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11 December 2009

Omega-3 Fatty Acids May Reduce Risk of Colon Cancer

ScienceDaily (Dec. 8, 2009) — Long-chain omega-3 fatty acids, primarily found in fish and seafood, may have a role in colorectal cancer prevention, according to results presented at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, held Dec. 6-9, 2009, in Houston.

"Experimental data have shown benefits of long-chain omega-3 fatty acids in colorectal carcinogenesis, ranging from reduced tumor growth, suppression of angiogenesis and inhibition of metastasis," said Sangmi Kim, Ph.D., a postdoctoral fellow at the National Institute of Environmental Health Sciences, Research Triangle Park, N.C. "Our finding of inverse association between dietary intakes of long-chain omega-3 fatty acids and distal large bowel cancer in white participants adds additional support to the hypothesis."

Although experimental and clinical data suggest that long-chain omega-3 fatty acids possess anti-neoplastic properties in the colon, epidemiologic data to date has been inconclusive.

Kim and colleagues studied the link between polyunsaturated fatty acid intake and distal large bowel cancer using data from a population-based control study. They recruited 1,509 white participants (716 cancer cases and 787 controls) and 369 black participants (213 cancer cases and 156 controls) using the State Cancer Registry and Division of Motor Vehicles records.

Nineteen polyunsaturated fatty acids were assessed using a validated food frequency questionnaire, which included 124 questions on food items. The researchers used the questionnaire to collect information on the frequency and amount of foods typically consumed in the past 12 months. Patients who consumed more long-chain omega-3 fatty acids had a reduced risk of distal large bowel cancer. Compared to the lowest quartile, fat intake in the highest quartile was linked with a 39 percent reduced risk of cancer.

The researchers detected these associations in white participants, but not in black participants.

"We were surprised that the association was not also observed among blacks," Kim said. "We considered several possible explanations but were not able to account for this difference with the data we had. This finding warrants future study, but we should be careful about drawing conclusions about potential racial differences in the benefit from long-chain omega-3 fatty acids from this study."

"An increase in dietary intake of long-chain omega-3 fatty acids, which mainly come from fish and seafood, may be beneficial in the prevention of distal large bowel cancer," Kim said.

Spices halt growth of breast stem cells, U-M study finds

Curcumin, piperine could play role in preventing breast cancer

ANN ARBOR, Mich. — A new study finds that compounds derived from the spices turmeric and pepper could help prevent breast cancer by limiting the growth of stem cells, the small number of cells that fuel a tumor’s growth.

Researchers at the University of Michigan Comprehensive Cancer Center have found that when the dietary compounds curcumin, which is derived from the Indian spice turmeric, and piperine, derived from black peppers, were applied to breast cells in culture, they decreased the number of stem cells while having no effect on normal differentiated cells.

“If we can limit the number of stem cells, we can limit the number of cells with potential to form tumors,” says lead author Madhuri Kakarala, M.D., Ph.D., R.D., clinical lecturer in internal medicine at the U-M Medical School and a research investigator at the VA Ann Arbor Healthcare System.

Cancer stem cells are the small number of cells within a tumor that fuel the tumor’s growth. Current chemotherapies do not work against these cells, which is why cancer recurs and spreads. Researchers believe that eliminating the cancer stem cells is key to controlling cancer. In addition, decreasing the number of normal stem cells – unspecialized cells that can give rise to any type of cell in that organ – can decrease the risk of cancer.

In this study, a solution of curcumin and piperine was applied to the cell cultures at the equivalent of about 20 times the potency of what could be consumed through diet. The compounds are available at this potency in a capsule form that could be taken by mouth. (Note: This work has not been tested in patients, and patients are not encouraged to add curcumin or piperine supplements to their diet at this time.)

The researchers applied a series of tests to the cells, looking at markers for breast stem cells and the effects of curcumin and piperine, both alone and combined, on the stem cell levels. They found that piperine enhanced the effects of curcumin, and that the compounds interrupted the self-renewal process that is the hallmark of cancer-initiating stem cells. At the same time, the compounds had no affect on cell differentiation, which is the normal process of cell development.

“This shows that these compounds are not toxic to normal breast tissue,” Kakarala says. “Women at high risk of breast cancer right now can choose to take the drugs tamoxifen or raloxifene for prevention, but most women won’t take these drugs because there is too much toxicity. The concept that dietary compounds can help is attractive, and curcumin and piperine appear to have very low toxicity.”

Curcumin and piperine have been explored by other researchers as a potential cancer treatment. But this paper, published online in the journal Breast Cancer Research and Treatment, is the first to suggest these dietary compounds could prevent cancer by targeting stem cells.

In addition, tamoxifen or raloxifene are designed to affect estrogen, which is a factor in most, but not all breast cancers. In fact, the aggressive tumors that tend to occur more often in women with a family history or genetic susceptibility are typically not affected by estrogen. Because curcumin and piperine limit the self renewal of stem cells, they would impact cancers that are not estrogen sensitive as well as those that are.

Researchers are planning an initial Phase I clinical trial to determine what dose of curcumin or piperine can be tolerated in people. The trial is not expected to begin accruing participants until spring.

Breast cancer statistics: 194,280 Americans will be diagnosed with breast cancer this year and 40,610 will die from the disease, according to the American Cancer Society

Additional authors: Dean Brenner, Hasan Korkaya, Connie Cheng, Karim Tazi, Christophe Ginestier, Suling Liu, Gabriel Dontu and Max Wicha, all from U-M

Feeding the World : Organic Production Delivers

Today's global population is around six billion people, and our dominant form of agriculture is based on using synthetic chemical inputs to produce high-yielding monocultures. Crops such as corn, wheat and soya are grown to be processed into foods for people, or for animals that then suffer short, miserable lives in factory conditions, before being fed to people as well.

According to population experts, by 2050 there will be nine billion of us. If our government-agreed target on greenhouse gas (GHG) is to be met, we will also have cut emissions by 80%. Oil and phosphate supplies, on which much modern agriculture is heavily dependent, will be tow. Climate change will present all kinds of challenges - with extreme and unpredictable weather events, increased flooding and drought. How can we meet the challenge of feeding more people in what will undoubtedly be a more resource-constrained and 'climate-difficult' future?

The current picture

Farming, food, forestry and land use change are together responsible for a third of total GHG emissions according to the International Panel on Climate Change (IPCC). Particularly in developed countries, a significant proportion of agricultural GHG emissions are nitrous oxide (N20), arising from the manufacture and use of artificial nitrogen fertiliser - N20 is around 300 times more powerful a GHG than CO2. However, the most significant GHG emissions associated with agriculture come from converting forests and permanent grassland to cropland, because this releases carbon stored in the soil.

Taking account of carbon stored in soil is vitally important when assessing the environmental impact of agriculture. Globally our soils are a carbon sink that hold more than five times as much carbon as all our forests. Organic farming, with its reliance on pasture rotation, grazing manure and compost to build fertility, generally stores more soil organic matter (and therefore carbon) than intensive farming, with its reliance on synthetic fertiliser. But because intensive systems currently dominate global systems, our soil is not sequestering as much carbon as it easil, could - Professor Pete Smith from the University of Aberdeen, who lead the agriculture work for the IPCC, estimates that better soil management could take around 4,000 million tons of CO2 out the atmosphere; a 'no brainer' he says in terms of trying to cut our GHG emissions.

Historically, the environmental cost of intensive agriculture has been justified by the high yields that such systems have produced. The policy of maximising food production has its origins in the food shortages caused by World War II. And modern methods do produce a lot of food; global increased yields have seen food production more than double since 1950 - all be it by an increasing inefficient use of non-renewable resources (oil at mineral phosphates, for example), and at huge cocost to our soil, water, wildlife and environment.

The problem is that much of this food has been produced in the developed world, with the help of subsidy that has the effect of reducing global prices - sometimes below the cost of production. Exporting these subsidised surpluses has frequently had the effect of making it impossible for farmers in developing countries to sell what they produce at a reasonable price. Intensive farming has gone hand in hand with increased control of the food chain by a smaller number of large companies (although many thriving small and artisan producers are increasingly bucking this trend).

Farmers in the global South haven't been able to compete on price, so have been encouraged, often through active development policy, to rely on growing cash-crops for export in order to earn enough to buy the food they need to eat. Today, while there is more than enough food in the world to feed us all comfortably, around one billion people in the developing world are going hungry each day.

Radical change?

If change to our food and farming systems is needed in the wake of the 'perfect storm of population growth, climate change, diet related ill-health and diminishing resources, what should it look like? The bio-tech and agribusiness sectors have not been slow to suggest that even more intensification of agriculture, based on new technology such as genetic modification (GM), is the only way to guarantee higher yields.

The aphorism that only GM and high-input farming can drive high-yields is accepted by many policy makers. However, this assumption isn't backed up by evidence. In recent years several studies have started to examine how yields in organic and low-input systems compare to intensive systems of farming. In 2006 a paper by Catherine Badgley found that, while yields from organic systems in temperate regions were typically 9% less than in non-organic systems, in. tropical regions, organic agriculture can increase yields by over 50%, with the possibility of more than doubling the production of some types of food. A report in 2006, by the UN Conference on Trade and Development (UNCTAD), based on 114 studies in Africa, found that organic agriculture could increase yields by up to 116% - more than double.

Combined with ecological, environmental and social benefits, the report was clear that these yields meant organic agriculture in the developing world could guarantee both food supply and equitable development.

This evidence is backed by Gathuru Mburu, the director of the Institute for Culture and Ecology (ICE) in Kenya, who has been working with communities in the Lari Division of central Kenya to move away from farming tea for export, and towards using indigenous seeds and plant varieties to organically farm food for consumption. 'The community was growing tea, in order to sell it and then buy food,' Mburu explains. 'But they weren't receiving enough income to cover their costs, because the price was controlled by the global market. We've encouraged them to take control by growing food to eat.' In 18 months since they started the project, the 100 or so households have produced enough surplus to sell at the local market; this in a time when 10 million Kenyans are heading towards famine brought on by the failure of the (intensively farmed, non-indigenous) maize crop.

Hand Sanitizer: Good Hygiene or Just Hype?

The H1N1 flu pandemic has made cleanliness a national obsession. From classrooms to theme parks, Americans are being reminded to wash their hands to prevent the spread of the flu.

But when soap and a sink aren't close by, people rely on the convenience of hand sanitizer.

Sales of the disinfecting gel are soaring, up more than 70 percent since this time last year, according to research by the Nielsen Company.

Casey Beard is a self-proclaimed "germ freak" who uses hand sanitizer up to 40 times a day. He keeps bottles in his bathroom, kitchen, bedroom and car. He even went as far as purchasing hand sanitizer for colleagues at his office. While he's always been wary of germs, reports of the H1N1 virus have made him even more diligent about hygiene.

"I hate shaking people's hands who I know are sick, but if they're not visibly sick or audibly sick, I'm completely OK with it -- because I have hand sanitizer everywhere," he said.

He uses it most frequently when commuting to work or traveling, but he's even careful to use it in his own car.

"The second I get in the car, I like to do a squirt there and rub it on my steering wheel," he said.

His methods may seem excessive, but it's hard to argue with the result.

"I haven't been sick in three years," said Beard.
Sandra Turco is the mother of two daughters, and she keeps the hand sanitizer close at all times.

In the wake of the H1N1 flu outbreak, she's focused on keeping her family healthy. She reminds her eight-year-old daughter to use hand sanitizer during the school day, especially before recess and when she gets off the school bus.

Turco's daughter Allesandra is well trained.

"She said use it a lot," Allesandra said. "It's sort of a pain because mommy always tells me to."

"We have not been sick, knock on wood," said Turco. "So far, we've had a lot of friends who have had the H1N1 [virus], so we were exposed to them. And I'm not sure if it was the hand sanitizer that did it, but we're still healthy and going strong."

How Clean Is Your Drinking Water?

Officials from the U.S. Environmental Protection Agency were under fire today as members of Congress demanded an explanation into reports that the agency has not enforced violations of the Safe Drinking Water Act.

The enforcement chief at the EPA responded by announcing new enforcement protocols designed to determine the most serious and repeating water pollution offenders and established a new mechanism to hold violators responsible.

"The new enforcement approach that we announced today is intended to target the violations that we find," Cynthia Giles, assistant administrator for enforcement and compliance assurance at the EPA, said. "What we are doing is implementing a targeting system that will identify the health threats where there's violation of health-based standards, and especially where there's been repeated violations at a system, and put those to the top of the list for enforcement potential."
The chairwoman of the Senate Environmental and Public Works Committee, Sen. Barbara Boxer, D-Calif., dismissed Giles' plan as "bureaucratic rhetoric," emphasizing that state and local water quality agencies are the first line of defense to ensure the water is safe enough to drink.

"We already know kids are being exposed to these contaminants and they're deadly and we already know there are problems," Boxer said. "We're not tracking schools, we're tracking public systems. And we don't know which public systems serve the schools. I need a lot more specificity from you. I'm not confident that we are now ready to go."

The Safe Drinking Water Act of 1974 does not authorize the EPA to monitor schools directly. Instead, the agency depends on the schools' water providers to comply with its monitoring requirements, and it relies on states to enforce violations.

A New York Times report published today said that more than 49 million people in the United States were exposed to drinking water containing illegal concentrations of chemicals like arsenic and radioactive substances, such as uranium. The report also found that just 6 percent of drinking water violations were actually enforced since 2004.

10 December 2009

Pregnant Women's Bodies Polluted With Chemicals Found In Consumer Products

The "Earliest Exposures" study, a research project conducted by Washington Toxics Coalition in collaboration with the Commonweal Biomonitoring Resource Center and the Toxic-Free Legacy Coalition found pregnant women's bodies were polluted with chemicals found in consumer products. This first-of-its kind study investigated the living environment of nine fetuses through testing the blood and urine of the nine mothers taking part in the biomonitoring study. Tests measured the levels of five chemical groups, including phthalates, mercury, perfluorinated compounds or "Teflon chemicals," bisphenol A (BPA), and the flame retardant tetrabromobisphenol A.

The women, all in their second trimester, were all found to have BPA, phthalates, mercury, and "Teflon chemicals" in their bodies. Cause for concern is that these toxic chemicals, known to disrupt development and hormonal systems cross the placenta and are absorbed by the fetus. They not only hinder fetal development, but the growing fetus has limited ability to detoxify these foreign substances.

Of the more than 80,000 chemicals found in consumer products today, only approximately 200 have been tested for safety since the inception of The Toxic Substances Control Act (TSCA) of 1976. Until more strict regulations govern the use of ingredients in consumer products, consumers can take an active role in lowering their toxic exposure. Start by purchasing Phthalate and BPA free products, switching from flame retardant clothing and bedding to organic, and substituting conventional body care for third-party certified organic body care.

Karen Ciesar, Founder and Formulator of Trillium Organics states, "I am sadly not surprised at these findings. The pervasiveness of petrochemicals in the modern world makes avoiding exposures a task which requires research and vigilance. Luckily, there are many non-profit organizations dedicated to informing consumers, some of my favorites are; (searchable database of cosmetic safety), (searchable database of family product safety),, a comprehensive and informative site about environmental exposures, (an activist website about all issues surrounding Organic, food, personal care and fibers). It takes some time and effort to find safe products for your family, but every green purchasing choice you make increases your child's chance at a healthy future in a greener world."

Trillium Organics has recently been endorsed by the Organic Consumers' Association as a "brand to trust" in their recent BUYcott campaign. Trillium Organics has been a leader in the movement for clean, safe personal care since 1994.

LONDON (Reuters) - Measuring body mass index or waist size in overweight people can accurately predict the risk of heart disease, Dutch scientists

A large 10-year study found that half of all fatal heart disease cases and a quarter of all non-fatal cases are linked to being overweight and having a high body mass index (BMI) or large waist.

Body mass index and waist circumference are well known risk factors for cardiovascular diseases but the Dutch researchers said their work showed BMI and waist size could actually help predict the risk of dying from or developing heart disease.

"What this study shows is the substantial effect which (being) overweight and obesity have on cardiovascular disease, whether fatal of non-fatal," said Ineke van Dis from the Netherlands Heart Foundation, who led the study.

"In the near future the impact of obesity on the burden of heart disease will be even greater."

Dis and colleagues at the monitoring project on risk factors for chronic diseases at the Dutch National Institute for Public Health and the Environment measured between both BMI and waist circumference in 20,500 men and women 1993 and 1997.

When age-adjusted BMI and waist sizes were correlated with hospital records and cause-of-death data over 10 years, more than half (53 percent) of all fatal heart disease cases and around a quarter (25-30 percent) of all non-fatal cases were in people defined as overweight and obese.

Overweight people are defined as having a BMI of between 25 and 30 and obese people of 30 or more, according to the World Health Organization (WHO). BMI is calculated by dividing weight in kilograms by height in meters squared.

Waist circumference measurements in men were defined as between 94 and 101.9 cm for overweight and more than 102 cm for obese. In women these measurements were 80-87.9 cm for overweight and more than 88 cm for obese.

Obesity is increasing throughout the world and is now recognized as a major global public health concern.

"These findings underline the need for policies and activities to prevent overweight in the general population," Dis said in the study, which was published in the European Journal of Cardiovascular Prevention and Rehabilitation.

8 December 2009

Breast-feeding may protect moms' health

Breast-feeding may offer mothers long-term protection against a condition linked to diabetes and heart disease, researchers report today.
The longer women breast-fed, the lower their chance of developing metabolic syndrome, a cluster of risk factors such as high blood pressure and high triglycerides associated with obesity, the scientists found.

"Pregnancy may have some adverse effects on some of these cardiovascular risk factors," lead author Erica Gunderson says, "and lactation (breast-feeding) may offset some of these effects."

The impact of breast-feeding on the risk of metabolic syndrome was "slightly stronger" in women who'd had gestational — or pregnancy-induced — diabetes, says Gunderson, an epidemiologist and research scientist at Kaiser Permanente's Division of Research in Oakland. "This is the first study to really look at lactation and the metabolic syndrome in women with GDM (gestational diabetes)."

Kavitha T. Ram, a New York Medical College obstetrician/gynecologist, called the study's suggestion that breast-feeding might reverse the metabolic changes associated with gestational diabetes exciting. "There's this emerging evidence that breast-feeding may confer long-term health benefits to the mom," says Ram, who wasn't involved in the study.

About 18%-37% of U.S. women ages 20 to 59 have metabolic syndrome, Gunderson says. A study she published in August found women with gestational diabetes are 2½ times more likely than other women to develop the condition after pregnancy.

Gunderson and her co-authors based their new findings on 704 women in an ongoing, government-funded study of heart-disease risk factors. When the women entered the study in 1985-1986, they were ages 18-30 and had never given birth; testing confirmed they didn't have metabolic syndrome.

They all went on to deliver at least one child; only 16% had more than two children. They returned for measurements of metabolic syndrome components seven, 10, 15 and 20 years after entering the study; 120 developed metabolic syndrome.

In women who didn't have gestational diabetes, breast-feeding cut metabolic syndrome risk 39%-56%. In those who did, it cut the risk 44%-86%. In both, the authors write in Diabetes: The Journal of the American Diabetes Association, the longer women breast-fed, the lower their risk.

Breast-feeding is associated with a quicker loss of pregnancy weight, but that's only "a little bit of the explanation," Gunderson says. Another possibility, she says: Breast-feeding might minimize the accumulation of belly fat, fat linked to type 2 diabetes risk.

Green Tea Chemical Combined With Another May Hold Promise for Treatment of Brain Disorders

Scientists at Boston Biomedical Research Institute (BBRI) and the University of Pennsylvania have found that combining two chemicals, one of which is the green tea component EGCG, can prevent and destroy a variety of protein structures known as amyloids. Amyloids are the primary culprits in fatal brain disorders such as Alzheimer's, Huntington's, and Parkinson's diseases. Their study, published in the current issue of Nature Chemical Biology (December 2009), may ultimately contribute to future therapies for these diseases.

"These findings are significant because it is the first time a combination of specific chemicals has successfully destroyed diverse forms of amyloids at the same time," says Dr. Martin Duennwald of BBRI, who co-led the study with Dr. James Shorter of University of Pennsylvania School of Medicine.

For decades a major goal of neurological research has been finding a way to prevent the formation of and to break up and destroy amyloid plaques in the brains and nervous systems of people with Alzheimer's and other degenerative diseases before they wreak havoc.

Amyloid plaques are tightly packed sheets of proteins that infiltrate the brain. These plaques, which are stable and seemingly impenetrable, fill nerve cells or wrap around brain tissues and eventually (as in the case of Alzheimer's) suffocate vital neurons or brain cells, causing loss of memory, language, motor function and eventually premature death.

To date, researchers have had no success in destroying plaques in the human brain and only minimal success in the laboratory. One reason for these difficulties in finding compounds that can dissolve amyloids is their immense stability and their complex composition.

Yet, Duennwald experienced success in previous studies when he exposed amyloids in living yeast cells to EGCG. Furthermore, he and his collaborators also found before that DAPH-12, too, inhibits amyloid production in yeast.

In their new study, the team decided to look in more detail at the impact of these two chemicals on the production of different amyloids produced by the yeast amyloid protein known as PSI+. They chose this yeast amyloid protein because it has been studied extensively in the past, and because it produces varieties of amyloid structures that are prototypes of those found in the damaged human brain. Thus, PSI+ amyloids are excellent experimental paradigms to study basic properties of all amyloid proteins.

The team's first step was to expose two different amyloid structures produced by yeast (e.g., a weak version and a strong version) to EGCG. They found that the EGCG effectively dissolved the amyloids in the weaker version. To their surprise, they found that the stronger amyloids were not dissolved and that some transformed to even stronger versions after exposure to EGCG.

The team then exposed the yeast amyloid structures to a combination of the EGCG and the DAPH-12 and found that all of the amyloid structures broke apart and dissolved.

The next steps for the research team will be to explore the mechanism and potency of such a combinatorial therapy for the treatment of diverse neurodegenerative diseases.

"Our findings are certainly preliminary and we need further work to fully comprehend the effects of EGCG in combination with other chemicals on amyloids. Yet, we see our study as a very exciting initial step towards combinatorial therapies for the treatment of amyloid-based diseases," says Duennwald.

Cigarette smoking increases colorectal cancer risk

PHILADELPHIA – New study results strengthen the evidence that people who smoke cigarettes over a long period of time have an increased risk for developing colorectal cancer, even after adjusting for other risk factors.

"This provides one more reason not to smoke, or to quit as soon as possible," said senior author Michael J. Thun, M.D., M.S., vice president emeritus, epidemiology and surveillance research at the American Cancer Society. "Colorectal cancer should be added to the list of cancers caused by smoking."

Findings are published in the December issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, as part of a special focus on tobacco.

Thun and colleagues tested the association between long-term cigarette smoking and colorectal cancer after adjusting for multiple other factors that are generally associated with risk, including screening. From 1992 through 2005 the researchers followed almost 185,000 participants aged 50 to 74 years old; participants described their behaviors and medical conditions.

Participants who smoked cigarettes for 40 or more years, or who did not quit before age 40, had a 30 percent to 50 percent increased risk of developing colon or rectal cancer during the follow-up, even in analyses that adjusted for 13 other potential risk factors, according to Thun. After 13 years of follow-up, the researchers identified 1,962 cases of invasive colorectal cancer.

While previous large studies conducted in long-term smokers showed similar results, Thun stated that this study is the first to control for screening and all of the suspected risk factors for colorectal cancer, such as alcohol consumption, physical inactivity and consumption of red or processed meat.

"These findings contributed to the evidence recently reviewed by the International Agency for Research on Cancer (IARC) in October of this year," Thun said. "IARC upgraded the evidence that smoking causes colorectal cancer from 'limited' to 'sufficient'."

This IARC reclassification brings the number of cancer organ sites causally related to cigarette use to 17, which includes cancers of the oral cavity, pharynx, nasopharynx, nasal cavity and paranasal sinuses, larynx, lung, esophagus (both squamous cell and adenocarcinoma), stomach, colorectum, liver, pancreas, kidney (both renal cell and transitional cell carcinoma), urinary bladder and lower urinary tract, uterine, cervix, and myeloid leukemia.

7 December 2009

Calcium and vit D show promise for colorectal health

Supplements of calcium and vitamin D may promote the health of the cells in the colon and rectum, offering potential protection from tumour development, says a new study.

The mineral-vitamin combination was found to normalise the health of cells in the colon and rectum, according to findings published in Cancer Epidemiology, Biomarkers & Prevention.

Researchers from Emory University, the University of Minnesota, and the National Cancer Institute and the National Institutes of Health conducted a pilot, randomized, double-blind, placebo-controlled, clinical trial in 92 men and women with a history of benign colorectal tumours.

Led by Veronika Fedirko, the researchers randomly assigned the participants to receive daily calcium (2.0 g) and/or vitamin D3 supplements (800 IU), or placebo for six months.

Markers of the health of cells were found to increase by 201, 242, and 25 per cent in the calcium, vitamin D, and calcium plus vitamin D groups relative to the placebo, said the researchers.

“These results indicate that calcium and vitamin D promote colorectal epithelial cell differentiation and may ‘normalize’ the colorectal crypt proliferative zone in sporadic adenoma patients, and support further investigation of calcium and vitamin D as chemopreventive agents against colorectal neoplasms,” wrote Febirko and her co-workers.

A wider view of the science

The potential benefits for the vitamin-mineral combination in relation to colorectal cancer is somewhat controversial, with some studies reporting benefits while others report null results.

Indeed, back in 2006 results from the Women's Health Initiative (WHI) stated that daily supplements of vitamin D and calcium 'had no effect' on the risk of colorectal cancer. The results were questioned however and independent cancer experts said at the time that the claims should be interpreted in the light of the complexities of the study.

Michele Forman and Bernard Levin from the MD Anderson Cancer Center at the University of Texas, noted that the WHI trial had three overlapping components, with 69 per cent of the women enrolled on the Dietary Modification trial, 54 per cent enrolled on the Hormone Therapy trial, and 14 per cent enrolled on both.

"The enrolment in three overlapping trials maximised the participation and size of the WHI trial but created a complex approach with potential confounders for biological interpretation," said Forman and Levin.

Colorectal cancer accounts for nine per cent of new cancer cases every year worldwide. The highest incidence rates are in the developed world, while Asia and Africa have the lowest incidence rates.

It remains one of the most curable cancers if diagnosis is made early.