literature. According to the Wall Street Journal, there was a 9-fold increase in quinoa imports to the US between 2000 and 2007 and the price per pound almost doubled. This is all good news for the Andean farmers who grow it but not for the Andean people who rely on this crop as a staple food. Quinoa is more likely to grace the shelves of niche food stores in Manhattan to feed the worried well than it is to feed the billion people who go to bed hungry every night.
Besides super-foods we have super-diets and to illustrate the nonsense of super-diets, I will draw heavily on the writings of Harvey Levenstein in his book: “Fear of Food[5]” and specifically the chapter on “Natural Foods in Shangri-La”.
Sir Robert McCarrison (1878-1960), a medical doctor with the British Army in India, toured a remote valley at the foot of the Himalayas, now in Kashmir, Pakistan, which was the home of the Hunza people, the Hunzakut. He attributed their longevity and their physical and sexual fitness to their diet of unprocessed natural foods of milk, eggs, grain, fruit and vegetables. In the late 1940’s a former employee of the US Inland Revenue Service, wrote a book on the Hunzakut, never having visited the region. His book began to attract some attention and by 1957, the New York Times chief foreign correspondent visited the Hunza valley and confirmed that indeed the inhabitants lived to a very old age on a diet of dried apricots and powdered milk. Films were made featuring the Hunzakut and more books were written on their great health, physique, longevity and sexual prowess which persisted well into their 90s. In 1959, President Eisenhower’s cardiologist had an air-force doctor fly to the Hunza valley to check out there cardiac function and sure enough, a perfect bill of health came back. He added: “ A man in really good shape can eat up to 3,000 apricots in one sitting”! If it takes say 20 seconds to eat an apricot, then an apricot feast would last over 16 hours!!! The Hunza fever in the US reached the dizzy heights of an editorial in the Journal of the American Medical Association[6]. Then in 1956, a US geologist set up a small clinic in the Hunza Valley and was instantly inundated with cases of malaria, dysentery, parasitic infestations and symptoms of vitamin deficiency. He noted that in Spring, the entire valley ran out of food and starved until the barley harvest arrived. The Mir who ruled the valley, owned 25% of the land and of course was well fed as were his lackeys. He did visit the clinic to be treated for dyspepsia, requiring an ant-acid for relief. Subsequent visits by British, Japanese and French physicians confirmed widespread deficiency diseases such as goiter, a deficiency of iodine. Malnutrition was found to be rampant. Hunzamania is still rampant. You can buy on Amazon “Crystal Energy Hunza Water” and if you buy 2 you get 1 free[7]. How much? US $99.99!!

The fashion for super-foods and super-diets isn’t new and we will see quinoa slip in favour of the next fad. Its mainly pseudo-science.

[5] Fear of Food is published by Chicago University Press (2012)
[6] JAMA (1961) February25th. “Longevity in Hunza land”

Friday, July 4, 2014

Sugar addiction: The myth re-visited

I have previously blogged on the myth of sugar addiction[1] but I return to that subject today on foot of some recent publications. The first is a chapter in a new book on sugars and health and the section that attracted my attention was an explanation of the rat studies, which first suggested that sugar was addictive[2]. The late Barley G. Hoebel carried out these studies. Rats were given either a 24-hour access to a 10% sugar solution or a 12-hour access to the same solution. Both groups of rats had access to a standard rat diet, perfectly balanced for the nutritional needs of this species. Rats live with a “dark” and “light” cycle of about 12 hours each and it is only during the dark period, when the lights are switched off, that rats eat. In this particular study, the rats in the 12-hour arm of the experiment, only received their sugar, some four hours after the start of the dark cycle. It was well known that if during this dark eating cycle, a rat is deprived of food for the first few hours, then, when presented with the food, the rat will gorge itself on the food and will fully compensate for the period of denial. So when the rats were offered their 10% sugar solution, having spent four hours without access to this highly palatable food, they did precisely as predicted: they gorged.  In fact, during this period of gorging, they amassed 30% of all their daily calories. Thus, without knowing the subtleties of rodent dining protocol, one would happily conclude that when rats were given a sugary solution for a limited period of time, they behaved like alcoholics let into a free bar after a period of booze restraint. Now what about the rats that had access to this sugary solution over a 24-hour period? Well, they consumed exactly the same amount of sugar as their binging, apparently addicted fellow rats that had just 12-hour access. And just to cap it all, neither group of rats went on to become obese as they simply reduced their intake of the standard rat diet. The “addicted” rats showed all the classic neurological signs of addiction including opioid withdrawal when the sugar is removed or when they are treated with opioid blocking drugs. However, the relevance of these studies to humans using this bizarre model is zero.

Which brings me to the second study led by Professor Gary Frost from Imperial College London[3]. This study used the Yale Food Addiction Score  (YFAS). Most criteria to measure addiction are based on clinical models but the Yale version is specifically designed to examine the hypothesis of food (fat and sugar) addiction. The researchers conducted a weight loss intervention study in 178 severely obese subjects (mean BMI of 36.1 kg/m2) taking part in a weight loss programme, which used behavioural therapy to reduce body weight over a 6- month period. They hypotesised that those patients that showed signs of food addiction according to YFAS would be the least successful in weight loss and that significantly more of those with food addiction would drop out. Both hypotheses were shown not to be valid. There was no difference in weight loss between the two groups and there was no difference in attrition. This is by far the largest study to examine food addiction in relation to weight loss.

Consider a study in which alcoholics and social drinkers are compared for their ability to abstain from alcohol or to minimise their alcohol intake. The predicted outcome would be that the alcoholics would fare much worse because their addiction to alcohol is so strong. But that doesn’t happen with this measure of food addiction. In all, some 15% of subjects were declared food addictive at baseline which tallies with the general range seen among the obese population seeking treatment (15-20%). Their “addiction” to food as measured by the Yale scale is so weak that it is simply over-ridden by a behavioural therapy programme.

All in all, while the concept of food addiction might seem attractive, the biology just doesn’t stack up. But, in the area of public health nutrition, why lets the facts spoil a good media story!

[2] Are Sugars addictive? Perspectives for practitioners, by Rebecca LW Corwin and John E Hayes in “Fructose, High fructose corn syrup, sucrose and health, edited by James M. Rippe and published by Humana Press (2014) 
[3] Lent MR et al (2014) Obesity, 22, 52-55