Medical Breakthrough: Genetics May Cause Anorexia, Other Forms Of Weight Loss

Researchers in Lausanne, Switzerland have discovered a chromosome anomaly in very skinny people that may explain pathologies that cause people to stop eating.

Medical Breakthrough: Genetics May Cause Anorexia, Other Forms Of Weight Loss
Caroline Depecker

LAUSANNE – Extreme thinness is a disease with diverse, hard-to-identify origins. Once other ailments are excluded, specialists tend to look at the possibility that excessive weight loss is brought on by social and psychological factors, such as those that cause anorexia nervosa.

But now, a team of French and Swiss researchers has turned the focus to genetics. In a study published by the British journal Nature, the research team shows evidence of surplus copies of certain chromosomal sections in the genome of those suffering from the disease.

"Just eat a little something…" Children scorning their food, losing their appetite, becoming nothing but skin and bones, getting worryingly thin. Because of inadequate caloric intake, the body has no choice but to stop growing.

"When faced with these kinds of patients, pediatricians feel like the parents: helpless', said Sébastien Jacquemont of the Medical Genetics Service at Lausanne's University Hospital, and one of the study's main authors. "Being underweight, as is the case for one to three percent of toddlers, is like a black box: we have no knowledge of its diagnostical limits or internal workings'.

For adults, extreme thinness is defined by their body mass index (BMI), which is a ratio of weight and height. Being underweight is defined as having a body mass index below 18.5. This is no trifling pathology, as it is said to affect 10 to 15% of the population, surprisingly close to the rate of those overweight: 15 to 20%.

Last year, Professor Jacques Beckmann of the University of Lausanne (UNIL) made a groundbreaking discovery about cases of morbid obesity: having only one copy of a particular fragment of chromosome 16 (instead of the usual two) could be responsible for being overweight.

But what could be the opposite effect of this genetic anomaly on weight? In other words, what might it entail if someone had three copies of this chromosomal fragment –that is, one too many? To answer that question, the team of scientists collected data from about 100 international laboratories. They gathered information concerning more than 100,000 patients, 138 of whom carried this particular genetic anomaly. Researchers demonstrated that such adult patients were 7 to 20 times more likely to be underweight than the rest of the population.

"This factor of genetic risk is four times greater than that of developing cholesterol-related heart diseases', said Philippe Froguel, a professor at the School of Public Health at Imperial College London, another lead researcher on the study. "Such a high level of risk shows that the patient's environment and choices only play a minor part in the evolution of the disease."

But the same is not true when it comes to children. The study showed that 50% of the people carrying that chromosomal anomaly were underweight. However, various factors (like exercising, or a healthy family environment, among others) could still change a lot of things during the evolution of the disease.

Discovering the genetic cause for extreme thinness is a major step for physicians, as it means that they can now rely on a simple diagnostic tool. "It will help prevent family tragedies', according to Froguel. "Sometimes social services suspect domestic abuse and tear the children away from their parents."

With this study, researchers may also be on the path to finding genes that are crucial to the feeling of satiety, and responsible for putting on weight.

Read the original story in French

Photo - st4rbucks

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Feed The Future

COP26 Should Mark A Turning Point In Solving The Climate Crisis

Slow Food calls for an action plan to significantly reduce and improve the production and consumption of meat, dairy, and eggs by 2050.

A new dawn?

If, as the saying goes, we are what we eat, the same also goes for the animals that end up on our plate. How we feed our own food can have knock-on effects, not just for our own health but also for the planet. We are now aware of the meat and dairy industry's significant carbon footprint, responsible for more than a third of global anthropogenic greenhouse gas emissions.

Large-scale cattle productions that favor pure profit over more sustainable practices also add to environmental woes through biodiversity loss, deforestation and pesticide use — with some of the world's richest countries contributing disproportionately: The five biggest meat and milk producers emit the same amount of greenhouse gases as the oil giant Exxon.

The good news is that we could meet — if we would — some of these challenges with an array of innovative solutions, as the fields of farming, breeding and nutrition look at ways to shift from centralized intensive agro industry toward a more localized, smaller-scale and more organic approach to production.

Cows fed corn and grain-based diets may grow larger and are ready to be processed at a younger age — but this requires significant energy, as well as land and water resources; in contrast, grass and hay-fed cows support a regenerative farming model in which grazing can contribute to restoring the health of soil through increased microbial diversity. Compared to highly processed GM crops, natural-grass diets with minimal cereals also lead to more nutrient-rich livestock, producing better quality meat, milk and cheese. Farmers have started focusing on breeding native animal species that are best adapted to local environmental contexts.

This new approach to agricultural practices is closely linked to the concept of agroecology, where farming works in tandem with the environment instead of exploiting it. If mowed a few times a year, for instance, natural meadows produce hay that is rich in grasses, legumes and flowers of the sunflower family, like daisies, dandelions, thistles and cornflowers. These biomes become reservoirs of biodiversity for our countryside, hosting countless species of vegetables, insects and birds, many of which are at risk of extinction. Until recently, these were common habitats in meadows that were not plugged or tilled and only required light fertilization. Today, however, they are becoming increasingly threatened: in the plains, where the terrain is used for monocultures like corn; or in hills and mountains, where fields are facing gradual abandonment.

It is worth noting that extensive agriculture, which requires smaller amounts of capital and labor in relation to the size of farmed land, can actually help curb climate change effects through carbon dioxide absorption. Researchers at the University of California, Davis determined that in their state, grasslands and rangelands have actually acted as more resilient carbon sinks than forests in recent years. Through a system of carbon uptake, these lands provide a form of natural compensation, going as far as canceling the farms' impact on the planet, rendering them carbon "creditors."

In the meantime, grasslands and pastures allow animals to live in accordance with their natural behavioral needs, spending most of the year outside being raised by bonafide farmers who care about animal welfare. A recent study by Nature found that allowing cows to graze out of doors has both psychological and physical health benefits, as they seem to enjoy the open space and ability to lie on the soft ground.

Some might worry about the economic losses that come with this slower and smaller business model, but there are also opportunities for creativity in diversifying activities, like agro-tourism and direct sales that can actually increase a farm's profit margin. This form of sustainable production goes hand-in-hand with the Slow Meat campaign, which encourages people to reduce their meat consumption while buying better quality, sustainable meat.

Others may assume that the only environmentally-conscious diet is entirely plant-based. That is indeed a valuable and viable option, but there are also thoughtful ways to consume meat in moderation — and more sustainably. It also should be noted that many fruits and vegetables have surprisingly large carbon footprints: The industrial-scale cultivation of avocados, for example, requires massive amounts of water and causes great hardship to farming communities in Latin America.

But forging a broad shift toward more "biodiversity-friendly" pastoralism requires action by both those producing and eating meat, and those with the legislative power to enact industry-wide change. It is urgent that policies be put into place to support a return to long-established agricultural practices that can sustainably feed future generations. Although no country in the world today has a defined strategy to decrease consumption while transforming production, governments are bound to play a key role in the green transition, present and future.

In Europe, Slow Food recommends that the Fit for 55 package include reducing emissions from agriculture activities by 65% (based on 2005 levels) by 2050. Agriculture-related land use emissions should also reach net-zero by 2040 and become a sink of -150 Mt CO2eq by 2050. But these targets can only be met if the EU farming sector adopts agroecological practices at a regional scale, and if consumers shift to more sustainable diets. If we are indeed what we eat, we should also care deeply about how the choices we make impact the planet that feeds us.

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