Epigenetics and how they affect you

0:02 A listener production. Hello, and welcome to another solo episode of Crappy to Hay. I have just come back from a trip to Amsterdam where I went and ran some workshops. On stress resilience. I talked about the window of tolerance, like I've talked to you about here on this podcast. It was great. I had really great feedback from the workshops that I ran. One souvenir that I brought back which I wasn't intending to was. This heavy head could so I apologize. The show must go on. I feel fine. I've taken cold tablets, but I do sound very nasally, so I apologize for that. Today, what I want to talk to you about is this study that I recently heard of which I found so fascinating. I know that you were going to find it fascinating as well. It's to do with epigenetics. So epigenetics is the study of changes in gene expression in response to behavior, vieral and environmental factors that don't change the underlying DNA sequence. All that means is you will have genes for certain things.

1:09 You have the DNA of both of your parents, and you may have genes for certain diseases, for certain conditions for cancer, diabetes, all sorts of things, and whether or not those genes are turned on or off can be influenced by environmental factors and those changes. Though the impact of the environment on your DNA on your genes can be passed down through your genetics, hence EPI genetics. So I guess to put this really bluntly, and what we're going to talk about today is that your grandmother may have experienced something and you, your physiology is affected by that because of the change in your grandmother's gene expression, which is past down to your parents and one of your parents and then ultimately passed down to you. Now, the study that I heard about, which actually isn't that new, It was about twenty fourteen, twenty thirteen, but I only recently heard about it, and it involved mice who were exposed to the scent of I'm going to say, cherry blossoms.

2:21 It's often referred to as the cherry blossom experiment. To be technical, it wasn't actual cherry blossoms. It's a particular chemical. It's an artificial scent that has been likened to the scent of cherry blossoms for the sake of simplicity, let's just call it cherry blossoms. So what they did was they took these mice and they exposed them to the scent of cherry blossoms at the same time that they administered shocks to their feet. I know, I can't stand the things that they do to animals for these experiments, but obviously we all benefit from what they find. So mice were exposed to shocks to their feet at the same time they were exposed to the scent of cherry blossoms, which meant that they eventually came to associate the scent of cherry blossoms to pain, physical pain distress. So then what would happen is every time they were exposed to the scent of cherry blossoms, even in the absence of any sort of electrical shock or any sort of pain or distress, their fight or flight response was activated. The amygdala in their brain lit up, they produced cortisol adrenaline. Essentially, that whole threat response, which is instinctive we all have that in us, was activated just by the scent.

3:30 Of cherry blossoms. Okay, so we understand how that works. Then what they found was that when they got pregnant or when they impregnated female mouse and they had babies, those baby mice also displayed an increased threat response, ammigual activation, all of those things in response to the scent of cherry blossoms, even though those baby mice had never been exposed to the foot shocks or to the smell of cherry blossoms before. To control for the fact that often babies, and this goes for human children as well, often are pick up fear from their parents.

4:16 If your parents, you know, we're often what little kids learn is modeled by their parents. If your parents demonstrate fear or avoidance of things. Then children will pick up that that is something scary. So to control for that possibility, what they also did was they took some of those baby mice and they adopted them out and had them raised by other mice that who had never been exposed to the scent of cherry blossoms. And they found that even those baby mice still had the same reaction, they had the same heightened stress response when exposed to the scent of cherry blossoms. Then what they did was they took the sperm from the male mice who had been exposed to the shocks and who had experienced that heightened threat response, and they used IVF to impregnate other female mice, again who had never been exposed to the shocks or to the cherry blossoms, so it was purely biological, purely genetic. Than those baby mice also demonstrated the same threat response, the same reaction to the scent of cherry blossoms, demonstrating that this fear, that this sensitivity to this particular smell, this environmental factor that was associated with something scary, something painful, was transmitted by the parent's DNA even when there was no environmental factor, no modeling of the parent's behavior that accounted for that response.

5:48 Those baby mice still demonstrated that same heightened threat response, that fear response to the sin of cherry blossoms. And they even found that the next generation experienced some of that same response in the face of the sense of cherry blossoms. So what does this mean for us? I guess the reason that I find they're so fascinating. And if you did listen to my earlier episode on the window of tolerance, I talked about the fact that we all have a range, like a range within which we can comfortably tolerate distress. Our nervous system is reacting all of the time to our environment and also to our internal you know, our thoughts and our feelings and the things that we do internally. And I said that everybody's window is unique, like everybody's window of tolerance is a different width.

6:37 And we talked about the fact. That sometimes the width of your window can be affected, like your window might be narrower than somebody else's because of your early childhood experiences, because of early trauma, because of chronic stress that you've been exposed to, because of a recent trauma, like a single major impact kind of trauma that temporarily narrows your window of tolerance. But I guess what this mice study demonstrates, this cherry blossom study demonstrates is that sometimes your window of tolerance might be a little narrower for reasons that have nothing to do with your own experience. There might be something that occurred in.

7:19 One of your parents' lives or even in one of your grandparents' lives that has been transmitted through your DNA. And this is very early research, Like I don't claim to have all of the answers about this. This is not necessarily definitive. This is just one example of a study, and there have been many studies that are happening at the moment in this area. It is relatively new research. But there might be factors that you can't account for. There might be things that you don't know. You can't put your finger on why a particular sand or why a particular site or something in your environment triggers a stress response in you and our human brains, we want to analyze everything, We want a reason for everything. The other thing that we want is to fix and solve every problem, of course, and so we can sometimes get a little obsessive about looking for why is this happening? Or why am I reacting on this? And we get very self critical as well, What's wrong with me? Why do I react like that in these situations? And the answer is maybe sometimes you just don't know. So the key here is simply to recognize that sometimes there is things going on that you may not be aware of, and the important thing is simply to acknowledge and to validate your response. I guess to honor your own feelings. Of course, it is our responsibility to start to try to widen that window to take care of ourselves, to support ourselves physically, mentally, emotionally,

8:51 to be able to widen that wind of tolerance, to increase the range of stress that we can comfortably cope with. But if you notice that you sometimes are a little more sensitive to things than somebody else might be, then it could be that you will never know what that answer is. Unless you have got. A full detailed personal history of everything that your parents and your grandparents have ever experienced in their lives, you may not ever know. I think this is really important also when we talk about the transmission of trauma, which is what we are talking about when we talk about intergenerational trauma, when we're talking about major traumatic experiences, the implications for that for collective trauma, racial trauma. They first started to notice these effects with the children and grandchildren of Holocaust survivors. We've also seen effects in terms of physical changes, higher risk of obesity and diabetes when a grandmother or a mother was exposed to malnutrition during a famine while she was pregnant. So if your grandmother was exposed to a famine was undernourished during pregnancy.

10:04 Then her babies are. At a significantly higher risk of obesity and diabetes and higher levels of bad cholesterol because essentially they've been programmed to operate with less calories, less caloric intake, So when they actually consume a normal, healthy diet, they're actually more likely to experience overweight, obesity and diabetes because they're genetically kind of not equipped to handle that. So there are very. Real physical effects, physiological changes that also can occur as a result of this transmission of changes in our DNA and how our DNA is expressed, and that effect may remain even for subsequent generations, at least to the grand children level. So getting back to trauma and the effect of trauma on subsequent generations, intergenerational trauma was first identified among children of Holocaust survivors, with children of Holocaust survivors being three hundred percent more likely to seek a psychiatric referral.

11:20 It's since been identified in indigenous populations in Australia and in Canada. And I guess the point of this is that, so this is not a new phenomenon, but I think in the past we probably assumed that some of that psychological and emotional vulnerability that was experienced by children of trauma survivors and grandchildren of trauma survivors was behavioral. If you've experienced significant trauma, then it is likely that you probably have difficulty bonding with your children. You might have very low tolerance for stimulus in the environment. You might be depressed, withdrawn, emotionally disconnected. There's all sorts of effects that we know can be experienced as a result of trauma.

12:07 Might be hypervigilant, very anxious, and that that's going to significantly affect your children. Children who have a traumatized parent are at an increased risk of experiencing their own psychological issues because of all of these reasons, because of issues with how you are parented. And I think what this more recent epigenetic studies is demonstrating that it is not just behavioral. It is not just what you're exposed to in your day to day relationship with your parent and the quality of that relationship, but there can actually be effects that are transmitted via DNA and that you can't see those things, you can't explain them, and that there might be trauma that is nowhere near at the same level as a holocaust or you know, those sorts of genocides.

12:59 But as we saw with the mice and the cherry blossoms, electric shocks to the feet, just exposure to something distressing that created a stress response that ultimately was passed down to children and grandchildren. Now I know this is all probably sounding very depressing, so I feel like I need to wrap this up with something that is a little more positive and optimistic. So to that end, I did also read a recent research article to do with this whole epigenetics thing which found that these effects, this transmission of changes to DNA, actually resolved after two generations, so this is interesting. This was actually quite controversial because some people thought that this was going to have assumed that these changes will continue to be passed down through generations.

13:50 So what this one study found was that actually that wasn't the case. That at the second generation the effects had pretty much resolved. And I think that this. Makes sense because what we're seeing really is a short term adaptive response to a particular environmental situation. So it kind of makes sense that there would be a short term adaptive effect something to help protect the offspring in you know, during a famine or whatever the case is, or during something stressful or difficult, so that that effect would be passed down to the offspring to equip them to deal with that present environmental situation, whatever that may be.

14:34 But then beyond that it is no longer required or relevant as long as the situation is resolved, as long as that stress or whatever that situation is is no longer applicable. The other thing I want to share with you is that we can use this in a really positive way as well. So let me share with you one other study, also to do with mice, and this is to do with maternal grand maternals I'm sorry, exercise habits. So if your grandmother. Exercises, particularly during pregnancy, then that can lead to significant improvements in metabolic health in grand children. So reduced risk of obesity, diabetes, lower body fat percentage, increased bone mineral density, and higher levels of glucose tolerance. So essentially, when they did glucose tolerance tests on grand babies of sedentary grandmothers, they had worsening glucose tolerance with age, whereas those who had exercise trained grandmothers I say exercise train because this was a mouse experiment did not have the same age related decline in glucose tolerance. So the effects of epigenetics and the transmission through our DNA through our and how

16:08 environmental factors can cause changes in our gene expression that are passed down through generations. It's not all negative, can have. Really positive effects as well, So keep that in mind when you're making your own choices about how you live your life and the healthy choices that you make in life, knowing that these are not just of benefit to you, but potentially of benefit to your children and your grandchildren. And also just. Going back to my first point about the mice in the cherry blossoms, showing yourself some kindness, some compassion, and just simply having some self awareness that sometimes you may not always know what is the cause of something that you're experiencing. So we can all just be a little bit kinder to ourselves and we've all got to work with what we've got. I think that will go a long way to help us all live happier and more peaceful lives and to be a little kinder to ourselves, which is also obviously known to be fantastic for our mental health and our physical health. I'm going to leave you with that. Please, by all means contact me if you've got any comments. Or questions about any of this, and I will catch you on the next episode of Crappy to Happy listener