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.
Prostate cancer is the second most common cause of cancer related deaths in men. Previous cell and animal research suggests that genistein, a potent soy isoflavone, may prevent the spread of prostate cancer. Now research reports that a genistein-derived drug may help prevent the spread of prostate cancer in men with prostate cancer.
The study, presented at the Ninth Annual American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, investigated the effect of the genistein-drug in men with localized prostate cancer. Researchers at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University administered the genistein-drug once daily to 38 men with localized prostate cancer one month before prostate surgery.
The participant’s prostate cancer cells were analyzed after surgery. The researchers found an increased expression of genes that stop cancer cell spread (metastasis). Furthermore, there was a decreased expression of genes that enhance metastasis.
“The first step is to see if the drug has the effect that you want on the cells and the prostate, and the answer is ‘yes, it does,'” says lead researcher Raymond Bergan, MD, professor of hematology and oncology at Northwestern University Feinberg School of Medicine, in a news release. “All therapies designed to stop cancer cell movement that have been tested to date in humans have basically failed have because they have been ineffective or toxic. If this drug can effectively stop prostate cancer from moving in the body, theoretically, a similar therapy could have the same effect on the cells of other cancers.”
OTHERWISE healthy teenage girls who diet regularly show worrying signs of malnutrition, Sydney researchers have found. The largest study of its kind shows pressure to be thin could be causing teenage girls serious harm, potentially preventing them from developing properly. The study of 480 girls, between 14 and 17, attending school in Sydney’s northern suburbs and on the central coast, found those who dieted often showed subtle but chronic signs of undernourishment compared to those who occasionally, or never, dieted. The girls were deficient in a number of nutrients and biochemicals, including calcium and protein, as well as haemoglobin, which is vital for transporting oxygen in the blood.
The study leader, Dr Ross Grant, said the teenagers were not getting the nutrients they needed to build their bodies. ”When you get through your adolescent years you should be the healthiest you are ever going to be, and these girls are not giving themselves the best chance to be healthy,” he said. Many students in the study were dieting even though, on average, they were not overweight. ”These are pretty much your average girls on the north shore. They are going to school and they are not unwell in any other way,” Dr Grant said. The low levels of calcium were particularly worrying, he said. ”Calcium is used as a signalling molecule for every cell in the body. If you are not getting enough calcium in your diet then your body starts to get it from wherever it can, which is the bones.”
Most researchers believe the amount of calcium consumed in a person’s teenage years sets the basic level available for the rest of their life. Media messages presenting excessively thin women as having an ideal body shape, or public health campaigns making girls overly aware of not consuming too many calories, could be to blame for dieting, said Dr Grant, who is the head of the Australasian Research Institute at the Sydney Adventist Hospital.
Christine Morgan, the chief executive of the Butterfly Foundation, an eating disorders advocacy group, said she was horrified, but not surprised, by the findings. ”Diets, by their very nature, are telling you to disregard your physiological appetite,” she said. ”These homespun diets result in us not putting the nutrients we need into our bodies.” Disordered eating – irregular eating behaviours that do not fall into the category of an eating disorder – had more than doubled in the past 10 years. ”It has become the norm,” Ms Morgan said.
Women suffering from diabetes plus depression have a greater risk of dying, especially from heart disease, a new study suggests.In fact, women with both conditions have a twofold increased risk of death, researchers say. “People with both conditions are at very high risk of death,” said lead researcher Dr. Frank B. Hu, a professor of medicine at Harvard Medical School. “Those are double whammies.” When people are afflicted by both diseases, these conditions can lead to a “vicious cycle,” Hu said. “People with diabetes are more likely to be depressed, because they are under long-term psychosocial stress, which is associated with diabetes complications.”
People with diabetes plus depression are less likely to take care of themselves and effectively manage their diabetes, he added. “That can lead to complications, which increase the risk of mortality.” Hu stressed that it is important to manage both the diabetes and the depression to lower the mortality risk. “It is possible that these two conditions not only influence each other biologically, but also behaviorally,” he said.
Type 2 diabetes plus depression are often related to unhealthy lifestyles, including smoking, poor diet and lack of exercise, according to the researchers. In addition, depression may trigger changes in the nervous system that adversely affect the heart, they said.
The report is published in the January issue of the Archives of General Psychiatry.
Commenting on the study, Dr. Luigi Meneghini, an associate professor of clinical medicine and director of the Eleanor and Joseph Kosow Diabetes Treatment Center at the Diabetes Research Institute of the University of Miami Miller School of Medicine, said the findings were not surprising.
“The study highlights that there is a clear increase in risk to your health and to your life when you have a combination of diabetes and depression,” he said. Meneghini noted there are many diabetics with undiagnosed depression. “I am willing to bet that there are quite a number of patients with diabetes and depression walking around without a clear diagnosis.” Patients and doctors need to be more aware that depression is an issue, Meneghini added.
For the study, Hu’s team collected data on 78,282 women who were aged 54 to 79 in 2000 and who were participants in the Nurses’ Health Study. Over six years of follow-up, 4,654 women died, including 979 who died of cardiovascular disease, the investigators found. Women who had diabetes had about a 35 percent increased risk of dying, and those with depression had about a 44 percent increased risk, compared with women with neither condition, the researchers calculated. Those with both conditions had about twice the risk of dying, the study authors found.
When Hu’s team looked only at deaths from heart disease, they found that women with diabetes had a 67 percent increased risk of dying and those with depression had a 37 percent increased risk of death. But women who had both diabetes and depression had a 2.7-fold increased risk of dying from heart disease, the researchers noted.
In the United States, some 15 million people suffer from depression and 23.5 million have diabetes, the researchers say. Up to one-fourth of people with diabetes also experience depression, which is nearly twice as many as among people who don’t have diabetes, they added. “The combination of diabetes and depression needs to be addressed,” Meneghini concluded. He added that patients need to tell their doctors if they are feeling depressed, and doctors also need to be on the lookout for signs of depression in their diabetic patients.
SOURCES: HealthDay News; Frank B. Hu, M.D., Ph.D., professor, medicine, Harvard Medical School, Boston; Luigi Meneghini, M.D., associate professor, clinical medicine and director, Eleanor and Joseph Kosow Diabetes Treatment Center, Diabetes Research Institute, University of Miami Miller School of Medicine; January 2011, Archives of General Psychiatry
Primary school children who don't like eating fruit and vegetables are 13 times more likely to develop functional constipation than children who do, according to a study in the December issue of the Journal of Clinical Nursing. Drinking less than 400ml of fluid a day also significantly increases the risk. Dr Moon Fai Chan, assistant professor at the National University of Singapore, teamed up with Yuk Ling Chan, from the Hong Kong Polytechnic University, to study the diet and toileting habits of 383 children aged from eight to ten from a school in Hong Kong. Fifty-one per cent were boys and children who were on regular medication or who paid regular hospital or clinic visits were excluded. Seventy per cent of the children who took part in the study were ten-years-old, 22 per cent were nine and eight per cent were eight.
“A number of studies have suggested that functional constipation – which is due to dietary habits, environmental habits and psychosocial factors rather than a particular health problem – is getting worse among school-age children” says Dr Moon Fai Chan from the Alice Lee Centre for Nursing Study at the University. “It is estimated that functional constipation accounts for 95 per cent of cases of constipation affecting children once they pass infancy. The condition has serious consequences, as it can cause a wide range of distressing emotional and physical problems such as stress, soiling, problems at school, damaged self-confidence and reduced social interaction.”
Key findings of the study included:
- Seven per cent of the children who took part suffered from functional constipation and there were clear dietary differences between the children who did and did not have problems.
- Girls were more likely to have functional constipation than boys (8.2 per cent versus 6.6 per cent) and nine-year-olds were more likely to report problems (13.3 per cent) than eight-year-olds (10 per cent) and ten-year-olds (5.2 per cent).
- Children who only drank 200ml to 400ml of fluid a day were eight times more likely to experience problems than children who drank 600ml to 800ml and 14 times more likely than children who drank a litre or more.
- Children who said they did not like fruit or vegetables were 13 times more likely to suffer from functional constipation than children who did.
- Nine out of ten children refused to use the school toilets for bowel movements and the figure was the same for children with and without constipation.
The biggest problems with school toilets were that children preferred to go at home. They also cited lack of toilet paper and dirty toilets. “When we compared our findings with previous studies we found that the levels of functional constipation among Hong Kong school children was higher than those in the USA and UK, but similar to Italy” says Dr Chan. The authors have made a number of recommendations that they feel would help to tackle the problem. They suggest that:
- Primary schools should work with healthcare professionals to make children more aware of the problem, with regular healthcare education sessions in classrooms and at assemblies.
- Parents need to be educated about functional constipation so that they can spot problems in their children and make sure that their diet provides sufficient fluid, vegetables and fruit. They should also remind their children to pay regular toilet visits at school.
- School tuck-shops should stock high-fibre snacks such as popcorn, fresh food and dried fruit, instead of crisps and sweets.
- Children should be encouraged to drink plain water during lessons and drinking fountains should be installed.
- School toilets should be more user-friendly, private and well stocked with paper so that children feel more comfortable using them.
“We hope that this study will help to raise awareness of functional constipation, which can cause children real physical and emotional distress and seriously affect their quality of life” says Dr Chan.
Source: Investigating factors associated with functional constipation of primary school children in Hong Kong. Chan MF and Chan YL. Journal of Clinical Nursing. 19, pp3390-3400. (December 2010). DOI: 10.1111/j.1365-2702.2010.03366.x
Whole-fat dairy products containing high levels of a natural fatty acid might help lower the risk of type 2 diabetes, according to a recent research by U.S. scientists. A diet rich in milk, cheese, yogurt and butter contains trans-palmitoleic acid which is known to shield against insulin resistance and diabetes. “Our results demonstrate an inverse relationship between levels of trans-palmitoleate and metabolic risk factors and diabetes incidence,” Dariush Mozaffarian, MD, DrPH, of the Harvard School of Public Health, and coauthors wrote in conclusion. “The small differences in trans-palmitoleate levels raise questions about whether this is the active compound or a marker for some other, unknown protective constituent of dairy or other ruminant foods.”
The study looked at 3,736 American seniors from Medicare eligibility lists aged 65 years or older. Physical tests, diagnostic testing, questionnaires on health status, and laboratory evaluation was conducted to evaluate the levels of 45 different fatty acids in the participants. They were further followed for 10 years with the help of annual clinic visits and interim telephone calls.
Trans-palmitoleate was responsible for an average of 0.18 percent of total fatty acid levels, with whole-fat dairy consumption accounting for the highest trans-palmitoleatele proportions. Participants who had consumed high levels of whole-fat dairy products revealed higher levels of trans-palmitoleate acid in their blood three years later, Dariush and his co-authors reported in the December issue of the journal ‘Annals of Internal Medicine.’ Further, participants with the highest levels of the acid circulating in their blood faced two-third the risk of suffering from type 2 diabetes as compared to the ones with the lowest levels. Such people also had lesser fat on their bodies, higher proportions of good cholesterol and lower levels of C-reactive protein.
“This is an extremely strong protective effect, stronger than other things we know can be beneficial against diabetes,” said Gökhan Hotamisligil, the study’s senior author and chair of the department of genetics and complex diseases at Harvard School of Public Health. “The next step is to move forward with an intervention trial to see if there is therapeutic value in people,” he added in a statement.
The research has been funded by the U.S. National Heart, Lung and Blood Institute, the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute of Health Office of Dietary Supplements and National Institute of Neurological Disorders and Stroke.
Researchers from the University of Hull and the Hull York Medical School have found dark chocolate has a significant effect on reducing the symptoms of Chronic Fatigue Syndrome (CFS). The research, published in Nutrition Journal, found that polyphenol rich chocolate eases the condition, with subjects noting significant improvements to their well-being. Chocolate is known to increase neurotransmitters like phenyl ethylamine, serotonin, and anandamide in the brain, but this is the first time that polyphenol rich chocolate in people with CFS has been studied.
Above: Professor Steve Atkin.
Subjects with CFS having severe fatigue of at least 10 out of 11 on Chalder Fatigue Scale were enrolled on the pilot study. Participants were given one of two types of chocolate, one with a high cocoa content and the other without.
Over an eight week period the volunteers consumed one type of chocolate followed by a two week wash out period and then another eight weeks of eating the other variety. The dark chocolate contained 85% cocoa solids with the alternative containing none. Each individual bar weighed 15g with each volunteer expected to eat three per day, and also told not to consume more or make changes to their diet.
Researchers also noted the weight of subject did not significantly alter despite consuming an extra 245 calories per day for two months.
Professor Steve Atkin who led the study says: “The significance of the results is particularly surprising because of the small number of subjects in the study. A further study is needed to see what the effects would be on a larger group of people, but this is potentially very encouraging news for those who suffer from Chronic Fatigue Syndrome.”
This latest finding follows recent research also carried out at the University of Hull and the Hull York Medical School where dark chocolate was found to help reduce the risk of heart attacks in people with Type 2 diabetes by increasing the amount of good cholesterol in the blood stream.
This month the federal Department of Agriculture and Health and Human Services will release the 2010 dietary guidelines. These guidelines directly impact the eating habits of one in every four Americans whose meals are subsidized by federal programs. The precise timing of the release this month is unknown, according to John Webster, a spokesman for the USDA.
The major question here is whether or not the new guidelines will impact the obesity epidemic that is increasing ever so quickly in our country. Decisions about what to eat are generally made at the supermarket, not while reading federal guidelines. “What we need to do is put more effort into figuring out how to engage people who don’t use nutrition as a major deciding point when buying food,” says Alice H. Lichtenstein, a professor at the Friedman School of Nutrition Science and Policy at Tufts University. “We really need to learn more about consumer behavior.’’ Some experts wonder if more nutrition information helps or confuses shoppers.
It is arguable that the guidance needs to be much clearer, more like the wildly popular “Eat This, Not That!,’’ a magazine column, which was then reworked into a book and an iPhone app, that made its mark by telling readers which fast food was nutritionally better than others. Dr. David L. Katz, director of Yale University’s Prevention Research Center and an associate professor at the university’s School of Medicine, is an advocate for more specific guidance. For example, 45 to 65 percent of daily calories should come from foods that contain carbohydrates. But “lollipops and lentils are both carbs,’’ Katz says. And while the current federal recommendations do stress eating carbohydrates from whole grains, fruits, and vegetables, he adds, “We need to do a better job of specifically defining highly recommended foods.’’
While no one is talking about the final 2010 recommendations before their release, a June advisory report, open for public comment, gives some clues. Cohen of UMass Amherst expects the final guidelines to place even greater emphasis on physical activity and continue to recommend that people include more fruits, vegetables, nuts, seeds, foods with Omega-3 fatty acids, and a suggestion to eat three servings of low-calorie dairy products a day (some argue that calcium supplements should be used in place of the third serving).
The authors used survey data from Project EAT (Eating Among Teens), in which two groups of adolescents (1608 middle school and 3074 high school students) completed surveys in 1999 and 2004 regarding eating habits, parental styles, and various socioeconomic variables.
Cross-sectional results for adolescent girls indicated a positive association between maternal and paternal authoritative parenting style and frequency of family meals. For adolescent boys, maternal authoritative parenting style was associated with more frequent family meals. Longitudinal results indicated that authoritative parenting style predicted higher frequency of family meals five years later, but only between mothers and sons or between fathers and daughters.