'Five-a-day' has limited impact on cancer risk

PARIS, 07 april 2010– Eating lots of fruit and vegetables has only a small effect on warding off cancer, a study published on Wednesday says, although its authors insist that tucking into the recommended "five-a-day" is still good for general health.

Doctors led by Paolo Boffetta at the Mount Sinai Medical Center, New York, pored over eight years of data from a major European investigation into the relationship between cancer risk and food.

The investigation, which is continuing, covers nearly 470,000 volunteers recruited in 10 Western European countries.

Between 1992 and 2000, more than 30,000 of the participants were diagnosed with cancer.

Boffetta's team found that high consumption of fruit and vegetables gave only modest protection against cancer.

An increase of 200 grammes (about seven ounces) a day resulted in a three-percent reduction of cancer risk.

Vegetable consumption by itself also gave a small benefit, although this was restricted to women, while heavy drinkers who ate a lot of fruit and veggies had a somewhat reduced risk, but only for cancers linked to alcohol and smoking.

"The bottom line here is that, yes, we did find a protective effect of fruit and vegetable intake against cancer, but it is a smaller connection than previously thought," Boffetta said in a press release issued by Mount Sinai.

"Any cancer protective effect of these foods is likely to be modest, at best. However, eating fruits and vegetables is beneficial for health in general and the results of this study do not justify changing current recommendations aiming at increasing intake of these foods."

The UN's World Health Organisation (WHO) issued a recommendation in 1990 suggesting that five servings of fruit and vegetables per day helped prevent cancer and other diseases.

"Worldwide, low intake of fruits and vegetables is estimated to cause about 19 percent of gastrointestinal cancer, about 31 percent of ischaemic heart disease and 11 percent stroke," the WHO says on its website.

Ischaemic heart disease is caused by lack of blood supply to the cardiac muscles, typically as a result of artery disease, hypertension, smoking or high cholesterol levels.

The new study appears online in the Journal of the National Cancer Institute, published by Britain's Oxford University Press.

1. WHO
2. Journal of the National Cancer Institute

More Research Links Alcohol Intake to Cancer Risk

In men, regular drinkers face higher risk of cancer at sites including stomach, esophagus

12 aug 2009-- Men who drink moderate or high amounts of alcohol over their lifetime may face a higher risk of several types of cancer, according to research published in the current issue of Cancer Detection and Prevention.

Andrea Benedetti, Ph.D., of McGill University in Montreal, and colleagues analyzed data from about 3,000 middle-aged and older men diagnosed with a variety of cancers in the early 1980s, as well as 507 population controls. Subjects reported on their history of alcohol consumption.

Among regular drinkers, the researchers found that lifetime drink-years of all alcoholic beverages appeared to have a dose-response association with risk of esophageal, stomach, colon, liver, lung, and prostate cancer. In the heaviest drinkers, odds ratios for cancer ranged from 1.6 for lung cancer to 7.9 for liver cancer.

"Our results indicate that alcohol might have an effect on several sites. This suggests that alcohol may have a systemic effect (e.g., due to effects on DNA repair or on the immune system). Because of the extent of exposure to alcohol and the number of cancer sites potentially affected, the present results suggest that alcohol consumption might have greater public health significance than previously thought," the authors conclude.

Abstract
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Chronic kidney disease may raise cancer risk

NEW YORK, 16 may 2009 – Older men with moderately reduced kidney function appear to be at increased risk for cancers of the lung and the urinary tract, Australian researchers report.

"Given that chronic kidney disease of this severity affects 20% of the male population, our finding suggests that chronic kidney disease prevention may be a novel and worthwhile strategy for reducing cancer risk in the general population," they conclude.

It's known that people with end stage renal disease, which requires dialysis or a kidney transplant, are at increased risk for cancer, Dr. Germaine Wong and colleagues explain in the Journal of the American Society of Nephrology. However, it has been unclear if this increased risk begins earlier in the course of chronic kidney disease.

To investigate this issue, Wong at Westmead Hospital and her team studied data on 3049 people, aged 49 to 97 years. Nearly a third had moderate kidney disease but none was on dialysis or had undergone kidney transplantation.

During an average follow-up of 10 years, men with chronic kidney disease, but not women, had a significantly higher cumulative occurrence of cancer. The rate was the equivalent of 23 cases annually per 1000 men with kidney disease, compared with 17 cases annually per 1000 men without kidney disease.

The risk of cancer increased with progressively worsening kidney function, "reaching a maximum three-fold increased risk ... which is similar to the risk increase seen in dialysis and kidney transplant patients."

While reduced kidney function in men was associated with lung and urinary tract cancers, it was not linked to colorectal or prostate cancers.

SOURCE: Journal of the American Society of Nephrology, online April 30, 2009.

Cancer Risk Increased by Excess Body Fat, Red and Processed Meats, and Alcohol

Roxanne Nelson

October 31, 2007 — There is convincing evidence that excess weight and obesity can increase the risk for 6 different cancers, including those of the colon, kidney, and pancreas, according to a report issued by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund. The second expert report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective, considered to be the most comprehensive scientific analysis of cancer prevention and causation ever undertaken, also reported that there is convincing evidence that the consumption of alcohol, red meat, and processed meat elevates cancer risk.
"The most striking finding in the report is that excess body fat increases risk for numerous cancers. That is why body weight is the focus of our first recommendation," expert panel member W. Phillip T. James, MD, DSc, from the International Obesity Task Force, in London, United Kingdom, told journalists.
The document, which was written by an international expert panel, reviewed 7000 research studies over a 5-year period and classified the accumulated evidence for specific diet-cancer links. It is the second one to be published in the past 10 years and provides the most inclusive evidence to date linking cancer risk to diet, physical activity, and weight.
Although cancer is considered to be a disease of genes that are vulnerable to mutation, evidence indicates that only a small number of cancers are inherited, write the experts. Instead, it appears that environmental factors are the most important, and these can often be modified with a resultant reduction in risk. These factors include tobacco use, infectious agents, radiation, industrial chemicals, pollution, medications, nutrition, physical activity, and body composition.
One of the strongest findings in the report was that excess body fat is associated with an increased cancer risk and can increase the risk for 6 different types of the disease: colon, kidney, pancreas, adenocarcinoma of the esophagus and endometrium, and postmenopausal breast cancer. They also reported that alcohol is convincingly linked to a number of cancers, including those of the colon, breast, esophagus, and mouth, larynx and pharynx.
To combat excess weight and maintain a healthy body-mass index, the experts recommend limiting the intake of energy-dense foods, particularly those that are highly processed. These products tend to be high in sugar and fat and low in fiber. They also advise increasing physical activity and getting some exercise for at least 30 minutes a day. Physical activity not only helps individuals keep excess weight off, but it helps reduce the risk for cancer in its own right.
Evidence has also increased since the first report, issued in 1997, which links the consumption of red meat (beef, pork, and lamb) to colorectal cancer. The panel's recommendation is to limit the consumption of red meat to 18 ounces per week because, beyond this amount, evidence shows that for every additional 1.7 ounces of red meat consumed per day, the risk for cancer rises by 15%.
Their recommendation concerning the consumption of processed meats is even more stringent. Processed meats, such as bacon, ham, sausage, and lunch meat, should be avoided entirely; the panel was unable to find a level at which the consumption of these products can be reliably considered completely safe. For every 1.7 ounces of processed meat consumed per day, the risk for colorectal cancer rises by 21%.
Evidence also indicates that the majority of diets that are protective against cancer are made up primarily of foods of plant origin. Higher consumption of several plant foods might offer protection against cancers of various sites.
"We are recommending 5 servings or more of vegetables and fruit daily because, like physical activity, they pack a double whammy against cancer. Probable evidence indicates that they help reduce cancer risk on their own and, as low energy-dense foods, they help maintain a healthy weight, which the evidence shows has a big influence on cancer risk," Dr. James said during a press conference.
The panel also looked at factors that included birth weight, childbearing, breast-feeding, and adult height and found that they all can influence the risk for cancer. High birth weight is associated with an increased risk for premenopausal breast cancer, which is likely linked to excess body fat and the resultant hormonal changes.
Exclusive breast-feeding appears to offer protection for both mother and child. It can help lower the risk for breast cancer in women and also lower the risk of becoming overweight and obese in children.
"The evidence is uniformly strong on breast-feeding, and the fact that it offers cancer protection to both mothers and their children is why we made breast-feeding 1 of our 10 recommendations to prevent cancer," said expert panel member Walter J. Willett, MD, PhD, from the Harvard School of Public Health, in Boston, Massachusetts, at a press conference.
The panel also found an association between adult height and cancer risk. Tall adults appear to have a higher risk of colorectal and postmenopausal breast cancer, and there is some evidence linking tallness to an increased risk for ovarian, pancreatic, and premenopausal cancer.
The recommendations made in this report are applicable to cancer survivors when appropriate and unless otherwise advised by their healthcare practitioner. Because increasing numbers of cancer patients survive their disease and live long enough to develop new primary cancers or other chronic diseases, the expert panel believes that these recommendations can help reduce the risk.
Recommendations for Cancer Prevention
1. Be as lean as possible within the normal range of body weight.2. Be physically active as part of everyday life.3. Limit consumption of energy-dense foods; avoid sugary drinks.4. Eat mostly foods of plant origin.5. Limit intake of red meat; avoid processed meat.6. Limit alcoholic drinks.7. Limit consumption of salt; avoid moldy cereals (grains) or pulses (legumes).8. Aim to meet nutritional needs through diet alone.
Special Population Recommendations
9. Mothers should breast-feed; children should be breast-fed.10. Cancer survivors should follow the recommendations for cancer prevention.
World Cancer Research Fund/American Institute for Cancer Research. Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective. Washington, DC: AICR; 2007.

Study: Low-fat diet may cut cancer risk

By LAURAN NEERGAARD, AP Medical WriterTue Oct 9, 8:50 PM ET
Cutting dietary fat may also cut the risk of ovarian cancer, says a study of almost 40,000 older women that found the first hard evidence that menu changes protect against this particularly lethal cancer.
But don't wait too long to get started: The protection didn't kick in until the women had eaten less fat for four years and counting.
Until now, the only known prescription against ovarian cancer — aside from surgically removing the ovaries — was to use birth control pills. Use for five years can lower the cancer risk by up to 60 percent, protection that lingers years after pill use ends.
The new findings now offer an option for postmenopausal women to try as well.
Those who followed a low-fat diet for eight years cut their chances of ovarian cancer by 40 percent, researchers reported Tuesday in the Journal of the National Cancer Institute.
"This is really good news," said Dr. Jacques Rossouw of the National Institutes of Health, which funded the work. "But you have to stick with the diet."
It's arguably the most promising finding of the mammoth Women's Health Initiative dietary study, which enrolled tens of thousands of healthy women ages 50 to 79 to track the role of fat in several leading killers. Some women were assigned to cut the total fat in their diets to 20 percent of calories — from an average of 35 percent — while others continued their usual diets for comparison.
Yet the study so far has found the diet made little impact on rates of breast cancer, colorectal cancer and heart disease. There are a number of theories: Maybe the women started healthier eating too late; most were overweight, a major risk factor, and the diet wasn't designed to shed pounds. Nor did most women actually cut enough fat.
But despite all those hurdles, a low-fat diet did appear protective against ovarian cancer — and the women who started with the worst diets and cut fat the most got the most benefit.
Ovarian cancer is fairly rare, affecting one in 60 women compared with the one in 9 who will get breast cancer. But it is among the grimmest of diagnoses, because ovarian cancer usually is detected only after it has spread throughout the abdomen, making it much harder to treat. Only 45 percent of patients survive five years.
The American Cancer Society estimates that 22,430 U.S. women will be diagnosed with ovarian cancer this year; 15,280 women will die of it.
Ovarian cancer can strike anytime in adulthood, but risk increases with age. Mutations in the so-called breast cancer genes BRCA1 and BRCA2 also increase the risk of ovarian cancer — and women in the new study have not yet been tested for those genes, to see if the low-fat diet proves more or less beneficial for them.
Why would diet affect ovaries? The theory is that fat intake increases the amount of estrogen circulating in the blood, which may in turn overstimulate sensitive ovaries.
Indeed, blood tests showed study participants on the low-fat diet experienced a 15 percent reduction in estradiol, a key form of estrogen, while non-dieters experienced no change, said study co-author Dr. Ross Prentice of Seattle's Fred Hutchinson Cancer Research Center.
"It's quite noteworthy," Prentice said of the ovarian protection. "We're really pleased to have something positive to say to American women — that undertaking a low-fat diet likely reduces your risk of ovarian cancer and perhaps other cancers as well."
Estrogen plays a role in breast cancer, too. Yet when researchers last year checked women in this same study, they found only a 9 percent drop in breast cancer risk, not quite large enough to be sure it wasn't due to chance. But even then, the women who cut the most fat fared better — just like with the new ovarian cancer data.
Most of the dieters cut their fat intake to 24 percent of calories, not quite as much as recommended. And over time, the fat crept back: Eight years later, they were up to 29 percent — still lower than the average American diet, noted Rossouw, of NIH's National Heart, Lung and Blood Institute.
"It's feasible," he said of the diet. And, "once there is news that this does work, it may be easier to motivate people to do."
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On the Net:
Cancer info: http://www.cancer.gov

Many Beliefs About Cancer Risks at Odds With Evidence

ATLANTA, July 26 -- Americans are having trouble sifting fact from fiction on the causes of cancer.
So found a survey by the American Cancer Society, a group that expends much effort, apparently often futilely, trying to dispel myths and misunderstandings about malignancies.
Consider that 39% of respondents believed that "living in a polluted city is a greater risk for lung cancer than smoking a pack of cigarettes a day," reported Kevin Stein, Ph.D., of the cancer society, and colleagues, in the July 26 issue of Cancer. Nineteen percent were uncertain.
They survey also found that 68% of the respondents believed that the risk of dying from cancer in the U.S. is increasing, a statement that is clearly false, the researchers said.
Those claiming to be "very informed" about cancer were significantly more likely to have a higher level of misunderstanding that those rating themselves as having lower cancer literacy, found Dr. Stein, and colleagues.
In the phone survey of 957 U.S. adults with no history of cancer there were 12 false statements presented about cancer risks and prevention, all contrary to evidence-based findings. Participants could agree, disagree, or express uncertainty about the truth of each statement.
The false statements, with percent marked "true" and "don't know," included:
The risk of dying from cancer in the U.S. is increasing. (67.7% true, 9.8% don't know)
Living in a polluted city is a greater risk for lung cancer than smoking a pack of cigarettes a day. (38.7%, 18.8%)
Some injuries can cause cancer later in life. (37.2%, 20.9%)
Electronic devices, like cell phones, can cause cancer in the people who use them. (29.7%, 24.7%)
What someone does as a young adult has little effect on their chance of getting cancer later in life. (24.8%, 7.1%)
Long-time smokers cannot reduce their cancer risk by quitting smoking. (16.2%, 5.7%)
People who smoke low-tar cigarettes have less chance of developing lung cancer than people who smoke regular cigarettes. (14.7%, 10.8%)
Personal hygiene products, like shampoo and deodorants, can cause cancer. (13.7%, 15.3%)
Getting a mammogram, or using a special x-ray machine to detect breast cancer, can cause cancer of the breast. (10.2%, 16.1%)
Getting a base tan or base coat at a tanning salon will provide protection from skin cancer when you go outside in the sun. (8.4%, 13.2%)
Underwire bras can cause breast cancer. (6.2%, 30.9%)
You cannot get skin cancer from using a tanning booth. (6.2%, 18.3%)
The sample was weighted to match national parameters for sex, age (35 to 64), education, race, Hispanic origin, and region of the country. Of the respondents, 86.3% had at least a high school education, and 56.2% reported a positive family history of cancer. Most participants said they were very or somewhat informed about cancer.
A consistent finding was that men were more likely to believe statements to be true than did women. Some research indicates that compared with women, men may be less attentive to and less likely to seek medical information and are thus likely to be less informed, the researchers said.
The study's limitations included a question of the degree to which these findings can be considered representative of the U.S. population.
The authors also noted a lack of strong evidence for some of the study statements (the cell phone issue and personal hygiene products statements, for example), which they termed "difficult to evaluate, probably false."
Despite these findings, the researchers said, it is important to recognize that individual beliefs are not always the most influential determinant of health behavior. For example, one of the most powerful predictors of the use of cancer screening is the healthcare provider's recommendation.
Also, the influence of broader socioeconomic issues (tobacco marketing, limited availability of healthful food choices, and safe venues for physical activity in certain neighborhoods) should not be overlooked.
No financial conflicts were reported. The study was supported by intramural funding of the American Cancer Society and outside funding from the Discovery Health Channel and Prevention Magazine.Primary source: CancerSource reference: Stein K, et al, "Prevalence and Sociodemographic Correlates of Beliefs Regarding Cancer Risks" Cancer 2007; doi 10.1002/cncr.22880.

Cancer Risk From Environmental Arsenic Can Last for Generations

Decades after residents of a region in northern Chile were exposed to high levels of arsenic in their drinking water, they still suffer from high lung and bladder cancer death rates, concludes a study by U.S. and Chilean researchers.
The finding indicates a pattern of long-term arsenic-related health effects that hasn't been documented before, said the authors of a study in the June 12 Journal of the National Cancer Institute.
"The results show that the risks of concentrated arsenic exposure are extraordinarily high, and that they last a very long time, both after initial exposure, and after the exposure ends," principal investigator Allan Smith, professor of epidemiology at the University of California, Berkeley, School of Public Health, said in a prepared statement.
From 1958 to 1970, arsenic levels in drinking water in the northern Chilean cities of Antofagasta and Mejillones averaged 870 micrograms per liter, nearly 90 times higher than current World Health Organization and U.S. standards of 10 micrograms per liter. The communities got their water from arsenic-contaminated rivers.
Improvements to the water treatment system that began in 1971, along with other measures, have reduced arsenic levels to about 10 micrograms per liter.
For this study, researchers analyzed data on lung and bladder cancer deaths in this area (Region II) from 1950 to 2000.
They found that those kinds of cancer deaths started to increase in 1968, which was 10 years after the major jump in arsenic levels in drinking water.
Death rates from these two kinds of cancer continued to increase and peaked between 1986 and 1997. Between 1992 and 1994 (more than 20 years after arsenic levels started to decline), the combined death rates for bladder and lung cancer in Region II were 153 per 100,000 men and 50 per 100,000 women -- 2.5 to three times higher than in another region in northern Chile that did not have high levels of arsenic in the drinking water.
"The impact of this environmental health risk on cancer mortality in a human population is without precedent. This study adds to the overall body of evidence of the harmful effects of arsenic," Smith said.
More information
The U.S. Agency for Toxic Substances and Disease Registry has more about arsenic.

Cutting Inflammation Could Cut Cancer Risk

TUESDAY, April 17 (HealthDay News) -- Reducing inflammation may help prevent cancer, suggest two Mayo Clinic studies presented Monday at the annual meeting of the American Association for Cancer Research in Los Angeles.
One study found that women who regularly used aspirin developed fewer cancers than women who didn't use the anti-inflammatory drug. Another study found that there may be an association between lung inflammation seen in asthma and increased risk of breast cancer spreading to the lungs.
The first study looked at more than 22,500 cancer-free postmenopausal women who took part in the Iowa Women's Health Study. A decade later, women who regularly used aspirin were 16 percent less likely to have developed cancer and 13 percent less likely to have died of cancer than women who did not use aspirin, the researchers found.
This same benefit was not seen in women who regularly used non-steroidal anti-inflammatory drugs
other than aspirin, said the study by researchers at the Mayo Clinic in Rochester, Minn.
And while aspirin helped protect former and "never smokers" from cancer, that was not the case for women who were active smokers.
The findings do not mean that women should toss aside their NSAIDs or start taking aspirin on a regular basis, the Mayo Clinic researchers said.

High blood sugar tied to increased cancer risk

Results of a study involving nearly 65,000 people point to an association between cancer and abnormally high blood sugar levels.
These results "have obvious implications for lifestyle guidance, as it is well known what factors cause blood glucose increases," Dr. Par Stattin from Umea University Medical Center, Sweden noted in comments to Reuters Health.
By avoiding excessive fat and other dietary risk factors, and by getting regular exercise, "you can decrease your risk of cardiovascular disease, diabetes -- and cancer," he added.
Type 2 diabetes is associated with an increased risk of liver, pancreas, colon cancer, as well as other cancers, Stattin and colleagues note in the journal Diabetes Care. However, less is known about the effect on cancer risk associated with moderately elevated blood sugar levels among non-diabetic subjects.
http://news.yahoo.com/s/nm/20070316/hl_nm/high_blood_sugar_dc