Scientists may have discovered a way of identifying dieters who are prone to piling the pounds back on after weight loss. A study at Maastricht University’s Department of Human Biology found a link between a gene involved in regulating blood pressure and post-diet weight gain in women. Women who regained weight after slimming had a high change in the concentration of a particular protein in their blood during dieting, research showed. Researchers now hope to develop a test to indicate how prone people are to yo-yo dieting.
Edwin Mariman, professor of functional genetics at Maastricht, said: “It was a surprising discovery, because until now there has been no clear link between this protein and obesity. “We do not yet have an explanation for the results, but it does appear that it should be possible within a few years to use this finding to develop a test to show who is at high risk of putting weight back on after a diet.”
Hospitals already conduct tests for the protein, known as the angiotensin I converting enzyme (ACE). But the test is currently carried out to check its activity in regulating blood pressure, rather than its concentration. Up 80% of dieters suffer from the yo-yo effect, returning to their original weight within a year.
The study looked at around 100 women aged 20 to 45, half of whom had maintained their post-diet weight and half of whom had put weight back on. The findings of the research have been published by Dr Ping Wang, a scientist in Professor Mariman’s research group, in the online scientific journal PloS ONE.
Eating more fruits and vegetables may not protect children from developing allergies, according to a large Swedish study that questions earlier hints of benefit. Fruits and vegetables are rich in antioxidants, which are thought to reduce airway inflammation. So recent studies reporting less asthma, wheezing and hay fever among children who consumed more produce appeared to make sense.
But not all research has found that link, and the studies that did may have had a surprising flaw, said Helen Rosenlund of Karolinska Institutet in Stockholm, who led the new study. She said some proteins in fruits like apples and pears resemble the pollen parts that trigger hay fever, meaning that kids might react to both. In other words, existing allergies may have caused them to eat around the produce, rather than the other way around. “This could confuse research findings,” explained Rosenlund, “falsely suggesting that diets with fewer fruits and vegetables result in more allergic disease.”
To find out if this was the case, Rosenlund and her colleagues looked at data on nearly 2,500 eight-year-olds who had participated since birth in a larger Swedish study. Based on blood tests and questionnaires filled out by parents, the researchers found that seven percent of the children had asthma. The rates of hay fever and skin rashes were more than twice as high. The average child ate between one and two servings of fruit, and between two and three servings of vegetables each day.
At first glance, some produce did seem helpful: Kids with the biggest appetite for fruit had less than two-thirds the odds of developing hay fever than those who ate the least amount. Apples, pears and carrots appeared to be particularly helpful, the researchers report in the Journal of Allergy and Clinical Immunology, but there was no such link for vegetables overall. However, it turned out that half the children with hay fever were sensitive to birch tree pollen, one of the pollens known to resemble the proteins in apples and carrots. And sure enough, after the team repeated their analysis excluding the 122 kids with food-related allergy symptoms, the hay fever link disappeared as well. “Fruits do not seem to offer protection against allergic if diet modifications are considered,” say Rosenlund.
The researchers say more studies are needed, particularly in other parts of the world that may have a different variety of allergy triggers, or allergens. And they advise those studies should not forget to look at how allergies might influence what participants eat. “Studying diet it is not so easy when it comes to the relation with allergic disease,” Rosenlund said, “because it is such a complex disease pattern.”
SOURCE: bit.ly/g3DpI7 The Journal of Allergy and Clinical Immunology, online January 10, 2011.
A controversial new Dutch study may have found a link between food allergies and ADHD. However, many experts are dismissing the findings. The study found that in children with ADHD, putting them on a restrictive diet to eliminate possible, previously unknown food allergies or sensitivities decreased hyperactivity for 64% of them. “There is a longstanding, somewhat inconsistent story about diet and ADHD,” said Jan Buitelaar, the lead author of the Dutch study and a psychiatrist at the Radboud University Nijmegen Medical Centre. “On the one hand, people think it’s sugar that’s the trigger, others think that food coloring could be causing ADHD. Our approach was quite different. We went [with] the idea that food may give some kind of allergic or hyperactivity reaction to the brain.”
There have been previous studies in this field, but they were limited. “This has long been viewed as a kind of a controversial approach,” Buitelaar said. “When we started the research, I was skeptical, but the results convinced me.”
In the study, of the 41 kids who completed the elimination diet, 32 saw decreased symptoms. When certain foods thought to be “triggers” for each child were reintroduced, most of the children relapsed. Among 50 kids given a “control” diet that was just a standard, healthy diet for children, no significant changes were noted. Given these findings, Buitelaar recommended that the elimination diet become part of standard of care for children with ADHD. However, while pediatricians acknowledge some effectiveness, they were against the elimination diet as part of the care for children with ADHD.
“People seem to think that dietary modification is essentially ‘free,’ but it is difficult, socially disruptive, and presents the risk for nutritional deficiency,” said Dr. Michael Daines, a pediatric allergist-immunologist at the University of Arizona. Though Daines is willing to work with families who want to try an elimination diet for treating ADHD, he feels it will only have an effect if the child is having a true food allergy or intolerance.
Many people snore. Many people have heart attacks. Researchers from the University of Pittsburgh say they have found a connection between the two conditions. “People often report in primary care offices that they or their spouse complains of loud snoring, that they have difficulty falling asleep or staying asleep. And we as sleep researchers were interested in how this broad array of sleep symptoms that are often reported might relate to later cardiovascular risk,” lead research author Wendy Troxel of the University of Pittsburgh School of Medicine said.
Previous research has looked at the link between heart disease and obstructive sleep apnea, a problem where excess tissue blocks the airway during sleep. But this study looked purely at snoring. “There are some people with loud snoring who don't have obstructive sleep apnea,” Troxel continued.
In Troxel's government-funded study, more that 800 relatively healthy people ages 45 to 78 were followed for three years. High blood sugar and low levels of good cholesterol, both risk factors for heart disease, were twice as likely to present in the participants who reported frequent, loud snoring.
In addition to snorers, participants who had trouble falling asleep and had unrefreshing sleep were also at increased risk for metabolic syndrome, when additional heart disease risk factors like obesity, high blood pressure, and high levels of triglyceride fats are present. “Sleep complaints aren't just benign annoyances but something that can really foretell important health consequences,” Troxel stressed, “and they should really be discussed with [medical] providers and referred for further treatment if necessary.”
The research conducted at Pitt was an observational study. Patients were not treated to see whether decreasing snoring could lower the risk of heart disease. Rather, the study shows that snorers should pay particular attention to their heart disease risk factors.
Could drinking one or more artificially sweetened, carbonated diet sodas a day boost a woman's odds of premature delivery? A new study from Denmark suggests such a link.dblclick('xxlA');
The researchers looked at the soft drink habits of nearly 60,000 Danish women enrolled in a national study there from 1996 to 2002. The investigators found a link between the intake of diet carbonated drinks and, to a lesser extent, diet noncarbonated drinks and delivering a baby early.
The study is published online and in the September print issue of the American Journal of Clinical Nutrition. In the report, the researchers conclude: “Daily intake of artificially sweetened soft drinks may increase the risk of preterm delivery.”
The researchers defined preterm as delivering before 37 weeks' gestation. They categorized the women into groups depending on beverage drinking habits: those who never drank soft drinks or those who drank less than one per week, one to six per week, one each day, two or three per day, or four or more daily. In all, 4.6 percent of the women delivered early, and one-third of those deliveries were medically induced. The team found no association between the premature delivery and the intake of carbonated drinks sweetened with sugar.
However, compared with those who never drank the beverages, women who downed four or more diet (artificially sweetened) carbonated drinks a day were 78 percent more likely to deliver early than women who never drank the beverages. And those who had four or more diet, noncarbonated drinks daily were 29 percent more likely to deliver early. Those who had one or more carbonated diet drinks a day were 38 percent more likely to deliver early.
Why the diet drinks, especially, were linked with early delivery is not known, but the researchers speculate that the link may be driven by high blood pressure disorders in pregnancy. They note that other studies have found a link between soft drinks and high blood pressure in non-pregnant women.
The new data come from an ongoing National Institutes of Health-AARP study and involved more than 300,000 participants. Researchers found that those study participants who reported eating the most processed meat had about a 30 percent greater risk of bladder cancer than those who ate the least.
What's more, those whose diets were highest in nitrites and nitrates (from processed meat as well as other sources) were about 33 percent more likely to develop bladder cancer than those whose diets contained the smallest amounts of these compounds.
Bladder cancer is currently the 10th most common cancer in the US, with over 70,000 cases diagnosed each year.
Link to Bladder Cancer Needs Confirmation; Link to Colorectal Cancer Convincing
The evidence that consumption of processed meat is linked to colorectal cancer was judged convincing by the independent expert panel behind the major AICR/WCRF report, Food, Nutrition, Physical Activity and the Prevention of Cancer: A Global Perspective.
This same report, published in 2007, found the evidence linking red and processed meat to bladder cancer too sparse to make a judgment. Although this new study's findings need to be confirmed, it represents a major contribution to the scientific literature on diet's role in bladder cancer.
Higginbotham noted that the AICR/WCRF report's findings are continually updated; data from this and other studies will be added to AICR/WCRF's database and are scheduled to be reassessed by independent experts in the future.
Until that time, AICR reiterates that for people who are concerned about cancer, there is already good reason to limit consumption of red meat and avoid processed meat.
Source: American Institute for Cancer Research
Several maladaptive eating behaviors, beyond anorexia, can affect women. Indeed, some 10 to 15 percent of women have maladaptive eating behaviours and attitudes according to new study from the Université de Montréal and the Douglas Mental Health University Institute published in the International Journal of Eating Disorders.
“Our results are disquieting,” says Lise Gauvin, a professor at the Université de Montréal Department of Social and Preventive Medicine. “Women are exposed to many contradictory messages. They are encouraged to lose weight yet also encouraged to eat for the simple pleasure of it.”
Some 1,501 women took part in the phone survey on eating disorders and disordered eating. Not one participant was classified as anorexic. The average age of these urban-dwelling participants was 31, the majority of respondents were non-smokers and university graduates.
Dr. Gauvin says the study sheds new light on binge eating and bulimia, which are characterized in part by excessive eating accompanied by feelings of having lost control. “About 13.7 percent of women interviewed for this study reported binge eating one to five days or one to seven times per month,” she says, noting 2.5 percent of women reported forcing themselves to vomit, use laxatives, or use diuretics to maintain their weight or shape.
The investigation also established a link between problematic eating behaviours and self-rated health. In other words, deviant eating behaviours are more likely to occur in women who perceived themselves to be in poor health.
Another finding of the study was that 28 percent of women complete intense exercise twice a month with the sole objective of losing weight or influencing. “We practice a sport for the pleasure it provides, to feel good, but when the activity is done to gain control over one's weight and figure, it is indicative of someone who could be excessively concerned about their weight,” says Dr. Gauvin. “Our data suggests that a proportion of the female population displays maladaptive eating patterns.”
This study was supported by the Canadian Institutes for Health Research.
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.