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.
About 10 to 15 percent of children experience recurrent abdominal pain, the researchers said. The pain can be due to irritable bowel syndrome — which is usually relieved by defecation — or can be “functional abdominal pain,” which is not explained by another disease. While LGG has been tested before in children with abdominal pain, the studies were small and showed mixed results. The new study, which involved 141 children with irritable bowel syndrome or functional abdominal pain, was conducted in Italy between 2004 and 2008. Researchers gave the kids either the probiotic or a placebo for eight weeks. Neither the doctors nor the patients were aware which treatment they received.
Following the treatment, the patients were followed up for another 8 weeks. During the treatment and follow-up, the severity and frequency of abdominal pain decreased for both groups, but the probiotic group experienced a more drastic reduction. For instance, after 12 weeks, patients who took the probiotic reported experiencing, on average, 1.1 episodes of pain per week, compared with 3.7 weekly episodes before the treatment. Those who took the placebo reported experiencing 2.2 pain episodes per week, compared with 3.5 episodes initially.
And a greater percentage of parents of children who took the probiotic reported that their children experienced a decline in pain,compared with those whose kids took the placebo. Among kids who took the probiotic, it was mostly children with irritable bowel syndrome who showed improvements, the researchers said.
Why does it work?
The results suggest LGG may be specifically beneficial for those with irritable bowel syndrome, the researchers said. It's possible that children with irritable bowel syndrome have an imbalance of good and bad bacteria in their guts, which contributes to the pain, and the probiotics relieves pain by restoring the proper balance, Francavilla said. Probiotics have also been suggested to reduce inflammation in the gut, as well as stimulate the release of analgesic substances that relieve pain. The researchers noted they cannot be sure whether the beneficial effects will last for more than a few weeks after treatment is stopped.
The results were published in the journal Pediatrics.
Extracts of broccoli and banana may help in fighting stomach problems, research suggests. Laboratory studies show fibres from the vegetables may boost the body's natural defences against stomach infections. Trials are under way to see if they could be used as a medical food for patients with Crohn's disease. Crohn's disease is an inflammatory bowel disease that causes symptoms such as diarrhoea and abdominal pain. It affects about 1 in 1,000 people, and is thought to be caused by a mixture of environmental and genetic factors. The condition is common in developed countries, where diets are often low in fibre and high in processed food.
Scientists at the University of Liverpool looked at how roughage from vegetables influenced the passage of harmful bacteria through cells inside the gut. They found that fibres from the plantain, a type of large banana, and broccoli, were particularly beneficial. But a common stabiliser added to processed foods during the manufacturing process had the opposite effect.
Dr Barry Campbell, from the University of Liverpool, said: “This research shows that different dietary components can have powerful effects on the movement of bacteria through the bowel. “We have known for some time the general health benefits of eating plantain and broccoli, which are both high in vitamins and minerals, but until now we have not understood how they can boost the body's natural defences against infection common in Crohn's patients. “Our work suggests that it might be important for patients with this condition to eat healthily and limit their intake of processed foods.”
The research, published in the journal Gut, and carried out in collaboration with experts in Sweden and Scotland, investigated special cells, called M-cells, which line the gut and ward off invading bacteria. Work was carried out in laboratory-grown cells and tissue samples from patients undergoing surgery for stomach problems. Clinical trials are now underway in 76 Crohn's patients to find out whether a medical food containing plantain fibres could help keep the disease at bay. “It may be that it makes sense for sufferers of Crohn's to take supplements of these fibres to help prevent relapse,” said Professor Jon Rhodes of the University of Liverpool.
Eating more olive oil could help prevent ulcerative colitis, according to a new study co-ordinated by medical researchers at the University of East Anglia (UEA).
Presented today at the Digestive Disease Week conference in New Orleans, the findings show that people with a diet rich in oleic acid – which is present in olive oil –are far less likely to develop ulcerative colitis. Oleic acid is a monounsaturated fatty acid found in olive oil, peanut oil and grapeseed oil, as well as in butter and certain margarines.
The researchers, led by Dr Andrew Hart of UEA's School of Medicine, studied more than 25,000 people aged 40-65 living in Norfolk, UK. The volunteers were recruited to the EPIC study (European Prospective Investigation into Diet and Cancer) between 1993 and 1997. The participants, none of whom had ulcerative colitis at the outset, completed detailed food diaries which were later analysed by specially trained nutritionists working in Cambridge.
By 2004, 22 participants in the study had developed ulcerative colitis and the researchers compared their diets with those who did not develop the disease. They found that those with the highest intake of oleic acid had a 90 per cent lower risk of developing the disease.
“Oleic acid seems to help prevent the development of ulcerative colitis by blocking chemicals in the bowel that aggravate the inflammation found in this illness,” said Dr Hart.
“We estimate that around half of the cases of ulcerative colitis could be prevented if larger amounts of oleic acid were consumed. Two-to-three tablespoons of olive oil per day would have a protective effect,” said Dr Hart.
Ulcerative colitis is a distressing disease affecting 120,000 people of all ages in the UK and 1 million in the US. It is characterized by inflammation of the lining of the colon or large bowel, which causes abdominal pain, diarrhoea and weight loss.
Similar work in other countries is now required to determine if these results are reproducible there, before the link can be said to be definite. If it is confirmed that oleic acid is truly protective, dietary modifications should be considered to prevent colitis. Additionally, the use of oleic acid supplements should also be assessed in the future as a possible treatment for colitis sufferers.
Lead researcher Dr. Jeffrey M. Lackner from the State University of New York, Buffalo said cognitive behavioral therapy was known to be a very promising treatment for IBS, with the current findings helping to identify which patients would likely maintain a positive response.
Lackner and his colleagues are conducting a larger, longer-term study, as the current study being a small one, it remains unclear how long the benefits of cognitive behavioral therapy may last i. e. do they carry over to 9 months, a year or more.
IBS symptoms include bouts of abdominal cramps, bloating and changes in bowel habits i. e. diarrhoea or constipation, or alternating episodes of both. While, no one knows the exact cause of the disorder, there are certain symptom triggers like particular foods, large meals and emotional stress.
Cognitive behavioral therapy helps IBS patients to recognize their symptom triggers and manage them. Other treatment options include general diet changes, like reducing gas-producing foods; fibre supplements, if constipation is a primary symptom; and anti-diarrhoeal medications, when diarrhoea is a primary symptom.
There are two prescription medications for specific IBS cases: Lotronex, for women with diarrhoea dominant IBS not responding to other treatments; and Amitiza, for constipation dominant IBS.
Around 20% of people have IBS symptoms, with women affected at about twice the rate of men
People who take aspirin regularly for a year or more may be at an increased risk of developing Crohn's disease, according to a new study by the University of East Anglia (UEA). Led by Dr Andrew Hart of UEA's School of Medicine, the research was presented for the first time at the Digestive Disease Week conference in New Orleans.
Crohn's disease is a serious condition affecting 60,000 people in the UK and 500,000 people in the US. It is characterized by inflammation and swelling of any part of the digestive system. This can lead to debilitating symptoms and requires patients to take life-long medication. Some patients need surgery and some sufferers have an increased risk of bowel cancer.
Though there are likely to be many causes of the disease, previous work on tissue samples has shown that aspirin can have a harmful effect on the bowel. To investigate this potential link further, the UEA team followed 200,000 volunteers aged 30-74 in the UK, Sweden, Denmark, Germany and Italy. The volunteers had been recruited for the EPIC study (European Prospective Investigation into Cancer and Nutrition) between 1993 and 1997.
The volunteers were all initially well, but by 2004 a small number had developed Crohn's disease. When looking for differences in aspirin use between those who did and did not develop the disease, the researchers discovered that those taking aspirin regularly for a year or more were around five times more likely to develop Crohn's disease.
The study also showed that aspirin use had no effect on the risk of developing ulcerative colitis — a condition similar to Crohn's disease.
“This is early work but our findings do suggest that the regular use of aspirin could be one of many factors which influences the development of this distressing disease in some patients,” said Dr Hart.
“Aspirin does have many beneficial effects, however, including helping to prevent heart attacks and strokes. I would urge aspirin users to continue taking this medication since the risk of aspirin users possibly developing Crohn's disease remains very low — only one in every 2000 users, and the link is not yet finally proved.”
Further work must now be done in other populations to establish whether there is a definite link and to check that aspirin use is not just a marker of another risk factor which is the real cause of Crohn's disease. The UEA team will also continue its wider research into other potential factors in the development of Crohn's disease, including diet.