Pancreatic cancers use fructose, common in the Western diet, to fuel their growth

Aug 03, 2010

(PhysOrg.com) -- 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 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 ," 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.

Sources of fructose in the Western diet include cane sugar (sucrose) and 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 . 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 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 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.

Explore further: Increased risk for head, neck cancers in patients with diabetes

Provided by University of California - Los Angeles

5 /5 (17 votes)

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User comments : 15

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jimbo92107
4.4 / 5 (7) Aug 03, 2010
"As in anti-smoking campaigns..." WTF??? This crap causes cancer and diabetes. It isn't advertised like cigarettes, it's an ingredient put anonymously into half the food Americans eat, including pop, spaghetti sauce, BBQ sauce, salad dressing, cereal and ketchup!

http://en.wikiped..._effects
sstritt
4 / 5 (5) Aug 03, 2010
The only effective way to avoid HFCS is to stay away from nearly all processed foods. This stuff is in everything!
JimB135
4.2 / 5 (6) Aug 03, 2010
The mantra from the food industry for so long was the fructose is just another form of sugar and no different in terms of metabolism. Clearly we all need to cut all refined sugars from our diets where we can. But HFCS more and more seems to be one bad actor.

And children get exposed to it everywhere.

This makes me crazy!
JimB135
3 / 5 (2) Aug 03, 2010
The mantra from the food industry for so long was the fructose is just another form of sugar and no different in terms of metabolism. Clearly we all need to cut all refined sugars from our diets where we can. But HFCS more and more seems to be one bad actor.

And children get exposed to it everywhere.

This makes me crazy!
Fionn
5 / 5 (3) Aug 03, 2010
@ sstrit: It's possible, albeit difficult, to avoid it almost entirely. Then again, between all my food allergies and sugar sensitivity I'm avoiding most processed food anyway...

This needs to be spread everywhere. HFCS is bad for you, worse than pure cane sugar, and yet the corn industry, which gets tens of millions in federal subsidies, is spending money on ad campaigns which outright lie to the American people. It's sickening.
sstritt
3.7 / 5 (6) Aug 03, 2010
@fionn: The same corn industry which demonized coconut oil as being an unhealthy saturated fat- causing a major switch to omega-6 laden corn oil and hydrogenated fats!
Fabian
2.3 / 5 (6) Aug 03, 2010
As is so often the case (unfortunately), the title of this article and the substance of the text present two different messages. I read the title thinking researchers had found a "smoking gun" as to the cause of pancreatic cancer. But they only say that pancreatic cancer cells can use fructose just like they use glucose. There doesn't seem to be any indication that such an ability causes pancreatic cancer to be more prevalent, or more agressive. If we all removed HFCS from our diets, the cancer cells could just use glucose to grow. I think previous commenters have made an inferential leap in determining this study implicates HFCS as causing pancreatic cancer, or making it worse.
Fabian
2.6 / 5 (5) Aug 03, 2010
To add to my previous comment, who's to say people haven't merely substituted HFCS for refined sucrose over the past several decades? If that is the case, and HFCS was removed from the market, people would likely switch back to sucrose as a sweetener, thereby providing cancer cells with plenty of glucose, instead of fructose, to fuel their growth. Pancreatic cancer rates would be unaffected.
SteveL
4 / 5 (2) Aug 03, 2010
The anti-smoking campaigns haven't been all that effective. In the states, smoking rates have basically been stable for the last six to seven years. As a pay-as-you-go methodology I'm not opposed to taxing proven health damaging food or consumer items to compensate for medical care and research - if only the politicians would leave it alone. Once they see money they can't help but seal it for unintended purposes.

I consider consumption taxes on unhealthy lifestyles to be the most fair way to compensate for private choices that adversely effect the public.
Parsec
4.7 / 5 (3) Aug 03, 2010
I am wondering if there is any danger from eating a lot of fruit. The main natural sweetener in fruit is fructose, and it worries me that eating something which I had always considered very healthy may have adverse side effects. Anyone care to comment on the relative quantities of fructose from fruit vs HFCS? Is there a danger here?
OUAnthony
5 / 5 (5) Aug 03, 2010
Parsec, this article only states that fructose helps the cancer cells multiply faster...it does not cause cancer. Fruits are very important to your health. If you ever develop cancer, you should obviously talk to your doctor about this study in determining a diet for yourself. As long as you're healthy though, you should definitely continue eating fruit, some of which are high in antioxidants which help prevent cancer.
DamienS
5 / 5 (1) Aug 04, 2010
@Parsec
In answer to your question, my comment isn't based on expert knowledge, but I would assume that deriving fructose from whole foods, ie fruit, would not be a problem in a 'normal' diet as it would be bound to natural fiber found in fruits and would thus be released more slowly into the blood stream. Also, the concentrations would be far lower compared to additives in processed foods.
mjb_TO
3 / 5 (2) Aug 04, 2010
Half of fruit sugar and half of table sugar is fructose. Less than half of HFCS is fructose. In fruit, only about one half of the fructose is free fructose, the rest is in sucrose. Honey and maple syrup have a lot of free fructose. The disgestion rate of sucrose is limited by the supply of the sucrase enzyme, but the fructose is eventually digested nonetheless. The difference with fruit is that there are benefits, so it is a trade-off between the damage caused by fructose (elevation of triglycerides, fatty liver, elevation of blood pressure, increase in ectopic fat storage, interference with leptin appetite suppressing hormone, increase in small dense LDL particles, accelerated cancer growth) and the anti-oxidants and other phytochemicals shown to benefit the health.
Jimee
not rated yet Aug 05, 2010
Legislative incentives built the huge corporate corn production system, and only legislation can change the focus of the incentive to development of a smarter, healthier food culture. Corn didn't get to be what it is purely through "free market" processes.
bottomlesssoul
3 / 5 (2) Aug 08, 2010
You can't legislate behavior, that is a time tested axiom as far as I'm concerned. Education however has an amazing effect.

An absolutely terrific diet plan has evolved to modern forms and is available on any government website. Unfortunately almost no one reads things at random so it's luck to even know about this.

Why food education and personal health are not taught in schools I will never know. Except for a few feeble attempts in my early school days I have never seen it involved in any school system anywhere in the world.

Outside the school system I've seen nice attempts by NGOs to reach villagers but it's a slow process and does not necessarily transfer to the children since it's directed at the parents.

I think it's time this enter formally through education at an early age.