A study from China suggests that increased time spent
outdoors reduce the risk of development and progression of myopia in
children. In this Chinese study involving 3051 children aged between 6
and 14 years, the study group of 1735 children was allowed 40 minutes
extra time outdoors during recess, compared to 1316 children who did not
get this extra time. New onset myopia and changes towards myopia were
significantly lesser in children who daily spent outdoors an extra 40
minutes. Changes in axial length and intraocular pressure were also
significantly lower in the ‘outdoor’ group. There have been several
other observational studies supporting the hypothesis that time spent
outdoors protects against myopia.
How does outdoor time reduce myopia? Bright light
outdoors may be the most possible mechanism. Brighter light potentially
reduces the development of myopia by pupil constriction, resulting in
less visual blur, or by stimulation of dopamine release from the retina.
Animal studies suggested that bright light prevented the development of
myopia and the protective effect was blocked by a dopamine antagonist.
More light needs to be shed on this fascinating subject. (BMC
Ophthalmol. 2015;15:73)
Vitamin D Guidelines for India
The Endocrine Society of India has published
guidelines for the use of Vitamin D in India. The recommendations for
daily vitamin D intake are 400 IU for infants, 600-1000 IU for children,
1000 IU for adolescents and pregnant women after 12 weeks’ gestation,
and 1000-2000 IU for adults.
The guidelines recommend testing for vitamin D only
in patients who have signs of osteomalacia, osteoporosis,
musculoskeletal disorders, chronic liver or kidney disease, inflammatory
bowel disease, or in those receiving drugs that increase the risk of
vitamin D deficiency. The society has also recommended large scale
fortification of vegetable oil and milk. On the other hand, the society
also warns against iatrogenic vitamin D intoxication which appears to be
on the rise due to excessive prescription of vitamin D. The reason
touted for high prevalence of vitamin D deficiency is that very few
foods naturally contain Vitamin D. Throughout evolution, humans have
depended on sunlight exposure for their vitamin D. In some countries
such as Australia, an alternative to vitamin D supplementation by
‘sensible sun exposure’ (time in the sun which is 25-50% of the time
required to develop a mild sunburn on extremities and trunk, at least
two to three times a week) is recommended.
It is raining vitamin D if only we are ready to take
it! (BMJ 2015;351:h5997)
Red Meat and Cancer
The International Agency for Research on Cancer
(IARC), WHO, has issued a warning against red and processed meat. The
IARC, which consists of 22 experts from 10 countries, analyzed around
800 studies including large prospective cohort studies over the past 20
years, which had studied the association of red and processed meat with
the risk of cancer. Processed meat was labeled as group 1 carcinogenic
with sufficient evidence that consumption causes colorectal cancer. Red
meat was classified as probably carcinogenic to humans (Group 2A). The
experts concluded that each 50 g portion of processed meat eaten daily
increases the risk of colorectal cancer by 18%, and every 100 g of red
meat eaten daily increases the risk of colon cancer by 17%. There are
also some links with pancreatic and prostrate cancer.
Red meat refers to all mammalian muscle meat,
including, beef, veal, pork, lamb, mutton, horse, and goat. Poultry and
fish are not included in red meat. Processed meat refers to meat that
has been transformed through salting, curing, fermentation, smoking, or
other processes to enhance flavor or improve preservation. Cooking at
high temperatures as in barbecuing or pan-frying has been shown to
produce more of certain types of carcinogenic chemicals such as
polycyclic aromatic hydrocarbons and heterocyclic aromatic amines. (The
Hindu 3 November 2015)
Defensive Medicine Reduces Litigation
A study from Harvard confirms what many doctors
believe. Increased resource use by physicians is correlated with fewer
malpractice claims. A huge criticism against the American style of
medical practice is that it encourages defensive medicine. What exactly
is defensive medicine? It is defined as medical care provided to
patients solely to reduce the threat of malpractice liability rather
than to further diagnosis or treatment. Defensive medicine is a major
contributor to medical costs, but the malady is widespread. In a survey
of US-based physicians, over 60% doctors reported ordering diagnostic
tests and consultations merely to reduce the risk of liability. In
Massachusetts, 80% of physicians reported practicing defensive medicine
with 20-30% of imaging tests and 13% of hospital admissions defensively
motivated.
Why do we need to look at this US data? The practice
of medicine in India is proceeding rather blindly in the footsteps of
our American counterparts. Have we really thought of what constitutes
good medicine? Good medicine is probably difficult without a good
long-term relationship between a doctor and a patient. This is
increasingly impossible in the sterile world of a corporate hospital.
Unless wisdom prevails, we are bound to repeat the mistakes made in the
West.(BMJ. 2015;351:h5516)