Transgenerational Epigenetic Inheritance & Systemic Racism in the United States
EFFECTS OF HISTORICAL TRAUMA AND SYSTEMIC RACISM Centuries of government and socially sanctioned atrocities against Africans and their descendants have had a toll, not just on the psyche, but on the physical body as well. Those experiences “get under the skin,” and increase risk of a whole host of negative social, psychiatric, and medical health problems. (6)
HISTORICAL TRAUMA Historical trauma has been defined as events that are so widespread as to affect an entire culture; such events also have effects intense enough to influence generations of the culture beyond those who experienced them directly. (7)
DESCENDANTS OF HOLOCAUST SURVIVORS. In 1967 Canadian Psychiatrist Vivan Rakoff, recorded elevated rates of psychological distress among children of Holocaust survivors.
Since then there have been multiple studies done showing that the children, and grandchildren of Holocaust survivors reported elevated levels of psychological distress. (pg 6)
ADVERSE CHILDHOOD EXPERIENCES (ACEs). Over the last two decades research has shown that ACEs are associated with an increased risk for a broad range of negative social outcomes, including psychiatric and substance abuse disorders, health risk behaviors and medical health problems, even after controlling for socioeconomic factors. (pg 14)
EPIGENETIC MECHANISMS — although every cell in the body has the same DNA, different genes are turned on in different cells, and the blueprint for each different cell type is programmed through epigenetic mechanisms, which are chemical modifications to the DNA that can affect the likelihood of a gene product being turned on or off. (pg 15)
METHYLATION – the addition of a carbon atom with three hydrogen atoms to DNA is known to shut off genes when added to the beginning of the gene sequence. One of the most highly replicated findings is that early stress in life can lead to methylation of the glucocorticoid receptor (GR)gene, which helps to turn off the stress response. Methylation of this receptor is associated with heightened stress reactivity. (pg 15)
ANIMAL RESEARCH — studies of transgenerational epigenetic research are difficult to execute in humans as it is difficult to obtain multi-generational cohorts and to exclude psychological and cultural everyday experiences that could also create trauma. But with animal studies it is much easier to obtain multi-generational cohorts and to control for various factors. (pg 15)
TRANSGENERATIONAL EPIGENETIC INHERITANCE — environmentally induced epigenetic modifications (modifications caused by socio-economic factors, such as trauma and stress) to the germline (the sperm or the egg), that are inherited across generations. (pg 15)
TRANSGENERATIONAL EPIGENETIC STUDIES (pg 17)
- Fear Conditioning. Rodents who were conditioned to fear certain odors via shock treatment prior to conception produced offspring and grandchildren with increased behavioral sensitivity to the conditioned odor, even though they had no prior exposures to the shock. The offspring were also found to have epigenetic alterations in their sperm and in brain regions involved with olfactory perception.
- Maternal and Infant Health Rodent Studies Across Four Generations.
Transgenerational and multigenerational prenatal stress resulted in low birth weight, and changes in genes pertaining to brain plasticity, parturition/childbirth and preterm birth. This finding is especially impactful considering that recent findings show that even with adequate prenatal care, African American women are still at an elevated risk for preterm births. (pg 19).
- High-Fat Diets Can Reprogram the Epigenome of Sperm and Transgenerationally Affect Metabolism In their Offspring.
The offspring of male rats fed a high-fat diet had reduced birth weight, which is a documented risk factor for obesity and type 2 diabetes. (pg 19)
- Exposure to DDT and Other Environmental Toxins Can Have Transgenerational Effects
In studies when the parent line of rats were the only ones exposed to DDT, the children and grandchildren of the rats developed several pathologies, such as ovary and kidney diseases. Also, when experiments were done with ZebraFish who had suffered from lead exposure, their offspring and grandchildren who had not been exposed to lead also exhibited the same lead-induced learning deficits as the fish who were directly exposed. (pg 20)
- Epigenetic Marks Found In Sperm of Mice Due to Trauma, Poor Nutrition, etc., Have Also Been Found in Sperm in Humans
Alterations to the ncRNAs of the sperm of mice who experienced parental separation have also been found in the sperm of humans who have experienced parental separation. (pg21)
MITIGATING EPIGENETIC TRANSGENERATIONAL TRAUMA
Studies show that the deleterious effects of epigenetic transgenerational trauma can be mitigated and prevented. (pg 22)
- African-Centered Culturally Prevention and Treatment Interventions There is a growing body of research suggesting that Afrocentric culturally-adapted prevention and treatment interventions are especially effective in addressing a range of different risks and promoting positive outcomes in African descendants. (Pg. 25)
- Extinction Training Treatment that includes the gradual elimination of the condition responses by repeat exposure (through talking about traumatic experiences) paired with relaxation training and cognitive processing. (Pg. 22)
- Nutrition Adopting a healthy lifestyle that may include diet, exercise, reducing red meat, eating plant protein, increasing fruit portions and foods rich in antioxidants, antioxidant supplements, decreasing alcohol intake, avoiding smoking, exercise and stress reduction activities. (Pg. 22)
- Enrichment Experiences Living in enhanced spaces that … provide rich social, physical and sensory experiences. Educational enrichment, including early childhood programs, academic enrichment, and team sports and art enrichment programs are examples. (Pg. 24)
- Familial Reinforcement Positive support from parents and/or other adults has consistently been found to be the most important factor in promoting resilience and recovery.