Health and Medical News and Resources

General interest items edited by Janice Flahiff

[Reblog] Epigenetics – how the environment influences our genes

Epigenetics – how the environment influences our genes › Lindau Blog.

“..today we must assume that if our generation is suffering hardship, violence or the like, not only will we struggle to forget these difficult periods ourselves but our genes too will remember them, carrying traces to be passed on to the next generation or even several generations.”

From the 8 May 2015 post at Scilogs

The science behind a rapid paradigm shift

When the first human genome was decoded, popular thinking went: “If we know the genes, we know the person.” Today, barely 15 years later, science is in the middle of an exciting new area of research, which is entertaining interested members of the public with exciting, if not always serious, headlines. The field alleges that traumatic experiences can be passed down through the generations and even significantly affect the lives of grandchildren. As it turns out, the reality is that genes not only control, but are also controlled. And that is what epigenetics is all about – how are genes controlled and what factors can influence them?

Epigenetics refers to the meta-level of genetic regulation. Under the influence of external factors, epigenetic mechanisms regulate which genes are turned on and off. This helps our fixed genetic material to be more flexible. At the biochemical micro level, epigenetic regulators are responsible for how closely packed individual genomic regions are and therefore how accessible or not they are. This works by small adhered or detached chemical groups. The resulting marking of the genome is read by specialised enzymes that then cause the switching on or off of the genes.

English: Structure of a nucleosome with histones from the fruit fly, Wikimedia Commons (Sponk)

As reasonable as this appears, one consequence is that we will have to say goodbye to a long-established dogma: the idea that genes are immutable in the creation of a living being. And, looking back through the history of science: was Lamarck right, after all? The 19th-century French biologist had claimed that organisms acquired traits to pass on to future generations . It is precisely this mechanism that epigeneticists are on the trail of today. Laboratory experiments with mice have demonstrated that a particular, targeted encoding of individual genes results in the changes being passed on to the offspring. Epigenetic changes, however, are so-called soft changes, as they can be undone. And that is medicine’s great hope – to be able to intervene in the control mechanism from the outside in order to be able to work against, for example, senile dementia.

PET scans showing the differances between a normal older adult's brain and the brain of an older adult afflicted with Alzheimer's disease, Wikimedia Commons (Health and Human Services Department, National Institutes of Health, National Institute on Aging)

At this point, the level of possible tension around this new field of research becomes clear. On the one hand, the idea that our human condition can be so strongly “manipulated” by environmental influences can be very disturbing. And rightly so. Previously, we may have had the upbeat expectation that although we are experiencing suffering, the next generation will have it better. However, today we must assume that if our generation is suffering hardship, violence or the like, not only will we struggle to forget these difficult periods ourselves but our genes too will remember them, carrying traces to be passed on to the next generation or even several generations.

study often mentioned in this context is based on the analysis of data collected in the Netherlands over the years of hunger in 1944-45, during which the population there suffered particularly difficult conditions. The children born at this time were not only smaller, but, as adults, had an increased risk of obesity, cardiovascular problems and neuropsychiatric disorders. In turn, their offspring were again smaller than average – despite food being in ready supply and living conditions having greatly improved.

 

May 18, 2015 Posted by | Medical and Health Research News | , , , | Leave a comment

[Reblog] Your Immune System Is Made, Not Born

From the 29 January 2015 post at Scientific American

New research dispels the belief that the strength of the body’s defense system is genetically programmed
Cytomegalovirus

Cytomegalovirus infection.
Credit: Yale Rosen via Wikimedia Commons

Some people seem better than others at fighting the flu, and you might suspect they were born that way. A new study of twins, however, suggests otherwise.

In one of the most comprehensive analyses of immune function performed to date, researchers analyzed blood samples from 105 sets of healthy twins. They measured immune cell populations and their chemical messengers—204 parameters in all—before and after participants received a flu shot. Differences in three fourths of these parameters depended less on genetics than on environmental factors, such as diet and prior infections. Genetics had almost no effect on how well individuals responded to the flu vaccine, judged by antibodies produced against the injected material. And among identical twin siblings, who have the same genome, immune system features differed more strikingly within older twin pairs than in younger sets. The findings, published January 15 in Cell, argue that life habits and experiences shape our body’s defenses more than the DNA passed down from our parents.

Although prior twin studies had hinted that nonheritable factors contribute to some autoimmune disorders, such as multiple sclerosis, the recent analysis was one of the first to quantify genetic and environmental effects on the general immune system. “We were surprised by the degree of environmental influence on so many components,” says Mark Davis of Stanford University School of Medicine, senior author on the new study.

One finding was particularly striking. A single environmental factor—a past infection with common cytomegalovirus—affected 58 percent of the tested parameters. Whereas the results don’t show whether these changes produce an overall stronger or weaker immune response, they do indicate “cytomegalovirus has a really profound effect,” Davis says. The Epstein–Barr virus, another microbe that frequently infects people, had no such effect.

Read the entire article at http://www.scientificamerican.com/article/your-immune-system-is-made-not-born/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Science360NewsServiceComplete+%28Science360+News+Service%3A+Complete%29&utm_content=Netvibes

January 30, 2015 Posted by | Medical and Health Research News | , , , , | Leave a comment

[Article] Pain sensitivity may be influenced by lifestyle, environment, twin study suggests

One way to address the growing heroin epidemic? Address lifestyle and environment components.
Certainly would be a public health way to stem folks dependence on substances that can often diminish quality of life and death.

Screen Shot 2014-02-05 at 6.48.46 AM

From the 4 January 2014 Science Daily article (read the entire article at this link)

Researchers have discovered that sensitivity to pain could be altered by a person’s lifestyle and environment throughout their lifetime. The study is the first to find that pain sensitivity, previously thought to be relatively inflexible, can change as a result of genes being switched on or off by lifestyle and environmental factors — a process called epigenetics, which chemically alters the expression of genes.

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February 5, 2014 Posted by | environmental health, Medical and Health Research News | , , , , | Leave a comment

[Reblog] The Environmental Factors That Influence Our Children’s Illnesses

POSTED ON OCTOBER 23, 2013 BY 

 

Screen Shot 2013-10-24 at 5.48.24 AM

© Ampyang | Dreamstime Stock Photos & Stock Free Images

In general, we know that most illnesses and diseases are caused by an interplay of genetics and environmental factors. While there is little we can do to alter genetic susceptibility, understanding what and how environmental factors exacerbate if not trigger illnesses and diseases can help you keep your child safe and healthy.

First, note that there are disease agents – chemical and biological – that your child is exposed to through ingestion, inhalation and dermal contact with soil, food, water and the air. That’s called direct exposure. The opposite, indirect exposure, involves contact with disease agents through interactions with parents and caretakers. For instance, if the father who works in the construction industry comes home and holds his baby, the baby may inhale industrial fumes from his work clothes or chemical residue from the father’s worksite may be transferred from the father’s skin to the baby. Through both modes, children absorb disease agents that alter hormones and disrupt metabolic processes thereby triggering a number of childhood illnesses. It’s also important to recognize that exploratory behavior for children includes putting objects in the mouth, hand-to-mouth contact, which increases the risk for exposure to environmental disease agents.

The chart below lists a number of common childhood illnesses, an associated environmental agent and potential direct and indirect sources of exposures. Use this list to determine if there are any sources of disease agents that you should keep away from your child.

Presenting Problem
Environmental                  Agent Potential Exposures
Abdominal Pain Lead Batteries, smelting, painting, ceramics, enameling, welding, plumbing
Acute Psychoses Lead

Carbon disulfide mercury

Fungicide, maternal infection, wood preserving, removing paint from old houses, viscose rayon
Angina Methylene chloride

Carbon monoxide

Improperly vented indoor combustion sources, traffic exhaust, car repair, furnaces, water heaters, gas grill, foundry, wood finishing
Asthma Formaldehyde

Pet dander

Tobacco smoke

Toluene diisocyanate

Plastics, textiles, lacquer, playing with pets, polyurethane kits
Cardiac Arrhythmia Fluorocarbons

Solvents

Refrigerator repair, automobile emissions, cigarette smoke, paint thinners, propane gas
Dermatosis Solvents

Soaps

Caustic alkali

Metals

Plastics, metal cleaning, electroplating, machining, housekeeping, leather tanning
Headache Carbon monoxide

Solvents

Unvented kerosene, tobacco smoke, firefighting, dry cleaning, wood finishing, gas grill, water heaters, furnaces, automobile exhaust, improperly vented indoor combustion mechanisms
Hepatitis Halogenated hydrocarbons Healthcare workers, lacquer
Pulmonary

Edema

Cadmium

Nitrogen oxides

Phosgene

Halogen gases

Farming, welding, smelting, chemical operations

 

 

October 24, 2013 Posted by | Consumer Health, environmental health | , , , , , , , , | 1 Comment

   

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