What Glucose Trackers Get Wrong About Women’s Bodies | Dr. Stacy Sims | Dr. Stacy Sims

0:00Welcome to Live Well, Be Well, a show to help high performers improve their health and well-being.

0:10Are there more times when we're more insulin resistant during our cycle? And if so, how should we be looking at that? Because I think it's important to talk about, because I don't want people to become scared of not having carbohydrates. So how should we be looking at this for oneself? So this comes to the ovulation standpoint. Yeah. Because after ovulation with progesterone, like I said, progesterone is catabolic. Its whole goal is to provide the building blocks for endometrial lining. So it is preventing a lot of the carbohydrate and glucose from being uptaken into cells that are not part of the endometrial lining.

0:46So we have a little bit of insulin resistance there. For the general woman who doesn't have any undercurrent of metabolic syndrome or diabetes, it's not a big thing. Okay. Because if it was, we wouldn't be here, right? There would be an evolutionary change that would have wiped up humankind. So if you're generally healthy and you're active, it's not a big thing to worry about. If you have metabolic syndrome or you have prediabetes or full diabetic, then it's something to consider within your treatment and understand that, yes, you have more insulin resistance after ovulation. that exists until your next bleed.

1:26So you have to time carbohydrate according to physical activity as well as when you are using your insulin. Okay. So it helps with insulin control in those clinical situations. Okay. But the normal woman that's training maybe three or four times a week. She shouldn't worry about it. She doesn't need to overthink. No. And the reason why it's become such a thing is because of continuous glucose monitors being used in a healthy population. Well, I was about to ask your opinion on that. Yeah. I don't know. So I look at it as one of my PhD students just finished doing a longitudinal study on ultra runners using CGM to determine fueling during ultra runs.

2:06And there's definitely a change across the menstrual cycle with the way your body uses glucose and how your body will use it during training. Does that impact what they should be doing? When we find out, no, actually, you can have a low amount of carbohydrate intake. As long as you have an elevation in blood sugar, your body's going to be fine. So when we look at continuous glucose monitors and people are using, going, oh, I can't have oatmeal because it makes my blood sugar spike. It's like, well, yeah, anything that you eat is going to bring blood sugar up. But the continuous glucose monitor isn't monitoring blood glucose.

2:40It's monitoring interstitial fluid. And there's about a 20-minute lag period. So people are freaking out about the actual notes that happen after each kind of food that they eat. Really, if they're worried about it, they should look at trends over time. And this is the problem when you're using something that has been designed to detect nuances in a clinical population, trying to bring it into the healthy population. It creates a whole bunch of confusion, which is what we're seeing now, about people not understanding how they should eat because they've been using a continuous glucose monitor as a healthy woman.

3:12so you actually think it's quite detrimental yeah i think that's a really big thing to say because i think it's become quite the norm i mean i just see it a lot now within my clinic where people walk in with a with a glucose monitor on an aura ring a whoop a garmin and they're tracking every single part of themselves and i i can understand the want and the need to become more preventative. I understand that. But I also think we're becoming hyper disconnected to actually how we're feeling. Yeah. Because my aura ring says, well, you slept badly tonight. So actually now my brain is telling me I've slept badly as opposed to thinking, well, how do I actually feel?

3:52Right. And we see that athletes from collegiate athletes, professional athletes who are sponsored by Whoop or sponsored by Aura or other wearables that are tracking sleep, the coaches are like, you can't wear that leading up to key events because the psychological aspect of getting something in the red is more damaging than actually maybe not have recovered well enough because that psychological impact is going to sit there and fester and really affect your performance. So if I think about that in that high performance environment, we're really cognate and saying we don't want you to look at any of that kind of data leading into a major event for the general person who's highly stressed and trying to interpret this data it's a problem yeah yeah and i think that's the thing they're trying to interpret data that they've not been trained in right and the algorithms are very rough and we also see that the algorithms for women are not there so the algorithms on the wearables are driven by male data and they're like well we're using ai now ai is learning from existing data which is perpetuating the misstep in health management between different ethnicities the different genders and so when you're getting this data all the time it's not truly representative of a female physiology and how a woman is responding well this is the biggest thing isn't it because none of our, none of the scientific research, I mean, three or five years ago was really done on women.

5:27And I think that's, I mean, that was the first part of our conversation, which I think is really important. It comes to another question before I move on to kind of perimenopause, which I will get to, is around the immune system. Because is it true that we have kind of more resilient immune system around 12 to 13 days around ovulation? Yeah. I find that quite fascinating. Why? So if we look leading up to ovulation, our body's really, really good at fighting off virus and bacteria. After ovulation, there's a change where we have more of a pro-inflammatory response. And the reason for that is the biological doesn't want the immune system attacking a fertilized egg, understanding that it might be a pathogen.

6:11So there's a change in the immune system. So you're very stress resilient and you're trying to maintain that stress resilience. And it's all about developing a really good egg for release. And part of that is keeping the body healthy. So it's really on target for fighting virus and bacteria. But then after ovulation with pro-inflammatory, it's all about, okay, let's invoke a fever or let's invoke some inflammatory responses to fight off anything that's coming in for infection. because we don't want to have the immune system attack a fertilized egg. Thanks so much for listening. To hear the full episode, there's a link in the description.