Mannose impairs tumour growth and enhances chemotherapy

Mannose impairs tumour growth and enhances chemotherapy

Mannose impairs tumour growth and enhances chemotherapy

Tumours use more glucose than normal, healthy tissues. However, it is very hard to control the amount of glucose in your body through diet alone. In this study, the researchers found that mannose can interfere with glucose to reduce how much sugar cancer cells can use*.

Pablo Sierra Gonzalez et al, Mannose impairs tumour growth and enhances chemotherapy, Nature (2018). DOI: 10.1038/s41586-018-0729-3

Tumor, tumours, cancer, mannose, d-mannose, sugar, glucose, energy

Sugar helps cancer cells regulate voltage

Sugar helps cancer cells regulate voltage

Sugar helps cancer cells regulate voltage

Researchers in an attempt to understand why Cancers will hold onto sugar yet not use it as fuel discovered that Cancer Cells use sugar as a sort of voltage regulator.

1. Ca2 -dependent demethylation of phosphatase PP2Ac promotes glucose deprivation–induced cell death independently of inhibiting glycolysis. Science Signaling, 2018; 11 (512): eaam7893 DOI: 10.1126/scisignal.aam7893

High Fructose Corn Syrup found to kill animals almost twice as fast as table sugar

High Fructose Corn Syrup found to kill animals almost twice as fast as table sugar
– SALT LAKE CITY, Jan. 5, 2015 – When University of Utah biologists fed mice sugar in doses proportional to what many people eat, the fructose-glucose mixture found in high-fructose corn syrup was more toxic than sucrose or table sugar, reducing both the reproduction and lifespan of female rodents.“This is the most robust study showing there is a difference between high-fructose corn syrup and table sugar at human-relevant doses,” says biology professor Wayne Potts, senior author of a new study scheduled for publication in the March 2015 issue of The Journal of Nutrition.

* First published December 10, 2014, doi: 10.3945/jn.114.202531
http://healthresearchreport.me/2015/01/08/high-fructose-corn-syrup-more-toxic-than-table-sugar-in-mice/

Continue reading “High Fructose Corn Syrup found to kill animals almost twice as fast as table sugar”

Pancreatic cancers use ( HFCS ) fructose, common in the Western diet, to fuel their growth ( Smoking Gun )

Public release date: 2-Aug-2010

HRR: Research was mostly ignored and covered up in 2010 – To date there has been no update on this study

– this is the first time a link has been shown between fructose and cancer proliferation

Between 1970 and 1990, the consumption of HFCS in the U.S. has increased over 1,000 percent

– found that the pancreatic cancer cells could easily distinguish between glucose and fructose even though they are very similar structurally, and contrary to conventional wisdom, the cancer cells metabolized the sugars in very different ways

In the case of fructose, the pancreatic cancer cells used the sugar in the transketolase-driven non-oxidative pentose phosphate pathway to generate nucleic acids, the building blocks of RNA and DNA, which the cancer cells need to divide and proliferate.

They have major significance for cancer patients, given dietary refined fructose consumption.”

Animation of the structure of a section of DNA...
Animation of the structure of a section of DNA. The bases lie horizontally between the two spiraling strands. (Photo credit: Wikipedia)

Pancreatic cancers use the sugar fructose, very common in the Western diet, to activate a key cellular pathway that drives cell division, helping the cancer to grow more quickly, a study by researchers at UCLA’s Jonsson Comprehensive Cancer Center has found.

Although it’s widely known that cancers use glucose, a simple sugar, to fuel their growth, this is the first time a link has been shown between fructose and cancer proliferation, said Dr. Anthony Heaney, an associate professor of medicine and neurosurgery, a Jonsson Cancer Center researcher and senior author of the study. Continue reading “Pancreatic cancers use ( HFCS ) fructose, common in the Western diet, to fuel their growth ( Smoking Gun )”

Fructose: the poison index

A ruling on fructose boosts the powerful sugar industry, either by incompetence or collusion, but is based on pseudoscience

    • Robert Lustig
    • The Guardian,              Monday 21 October 2013 16.00 EDT
Fructose Lustig

Fizzy drinks can have a ‘serum fructose concentration of six micromolar, enough to do major arterial and pancreatic damage’. Photograph: Nathalie Louvel/Getty Images

The battle over the compound fructose now reaches new levels of obfuscation. The food industry is a strong – and loud, and rich – proponent, hard to ignore. The European Food and Safety Agency has just weighed in, in favour of the substitution of sucrose (table sugar: a disaccharide composed of the monosaccharides glucose and fructose) with fructose alone, the sweeter of the two – even to the point of allowing health claims for fructose on the packaging of processed foods.

And yet the scientific data on fructose says it is one of the most egregious components of the western diet, directly contributing to heart disease and diabetes, and associated with cancer and dementia. Nature magazine has just published a scathing indictment of fructose by Dr Lewis Cantley, one of the US’s leading cancer researchers. But the EFSA says it sees no harm, justifying its stance on the basis that fructose has a lower glycaemic index than glucose.

The concept of glycaemic index is simple. This is how high your blood glucose rises after ingesting 50 grams of carbohydrate in any specific food, which is a measure of a food’s generation of an insulin response, and is used as a way of showing a food’s potential for weight gain. Glycaemic index is a proxy for how high your insulin level will rise, which determines whether that blood glucose will get shunted to fat cells for storage. Low-glycaemic-index diets promote blood sugar stability and are associated with weight loss. But the EFSA has missed the point. Glycaemic index is not the issue.

Glycaemic load is where it’s at. This takes into account how much of a given food one must eat to obtain 50 grams of carbohydrate. The perfect example is carrots. Carrots have a high glycaemic index – if you consume 50 grams of carbohydrate in carrots, your blood sugar will rise pretty high. But you would have to eat 1.3lbs – 600 grams – of carrots to get 50 grams of carbohydrate. Highly unlikely. Any high-glycaemic-index food can become a low-glycaemic-load food if it’s eaten with its inherent fibre. That means “real food”. But fructose is made in a lab. It’s anything but “real”.

Yes, fructose has a low glycaemic index of 19, because it doesn’t increase blood glucose. It’s fructose, for goodness sake. It increases blood fructose, which is way worse. Fructose causes seven times as much cell damage as does glucose, because it binds to cellular proteins seven times faster; and it releases 100 times the number of oxygen radicals (such as hydrogen peroxide, which kills everything in sight). Indeed, a 20oz soda results in a serum fructose concentration of six micromolar, enough to do major arterial and pancreatic damage. Glycaemic index is a canard; and fructose makes it so. Because fructose’s poisonous effects have nothing to do with glycaemic index; they are beyond glycaemic index.

The food industry is fond of referring to a 1999 study showing that liver fat generation from oral fructose occurs at a very low rate (less than 5%). And that’s true, if you’re thin, insulin sensitive, fasting (and therefore glycogen-depleted), and given just fructose alone (which is poorly absorbed). Conversely, if you’re obese, insulin resistant, well fed, and getting both fructose and glucose together (like a sizable percentage of the population), then fructose gets converted to fat at a much higher rate, approximating 30%. In other words, the toxicity of fructose depends on context.

The industry points to meta-analyses of controlled isocaloric “fructose for glucose” exchange studies that demonstrate no effect from fructose on weight gain or other morbidities. Perhaps one reason for this is because crystalline fructose is incompletely absorbed. When that happens, residual fructose in the gastrointestinal system causes pain, bloating, and diarrhoea: ask any child the morning after Halloween in between trips to the bathroom relieving his diarrhoea. Furthermore, those meta-analyses where fructose was supplied in excess do show weight gain, high levels of lipids in the blood, and insulin resistance. The dose determines the poison.

The EFSA has boosted the position of the sugar industry, either through incompetence or collusion. But it is clear that this recommendation is scientifically bogus. Nutritional policy should be based on science – not pseudoscience, as we have seen over the past 30 years.

http://www.theguardian.com/commentisfree/2013/oct/21/fructose-poison-sugar-industry-pseudoscience

 

Sugar is toxic to mice in ‘safe’ doses

Contact: Annalisa Purser annalisa.purser@utah.edu 801-581-7295 University of Utah

New test hints 3 sodas daily hurt lifespan, reproduction

SALT LAKE CITY, Aug. 13, 2013 – When mice ate a diet of 25 percent extra sugar – the mouse equivalent of a healthy human diet plus three cans of soda daily – females died at twice the normal rate and males were a quarter less likely to hold territory and reproduce, according to a toxicity test developed at the University of Utah.

“Our results provide evidence that added sugar consumed at concentrations currently considered safe exerts dramatic adverse impacts on mammalian health,” the researchers say in a study set for online publication Tuesday, Aug. 13 in the journal Nature Communications.

“This demonstrates the adverse effects of added sugars at human-relevant levels,” says University of Utah biology professor Wayne Potts, the study’s senior author. He says previous studies using other tests fed mice large doses of sugar disproportionate to the amount people consume in sweetened beverages, baked goods and candy.

“I have reduced refined sugar intake and encouraged my family to do the same,” he adds, noting that the new test showed that the 25 percent “added-sugar” diet – 12.5 percent dextrose (the industrial name for glucose) and 12.5 percent fructose – was just as harmful to the health of mice as being the inbred offspring of first cousins.

Even though the mice didn’t become obese and showed few metabolic symptoms, the sensitive test showed “they died more often and tended to have fewer babies,” says the study’s first author, James Ruff, who recently earned his Ph.D. at the University of Utah. “We have shown that levels of sugar that people typically consume – and that are considered safe by regulatory agencies – impair the health of mice.”

The new toxicity test placed groups of mice in room-sized pens nicknamed “mouse barns” with multiple nest boxes – a much more realistic environment than small cages, allowing the mice to compete more naturally for mates and desirable territories, and thereby revealing subtle toxic effects on their performance, Potts says.

“This is a sensitive test for health and vigor declines,” he says, noting that in a previous study, he used the same test to show how inbreeding hurt the health of mice.

“One advantage of this assay is we get the same readout no matter if we are testing inbreeding or added sugar,” Potts says. “The mice tell us the level of health degradation is almost identical” from added-sugar and from cousin-level inbreeding.

The study says the need for a sensitive toxicity test exists not only for components of our diet, but “is particularly strong for both pharmaceutical science, where 73 percent of drugs that pass preclinical trials fail due to safety concerns, and for toxicology, where shockingly few compounds receive critical or long-term toxicity testing.”

The study was funded by the National Institutes of Health and the National Science Foundation.

A Mouse Diet Equal to What a Quarter of Americans Eat

The experimental diet in the study provided 25 percent of calories from added sugar – half fructose and half glucose – no matter how many calories the mice ate. Both high-fructose corn syrup and table sugar (sucrose) are half fructose and half glucose.

Potts says the National Research Council recommends that for people, no more than 25 percent of calories should be from “added sugar,” which means “they don’t count what’s naturally in an apple, banana, potato or other nonprocessed food. … The dose we selected is consumed by 13 percent to 25 percent of Americans.”

The diet fed to the mice with the 25 percent sugar-added diet is equivalent to the diet of a person who drinks three cans daily of sweetened soda pop “plus a perfectly healthy, no-sugar-added diet,” Potts says.

Ruff notes that sugar consumption in the American diet has increased 50 percent since the 1970s, accompanied by a dramatic increase in metabolic diseases such as diabetes, obesity, fatty liver and cardiovascular disease.

The researchers used a mouse supply company that makes specialized diets for research. Chow for the mice was a highly nutritious wheat-corn-soybean mix with vitamins and minerals. For experimental mice, glucose and fructose amounting to 25 percent of calories was included in the chow. For control mice, corn starch was used as a carbohydrate in place of the added sugars.

House Mice Behaving Naturally

Mice often live in homes with people, so “mice happen to be an excellent mammal to model human dietary issues because they’ve been living on the same diet as we have ever since the agricultural revolution 10,000 years ago,” Potts says.

Mice typically used in labs come from strains bred in captivity for decades. They lack the territoriality shown by wild mice. So the study used mice descended from wild house mice that were “outbred” to prevent inbreeding typical of lab mice.

“They are highly competitive over food, nesting sites and territories,” he says. “This competition demands high performance from their bodies, so if there is a defect in any physiological systems, they tend to do more poorly during high competition.”

So Potts’ new test – named the Organismal Performance Assay, or OPA – uses mice “in a more natural ecological context” more likely to reveal toxic effects of whatever is being tested, he says.

“When you look at a mouse in a cage, it’s like trying to evaluate the performance of a car by turning it on in a garage,” Ruff says. “If it doesn’t turn on, you’ve got a problem. But just because it does turn on, doesn’t mean you don’t have a problem. To really test it, you take it out on the road.”

A big room was divided into 11 “mouse barns” used for the new test. Six were used in the study. Each “barn” was a 377-square-foot enclosure ringed by 3-foot walls.

Each mouse barn was divided by wire mesh fencing into six sections or “territories,” but the mice could climb easily over the mesh. Within each of the six sections was a nest box, a feeding station and drinking water.

Four of the six sections in each barn were “optimal,” more desirable territories because the nest boxes were opaque plastic storage bins, which mice entered via 2-inch holes at the bottom. Each bin had four nesting cages in it, and an enclosed feeder.

The two other sections were “suboptimal” territories with open planter trays instead of enclosed bins. Female mice had to nest communally in the trays.

Running the Experiment

The mice in the experiment began with 156 “founders” that were bred in Potts’ colony, weaned at four weeks, and then assigned either to the added-sugar diet or the control diet, with half the males and half the females on each diet.

The mice stayed in cages with siblings of the same sex (to prevent reproduction) for 26 weeks while they were fed these diets. Then the mice were placed in the mouse barns to live, compete with each other and breed for 32 more weeks. They all received the same added-sugar diet while in the mouse barns, so the study only tested for differences caused by the mice eating different diets for the previous 26 weeks.

The founder mice had implanted microchips, like those put in pets. Microchip readers were placed near the feeding stations to record which mice fed where and for how long. A male was considered dominant if he made more than 75 percent of the visits by males to a given feeding station. In reality, the dominant males made almost 100 percent of male visits to the feeder in the desirable territory they dominated.

With the 156 founder mice (58 male, 98 female), the researchers ran the experiment six times, with an average of 26 mice per experiment: eight to 10 males (competing for six territories, four desirable and two suboptimal) and 14 to 18 females.

The Findings: Added Sugar Impairs Mouse Lifespan and Reproduction

  • After 32 weeks in mouse barns, 35 percent of the females fed extra sugar died, twice the 17 percent death rate for female control mice. There was no difference in the 55 percent death among males who did and did not get added sugar. Ruff says males have much higher death rates than females in natural settings because they compete for territory, “but there’s no relation to sugar.” 

     

  • Males on the added-sugar diet acquired and held 26 percent fewer territories than males on the control diet: control males occupied 47 percent of the territories while sugar-added mice controlled less than 36 percent. Male mice shared the remaining 17 percent of territories. 

     

  • Males on the added-sugar diet produced 25 percent fewer offspring than control males, as determined by genetic analysis of the offspring. The sugar-added females had higher reproduction rates than controls initially – likely because the sugar gave them extra energy to handle the burden of pregnancy – but then had lower reproductive rates as the study progressed, partly because they had higher death rates linked to sugar. 

The researchers studied another group of mice for metabolic changes. The only differences were minor: cholesterol was elevated in sugar-fed mice, and the ability to clear glucose from the blood was impaired in female sugar-fed mice. The study found no difference between mice on a regular diet and mice with the 25 percent sugar-added diet when it came to obesity, fasting insulin levels, fasting glucose or fasting triglycerides.

“Our test shows an adverse outcome from the added-sugar diet that couldn’t be detected by conventional tests,” Potts says.

Human-made toxic substances in the environment potentially affect all of us, and more are continually discovered, Potts says.

“You have to ask why we didn’t discover them 20 years ago,” he adds. “The answer is that until now, we haven’t had a functional, broad and sensitive test to screen the potential toxic substances that are being released into the environment or in our drugs or our food supply.”

###

 

Potts and Ruff conducted the study with University of Utah biology lab manager Linda Morrison and undergraduates Amanda Suchy, Sara Hugentobler, Mirtha Sosa and Bradley Schwartz, and with researchers Sin Gieng and Mark Shigenaga of Children’s Hospital Oakland Research Institute in California.

University of Utah Communications  75 Fort Douglas Boulevard  Salt Lake City, UT 84113  801-581-6773 fax: 801-585-3350  http://www.unews.utah.edu

 

 

The dark side of artificial sweeteners

Contact: Mary Beth O’Leary moleary@cell.com 617-397-2802 Cell Press

More and more Americans are consuming artificial sweeteners as an alternative to sugar, but whether this translates into better health has been heavily debated. An opinion article published by Cell Press on July 10th in the journal Trends in Endocrinology & Metabolism reviews surprising evidence on the negative impact of artificial sweeteners on health, raising red flags about all sweeteners—even those that don’t have any calories.

“It is not uncommon for people to be given messages that artificially-sweetened products are healthy, will help them lose weight or will help prevent weight gain,” says author Susan E. Swithers of Purdue University. “The data to support those claims are not very strong, and although it seems like common sense that diet sodas would not be as problematic as regular sodas, common sense is not always right.”

Consumption of sugar-sweetened drinks has been linked to obesity, type 2 diabetes, and metabolic syndrome—a group of risk factors that raises the risk for heart disease and stroke. As a result, many Americans have turned to artificial sweeteners, which are hundreds of times sweeter than sugar but contain few, if any, calories. However, studies in humans have shown that consumption of artificially sweetened beverages is also associated with obesity, type 2 diabetes, and metabolic syndrome as well as cardiovascular disease. As few as one of these drinks per day is enough to significantly increase the risk for health problems.

Moreover, people who regularly consume artificial sweeteners show altered activation patterns in the brain’s pleasure centers in response to sweet taste, suggesting that these products may not satisfy the desire for sweets. Similarly, studies in mice and rats have shown that consumption of noncaloric sweeteners dampens physiological responses to sweet taste, causing the animals to overindulge in calorie-rich, sweet-tasting food and pack on extra pounds.

Taken together, the findings suggest that artificial sweeteners increase the risk for health problems to an extent similar to that of sugar and may also exacerbate the negative effects of sugar. “These studies suggest that telling people to drink diet sodas could backfire as a public health message,” Swithers says. “So the current public health message to limit the intake of sugars needs to be expanded to limit intake of all sweeteners, not just sugars.”

###

Trends in Endocrinology & Metabolism, Swithers et al.: “Artificial sweeteners produce the counterintuitive effect of inducing metabolic derangements.”

Think that’s ACTUAL fruit in your cereal? How food companies replace the real deal with ‘imposter’ sugar balls and soybean oil

  • Consumer watchdogs warn lebals are fooling  us with high-sugar ‘fruit imposters’ inside packaging promising ‘real fruit,  full of vitamins’
  • The FDA permits labels to say ‘real fruit’  as long as the word ‘flavoured’ also appears on the  packaging

By Daily Mail Reporter

PUBLISHED:12:41 EST, 14  November 2012| UPDATED:18:15 EST, 14 November 2012

When consumers see a picture of fresh berries  on a cereal box, yogurt tub, and other food packaging, they are lead to believe  they are buying ‘real berry pieces  inside.’

But food experts have pointed out that the  ‘fruit’ many companies claim on their packaging is actually just balls of sugar  and soybean oil, mixed with tiny bits of dried fruit.

Consumer watchdogs warn that some of biggest  food companies are fooling us with unhealthy and high-sugar ‘fruit  imposters’ inside labels promising  ‘real fruit, full of  vitamins’.

Scroll down for video

How real? Food experts warn that the 'real fruit' many companies claim on their packaging is actually just balls of sugar and soybean oil, mixed with tiny bits of dried fruit

How real? Food experts warn that the ‘real fruit’ many  companies claim on their packaging is actually just balls of sugar and soybean  oil, mixed with tiny bits of dried fruit

An example is Special K Fruit and Yogurt  cereal, with fresh berries on the front of the box.

Michael Jacobson, the head of the Center for  Science in the Public Interest, a consumer watchdog group, told Today it actually contains ‘no berries  whatsoever’.

Mr Jacobson explained that these berry  ‘imposters’ are in a lot of foods, like blueberry Eggos and Aunt Jemima’s  Blueberry Pancakes.

While the label proclaims ‘made with real  blueberries,’ it  actually contains ‘blueberry bits’ which  are blue chucks shaped into balls made from ‘mostly sugar and soybean oil, then  little bits of real blueberry that’s been artificially colored.’

Today’s National Investigative  Correspondent  Jeff RossenIf said: ‘If the companies were in this room,  they would say: “Look,  we’re printing the ingredients on the label. No  misleading advertising  here”‘

False advertising: Consumer watchdogs say that some of biggest food companies are fooling us with unhealthy and high-sugar 'fruit imposters' inside labels promising 'real fruit, full of vitamins'

False advertising: Consumer watchdogs say that some of  biggest food companies are fooling us with unhealthy and high-sugar ‘fruit  imposters’ inside labels promising ‘real fruit, full of vitamins’

Fresh fruit: Some food companies said the real fruit on the package is meant as a serving suggestion, which is disclosed in small print

Fresh fruit: Some food companies said the real fruit on  the package is meant as a serving suggestion, which is disclosed in small  print

Fruity breakfast: While the label proclaims 'made with real blueberries,' it actually contains 'blueberry bits' which are blue chucks shaped into balls made from sugar and soybean oil, with little bits of blueberry that is artificially colored

Fruity breakfast: The label proclaims ‘made with real  blueberries,’ but it actually contains ‘blueberry bits’ shaped into balls made  from sugar and soybean oil, with little bits of blueberry that is artificially  colored

But Mr Jacobsen disagreed: ‘You can’t deceive  people in big print and pictures on the front of the label, and then give the  correct answers on the back of the label,’

One shopper said: ‘I think they’re duping  people. It’s complete false advertising.’

The Food and Drug Administration, which  oversees such labeling, told Today that it ‘supports laws requiring labels to be  truthful and non-misleading,’ and these labels ‘are permitted’ under FDA  regulations as long as the word ‘flavored’ is also printed.

Nutritionist Joy Bauer explained:  ‘If you see the word “flavored,” either  natural or artificial, it could be a red flag that there’s actually no fruit  within that product.’

‘The Food and Drug Administration is asleep  at the wheel. It rarely brings  complaints against these companies, said Mr  Jacobsen, whose own group is suing Coca-Cola, which owns vitaminwater  because ‘there aren’t any strawberries  and there aren’t any kiwis in there,’

Read the back: The FDA says it is consumers' responsibility to read the entire label, not just the front

Read the back: The FDA says it is consumers’  responsibility to read the entire label, not just the front

‘I suspect the FDA doesn’t want to tangle  with big companies who could keep them tied up in court for years… [But] that bottle contains almost as much sugar  as a 12-ounce can of Coca-Cola.

‘Companies are gonna make a lot more money if they can  imply that there are berries in the product, but not put them there. They’re  saving a lot of money, but they’re cheating consumers.’

Mr RossenIf added: ‘The  food companies told us some of that real fruit on the package is meant as a  serving suggestion, and is disclosed in small print.

‘The FDA says it does inspect labels, and  it’s cracking down on companies that break the law. The agency told us it’s your  responsibility to read the entire label, not just the front.’

Read more: http://www.dailymail.co.uk/femail/article-2232897/How-food-companies-replace-fruit-imposter-sugar-balls-soybean-oil.html#ixzz2CG5PH200 Follow us: @MailOnline on Twitter | DailyMail on Facebook

Not so sweet: Over-consumption of sugar linked to aging

2009 study posted for filing

Contact: Sylvain-Jacques Desjardins
sylvain-jacques.desjardins@umontreal.ca
514-343-7593
University of Montreal

University of Montreal scientists explain how sugar shortens lifespan in PLoS Genetics

This release is available in French.

From left to right: Antoine Roux, Pascal Chartrand, Gerardo Ferbeyre and Luis Rokeach.

Click here for more information.

Montreal, March 6, 2009 – We know that lifespan can be extended in animals by restricting calories such as sugar intake. Now, according to a study published in the journal PLoS Genetics, Université de Montréal scientists have discovered that it’s not sugar itself that is important in this process but the ability of cells to sense its presence.

Aging is a complex phenomenon and the mechanisms underlying aging are yet to be explained. What researchers do know is that there is a clear relationship between aging and calorie intake. For example, mice fed with half the calories they usually eat can live 40 percent longer. How does this work?

As part of the PLoS Genetics study, Université de Montréal Biochemistry Professor Luis Rokeach and his student Antoine Roux discovered to their surprise that if they removed the gene for a glucose sensor from yeast cells, they lived just as long as those living on a glucose-restricted diet. In short, the fate of these cells doesn’t depend on what they eat but what they think they’re eating.

There are two obvious aspects of calorie intake: tasting and digestion. By the time nutrients get to our cells there is an analogous process: sensors on the surface of the cell detect the presence of, for example, the sugar glucose and molecules inside the cell break down the glucose, converting it to energy. Of these processes, it is widely thought that the by-products of broken down sugars are the culprits in aging. The study by Rokeach and Roux suggests otherwise.

To understand aging, Rokeach and Roux in collaboration with Université de Montréal Biochemistry Professors Pascal Chartrand and Gerardo Ferbeyre used yeast as a model organism. At a basic level, yeast cells are surprisingly similar and age much like human cells, as well as being easy to study.

The research team found that the lifespan of yeast cells increased when glucose was decreased from their diet. They then asked whether the increase in lifespan was due to cells decreasing their ability to produce energy or to the decrease in signal to the cells by the glucose sensor.

The scientists found that cells unable to consume glucose as energy source are still sensitive to the pro-aging effects of glucose. Conversely, obliterating the sensor that measures the levels of glucose significantly increased lifespan.

“Thanks to this study, the link between the rise in age-related diseases and the over-consumption of sugar in today’s diet is clearer. Our research opens a door to new therapeutic strategies for fighting age-related diseases,” says Professor Rokeach.

###

Partners in research:
Professor Rokeach’s research is supported by the Canadian Institutes of Health Research (www.cihr-irsc.gc.ca) and by the National Science and Engineering Research Council (www.nserc-crsng.gc.ca). Professor Ferbeyre’s and Professor Chartrand’s research are funded by the Canadian Institutes of Health Research (www.cihr-irsc.gc.ca)

On the web:
About PLoS Genetics: http://www.plosgenetics.org/home.action
About the Université de Montréal: www.umontreal.ca/english/index.html
About the Department of Biochemistry www.bcm.umontreal.ca
About Professor Rokeach www.mapageweb.umontreal.ca/rokeach/index-en.html
About Professor Ferbeyre http://www.mapageweb.umontreal.ca/ferbeyre/index-en.htm
About Professor Chartrand: http://www.bcm.umontreal.ca/bottin/chartrand.html

Pancreatic cancers use high fructose corn syrup (HFCS), common in the Western diet to fuel their growth

Contact: Kim Irwin
kirwin@mednet.ucla.edu310-206-2805
University of California – Los Angeles Health Sciences

Pancreatic cancers use the sugar fructose, very common in the Western diet, to activate a key cellular pathway that drives cell division, helping the cancer to grow more quickly, a study by researchers at UCLA’s Jonsson Comprehensive Cancer Center has found.

Although it’s widely known that cancers use glucose, a simple sugar, to fuel their growth, this is the first time a link has been shown between fructose and cancer proliferation, said Dr. Anthony Heaney, an associate professor of medicine and neurosurgery, a Jonsson Cancer Center researcher and senior author of the study.

“The bottom line is the modern diet contains a lot of refined sugar including fructose and it’s a hidden danger implicated in  a lot of modern diseases, such as obesity, diabetes and fatty liver,” said Heaney, who also serves as director of the Pituitary Tumor and Neuroendocrine Program at UCLA. “In this study, we show that cancers can use fructose just as readily as glucose to fuel their growth.”

The study appeared in the Aug. 1 issue of the peer-reviewed journal Cancer Research.

The source of fructose in the Western diet is high fructose corn syrup (HFCS), a corn-based sweetener that has been on the market since about 1970. HFCS accounts for more than 40 percent of the caloric sweeteners added to foods and beverages, and it is the sole sweetener used in American soft drinks.

Between 1970 and 1990, the consumption of HFCS in the U.S. has increased over 1,000 percent, according to an article in the April 2004 issue of the American Journal of Clinical Nutrition. Food companies use HFCS – a mixture of fructose and glucose – because it’s inexpensive, easy to transport and keeps foods moist. And because it is so sweet, it’s cost effective for companies to use small quantities of HCFS in place of more expensive sweeteners or flavorings.

In his study, Heaney and his team took pancreatic tumors from patients and cultured and grew the malignant cells in Petri dishes. They then added glucose to one set of cells and fructose to another. Using mass spectrometry, they were able to follow the carbon-labeled sugars in the cells to determine what exactly they were being used for and how.

Heaney found that the pancreatic cancer cells could easily distinguish between glucose and fructose even though they are very similar structurally, and contrary to conventional wisdom, the cancer cells metabolized the sugars in very different ways. In the case of fructose, the pancreatic cancer cells used the sugar in the transketolase-driven non-oxidative pentose phosphate pathway to generate nucleic acids, the building blocks of RNA and DNA, which the cancer cells need to divide and proliferate.

“Traditionally, glucose and fructose have been considered as interchangeable monosaccharide substrates that are similarly metabolized, and little attention has been given to sugars other than glucose,” the study states. “However, fructose intake has increased dramatically in recent decades and cellular uptake of glucose and fructose uses distinct transporters … These findings show that cancer cells can readily metabolize fructose to increase proliferation. They have major significance for cancer patients, given dietary refined fructose consumption.”

As in anti-smoking campaigns, a federal effort should be launched to reduce refined fructose intake, Heaney said.

“I think this paper has a lot of public health implications,” Heaney said. “Hopefully, at the federal level there will be some effort to step back on the amount of HFCS in our diets.”

Heaney said that while this study was done in pancreatic cancer, these finding may not be unique to that cancer type.

Going forward, Heaney and his team are exploring whether it’s possible to block the uptake of fructose in the cancer cells with a small molecule, taking away one of the fuels they need to grow. The work is being done in cell lines and in mice, Heaney said.

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The study was funded by the National Institutes of Health, the Hirschberg Foundation and the Jonsson Cancer Center.

UCLA’s Jonsson Comprehensive Cancer Center has more than 240 researchers and clinicians engaged in disease research, prevention, detection, control, treatment and education. One of the nation’s largest comprehensive cancer centers, the Jonsson center is dedicated to promoting research and translating basic science into leading-edge clinical studies. In July 2010, the Jonsson Cancer Center was named among the top 10 cancer centers nationwide by U.S. News & World Report, a ranking it has held for 10 of the last 11 years. For more information on the Jonsson Cancer Center, visit our website at http://www.cancer.ucla.edu.

Resposted from 2010

Too much sugar turns off gene that controls the effects of sex steroids

 

 

Eating too much fructose and glucose can turn off the gene that regulates the levels of active testosterone and estrogen in the body, shows a new study in mice and human cell cultures that’s published this month in the Journal of Clinical Investigation. This discovery reinforces public health advice to eat complex carbohydrates and avoid sugar. Table sugar is made of glucose and fructose, while fructose is also commonly used in sweetened beverages, syrups, and low-fat food products. Estimates suggest North Americans consume 33 kg of refined sugar and an additional 20 kg of high fructose corn syrup per person per year.

 

Glucose and fructose are metabolized in the liver. When there’s too much sugar in the

diet, the liver converts it to lipid. Using a mouse model and human liver cell cultures, the

scientists discovered that the increased production of lipid shut down a gene called

SHBG (sex hormone binding globulin), reducing the amount of SHBG protein in the

blood. SHBG protein plays a key role in controlling the amount of testosterone and

estrogen that’s available throughout the body. If there’s less SHBG protein, then more

testosterone and estrogen will be released throughout the body, which is associated with

an increased risk of acne, infertility, polycystic ovaries, and uterine cancer in overweight

women. Abnormal amounts of SHBG also disturb the delicate balance between estrogen

and testosterone, which is associated with the development of cardiovascular disease,

especially in women.

 

“We discovered that low levels of SHBG in a person’s blood means the liver’s metabolic

state is out of whack – because of inappropriate diet or something that’s inherently wrong

with the liver – long before there are any disease symptoms,” says Dr. Geoffrey

Hammond, the study’s principal investigator, scientific director of the Child & Family

Research Institute in Vancouver, Canada, and professor in the Department of Obstetrics

& Gynecology at the University of British Columbia.

* Requested Repost 2007

 

Fizzical harm: Drinking sugary drinks doesn’t just pile on the pounds – it changes your body so it’s harder to lose weight

By Rob Waugh

  • Drinking sugary drinks for just a month  alters body chemistry
  • More difficult to lose weight
  • Body grows to ‘prefer’ sugar to digesting  own fat

Drinking sugared fizzy drinks for just a  month changes the body permanently so it’s more difficult to lose  weight.

The soft drinks don’t just pile on the pounds  because of the calories in them – they alter the way your body burns  fuel.

Your muscles grow to ‘prefer’ sugar to fat as  a fuel, and thus losing weight becomes harder.

Drinking sugary drinks could be even more  harmful than previously thought.

Soft drinks alter the way our muscles burn  fuel preferring sugar over fat which makes the pounds harder to  shift.

And worryingly this effect lasts long-term  which can raise levels of blood glucose leading to diabetes.

Dr Hans-Peter Kubis, of Bangor University,  said: ‘This study proves our concerns over sugary drinks have been  correct.

‘Not only can regular sugar intake acutely  change our body metabolism; in fact it seems that our muscles are able to sense  the sugars and make our metabolism more inefficient, not only in the present but  in the future as well.

‘This will lead a reduced ability to burn fat  and to fat gain. Moreover, it will make it more difficult for our body to cope  with rises in blood sugar.’

Dr Kubis warned the drinks can compromise  long term health and, when in need of refreshment, people should reach for water  instead.

His researchers also showed isolated muscle  cells identify and respond to the sugary diet, and switch how they use the  fuel.

‘Together with our findings about how  drinking soft drinks dulls the perception of sweetness, our new results  give a  stark warning against regularly drinking sugar sweetened  drinks.’

The move to an inefficient metabolism was  seen in male and female participants who were lightly active, and drinking soft  drinks for just four weeks.

These factors show that regular use of sugar  sweetened soft drinks drives alterations in muscles similar to those found in  people with obesity problems and type 2 diabetes.

Dr Kubis said: ‘What is clear is our body  adjusts to regular soft drink consumption and prepares itself for the future  diet by changing muscle metabolism via altered gene activity – encouraging  unhealthy adaptations similar to those seen in people with obesity problems and  type 2 diabetes.

‘Together with our findings about how  drinking soft drinks dulls the perception of sweetness, our new results  give a  stark warning against regularly drinking sugar sweetened drinks.’

In the study 11 people in their twenties took  part in a sugar sweetened soft drink supplementation for a month and before and  after had their blood and muscle tissue as well as their whole body metabolism  and composition tested.

Genes and proteins important for fat and  sugar metabolism were analysed and blood sugar and fats assessed.

As it turned out metabolism shifted towards  sugar away from using fat and genes for inefficient sugar metabolism were  activated and a particular factor which is known to be crucial for genes of  aerobic metabolism was reduced. Moreover the subjects gained fat and blood sugar  was elevated.

Dr Kubis said: ‘What we found is that it is  not the sugar in itselt that puts on weight but the way it gets the body to  store more. ‘This would relate to all  kinds of soft drinks with a high sugar content, including fruit juices.

‘It was a small study because it is difficult  to find young people who have not previously been exposed to a lot of soft  drinks and who are willing to undergo muscle biopsies.

‘But we are now hoping to carry out a bigger  study with more particpants over a longer period of time.’

He has been campaigning for the government to  take action to address the problem of soft drink consumption.

Added Dr Kubis: ‘Clearly taxation on sugary  drinks is overdue. This money could be invested in the NHS where it is urgently  needed to treat people with obesity problems and diabetes.’

Read more: http://www.dailymail.co.uk/sciencetech/article-2176549/Drinking-sugary-drinks-doesnt-just-pile-pounds–changes-body-difficult-lose-weight.html#ixzz21PD8GBFb