BioQuakes

AP Biology class blog for discussing current research in Biology

Author: maggiechondria

Is Air Pollution Exposure In Childhood Linked To Schizophrenia?

Research has shown that pollution affects physical health, but does air pollution also affect our psychological health? A study, which combines genetic data from iPSYCH with air pollution data from the Department of Environmental Science, reveals that children who are exposed to a high level of air pollution while growing up have an increased risk of developing schizophrenia.

“The study shows that the higher the level of air pollution, the higher the risk of schizophrenia. For each 10 ?g/m3 (concentration of air pollution per cubic metre) increase in the daily average, the risk of schizophrenia increases by approximately twenty per cent. Children who are exposed to an average daily level above 25 ?g/m3 have an approx. sixty per cent greater risk of developing schizophrenia compared to those who are exposed to less than 10 ?g/m3,” explains Senior Researcher Henriette Thisted Horsdal, who is behind the study.

To put this research into perspective, the lifetime risk of developing schizophrenia is approximately two percent, which is equal to two out of a hundred people developing schizophrenia in one’s life. For people exposed to the lowest level of air pollution, the lifetime risk is just under two percent. The lifetime risk for people exposed to the highest level of air pollution is approximately three percent.

“The risk of developing schizophrenia is also higher if you have a higher genetic liability for the disease. Our data shows that these associations are independent of each other. The association between air pollution and schizophrenia cannot be explained by a higher genetic liability in people who grow up in areas with high levels of air pollution,” says Henriette Thisted Horsdal about the study, which is the first of its kind to combine air pollution and genetics in relation to the risk of developing schizophrenia.

The study included 23,355 people in total. Out of those people, 3,531 developed schizophrenia. Through the results of this research one can see that there is an increased risk of schizophrenia when the level of air pollution during childhood increases; however, the researches cannot comment on the cause. Instead, the researched emphasize that further studies are needed before they can identify the cause of this association.

Schizophrenia is thought to mainly be a result of genetics, brain chemistry, substance use, and exposure to viruses or malnutrition before birth. So, I think it is very interesting that exposure to air pollution during childhood may be a cause as well. Additionally, I hope that these findings and further studies become very useful to schizophrenia research and prevention, as schizophrenia is a very serious mental illness and there is no cure.

 

Can your diet’s effect on gut bacteria play a role in reducing Alzheimer’s risk?

Could following a certain type of diet affect the gut microbiome in ways that decrease the risk of Alzheimer’s disease? According to researchers at Wake Forest School of Medicine, that is a possibility.

In a small study, researchers were able to identify several distinct gut microbiome signatures in study participants with mild cognitive impairment (MCI), but not in the other participants with normal cognition. Researchers found that these bacterial signatures correlated with higher levels of markers of Alzheimer’s disease in the cerebrospinal fluid of the participants with MCI. Additionally, through cross-group dietary intervention, the study also revealed that a modified Mediterranean-ketogenic diet resulted in changes in the gut microbiome and its metabolites that correlated with reduced levels of Alzheimer’s markers in the members of both study groups.

“The relationship of the gut microbiome and diet to neurodegenerative diseases has recently received considerable attention, and this study suggests that Alzheimer’s disease is associated with specific changes in gut bacteria and that a type of ketogenic Mediterranean diet can affect the microbiome in ways that could impact the development of dementia,” said Hariom Yadav, Ph.D., assistant professor of molecular medicine at Wake Forest School of Medicine.

The randomized, double-blind, single-site study involved 17 older adults, 11 diagnosed with MCI and six with normal cognition. These participants were randomly assigned to follow either the low-carbohydrate modified Mediterranean-ketogenic diet or a low-fat, higher carbohydrate diet for six weeks then, after a six week “washout” period, to switch to the other diet. Gut microbiome, fecal short chain fatty acids, and markers of Alzheimer’s in the cerebrospinal fluid were measured before and after each dieting period.

The limitations of the study included the subject’s group size, which also accountns for the lack of diversity in terms of gender, ethnicity, and age.

“Our findings provide important information that future interventional and clinical studies can be based on,” Yadav said. “Determining the specific role these gut microbiome signatures have in the progression of Alzheimer’s disease could lead to novel nutritional and therapeutic approaches that would be effective against the disease.”

Each human contains trillions of organisms that influence our metabolism, immune function, weight, and even cognitive health. It is so fascinating to examine the role of gut microbiomes in the progression of Alzheimer’s disease. I believe diets can be very controversial, and I find it interesting to see researchers in this study show how the Mediterranean-ketogenic diet may be effective against Alzheimer’s. However, I am so intrigued to see where these findings may take us with approaches that may be effective against Alzheimer’s, whether they be nutritional or therapeutic approaches.

Does Exposure to Toxins In the Environment Affect One’s Offspring’s Immune System?

A study has recently surfaced stating that maternal exposure to industrial pollution may harm the immune system of one’s offspring and that this impairment is then passed from generation to generation, resulting in weak body defenses against viruses.

Paige Lawrence, Ph.D., with the University of Rochester Medical Center’s Department of Environmental Medicine, led the study and conducted research in mice, which have similar immune system functions as humans. Previously, studies have shown that exposure to toxins in the environment can have effects on the respiratory, reproductive, and nervous system function among generations; however, Lawrence’s research is the first study to declare that the immune system is also impacted.

“The old adage ‘you are what you eat’ is a touchstone for many aspects of human health,” said Lawrence. “But in terms of the body’s ability to fights off infections, this study suggests that, to a certain extent, you may also be what your great-grandmother ate.”

“When you are infected or receive a flu vaccine, the immune system ramps up production of specific kinds of white blood cells in response,” said Lawrence. “The larger the response, the larger the army of white blood cells, enhancing the ability of the body to successfully fight off an infection. Having a smaller size army — which we see across multiple generations of mice in this study — means that you’re at risk for not fighting the infection as effectively.”

In the study, researchers exposed pregnant mice to environmentally relevant levels of a chemical called dioxin, which is a common by-product of industrial production and wast incineration, and is also found in some consumer products. These chemicals eventually are consumed by humans as a result of them getting into the food system, mainly found in animal-based food products.

The scientists found the production and function of the mice’s white blood cells was impaired after being infected with the influenza A virus. Researchers observed the immune response in the offspring of the mice whose mothers were exposed to dioxin. Additionally, the immune response was also found in the following generations, as fas as the great-grandchildren (or great- grandmice). It was also found that this immune response was greater in female mice.  This discovery now allows researchers to have more information and evidence to be able to more accurately create a claim about this theory.

As a result of the study, researchers were able to state that the exposure to dioxin alters the transcription of genetic instructions. According to the researchers, the environmental exposure to pollutants does not trigger a genetic mutation. Instead, ones cellular machinery is changed and the immune response is passed down generation to generation. This discovery explains information that was originally unexplainable. It is obviously difficult to just avoid how much toxins you are exposed to in the environment, but it is definitely interesting to see the extent of the immune responses in subsequent generations. We can only hope that this new information, and further discoveries, help people adjust what they release into this world that results in these harmful toxins humans are exposed to, and their offsprings.

 

 

 

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