On my homepage blog, I wrote about the power of our lifestyle choices impacting our health outcomes at the DNA level. It’s the science of epigenetics which refers to how the physical and chemical environment of our cells impact how our genes play out in “our book of life.” For example, our diet, our genetic variances, our lifestyle choices, and our little buggy friends all have profound impacts in how our genes express themselves.
This month, there were many examples of these interactions in various studies. In this blog, I’ll be discussing some of them.
Fido and Asthma
Being around our loyal four legged friends may impact our children’s buggy insides. This then effects the interplay with their biochemistry to modulate their immunity and overall health. According to Medical News Today, Good old Fido may bring joy to the family, but new research suggests he may also bring health benefits; a new study suggests early exposure to dogs and farm animals reduces asthma risks in children.
Epigenetics of the Environment-Toxins & Farming Smoking Effects Baby’s Lifelong Health
A new study in Environmental Research demonstrated that prenatal exposure to smoking has implications on baby’s health outcomes. Specifically, second-hand tobacco smoke caused changes in their DNA expression via methylation. Furthermore, the researchers indicated that blood-derived methylation markers could serve as indicators for prenatal smoke exposure:
Prenatal exposure to tobacco smoke has lifelong health consequences. Epigenetic signatures such as differences in DNA methylation (DNAm) may be a biomarker of exposure and, further, might have functional significance for how in utero tobacco exposure may influence disease risk. Differences in infant DNAm associated with maternal smoking during pregnancy have been identified. Here we assessed whether these infant DNAm patterns are detectable in early childhood, whether they are specific to smoking, and whether childhood DNAm can classify prenatal smoke exposure status. Using the Infinium 450 K array, we measured methylation at 26 CpG loci that were previously associated with prenatal smoking in infant cord blood from 572 children, aged 3-5, with differing prenatal exposure to cigarette smoke in the Study to Explore Early Development (SEED). Striking concordance was found between the pattern of prenatal smoking associated DNAm among preschool aged children in SEED and those observed at birth in other studies. These DNAm changes appear to be tobacco-specific. Support vector machine classification models and 10-fold cross-validation were applied to show classification accuracy for childhood DNAm at these 26 sites as a biomarker of prenatal smoking exposure.
Classification models showed prenatal exposure to smoking can be assigned with 81% accuracy using childhood DNAm patterns at these 26 loci. These findings support the potential for blood-derived DNAm measurements to serve as biomarkers for prenatal exposure.
Arsenic and Babies
MONDAY, Nov. 23, 2015 (HealthDay News) — Babies exposed to high levels of arsenic in the womb are at increased risk for infections and respiratory symptoms in their first year of life, a new
study suggests. Researchers measured levels of arsenic in 412 pregnant women in New Hampshire whose homes had private wells. For a year after their babies were born, the women were surveyed every four months about the number and severity of their children’s infections and respiratory symptoms, such as wheezing.
Infants exposed to arsenic in the womb had more infections that led to a doctor visit or treatment with prescription medications, the investigators found. In addition, those exposed to higher
levels of arsenic in the womb tended to have more upper and lower respiratory tract infections, as well as respiratory symptoms. The study was published recently in the journal Environmental Health Perspectives.
How Farming Changed the Human Genome
Genomic analysis of ancient human remains identifies specific genes that changed during and after the transition in Europe from hunting and gathering to farming about 8,500 years ago. Many of the genes are associated with height, immunity, lactose digestion, light skin pigmentation, blue eye color and celiac disease risk.
How Our Buggy Insides Modulate our Health-The Human Virome
It’s not just the bacterial microbes in our bellies that modulate our health. Viruses may be important too!
Genetic material from ancient viral infections is critical to human development, according to researchers at the Stanford University School of Medicine.
They’ve identified several noncoding RNA molecules of viral origins that are necessary for a fertilized human egg to acquire the ability in early development to become all the cells and tissues of the body. Blocking the production of this RNA molecule stops development in its tracks, they found.
Intake of Certain B Vitamins Modulate Risk Between PMS and High Blood Pressure
One prospective study compared 1, 257 women who struggled with premenstrual syndrome (PMS) to 2,463 age-matched controls. After adjusting for age, smoking, body mass index, and other risk factors, it was found that those women with PMS had a higher risk of hypertension. However, women who had high intakes of thiamine and riboflavin attenuated the risk.
The prevalence of hypertension is increasing among younger women, and new strategies are needed to identify high-risk women who should be targets for early intervention. Several
mechanisms underlying hypertension might also contribute to premenstrual syndrome (PMS), but whether women with PMS have a higher risk of subsequently developing hypertension has not been assessed. We prospectively evaluated this possibility in a substudy of the Nurses’ Health Study II. Participants were 1,257 women with clinically significant PMS (1991-2005) and 2,463 age-matched comparison women with few menstrual symptoms. Participants were followed for incident hypertension until 2011. Over 6-20 years, hypertension was reported by
342 women with PMS and 541 women without. After adjustment for age, smoking, body mass index, and other risk factors for hypertension, women with PMS had a hazard ratio for hypertension of 1.4 (95% confidence interval: 1.2, 1.6) compared with women without PMS. Risk was highest for hypertension that occurred before 40 years of age (hazard ratio = 3.3; 95% confidence interval: 1.7, 6.5; P for interaction = 0.0002). The risk associated with PMS was not modified by use of oral contraceptives or antidepressants but was attenuated among women with high intakes of thiamine and riboflavin (P < 0.05). These results suggest that PMS might be associated with future development of hypertension and that this risk may be modifiable.
Conclusion & Final Thoughts
We no longer can use genetics as our excuse for poor health. It’s becoming clearer that how we live, the choices we make, and our environment all add up to whether our genetic risks manifest into disease. It’s empowering that we no longer have to be victims of our genes, isn’t it!
Could the family dog lower your child’s asthma risk? Medical News Today, November 2, 2015. http://www.medicalnewstoday.com/articles/301881.php
Ladd-Acosta C, et al. Presence of an epigenetic signature of prenatal cigarette smoke exposure in childhood. Environmental Research. January 2016; 144A: 139-148.
Preidt R. Arsenic Exposure in Womb Linked to Respiratory Risks in Babies. Health Day, November 23, 2015.
Harvard Medical School. How the introduction of farming changed the human genome. Science Daily, November 23, 2015.
Stanford University Medical Center. Ancient viral molecules essential for human development. Science Daily, November 23, 2015.
Am. J. Epidemiol. 2015; doi: 10.1093/aje/kwv159