Eating nuts during pregnancy 'may curb allergies'

Children are less likely to have a nut allergy if their mother ate nuts while pregnant, a study has concluded.

The work, published in JAMA Pediatrics, looked at the health and diets of more than 8,000 children and their mothers.

The US researchers believe that early exposure in the womb creates natural tolerance to certain foods.

But the findings conflict with other studies that have shown either no effect or a possible risk from nut consumption.

Current international guidance is that there is no need to either avoid nuts, nor to actively eat them”

Dr Adam Fox, Consultant children's allergist at Guy's and St Thomas's NHS Foundation Trust

Experts say this makes it difficult to offer firm advice to mothers-to-be, with the exception of women who are themselves allergic to nuts and should therefore always avoid eating them.

Conflicting evidence

The study authors, led by Dr Lindsay Frazier of the Dana-Faber Children's Cancer in Boston, concluded children were a third less likely to have a nut allergy if their mothers had eating nuts during pregnancy.

This included tree nuts such as walnuts, almonds, pistachios, cashews, pecans, brazils, hazelnuts and macadamias as well as peanuts.

The authors say this suggests that nut consumption may protect against future allergies.

But there are other factors that may also explain this difference.

For example, the women who ate nuts were also more likely to have healthier diets containing plenty of fruit and vegetables.

Dr Adam Fox, consultant children's allergist at Guy's and St Thomas's NHS Foundation Trust, said the findings were interesting but inconclusive.

"To make things even more complicated, there is also strong evidence to suggest that nut allergy doesn't develop until after birth and that it is exposure of the infant's skin to nut protein that is most important in the development of allergy.

"With such differing results from different studies, it is currently impossible to offer advice about exactly what mothers should do regarding nut consumption during pregnancy but current international guidance is that there is no need to either avoid nuts, nor to actively eat them.

Source : BBC

N.H.Khider

Coffee or Tea: Enjoy Both in Moderation for Heart Benefits, Dutch Study Suggests

Coffee and tea drinkers may not need to worry about indulging -- high and moderate consumption of tea and moderate coffee consumption are linked with reduced heart disease, according to a study published in Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association.

Researchers in The Netherlands found:

  • Drinking more than six cups of tea per day was associated with a 36 percent lower risk of heart disease compared to those who drank less than one cup of tea per day.
  • Drinking three to six cups of tea per day was associated with a 45 percent reduced risk of death from heart disease, compared to consumption of less than one cup per day.

And for coffee they found:

  • Coffee drinkers with a modest intake, two to four cups per day, had a 20 percent lower risk of heart disease compared to those drinking less than two cups or more than four cups.
  • Although not considered significant, moderate coffee consumption slightly reduced the risk of heart disease death and deaths from all causes.

Researchers also found that neither coffee nor tea consumption affected stroke risk.

"While previous studies have shown that coffee and tea seem to reduce the risk of heart disease, evidence on stroke risk and the risk of death from heart disease was not conclusive," said Yvonne T. van der Schouw, Ph.D., study senior author and professor of chronic disease epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands. "Our results found the benefits of drinking coffee and tea occur without increasing risk of stroke or death from all causes.

Van der Schouw and colleagues used a questionnaire to evaluate coffee and tea consumption among 37,514 participants. They followed the participants for 13 years for occurrences of cardiovascular disease and death.

Study limitations included self-reported tea and coffee consumption, and the lack of specific information on the type of tea participants drank. However, black tea accounts for 78 percent of the total tea consumed in The Netherlands and green tea accounts for 4.6 percent. Coffee and tea drinkers have very different health behaviors, researchers note. Many coffee drinkers tend to also smoke and have a less healthy diet compared to tea drinkers.

Researchers suggest that the cardiovascular benefit of drinking tea may be explained by antioxidants. Flavonoids in tea are thought to contribute to reduced risk, but the underlying mechanism is still not known.

Source : science Daily

N.H.Khider

Stomach 'Clock' Tells Us How Much to Eat

University of Adelaide researchers have discovered the first evidence that the nerves in the stomach act as a circadian clock, limiting food intake to specific times of the day.

The discovery, published today in The Journal of Neuroscience, could lead to new information about how the gut signals to our brains about when we're full, and when to keep eating.

In the University's Nerve-Gut Research Laboratory, Dr Stephen Kentish investigated how the nerves in the stomach respond to stretch, which occurs as a consequence of food intake, at three-hourly intervals across one day.

"These nerves are responsible for letting the brain know how much food we have eaten and when to stop eating," says Dr Kentish, who is the lead author of the paper.

"What we've found is that the nerves in the gut are at their least sensitive at time periods associated with being awake. This means more food can be consumed before we feel full at times of high activity, when more energy is required.

"However, with a change in the day-night cycle to a period associated with sleeping, the nerves in the stomach become more sensitive to stretch, signaling fullness to the brain quicker and thus limiting food intake. This variation repeats every 24 hours in a circadian manner, with the nerves acting as a clock to coordinate food intake with energy requirements," he says.

So far this discovery has been made in laboratory studies, not in humans.

"Our theory is that the same variations in nerve responses exist in human stomachs, with the gut nerves being less sensitive to fullness during the day and more sensitive at night," Dr Kentish says.

Study leader Associate Professor Amanda Page says this research could lead to further discoveries about how changes in people's circadian clocks affect their eating habits.

"We know that shift workers, for example, are more prone to disruptions in sleep and eating behavior, leading to obesity and other health problems. We are now conducting further research to see what kind of impact such changes to the circadian rhythm will have on eating behavior, and how the nerves in the stomach react to those changes," Associate Professor Page says.

Source: science Daily

N.H.Khider

'Healthy and overweight' is a myth, study suggests

Excess fat still carries health risks even when cholesterol, blood pressure and sugar levels are normal, according to a study of more than 60,000 people.

It has been argued that being overweight does not necessarily imply health risks if individuals remain healthy in other ways.

The research, published in Annals of Internal Medicine, contradicts this idea.

The study looked at findings from published studies tracking heart health and weight in more than 60,000 adults.

This really casts doubt on the existence of healthy obesity”

Dr Ravi Retnakaran Mount Sinai Hospital, Toronto

Researchers from the Mount Sinai Hospital, Toronto, found there was no healthy pattern of increased weight when heart health was monitored for more than 10 years.

They argue that people who are metabolically healthy but overweight probably have underlying risk factors that worsen over time.

Study leader Dr Ravi Retnakaran told BBC News: "This really casts doubt on the existence of healthy obesity.

"This data is suggesting that both patients who are obese who are metabolically unhealthy and patients who are obese who are metabolically healthy are both at increased risk of death from cardiovascular disease, such that benign obesity may indeed be a myth."

Heart risk

The British Heart Foundation says obesity is a known risk factor for heart disease and the research shows there is no healthy level of obesity.

Senior cardiac nurse, Doireann Maddock, said: "So, even if your blood pressure, cholesterol and blood sugar levels are normal, being obese can still put your heart at risk."

She said it was useful to think of lifestyle overall rather than individual risk factors.

"As well as watching your weight, if you stop smoking, get regular physical activity and keep your blood pressure and cholesterol levels at a healthy level, you can make a real difference in reducing your risk of heart disease.

"If you are concerned about your weight and want to know more about the changes you should make, visit your GP to talk it through."

Source : BBC

N.H.Khider

Human Stem Cells Converted to Functional Lung Cells

For the first time, scientists have succeeded in transforming human stem cells into functional lung and airway cells. The advance, reported by Columbia University Medical Center (CUMC) researchers, has significant potential for modeling lung disease, screening drugs, studying human lung development, and, ultimately, generating lung tissue for transplantation. The study was published today in the journal Nature Biotechnology.

"Researchers have had relative success in turning human stem cells into heart cells, pancreatic beta cells, intestinal cells, liver cells, and nerve cells, raising all sorts of possibilities for regenerative medicine," said study leader Hans-Willem Snoeck, MD, PhD, professor of medicine (in microbiology & immunology) and affiliated with the Columbia Center for Translational Immunology and the Columbia Stem Cell Initiative. "Now, we are finally able to make lung and airway cells. This is important because lung transplants have a particularly poor prognosis. Although any clinical application is still many years away, we can begin thinking about making autologous lung transplants -- that is, transplants that use a patient's own skin cells to generate functional lung tissue."

The research builds on Dr. Snoeck's 2011 discovery of a set of chemical factors that can turn human embryonic stem (ES) cells or human induced pluripotent stem (iPS) cells into anterior foregut endoderm -- precursors of lung and airway cells. (Human iPS cells closely resemble human ES cells but are generated from skin cells, by coaxing them into taking a developmental step backwards. Human iPS cells can then be stimulated to differentiate into specialized cells -- offering researchers an alternative to human ES cells.)

In the current study, Dr. Snoeck and his colleagues found new factors that can complete the transformation of human ES or iPS cells into functional lung epithelial cells (cells that cover the lung surface). The resultant cells were found to express markers of at least six types of lung and airway epithelial cells, particularly markers of type 2 alveolar epithelial cells. Type 2 cells are important because they produce surfactant, a substance critical to maintain the lung alveoli, where gas exchange takes place; they also participate in repair of the lung after injury and damage.

The findings have implications for the study of a number of lung diseases, including idiopathic pulmonary fibrosis (IPF), in which type 2 alveolar epithelial cells are thought to play a central role. "No one knows what causes the disease, and there's no way to treat it," says Dr. Snoeck. "Using this technology, researchers will finally be able to create laboratory models of IPF, study the disease at the molecular level, and screen drugs for possible treatments or cures."

"In the longer term, we hope to use this technology to make an autologous lung graft," Dr. Snoeck said. "This would entail taking a lung from a donor; removing all the lung cells, leaving only the lung scaffold; and seeding the scaffold with new lung cells derived from the patient. In this way, rejection problems could be avoided." Dr. Snoeck is investigating this approach in collaboration with researchers in the Columbia University Department of Biomedical Engineering.

"I am excited about this collaboration with Hans Snoeck, integrating stem cell science with bioengineering in the search for new treatments for lung disease," said GordanaVunjak-Novakovic, PhD, co-author of the paper and Mikati Foundation Professor of Biomedical Engineering at Columbia's Engineering School and professor of medical sciences at Columbia University College of Physicians and Surgeons.

Source: Science Daily

R.Sawas