Cancer is our biggest killer (yep, even worse than heart disease). And sugar consumption has been in the frame as a cancer risk for a while now, but a study released last week appears to have put the matter beyond doubt (at least for pancreatic cancer).
A 2002 a study tried to find which food had the greatest association with pancreatic cancer, and fructose (remembering sugar is half fructose and half glucose) got first prize.
The study conducted by the US National Cancer Institute identified 180 cases of pancreatic cancer from among 88,802 women who were monitored for 18 years as part of the Nurses’ Health Study. Women who were overweight and sedentary and had a high fructose intake were shown to have a 317 per cent greater chance of developing pancreatic cancer.
A 2006 study published by the Karolinska Institute in Sweden decided soft drinkers were in significant jeopardy, and had warnings for anyone eating sugar at all.
In the Swedish study, the researchers were able to demonstrate that the risk of developing pancreatic cancer was directly related to the amount of sugar in the diet. The people who said that they drank soft drinks twice a day or more were 90 per cent more likely to develop pancreatic cancer than those who never drank them.
And then a study published in February this year found that we are 87 percent more likely to contract pancreatic cancer if we have two cans of soft drink a week (about 10 grams of sugar a day on average).
These were all population studies. And while they are good for suggesting there may be a problem, they give no clue as the possible mechanism. Why does consuming fructose mean you are at greater risk of pancreatic cancer?
Last week a study out of the University of California (UCLA) nailed down the likely reason.In the study, human pancreatic cancer cells were exposed to solutions of pure glucose and pure fructose in the lab.
Sugar is half glucose and half fructose. The researchers knew that consistently high blood-glucose levels (such as that suffered by a Type II Diabetic) will accelerate the growth of cancerous cells. They also knew that eating fructose directly increases circulating fatty acids which reduces the effectiveness of insulin in clearing the blood of glucose.
The persistently increased blood glucose leads to type II diabetes and feeds cancer. But in this new study, the researchers were trying to determine whether fructose had a more direct involvement in cancer growth.
To find out they tagged the sugars with radioactive carbon (so they could see what the cells were doing with them).What they found was that the fructose was metabolised very differently by the cancerous cells.
Cancer is out-of-control cellular reproduction.The fructose was being used by the cells to create a much higher output of the genetic material which cells need in order to divide and proliferate (nucleic acids used to make DNA and RNA).
The difference between glucose and fructose appeared to be that while both could be used for energy, only one supplied significant quantities of the building materials for tumour growth. A tumour treated with fructose grew much more aggressively than one in a bath of glucose.
Having lots of fructose in the diet appears to create a perfect environment for cancer growth. The persistently high blood glucose caused by the metabolism of fructose by the liver (into fatty acids), provides fuel. And the fructose itself provides the DNA and RNA required for multiplication. What a perfect storm!
Studies of cells in a lab setting are not overly persuasive on their own. There are a lot of checks and balances in a living organism that simply do not exist when you isolate one type of cell. But these tests on pancreatic tumours combined with the strong line of population studies (coming to pretty much the same conclusion) is worth paying attention to.
These studies are all on cancer of the pancreas, the organ most involved with detecting the presence of sugar in the blood. But according to the authors of the study there is no reason that the observations about fructose should not apply to any kind of cancer.
In 2007 almost one in three (29 per cent) deaths were caused by cancer. Breast cancer (the biggest cancer for Australian women) incidence has increased by 32 per cent in the last two decades. And the incidence of prostate cancer (the biggest cancer for men) has more than doubled in the same timeframe.
There is no higher priority in our health system than slowing (or stopping) the accelerating trend in cancer suffering. This study suggests that sugar (a major component of the average Australian diet and the primary source of fructose) is directly implicated.
Fructose is not a disinterested bystander in the development of cancer. Our renegade cells use it directly (and significantly) to accelerate their reproduction. There is no sane reason for fructose (and therefore sugar) to be part of our diet. And there is no sane reason for the health hierarchy not to be saying exactly what I am saying – stop eating sugar immediately!