Friday, February 28, 2014
Breast milk is 'no better for a baby than bottled milk' - and it INCREASES the risk of asthma, expert claims
A new round in the great breastfeeding war. This study measured IQ as a confounder -- rarely done but important. So I think its conclusions are the best yet
The benefits of breastfeeding have been exaggerated, a new study has suggested. A comparison of siblings fed differently during infancy suggests breast milk is no better than bottled milk at improving long-term health.
Dr Cynthia Colen, from Ohio State University, said her findings are not meant to challenge established ideas, but could prevent women who cannot breastfeed from feeling stigmatised.
Those promoting the 'breast is best' message, including the Department of Health, say a mother's milk wards off a host of ills. NHS leaflets given to pregnant women and new mothers claim breastfeeding protects against obesity, allergies, asthma and diabetes.
But Dr Colen’s research suggests breastfed children perform no better than their siblings who are bottle-fed.
It showed they are no more likely to be obese and that they do not perform better academically.
Dr Colen also claims that children who are breastfed are more likely to develop asthma than those who are bottle-fed.
She said: ‘Many previous studies suffer from selection bias. They either do not or cannot statistically control for factors such as race, age, family income, mother's employment - things we know that can affect both breast-feeding and health outcomes.
‘Mums with more resources - with higher levels of education and higher levels of income - and more flexibility in their daily schedules are more likely to breastfeed their children and do so for longer periods of time.’
Dr Colen said: ‘I'm not saying breastfeeding is not beneficial, especially for boosting nutrition and immunity in newborns.
‘But if we really want to improve maternal and child health, let's also focus on things that can really do that in the long term - like subsidised day care, better maternity leave policies and more employment opportunities for low-income mothers that pay a living wage, for example.’
She used data from the 1979 cohort of the National Longitudinal Survey of Youth, a nationally representative sample of young men and women.
She analysed a total of 8,237 children made up of 7,319 siblings and 1,773 ‘discordant’ sibling pairs, where one was breastfed with the other given a bottle.
The study measured BMI (body mass index), obesity, asthma, hyperactivity, parental attachment and behaviour as well as scores predicting academic achievement in vocabulary, reading, maths, intelligence and scholastic competence.
Across all of the families, breastfeeding resulted in better outcomes in BMI, hyperactivity, maths, reading recognition, vocabulary word identification, digit recollection, scholastic competence and obesity.
But when restricted to siblings differently fed within the same families, scores reflecting breastfeeding's positive effects on 10 of the indicators were closer to zero and not statistically significant - meaning any differences could have occurred by chance.
The researchers believe this means the siblings who were all breastfed probably performed better because of other factors, such as socioeconomic status.
The most surprising finding was that children who were breastfed were at greater risk of asthma.
However, this could be because the data relied on whether people said they had asthma, rather than whether they had been formally diagnosed with the condition.
Dr Colen said: ‘Instead of comparing across families we are comparing within families completely taking into account all of those characteristics - both measured and unmeasured - that differ by family such as parental education, household income and race/ethnicity.
‘If breastfeeding doesn't have the impact we think it will have on long-term childhood outcomes then even though it's very important in the short-term we really need to focus on other things.
‘We need to look at school quality, adequate housing and the type of employment parents have when their kids are growing up.
‘We need to take a much more careful look at what happens past that first year of life and understand breastfeeding might be very difficult, even untenable, for certain groups of women.
‘Rather than placing the blame at their feet let's be more realistic about what breastfeeding does and doesn't do.'
When an abject failure becomes a success
When I was young enough still to consider myself rational, I was irritated by patients who tried any remedy in desperation to save themselves from their fatal disease. I have long since mellowed and when an acquaintance of mine with glioblastoma, a rapidly fatal brain tumor, decided recently to go to India to try Ayurvedic medicine, all I could do was wish him luck – sincerely so. After all, the scientific medicine — which he would continue to take while there — offered him little enough hope, a few months at most. (This case, incidentally, illustrates an important point: alternative medicine, so called, is not generally alternative, it is additional.)
Two trials of a very expensive monoclonal antibody, bevacizumab, in glioblastoma, published recently in the New England Journal of Medicine, make disappointing or even dismal reading. This antibody is directed at vascular endothelial growth factor that promotes the growth of new blood vessels; glioblastoma is a tumor particularly rich in new blood vessels, and so it was hoped that by preventing them from forming, tumor growth would either be prevented or at least slowed. Early results were promising but as has so often been the way in the history of medicine, early promise is not fulfillment of promise.
In one trial, for example, 637 patients with this terrible tumor were randomized to conventional treatment plus placebo and conventional treatment plus bevacizumab. Although the latter had a slightly longer period free of progression of the tumor, their overall length of survival was not increased, and indeed they suffered so many more side effects that the overall quality of their lives was worse. The patients taking bevacizumab survived on average 15.7 months; those taking placebo survived 16.1 months. The authors of the paper end:
"In conclusion, we did not observe an overall survival advantage first-line use of bevacizumab in patients with newly diagnosed glioblastoma. Furthermore, higher rates of neurocognitive decline, increased symptom severity, and decline in health-related quality of life were found over time among patients who were treated with bevacizumab."
This makes rather odd the concluding words of an editorial that accompanies the trials in the Journal:
"Finally, it is worth noting that despite its limitations, bevacizumab remains the single most important therapeutic agent for glioblastoma since temozolemide. Ongoing and future trials will better define how and when it should be used in this population of patients for whom so few treatment options currently exist."
Posted by jonjayray at 12:15 AM