Just as too much of anything is bad, extreme strenuous workouts such as high intensity training could be bad for the heart, warns a new study.

According to researchers, high levels of intense exercise may be cardiotoxic and promote permanent structural changes in the heart.

The research, published in the Canadian Journal of Cardiology, is based on studies that looked into the relationship between exercise and heart problems.

There is already fairly compelling evidence supporting the association between long-term sports practice and increased prevalence of atrial fibrillation -- abnormal heart rhythm characterised by rapid and irregular beating.

"Much of the discussion regarding the relative risks and benefits of long-term endurance sports training is hijacked by definitive media-grabbing statements, which has fuelled an environment in which one may be criticized for even questioning the benefits of exercise," explained study author Andre La Gerche from the Baker IDI Heart and Diabetes Institute, Melbourne, Australia.

"This paper discusses the often questionable, incomplete, and controversial science behind the emerging concern that high levels of intense exercise may be associated with some adverse health effects," La Gerche noted.

"The answers regarding the healthfulness of 'extreme' exercise are not complete and there are valid questions being raised," La Gerche said.

"Given that this is a concern that affects such a large proportion of society, it is something that deserves investment. The lack of large prospective studies of persons engaged in high-volume and high-intensity exercise represents the biggest deficiency in the literature to date, and, although such work presents a logistical and financial challenge, many questions will remain controversies until such data emege," La Gerche observed.

Researchers argue that before a definitive link between exercise and heart can be made, much more research needs to be carried out.

Nearly five billion people, that is about half the world's population, are poised to become myopic or short-sighted by the end of 2050, indicates a study.

Also called nearsightedness, myopia is a vision condition in which people can see clearly the objects that are close to eyes but objects far away appear to be blurred to the sight.

Acting like a silent epidemic, myopia is all set to become the leading cause of permanent blindness globally

With up to one billion people at an increased risk of blindness, myopia is all set to become the leading cause of permanent blindness globally.

Further, with the findings suggesting that the US will have 260 million myopes by 2050, up from the 90 million in 2000, and Canada will see 66 million high myopes by 2050, up from the 11 million in 2000, the vision loss from high myopia is expected to increase seven-fold from 2000 to 2050.

The rapid increase in the prevalence of myopia globally is attributed to "environmental factors, lifestyle changes resulting from a combination of decreased time outdoors and increased near work activities, among other factors", said the researchers.

Parents need to ensure that the children's eyes are regularly checked, improve time outdoors and moderate time on near based activities, including electronic devices.

Also, comprehensive eye care services is needed to check the rapid increase in high myopes, along with the development of treatments to control the progression of myopia and prevent people from becoming highly myopic, the researchers suggested in the study published in the journal Ophthalmology revealed.

"We also need to ensure our children receive a regular eye examination from an optometrist or ophthalmologist, preferably each year, so that preventative strategies can be employed if they are at risk," said Kovin Naidoo, a professor at the University of New South Wales in Australia.

For those who do meditation regularly, here is another good news. Researchers report that apart from reducing blood pressure and heart disease risk, Transcendental Meditation technique and lifestyle changes can slow cellular death too.

The new study examined what was happening at the level of DNA, showing that the Transcendental Meditation technique increases telomerase gene expression which may contribute to the cardiovascular and aging benefits.

Specifically, this was found to activate two genes that code for telomerase -- which adds molecules to the ends of chromosomes or telomeres -- protecting them from deteriorating.

"The finding that telomerase gene expression is increased with a reduction in blood pressure in a high-risk population suggests that this may be a mechanism by which stress reduction improves cardiovascular health," said Robert Schneider, from Iowa-based Maharishi University of Management (MUM).

Earlier research on the Transcendental Meditation technique found lower rates of high blood pressure, heart attack, stroke and early death.

For this trial, the participants included 48 men and women with high blood pressure who were recruited and studied at Howard University Medical Center.

Half were assigned to a group that learned the Transcendental Meditation technique and received a basic health education course.

The other half were assigned to a group that focused on achieving significant lifestyle modifications such as weight reduction, reducing salt intake, engaging in regular physical activity and moderating alcohol.

After 16 weeks, both groups showed significant increases in telomerase gene expression and reductions in blood pressure.

"These findings are very encouraging for prevention. They show that both the Transcendental Meditation technique and active lifestyle modification can contribute to heart health," said Schneider, director of the Institute for Natural Medicine and Prevention at MUM.

"The result is valuable new information, relevant both to cardiovascular disease and to the molecular mechanisms involved in Transcendental Meditation," noted John Fagan, professor of molecular biology in a paper published in the journal PLOS ONE.

Hate the taste of broccoli? Do you perceive honey as too sweet? According to a new study, a common gene variant should be blamed for our food choices.

The McGill-led research team has recently discovered that for girls who are carriers of a particular gene variant (DRD4 VNTR with 7 repeats), the crucial element that influences a child's fat intake is not the gene variant itself.

Instead, it is the interplay between the gene and girls' early socio-economic environment that may determine whether they have increased fat intake OR healthier than average eating compared to their peers from the same class background. The DRD4 repeat 7 is found in approximately 20 per cent of the population and is known to be associated with obesity, especially in women.

Lead researcher Laurette Dube said that they found that among girls raised in poorer families, those with DRD4 repeat 7 had a higher fat intake than other girls from the same socio-economic background, but they also found that girls with exactly the same gene variant who came from wealthier families, compared to these with the same economic conditions, had a lower fat intake.

Dube noted that this suggests that it's not the gene acting by itself, but rather how the gene makes an individual more sensitive to environmental conditions that determines "for better or worse" a child's preference for fat and consequent obesity as the years pass by.

Interestingly, the researchers found this effect to be true only in the girls that they tested. They speculate that this may be because, from an evolutionary standpoint, it may have been more important for girls to be able to gain weight easily to adapt to adverse conditions in order to reproduce.

Another possibility they advance is that at age four, it may simply be too early to see these effects in boys since boys and girls gain weight at different stages at this age, and may also have different behavioural responses to hunger and feelings of satiety.

These results underscore the importance of moving beyond a 'one-size-fits-all' approach to childhood obesity prevention, said Dube, adding "we need to move towards targeted approaches that focus on populations that are particularly vulnerable to both genetic and environmental factors: those who are biologically more vulnerable under adverse environments are those likely to be more responsive to improvements in their conditions."

The study appears in JAMA Pediatrics.

Since the Nobel Prize-winning discovery of the enzyme telomerase in 1984, identifying other biological molecules that lengthen or shorten the protective caps on the ends of chromosomes has been slow going.

A new Maharishi University of Management study found that the Transcendental Meditation technique and lifestyle changes both appear to stimulate genes that produce telomerase, an enzyme that's associated with reduced blood pressure, cardiovascular disease and mortality.

Specifically, these approaches were found to activate two genes that code for telomerase, which adds molecules to the ends of chromosomes, or telomeres, protecting them from deteriorating.

The finding that telomerase gene expression is increased and that this is associated with a reduction in blood pressure in a high-risk population, suggests that this may be a mechanism by which stress reduction improves cardiovascular health, said coauthor Robert Schneider.

The new study examined what was happening at the level of DNA, showing that the Transcendental Meditation technique increases telomerase gene expression and suggesting that this may contribute to the cardiovascular and aging benefits.

Coauthor Otelio Randall of Howard University College of Medicine concluded this pilot study in African Americans suggests stress reduction and lifestyle modifications may reduce blood pressure with an increase in telomerase.

The study appears in PLOS ONE.