All posts by William Stiff

Dangerous cigarette compounds “travel” in every environment clinging to smokers’ clothes

A further study focuses on so-called “third-hand smoke”, i.e. that type of second-hand smoke in which the injured party is in an environment, usually closed, where someone has smoked. The most striking example may be the interior of a car in which someone has smoked and there are still cigarette butts and ashes in the ashtrays.

This new study confirms that the remains of smoked cigarettes can cling to the bodies or clothes of smokers and then be released into non-smoking environments.
The team of researchers, led by Drew Gentner of Yale, shows in this study that these cigarette compounds can literally travel, and even in abundant quantities, in indoor environments frequented by non-smokers transported by smokers themselves.

According to the researchers, a person, even if he or she is in a room where no one has smoked, can still be exposed to many of the chemical compounds found in a cigarette if a person who had previously smoked has entered that room.
As Gentner explains, “People are substantial carriers of third-hand smoke contaminants in other rooms. Therefore, the idea that someone is protected from the potential health effects of cigarette smoke because they are not directly exposed to second-hand smoke is not right”.

To reach these conclusions, the researchers analysed the traces of cigarette compounds in a movie theatre. The researchers found that the amounts of these substances left by smokers, for example through their clothes on armchairs or in the air, increased dramatically after the screening of R-rated films, i.e. films for adults who naturally saw more smokers in the cinema.

The quantities of these dangerous substances, of which nicotine was the largest representative, were not even to be overlooked, according to the researchers: they were comparable to those of exposure to second-hand smoke.
These compounds continue to make their way into enclosed spaces despite strong bans and numerous regulations in many states around the world prohibiting people from smoking not only inside public places but also near entrances or near air vents.

Exposure to sunlight can modify intestinal microbiome

Exposure of the skin to ultraviolet light from the sun can modify the intestinal microbiome according to a new study published in Frontiers in Microbiology. To mediate this change would be vitamin D and this would also explain the protective effect of ultraviolet light itself with regard to inflammatory bowel diseases.

It is well known that exposure to sunlight gives greater production of vitamin D in the skin. It is known, however, through studies published in recent years, also that the same greater quantity of vitamin D can alter the human intestinal microbiome. It follows that solar radiation on the skin can change the human intestinal microbiome but this has only been shown in rodents. This new study shows that this effect is also real for humans.

The researchers performed experiments on 21 healthy volunteer women. The 21 patients underwent three one-minute ultraviolet exposure sessions throughout the body for a week. Throughout the treatment, stool samples were taken and intestinal bacteria were analyzed. Blood samples were also taken to analyze vitamin D levels. The researchers discovered that the exposure of the skin to ultraviolet rays significantly increased the intestinal microbial diversity and this happened only in those people who had not taken vitamin D supplements in the course of experiments.

As explained by Bruce Vallance, a researcher at the University of British Columbia who led the study, exposure to UVB rays increased the richness and uniformity of the subjects’ microbiome. Before exposure to rays, women who did not take supplements showed a less diversified intestinal microbiome than women who already took vitamin D supplements. Among the bacteria that increased the most were the Lachnospiraceae, a genus of bacteria already previously linked with vitamin D.

“UVB light is able to modulate the composition of the intestinal microbiome in humans, through the synthesis of vitamin D,” says Vallance. Now researchers would like to discover the underlying causes but according to Vallance, it is likely that exposure to UVB light somehow affects the immune system of the skin and this, in turn, has a favorable influence on the intestinal environment for different species of bacteria.

Gluten-free diets do not help intestines of non-celiac people

People who avoid foods containing gluten by choice, therefore not for reasons related to allergies or particular sensitivities, do not receive any benefit from this dietary restriction according to a new study published in Gastroenterology and carried out by researchers from the University of Reading, that of Sheffield and the Sheffield Teaching Hospitals NHS Foundation Trust.

The researchers made use of experiments carried out on healthy volunteers who had no history of celiac disease or particular sensitivity to gluten. The participants were divided into two groups: the first received organic gluten, the second a missing gluten mixture in the form of flour sachets to add to their dishes twice a day. Patients in the group taking gluten had no adverse effects compared to the group of patients who did not take it.

According to Paola Tosi, a researcher at the University of Reading and one of the authors of the study, nowadays gluten is increasingly referred to as a negative element of our diet but cereals that contain it, especially when taken as a whole, are instead a very source important of essential nutrients such as proteins, fibers and micronutrients.

David Sanders, a professor of gastroenterology in Sheffield and another author of the study, believes that carrying on gluten-free diets, in the belief that gluten itself is intrinsically “bad” in particular for the intestine, does not lead to particular health benefits. Gluten does not cause particular stomach problems in those subjects who do not have a particular sensitivity towards it.

As a result of these incorrect beliefs, more and more people, in fact, are carrying out restrictive gluten-free diets or buying food, taking them from supermarket shelves, making sure that there is no gluten inside.

Breastmilk sharing is becoming increasingly widespread despite risks to the baby

More and more often, women who are unable to produce enough breast milk for their children resort to the practice of sharing breast milk, also known as “milk sharing,” a practice that even sees the sale of milk online from the same mothers.

Using milk donated by other mothers on an informal basis is a practice that is not universally considered safe and is discouraged by the pediatric medical community, as reported by a press release presenting a new study presented in turn at the American Academy of Pediatrics (AAP) conference.

According to Nikita Sood, a researcher at Cohen Children’s Medical Center – Northwell Health in New York and author of the study, sharing breast milk is becoming increasingly widespread and popular and it is therefore important that the same doctors are aware of this level of diffusion and deepen the risks associated with this practice.

The study made use of the answers provided by 650 mothers, more than half of whom declared that they had no problems regarding this practice, carried out informally and not, for example, through “official” milk berries. Almost 80% of the mothers interviewed did not give their breast milk donors a medical examination because they “trusted them.” However, there is a fairly high risk of the potential spread of disease or exposure to substances such as drugs, alcohol, drugs or other types of contaminants when supplying the baby with milk from another mother’s breast.

According to the AAP’s own recommendation, those women who are unable to produce breast milk can supplement diets in other ways, such as with artificial milk or with breast milk stored in formal milk banks. More than half of the people interviewed stated that they did not use “official” milk banks as they were mostly concerned with the cost or, to a lesser extent, with the quality or ability to obtain a prescription.

Westernization has profoundly changed our microbiome

Lifestyle can change the intestinal microbiome, a sort of ecosystem of bacteria existing in our intestine that can have various roles and that can also be a support for our immune system. This is confirmed by a new study, which appeared in Cell Host & Microbe and was conducted by researchers from the University of Trento and Eurac of Bolzano, who made up above all the analysis of the remains of Ötzi, human remains found in 1991 in the Alps belonging to a man lived between 3300 and 3100 BC.

By examining the intestine specimens of Ötzi’s remains, the researchers confirmed that there is a connection between the microbiome bacteria and the lifestyle change that today distinguishes the Western world above all. In particular, the connection exists between the bacteria and the increase of conditions such as obesity, autoimmune and gastrointestinal diseases, allergies and other complex conditions. In the press release that presents the study, they talk about a “Westernization process” that has brought about profound changes in our diet and that has meant that today foods are much richer in fat and poorer in fiber. This, combined with a more sedentary lifestyle and the development of new hygiene habits as well as medical products of various kinds, while making our lives safer has profoundly affected our microbiome.

In particular, the researchers analyzed the Prevotella copri, an intestinal bacterium. Nicola Segata, one of the main authors of the study together with Adrian Tett of the CIBio of the University of Trento, explains that they first discovered that it is not a single species. In fact, the bacterium is part of four different species. They later discovered that three of them had always been found in the microbiomes of non-westernized populations rather than in westernized ones. When the bacterium is found in the intestines of westernized populations, it is usually of a single species, which of course goes to the detriment of diversification.

The researchers, therefore, thought that the same phenomenon of “westernization” of our habits, above all food habits, caused the decrease of the diversification of this bacterium in our intestines, which probably happened also for other species of bacteria not analyzed by researchers. This same hypothesis, according to Segata, is supported by the analyzes that the same researchers carried out on ancient DNA, which was possible with a collaboration with the Institute for the study of mummies of Eurac Research. In particular, analyzing Ötzi’s intestines, the researchers noticed that three of the species of this bacterium were present in his intestine.

This multiple presence can also be identified in various fossilized stool samples dating back over a thousand years ago and found in Mexico. Now the only thing to understand is to what consequences this decrease in the diversification of our intestine bacteria and in general the changes of our intestinal biome that are taking place over the last few centuries can bring, considering also that the human body itself has never substantially changed to genetic level during the same period.

Oxytocin in babies is influenced by the behaviour of the mother

A new study analyzes the development of oxytocin in the body of children, a development that can be influenced by the behavior of mothers themselves. Oxytocin is an important hormone linked mainly to social interaction and plays this role in many mammals. This same hormone, as reported in the press release presenting the study on the Max Planck Society website, elaborates trust levels and relationships and can also be triggered with a simple visual contact or a touch.

In the new epigenetic study, conducted by researchers Kathleen Krol and Jessica Connelly of the University of Virginia and Tobias Grossmann of the Max Planck Institute for Human Cognitive and Cerebral Sciences, researchers show that mothers’ behavior itself can have a significant influence on the development of oxytocin in children.

As Grossmann himself explains, it is already known that oxytocin is involved in the first social processes of the child and may in the long run also influence social behavior later, the more complex ones. The researcher himself explains the meaning of the research they produced: “However, in this study, we asked ourselves whether the mother’s behavior could have a decisive influence on the development of the child’s oxytocin system. The advances in molecular biology, in particular epigenetics, have recently allowed us to study the interaction between nature and breeding, in this case, the care of children, down to the smallest detail. This is exactly what we did here.”

The researchers analyzed various saliva samples taken from the mother and child when he was five months old and then a year later when he was 18 months, all while observing free play interactions between the mothers and the children themselves. According to Krol, the results show that “The oxytocin receptor is essential for the hormone oxytocin to exert its effects and the gene can determine how many are produced.”

In general, the results of this study show that people do not interact with each other simply based on genetics but that the same interaction is based on a balance between genetics and experiences. This means that the first social interactions that the child may have, even with a breeder who is not a parent, can strongly influence biological and psychological development through changes in oxytocin.