All Posts tagged cancer

Most Brits are “replete’ in iron

A UK report has found most Brits gain adequate levels of iron, but warned that the elderly, small children, girls, some women and the poor may be susceptible to deficiencies and should consider iron supplementation among other measures. “While most people in the UK are iron replete, health professionals need to be alert to increased risk of iron deficiency anaemia in toddlers, girls and women of reproductive age (particularly those from low income groups) and some adults aged over 65 years,” wrote the Scientific Advisory Committee on Nutrition’s Committee on Medical Aspects of Food and Nutrition Policy (COMA).

“Those with symptoms suggesting iron deficiency anaemia should receive appropriate clinical assessment and advice, including dietary advice on how to increase their iron intakes and to consider use of iron supplements if required.” The report updated COMA’s 1998 finding that high levels of red meat consumption were linked to colorectal cancer and also investigated the effects of reduced iron-rich red meat consumption. COMA concluded that a, “healthy balanced diet, which includes a variety of foods containing iron” is the best way to attain, “adequate iron status”.

“Such an approach is more important than consuming iron-rich foods at the same time as foods/drinks that enhance iron absorption (e.g., fruit juice, meat) or not consuming iron rich foods with those that inhibit iron absorption (e.g., tea, coffee, milk),” the committee said.

On the issue or red meat consumption COMA found that reduced red meat consumption levels would not cause widespread iron deficiencies. “Adults with relatively high intakes of red and processed meat (around 90 g/day or more) should consider reducing their intakes. A reduction to the UK population average for adult consumers (70 g/day cooked weight) would have little impact on the proportion of the adult population with low iron intakes.”

Current UK guidelines state that 3.2 oz (90g) is a healthy daily portion of red meat, and that only those who eat more than 5oz (140g) need to cut back. However some research has challenged these levels. A 2005 European study found those who regularly eat more than 5.6oz (160g) of red meat daily increase their risk of contracting bowel cancer by a third. In 2007, the World Cancer Research Fund report in 2007 concluded that there was a link between red meat consumption and an increased risk of bowel cancer.

The COMA report follows research from the British Nutrition Foundation (BNF) which contradicts these recommendations

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Tomatoes Fight Cholesterol

If you want to wage battle against cholesterol and other lipids (fat) that can contribute to vascular disease, then make tomatoes a big part of your diet. Scientists say this popular fruit contains a nutrient that can fight vascular disease such as stroke and arteriosclerosis.

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Tomatoes fight more than cholesterol and fat

Excessive levels of lipids, such as cholesterol and triglycerides in the bloodstream, a condition known as dyslipidemia, can lead to potentially deadly diseases such as arteriosclerosis, cirrhosis, and stroke. Scientists from Kyoto University and New Bio-industry Initiatives, Japan, report that a compound called 9-oxo-octadecadienoic extracted from tomatoes can boost oxidation of fatty acids and contribute to the regulation of lipid metabolism by the liver. These qualities indicate that 9-oxo-octadecadienoic acid can fight cholesterol and other lipids and therefore help prevent vascular diseases.

Vascular disease is a general term used to describe diseases that affect the blood vessels. The Vascular Disease Foundation offers information on nearly two dozen different conditions that fit this category, including abdominal aortic aneurysm, carotid artery disease, deep vein thrombosis, lymphedema, peripheral artery disease, and stroke.

Tomatoes are also valued for other health benefits. Much research has been dedicated to a potent antioxidant in tomatoes, lycopene, and its potential in the fight against various types of cancer, and especially prostate cancer. Tomatoes also contain excellent levels of other nutrients, including niacin, which helps lower cholesterol; and potassium, which reduces blood pressure and the risk of heart disease.

Dr. Teruo Kawada, who is from Kyoto University and who led the study, noted that “Finding a compound which helps the prevention of obesity-related chronic diseases in foodstuffs is a great advantage to tackling these diseases. It means that the tomato allows people to easily manage the onset of dyslipidemia through their daily diet.” To help the fight against cholesterol and other fats that contribute to vascular disease, enjoy more tomatoes.

SOURCES:
Kim YI et al. Molecular Nutrition & Food Research doi:10.1002/mnfr.201000264

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Yet another benefit of green tea

For thousands of years, the people of China, Japan, India, and Thailand have consumed green tea and used it medicinally to treat everything from headaches to heart diseases. Over the past few decades, however, research in both Asia and the West have taken place providing scientific evidence of green tea’s numerous health benefits. As a whole, studies indicate that regular consumption of green tea may slow or prevent conditions including high cholesterol, heart disease, arthritis, impaired immune disease and liver disease. In yet another recent study on the beverage’s healthful properties, published in the academic journal Phytomedicine, researchers have found evidence that enzymes in the drink may help in fighting Alzheimer’s and other forms of dementia.

Researchers at the Newcastle University have also found that the Chinese brew may also play a vital role in guarding against cancer. The Newcastle team focused on whether or not once the tea was in the digestive system if the protective properties were still as effective. “What was really exciting was that we found when green tea is digested, the resulting chemicals are actually more effective against key triggers of Alzheimer’s,” said Ed Okello, from the university’s School of Agriculture, Food and Rural Development. “The digested compounds also had anti-cancer properties, significantly slowing down the growth of tumour cells which we were using in our experiments,” Okello said.

Previous studies have shown that polyphenols, present in black and green tea, bind with the toxic compounds and protect brain cells. When ingested, the polyphenols are broken down to produce a mix of compounds and it was these the team tested in their research. According to Okello, there are many factors that together have an influence on diseases such as cancer and dementia – a good diet, plenty of exercise and a healthy lifestyle are all important. “But I think it’s fair to say that at least one cup of green tea a day may be good for you and I would certainly recommend it,” he added.

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Simple steps to prevent cancer

About a third of some of the most common forms of cancer could be prevented through healthy diet, physical fitness, and limiting alcohol intake, the American Institute for Cancer Research and the World Cancer Research Fund say in a new report. About 7.6 million people die from cancer every year worldwide, and 12.7 million new cases are diagnosed. According to the Union for International Cancer Control, a third of cancer cases could be cured through early diagnosis and treatment and 30% to 40% could be prevented. About 340,000 cases of cancer could be prevented annually in the U.S. if more people started eating a varied and healthy diet, started a regimen of physical activity, limited alcohol intake, and maintained a healthy weight, the new report says.

“Physical activity is recommended for people of all ages as a means to reduce risks for certain types of cancers and other non-communicable diseases,” says Tim Armstrong, MD, of the World Health Organization, says in a news release. “In order to improve their health and prevent several diseases, adults should do at least 150 minutes moderate physical activity throughout the week. This can be achieved by simply walking 30 minutes five times per week or by cycling to work daily.”

To reduce cancer risk, people also should quit smoking, avoid excessive sun exposure, and protect themselves against cancer-causing infections.

Tim Byers, MD, MPH, of the Colorado School of Public Health, says scientists urge Americans “to make the simple lifestyle changes of eating healthy food, getting regular physical activity, and maintaining a healthy weight to reduce cancer risk.” The World Cancer Declaration outlines 11 targets it says could be achieved by 2020 to fight cancer. These goals include: significant drops in global tobacco use, obesity, and alcohol intake; universal vaccination programs for hepatitis B and human papilloma virus (HPV); universal availability of effective pain medication; and efforts to dispel misconceptions about cancer. The health organizations say in a detailed report that the most common cancers in the U.S. and Britain are of the breast, colon/rectum, lung, and prostate.

The American Institute for Cancer Research recommends the following cancer-prevention steps.

  • Limit consumption of calorie-dense foods, particularly processed foods high in added sugar, low in fiber, or high in fat.
  • Avoid sugary drinks.
  • Eat more of a variety of vegetables, fruits, whole grains, and beans.
  • Limit consumption of red meats such as beef, pork, and lamb, and avoid processed meats.
  • Limit consumption of salty foods and foods processed with sodium.
  • Dietary supplements for lowering cancer risk are not recommended.
  • Be as lean as possible without becoming underweight.
  • Be physically active for 30 minutes or more every day.
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Does milk fight bowel cancer

The study was carried out by researchers from University of Otago Medical School, New Zealand. Funding was provided by Genesis Oncology Trust, the Dean’s Bequest Funds of the Dunedin School of Medicine, the Gisborne East Coast Cancer Research Trust and the Director’s Cancer Research Trust. The research was published in the peer-reviewed American Journal of Epidemiology. This was a case-control study in New Zealand that compared a group of adults with bowel cancer, and a group without bowel cancer, and looked at whether they drank milk at school. School milk was freely available in most schools in New Zealand until 1967 when the government programme was stopped. Many schools in the Southland region stopped free milk as long ago as 1950.

Case-control studies are appropriate for looking at whether people with and without a disease have had a particular exposure (milk in this case). The difficulty is in accounting for all potential confounding factors, particularly other health and lifestyle factors, which could be related to both diet and bowel cancer risk, for example regular childhood milk consumption could be a reflection of a ‘healthy’ diet and other healthy lifestyle behaviours that may reduce risk of cancer. In addition, when examining such a specific dietary factor – ie milk consumed in school – it is difficult to account for all possible milk or other dairy products consumed outside of school.

In this case-control study, 562 adults (aged 30 to 69) with newly diagnosed bowel cancer were identified from the New Zealand Cancer Registry in 2007. For a control group, 571 age-matched adults without cancer were randomly selected from the electoral register. All participants were mailed a questionnaire that asked about any previous illness, use of aspirin or dietary supplements in childhood, participation in school milk programmes, other childhood milk consumption, childhood diet (including other milk and dairy), smoking, alcohol consumption prior to 25 years of age, screening tests for bowel cancer, family history of cancer, education and sociodemographic characteristics. Childhood weight and height were not questioned. For school milk consumption they were specifically asked:

  • Whether they drank school milk
  • How many half-pint bottles they drank a week
  • What age they first drank school milk
  • When they stopped drinking school milk

Statistical risk associations between school milk participation and cancer were calculated. The calculations took into account several risk factors for bowel cancer risk including age, sex, ethnicity and family history.

What were the basic results?

Data on school milk consumption was available for 552 cases and 569 controls. As expected, people who started school before 1967 were more likely to have had free school milk than those who began school after 1968. Seventy-eight percent of cases participated in the school milk programme compared with 82% of controls. School milk consumption was associated with a 30% reduced risk of developing bowel cancer (odds ratio 0.70, 95% confidence interval 0.51 to 0.96).

When looking at the effect of number of bottles consumed per week they found that compared with no bottles, five bottles per week was associated with 32% significantly decreased risk, and 10 or more bottles with 61% significantly decreased risk. However, there was no significant association with one to four bottles or six to nine bottles. The researchers found a similar trend when the total school consumption of milk was compared with no consumption: 1,200-1,599 bottles was associated with 38% significantly decreased risk; 1,600-1,799 with 43% decreased risk; and 1,800 or more bottles associated with 38% significantly decreased risk. There was no significant association with fewer than 1,200 bottles. The researchers calculated that for every 100 half-pint bottles consumed at school there was a 2.1% reduction in the risk of bowel cancer. Outside of school, there was a significantly reduced risk of bowel cancer with more than 20 dairy products a week compared with none to nine dairy products a week.

The researchers conclude that their national case-control study ‘provides evidence that school milk consumption was associated with a reduction in the risk of adult colorectal cancer in New Zealand. Furthermore, a dose-dependent relation was evident’. This study has strengths in its relatively large size, its reliable and nationally representative identification of cases and controls, and its thorough data collection. However, the conclusion that school milk consumption is associated with a reduced risk of bowel cancer in adulthood must be interpreted in light of a number of considerations:

The analysis took into account established risk factors for bowel cancer including age, sex, ethnicity and family history. However, many other potential confounders were not considered, including diet, physical activity, overweight and obesity, smoking or alcohol consumption. Diet in particular has been implicated in bowel cancer risk, with diets high in saturated fat, red meat and processed foods and low in fibre, fruit and vegetables thought to increase risk. Potentially, any of these lifestyle behaviours could be confounding the relationship between school milk consumption and bowel cancer and regular childhood milk consumption could be a reflection of a ‘healthy’ diet and other healthy lifestyle behaviours that reduce risk of cancer. When looking at the effect of number of bottles consumed per week, the researchers found that, compared with no bottles, five bottles were associated with 32% significantly decreased risk and 10 or more bottles with 61% significantly decreased risk. However, there was no significant association with one to four bottles or six to nine bottles. Therefore, the trend here is not very clear. Particularly as only 16 cases and 31 controls drank 10 or more bottles a week, statistical comparison between such small numbers should be viewed with caution. With many food questionnaires there is the potential for recall bias. For example, adults may have difficulty remembering how many bottles of school milk they drank many years before. When estimating their average weekly amount, it is highly possible that this could be inaccurate or that their consumption varied slightly from week to week and year to year. Particularly when researchers were using this response and combining it with the number of weeks in the school year and their total years at school to give a total number of bottles consumed at school (figures in 100s or 1,000s), there is the possibility of being incorrectly categorised. Hence, there may be less reliability when calculating risk according to the category of total milk bottles consumed. Cancer prevalence, and particularly environmental and lifestyle risk factors for cancer, can vary between countries. These findings in New Zealand may not be represented elsewhere. Of note, the researchers acknowledge that a cohort study in the UK found the opposite: increased childhood dairy consumption was associated with increased risk of bowel cancer. Case-control studies are most appropriate for looking at rare diseases, where you would expect there to be only a small number of cases developing among a large number of people. In the case of bowel cancer, which is common, the slightly more reliable cohort design could have also been used, where children who drank milk at school and those who didn’t were followed over time to see if they developed cancer. However, such a cohort would consequently need extensive long-term follow-up.

The possible association between milk/dairy consumption, or calcium intake, in childhood, or in later years, is worthy of further study. However, from this study alone, it cannot be concluded that school milk prevents bowel cancer later in life.

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Protective properties of green tea

Regularly drinking green tea could protect the brain against developing Alzheimer’s and other forms of dementia. The study, published in the academic journal Phytomedicine, also suggests this ancient Chinese remedy could play a vital role in protecting the body against cancer. Led by Dr Ed Okello, the Newcastle team wanted to know if the protective properties of green tea – which have previously been shown to be present in the undigested, freshly brewed form of the drink – were still active once the tea had been digested. Digestion is a vital process which provides our bodies with the nutrients we need to survive. But, says Dr Okello, it also means that just because the food we put into our mouths is generally accepted to contain health-boosting properties, we can’t assume these compounds will ever be absorbed by the body.

“What was really exciting about this study was that we found when green tea is digested by enzymes in the gut, the resulting chemicals are actually more effective against key triggers of Alzheimer’s development than the undigested form of the tea,” explains Dr Okello, based in the School of Agriculture, Food and Rural Development at Newcastle University and executive director of the university’s Medicinal Plant Research Group. “In addition to this, we also found the digested compounds had anti-cancer properties, significantly slowing down the growth of the tumour cells which we were using in our experiments.”

As part of the research, the Newcastle team worked in collaboration with Dr Gordon McDougall of the Plant Products and Food Quality Group at the Scottish Crop Research Institute in Dundee, who developed technology which simulates the human digestive system. It is this which made it possible for the team to analyse the protective properties of the products of digestion. Two compounds are known to play a significant role in the development of Alzheimer’s disease – hydrogen peroxide and a protein known as beta-amyloid. Previous studies have shown that compounds known as polyphenols, present in black and green tea, possess neuroprotective properties, binding with the toxic compounds and protecting the brain cells.

When ingested, the polyphenols are broken down to produce a mix of compounds and it was these the Newcastle team tested in their latest research. “It’s one of the reasons why we have to be so careful when we make claims about the health benefits of various foods and supplements,” explains Dr Okello. “There are certain chemicals we know to be beneficial and we can identify foods which are rich in them but what happens during the digestion process is crucial to whether these foods are actually doing us any good.” Carrying out the experiments in the lab using a tumour cell model, they exposed the cells to varying concentrations of the different toxins and the digested green tea compounds.

Dr Okello explained: “The digested chemicals protected the cells, preventing the toxins from destroying the cells. “We also saw them affecting the cancer cells, significantly slowing down their growth. Green tea has been used in Traditional Chinese medicine for centuries and what we have here provides the scientific evidence why it may be effective against some of the key diseases we face today.”

The next step is to discover whether the beneficial compounds are produced during digestion after healthy human volunteers consume tea polyphenols. The team has already received funding from the Biotechnology and Biological Sciences Research Council (BBSRC) to take this forward. Dr Okello adds: “There are obviously many factors which together have an influence on diseases such as cancer and dementia – a good diet, plenty of exercise and a healthy lifestyle are all important. “But I think it’s fair to say that at least one cup of green tea every day may be good for you and I would certainly recommend it.”

(Source: Newcastle University: Phytomedicine)

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World Cancer Day

Cancer is a leading cause of death around the world. WHO estimates that 84 million people will die of cancer between 2005 and 2015 without intervention. Each year on 4 February, WHO supports International Union Against Cancer to promote ways to ease the global burden of cancer. Preventing cancer and raising quality of life for cancer patients are recurring themes.

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Age related protein linked to cancer

Age related protein linked to cancer

The most common type of breast cancer in older women — estrogen and progesterone receptor (ER/PR) positive breast cancer — has been linked to a protein that fends off aging-related cellular damage. A new study led by Vanderbilt-Ingram Cancer Center researcher David Gius, M.D., Ph.D., now shows how a deficiency in this aging-associated protein may set the stage for these tumors to develop.

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The findings, published in Molecular Cell, provide information that could assist in the screening, prevention and treatment of these common age-related cancers. While the young are certainly not spared cancer’s wrath, cancer is primarily a disease of aging, with the majority of cases occurring in people over 50. However, the biological processes that underlie this association are not clear.

“The connection between aging and cancer is one of the most established phenomena in cancer research,” said Gius, associate professor of Cancer Biology, Pediatrics and Radiation Oncology. “The problem to address this clinically significant question is that this field lacks in vivo models to study this.”

In the late-1990s, proteins called “sirtuins” were linked to extended lifespan observed in several species maintained on a calorically restricted diet. These nutrient-sensing sirtuin proteins seemed to defend against aging-related cellular damage. Sirtuins are present in all living organisms, with humans having seven different sirtuin proteins. “When (the sirtuins) were discovered, it seemed obvious to conclude that there might be a mechanistic connection between the genes that determine length of survival and cancer,” Gius said. Previously, while at the National Cancer Institute, Gius and colleagues created mice lacking some of these sirtuins.

They reported last January in Cancer Cell that when they knocked out Sirt3 — a sirtuin localized in the mitochondria, the cellular “power plants” — the mice developed ER/PR positive breast tumors, the most common type of breast cancer in postmenopausal women. These tumors also exhibited increased levels of damaging free radicals and “reactive oxygen species” (ROS) — including superoxide, the primary metabolite of oxygen in the mitochondria — which provided an important clue as to how Sirt3 deficiency might permit these tumors to develop. “The mechanism, at least in part, for why these mice develop receptor positive breast cancer is altered mitochondrial ROS, including superoxide,” Gius said. But how deficiency in a longevity gene led to increased ROS was not clear. Since superoxide is generally removed from the cell with the help of a detoxifying enzyme called manganese superoxide dismutase (MnSOD), Gius hypothesized that the Sirt3 deficiency may abnormally regulate MnSOD.

In the current study, the researchers show that Sirt3 knockout mice have decreased MnSOD activity despite having normal levels of the protein. Gius and colleagues determined that the MnSOD in Sirt3 knockout mice was abnormally modified (with a chemical “acetyl” group) at a specific amino acid (lysine 122). This aberrant modification of MnSOD reduced the enzyme’s ability to detoxify superoxide and appeared to explain the increase in ROS in Sirt3 knockout mouse tumors. “These results suggest that aberrant regulation of MnSOD plays a role in receptor positive breast cancer,” said Gius.

Gius and colleagues also developed an antibody that can assess the acetylation status of MnSOD, which he says can potentially be used “to screen breast tissue samples to determine what women are at risk for (receptor positive) cancer or for recurrence because of this dysregulation of MnSOD.” Additionally, agents that target the acetylation of this amino acid on MnSOD may be useful as chemopreventive therapies in women at risk of these cancers and of recurrence, he noted. The research was supported by grants from the National Cancer Institute and the Department of Defense.

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Social ties help breast cancer

Breast cancer patients who have a strong social support system in the first year after diagnosis are less likely to die or have a recurrence of cancer, according to new research from investigators at Vanderbilt-Ingram Cancer Center and the Shanghai Institute of Preventive Medicine. The study, led by first author Meira Epplein, Ph.D., assistant professor of Medicine, was published in a recent edition of the Journal of Clinical Oncology.

 

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Patients in the study were enrolled in the Shanghai Breast Cancer Survivor Study, a large, population-based review of female breast cancer survivors in China, which Vanderbilt University Medical Center and the Shanghai Institute of Preventive Medicine have carried out since 2002 under the leadership of principal investigator Xiao Ou Shu, M.D., Ph.D., professor of Medicine, and senior author of the study.

From 2002 to 2004, a total of 2,230 breast cancer survivors completed a quality of life survey six months after diagnosis and a majority responded to a follow-up survey 36 months postdiagnosis. The women were asked about physical issues like sleep, eating, pain, psychological well-being, social support and material well-being. The answers were converted to an overall quality of life score. During a median follow-up of 4.8 years after the quality of life assessment, the investigators documented participants who had died or been diagnosed with a cancer recurrence.

Six months after diagnosis, only greater social well-being was significantly associated with a decreased risk of dying or having a cancer recurrence. Compared to women with the lowest scores, women who scored highest on the social well-being quality of life scale had a 48 percent reduction in their risk of a cancer recurrence and a 38 percent reduction in the risk of death.

Among the facets that comprise the social well-being domain, emotional support was the strongest predictor of cancer recurrence. Specifically, women reporting the highest satisfaction with marriage and family had a 43 percent risk reduction, while those with strong social support had a 40 percent risk reduction and those with favorable interpersonal relationships had a 35 percent risk reduction.

“We found that social well-being in the first year after cancer diagnosis is an important prognostic factor for breast cancer recurrence or death,” said Epplein. “This suggests that the opportunity exists for the design of treatment interventions to maintain or enhance social support soon after diagnosis to improve disease outcomes.” While a strong social support network influenced cancer recurrence and mortality during the first year, the association tapered off and was no longer statistically significant by the third year after diagnosis.

This may be related to a smaller sample size of patients who answered the questionnaire, or other factors beyond quality of life that take precedence in the later years of survival. The study was supported by grants from the U.S. Department of Defense Breast Cancer Research Program and the National Cancer Institute.

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Genetic damage minutes after smoking

In research described as “a stark warning” to those tempted to start smoking, scientists are reporting that cigarette smoke begins to cause genetic damage within minutes — not years — after inhalation into the lungs. Their report, the first human study to detail the way certain substances in tobacco cause DNA damage linked to cancer, appears in Chemical Research in Toxicology, one of 38 peer-reviewed scientific journals published by the American Chemical Society.

Stephen S. Hecht, Ph.D., and colleagues point out in the report that lung cancer claims a global toll of 3,000 lives each day, largely as a result of cigarette smoking. Smoking also is linked to at least 18 other types of cancer. Evidence indicates that harmful substances in tobacco smoke termed polycyclic aromatic hydrocarbons, or PAHs, are one of the culprits in causing lung cancer. Until now, however, scientists had not detailed the specific way in which the PAHs in cigarette smoke cause DNA damage in humans.

The scientists added a labeled PAH, phenanthrene, to cigarettes and tracked its fate in 12 volunteers who smoked the cigarettes. They found that phenanthrene quickly forms a toxic substance in the blood known to trash DNA, causing mutations that can cause cancer. The smokers developed maximum levels of the substance in a time frame that surprised even the researchers: Just 15-30 minutes after the volunteers finished smoking. Researchers said the effect is so fast that it’s equivalent to injecting the substance directly into the bloodstream.

“This study is unique,” writes Hecht, an internationally recognized expert on cancer-causing substances found in cigarette smoke and smokeless tobacco. “It is the first to investigate human metabolism of a PAH specifically delivered by inhalation in cigarette smoke, without interference by other sources of exposure such as air pollution or the diet. The results reported here should serve as a stark warning to those who are considering starting to smoke cigarettes,” the article notes. The authors acknowledged funding from the National Cancer Institute.

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