The researchers at the Karolinska Institute say that people who drink large quantities of fizzy drinks or add sugar to coffee or tea run a higher risk of developing cancer of the pancreas.
The team reached this conclusion after studying the diets of almost 80,000 men and women between 1997 and 2005.
Of that number a total of 131 developed pancreatic cancer, a deadly form of the disease that is difficult to treat.
The researchers say the risk of developing pancreatic cancer is related to the amount of sugar in the diet.
In the study the people who drank fizzy or syrup-based drinks twice a day were found to have a 90 percent higher risk of getting cancer of the pancreas than those who never drank them.
The risk was 70 percent higher for those who added sugar to their drinks about five times a day, and 50 percent for those eating creamed fruit, a sugary, fruit-based Swedish dessert, at least once a day.
Susanna Larsson, from the department of environmental medicine at the Karolinska Institute, Stockholm, says even though the chances of developing pancreatic cancer are relatively small, it is important to learn more about the risk factors behind the disease.
Figures suggest that about 216,000 new cases of pancreatic cancer, mostly in developed countries, are diagnosed each year.
The illness commonly appears in people over 60 and is difficult to treat because it is often not diagnosed until it has spread beyond the pancreas.
Almost all the 7,000 people who get pancreatic cancer annually in the UK die shortly after diagnosis, partly because the symptoms are spotted too late.
Smoking is thought to be one of the biggest triggers for pancreatic cancer.
Tumours are also hard to detect because the pancreas is buried deep in the body.
Only two per cent of patients are alive five years after first being treated, although surgery followed by chemotherapy can increase survival rates.
Larsson believes it is perhaps the most serious form of cancer, with very poor prognoses for its victims and it is important that we learn how to prevent it.
The research is published in the American Journal of Clinical Nutrition.
A 23-Year Survival Analysis of Prediagnostic BMI and Risk of Lethal Prostate Cancer
A team of Harvard scientists has peered into 23 years of health data on more than 22,000 physicians and concluded that men who are overweight or obese years before being diagnosed with prostate cancer are more likely to die of the disease than those who are of normal weight.
While no studies have definitively shown that obesity and/or higher Body Mass Index, or BMI, which measures body fat, increases the risk of developing prostate cancer, these studies showed that obese men at the time of diagnosis were more likely to have a cancer recurrence.
But according to Jing Ma, M.D., Ph.D., a researcher at the Brigham and Women's Hospital-based Channing Laboratory and associate professor of medicine at Harvard Medical School, few studies have focused on obesity and the risk of dying from prostate cancer.
In fact, she said, there is "considerable debate in the urology and cancer fields regarding whether rising PSA (Prostate Specific Antigen) is a good indicator for whether people will eventually die from prostate cancer or not."
Ma and her co-workers at Brigham and Women's Hospital and at the Harvard School of Public Health examined 23 years of data from the Physician's Health Study, which began in 1982 as a randomized, double-blind trial of aspirin and beta-carotene. More than 22,000 U.S. male physicians were recruited for the trial to study the role of aspirin and beta-carotene in preventing heart disease and cancer.
About 15,000 men provided blood samples at enrollment, along with information on their body weight and height, and their BMI was calculated. Approximately 99 percent of the original participants were tracked through questionnaires for 23 years, including cause of death.
By the end of 2005, 2,367 men had developed prostate cancer, while 265 died of the disease. They found that 39 percent of the participants were overweight and 3.4 percent were obese at the beginning of the study, and that higher BMI was positively associated with the risk of dying from prostate cancer. They also showed that the risk of dying from prostate cancer increased 8 percent for each point increase in BMI.
A person with a BMI of between 25 and 29.9 is considered overweight, whereas someone with a BMI of 30-plus is called obese. The physicians were in relatively good shape compared to the U.S. population in general. U.S. males between 50 and 69 are approximately 40 percent overweight and more than 30 percent are obese.
"It was surprising since it is a moderate association and the BMI was measured in 1982 and was on average eight to 10 years before developing prostate cancer," Ma said. "The beauty of the study is that we could factor out smoking at baseline, and tumor grade and stage didn't affect the trend."
"Some people might think that what they do today has little to do with cancer risk, especially for prostate cancer," Ma said, "and some individuals probably wouldn't believe that obesity has anything to do with prostate cancer. But we have found that if a man develops prostate cancer, being obese could put him at a higher risk of dying from the cancer. There is something many men can do about that."
She and her co-workers are exploring the underlying mechanisms that link being overweight and/or obese to prostate cancer progression. A better understanding of the risk factors that influence the disease's progression, said Ma, is imperative.
Prostate cancer is the most common type of cancer found in American men, other than skin cancer, and the third leading cause of cancer death in men. The American Cancer Society estimates that there will be about 234,460 new cases of prostate cancer in the United States in 2006, with approximately 27,350 deaths from the disease.
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