Conditioning Research

interesting comment in the Guardian today from the artist David Hockney on obesity.... Is there a link between the decline of smoking and the rise of obesity and diabetes? It's been suggested that with a previous "health" scare of fat being bad for you, they took it out of a lot of food and thus the flavour, and then, to give it some flavour, added sugar. This was 30 years ago. It turned out some fat was not only essential, it was good for the heart after all, but they have now given a lot of people a sweet tooth. This is why it is so appalling that there is no debate at all about smoking. Some people might be much better off smoking instead of nibbling. There are still 10 million smokers, now treated like very naughty children. It seems there is no free lunch, and the media and political elite look like the cause of it all, exaggerating constantly to people they seem to despise.

I've had stuff up here over the years (e.g. here and here )about how cancer cells seem to survive by burning sugar and not fat and so some doctors have tried to starve cancers by using a ketogenic diet , with some success. Anyway, here is a video outlining new research into this same topic: The research is r eported here and the full article is available here Cancer cells tend to take up more glucose than healthy cells, and researchers are increasingly interested in exploiting this tendency with drugs that target cancer cells' altered metabolism. Cancer cells' sugar cravings arise partly because they turn off their mitochondria, power sources that burn glucose efficiently, in favor of a more inefficient mode of using glucose. They benefit because the byproducts can be used as building blocks for fast-growing cells. Drugs or diet, if this knowledge can help find a solution to cancer then that is good.

first of a few posts highlighting some interesting news releases over the last couple of days: Scientist shows link between diet and onset of mental illness It is worth reading the report....and I know it is in mice etc but the bit that caught my eye was: Garner's study raises questions of how diet might be affecting other behavioral or mental illnesses such as autism, Tourette syndrome, trichotillomania and skin-picking. He said that before now, a link between diet and the onset of mental disorders hadn't been shown. " What if the increase of simple sugars in the American diet is contributing to the increase of these diseases?" Garner said. "Because we fed the mice more tryptophan than in the typical human diet, this experiment doesn't show that, but it certainly makes it a possibility." Excess frutose again?  Imagine.....more sugar causing disease.  Whatever will they come up with next! UPDATE see the excellent analysis of this article at P...

I spotted this via Chris Masterjohn Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology, explores the damage caused by sugary foods. He argues that fructose (too much) and fiber (not enough) appear to be cornerstones of the obesity epidemic through their effects on insulin.

I've had material on here before about the relationship between sugar and cancer . Cancer cells apparently rely on sugar to survive, so remove the sugar and you starve the cells. There have been experiments using ketogenic diets to treat cancer and other approaches using drugs to intervene down similar pathways. I saw this in the New Scientist yesterday: Cancer's sweet tooth becomes a target It is intersesting stuff. Most of these efforts stem from an observation dating back to the 1930s - that cancer cells generate energy via glycolysis. This is different to the way cells normally make energy, through aerobic respiration in specialised chambers called mitochondria. Ordinary cells do use glycolysis but only if they are short of oxygen, as it is hugely inefficient, gobbling up large amounts of glucose for very little energy . The focus is all on drugs though rather than diet

I've had stuff previously on sugar and cancer Interesting to spot this abstract which - as far as I read it - indicates that intakes of available carbohydrate, glycemic load and sucrose are associated with elevated risks for pancreatic cancer, while fat - particularly saturated fat - intake is associated with diminished risks. Available Carbohydrates, Glycemic Load, and Pancreatic Cancer: Is There a Link? I haven't seen the full study (does anyone have it?) so I am not sure why the abstract finishes with the statement: Rather than being causal, the short-term increase in pancreatic cancer risk associated with high available carbohydrate and low fat intake may be capturing dietary changes associated with subclinical disease. So they are saying that subclinical pancreatic cancer makes you eat more carbs and less fat!

I've had lots of stuff here before about sugary diets and cancer - for example this here . I usually post the simple science, the idea being that starving cancers of sugar can kill them. Other cells can be fuelled in other means but tumours need sugar, so if you cut off the supply then they struggle to grow: unlike healthy cells, which generate energy by metabolizing sugar in their mitochondria, cancer cells appeared to fuel themselves exclusively through glycolysis, a less-efficient means of creating energy through the fermentation of sugar in the cytoplasm. The theory is simple: If most aggressive cancers rely on the fermentation of sugar for growing and dividing, then take away the sugar and they should stop spreading. Meanwhile, normal body and brain cells should be able to handle the sugar starvation; they can switch to generating energy from fatty molecules called ketone bodies — the body's main source of energy on a fat-rich diet — an ability that some or most fast-growi...

I've posted stuff previously ( here and here ) about sugar and cancer the idea being that starving cancers of sugar can kill them. Other cells can be fuelled in other means but tumours need sugar, so if you cut off the supply then they struggle to grow: unlike healthy cells, which generate energy by metabolizing sugar in their mitochondria, cancer cells appeared to fuel themselves exclusively through glycolysis, a less-efficient means of creating energy through the fermentation of sugar in the cytoplasm. The theory is simple: If most aggressive cancers rely on the fermentation of sugar for growing and dividing, then take away the sugar and they should stop spreading. Meanwhile, normal body and brain cells should be able to handle the sugar starvation; they can switch to generating energy from fatty molecules called ketone bodies — the body's main source of energy on a fat-rich diet — an ability that some or most fast-growing and invasive cancers seem to lack. Here is another ...

Just in case you missed this one: A Princeton University scientist will present new evidence today demonstrating that sugar can be an addictive substance, wielding its power over the brains of lab animals in a manner similar to many drugs of abuse Sugar can be addictive, Princeton scientist says I think we knew that already

The whole text of this study is available. Here is the abstract: Background End-stage renal disease rates rose following widespread introduction of high fructose corn syrup in the American diet, supporting speculation that fructose harms the kidney. Sugar-sweetened soda is a primary source of fructose. We therefore hypothesized that sugary soda consumption was associated with albuminuria, a sensitive marker for kidney disease. Methodology/Principal Findings Design was a cross-sectional analysis. Data were drawn from the National Health and Nutrition Examination Survey (NHANES), 1999–2004. The setting was a representative United States population sample. Participants included adults 20 years and older with no history of diabetes mellitus (n = 12,601); after exclusions for missing outcome and covariate information (n = 3,243), the analysis dataset consisted of 9,358 subjects. Exposure was consumption of two or more sugary soft drinks, based on 24-hour dietary recall. The main outcome mea...

Perhaps. Here is a press release from Monash University (I'd never heard of it either. It is in Australia ). Anyway this is published in Nature - a very prestigious journal - so it must have some rigour. Basically the idea is that this guy has identified a mechanism by which eating carbs can lead to you overeating. It is not about insulin this time but rather about the way in which carbs damage appetite control Dr Andrews found that appetite-suppressing cells are attacked by free radicals after eating and said the degeneration is more significant following meals rich in carbohydrates and sugars. "The more carbs and sugars you eat, the more your appetite-control cells are damaged, and potentially you consume more," It would be interesting to read the full paper if any one has access to it? Killer carbs -- Monash scientist finds the key to overeating as we age UPDATE Here is the abstract . The gut-derived hormone ghrelin exerts its effect on the brain by regulating neur...

Fructose Converts Quickly to Lipids Triggering Hyperlipidemia . ...Lipogenesis increased significantly when glucose was replaced with fructose on a gram-for-gram basis in energy drinks consumed by six healthy volunteers, researchers here found. Conversion of fructose to lipid occurred quickly, usually within four hours after ingestion, Elizabeth Parks, Ph.D., of the University of Texas Southwestern Medical Center, and colleagues reported in the June issue of the Journal of Nutrition. Moreover, consumption of a high-fructose drink for breakfast increased liver-mediated fat storage after lunch, the researchers said. "Our study shows for the first time the surprising speed with which humans make body fat from fructose," said Dr. Park. "Once you start the process of fat synthesis from fructose, it's hard to slow it down." Read this bit: "The message from this study is powerful because body fat synthesis was measured immediately after the sweet drinks were consu...

Back in January I pointed out that the Guardian had a thought-provoking piece on fruit, saying that the current focus on fruit in the diet is not necessarily healthy: The myths of fruit I was thinking of this reading Dr Briffa's latest post: Study links fruit juice consumption with increased risk of diabetes

For a while now Barry Groves has had an article on his site about the dangers of fructose There are many good reasons to avoid the fruit sugar, fructose, but all you need is one: type 2 diabetes. And even worse that fruit itself that ubiquitous additive to many processed foods — high fructose corn syrup. A recent study highlighted diabetes and all the other key reasons why it's a healthy idea to avoid this truly awful component of processed foods and soft drinks. I thought of his article when I saw this abstract that noted that: Long-term exposure of normal rats to a fructose-enriched diet or drinking water is currently used as an animal model for experimental insulin resistance. When scientists want to induce insulin resistance - a precursor to diabetes - they give rats lots of fructose. Scary. Barry Groves states: "Eat 5 portions of fruti and veg? Not if you want to avoid diabetes"

Popular Energy Drinks Cause Tooth Erosion, Study Shows I was thinking of this study today while watching the 6 nations rugby matches, the cameras often showing the players slurping down bright blue (!) Powerade. I've posted before about some of the dodgy science behind these energy drinks. Art DeVany also had something good : You are slightly insulin resistant after a work out because growth hormone is an antagonist of insulin. Hence, any glucose that makes it into your blood stream will not be well-controlled and you will have excessive blood glucose, with all the consequences that this entails. It will be a mild form of elevated blood glucose, but it will be there nonetheless and it is to be avoided. Sports and gainer drinks are sold on the theory that exercise drains glycogen from the muscles and you must refill those stores. Nonsense. You want to drain the glycogen from your muscles, which you do through the glycolytic exercises that are part of the Evolutionary Fitness work...

Just skimming through these recent articles from the American Journal of Clinical Nutrition , you would think that refined carbohydrates are associated with: cancer; loss of sight ( updated 8/10/07...the Modern Forager blog has a good posting about this story) ; and increases in the so-called "bad" LDL cholesterol . Indeed, fructose is presented as a pretty dodgy thing to eat. It is amazing that we are told to eat so many carbohydrates!

I was going to call this post "Fat People Lie about how much they eat!" ....but that may not have been helpful. The BBC highlighted an interesting article - and also drew out the conclusions which are a little bit obscure in the abstract. Basically, previous studies have not been able to link sugar intake with how fat people were. The problem however was that people were not being accurate in reporting how much they were eating - they didn't list all the sugar they were stuffing in (OK I'll be fair - if you are eating a dodgy diet with lots for processed food there will be a lot of hidden sugars in there). Anyway, a new urine test was able to identify exactly how much sugar people were eating and the outcome was that it was now clear that sugar consumption and obesity are linked after all! Not really a shock. The study is here Epidemiologic Assessment of Sugars Consumption Using Biomarkers: Comparisons of Obese and Nonobese Individuals in the European Prospect...