Month: May 2023

CGM Experiment (part 3) – cold therapy post

I’d wanted to learn about the benefits of cold therapy, to extract the physiological and psychological effects, benefits of getting into cold water, especially as it relates to health benefits, insulin sensitivity etc.

As an intro to this topic – this post covers Professor Andrew Huberman interviewing Dr. Susanna Soberg, an expert in deliberate cold and heat exposure protocols, talking about the science and impact of deliberate cold exposure from this study (Cell reports). The interview also covers the importance of the cold shock response and how to approach a deliberate cold exposure protocol.

FYI – this post has been ‘co-written’ using tools such as:

The study

The study was done in Denmark on a male cohort, and carried out by having participants do winter swimming for minimum two days per week, measuring brown fat activation with an infrared camera, and taking fat biopsies. The study was done in a field setting, and participants were encouraged to do the winter swimming whenever they had time. The relevant ‘minimum viable dose’ was 11 minutes of weekly cold exposure.

Why cold therapy?

Cold exposure can improve insulin sensitivity, which can help to prevent type 2 diabetes. 

“ We did see that the winter swimmers had an increased insulin sensitivity. They produced less insulin on all the experimental days. We measured insulin when they were fasting, meaning that they hadn’t eaten in eight hours before the study day. We could see that the winter swimmers had lower production of insulin. Also when they had glucose drinks, the winter swimmers had a faster glucose clearance in the bloodstream. So after two hours, we could see that they had a lower level and the curve went down faster than in the control group.”

Cold exposure can increase brown fat, which is a type of fat that helps to burn calories and generate heat.

“ What happens is that you get adapted a little bit every time you go, like exercise, you get a little bit stronger. So every time you go into the cold water you will feel more comfortable in the cold. You are building your adaptation, which happens on a metabolic level, which is happening via activation of your brown fat. 

The mitochondria in the brown fat cells are gonna be activated, you’ll have more of those and they will be more efficient at heating you up because the body expects you to do this again. The capillaries in your skin will also become better at constricting. So you will have a better shield of your body to prepare you for the next time.”

Also your stress response will subside a bit, so you will have a less increase of your catecholamines with time. With time also you have, because of this activation of your brown fat or your muscles, you will have an increase in your metabolism, which will then make your insulin sensitivity better.”

Cold exposure can reduce inflammation, which can improve overall health, mood and cognitive function.

  • The winter swimmers had lower levels of cortisol at night time – which is beneficial for sleep quality. 

And I think it’s very important to think about the cold exposure and the heat exposure as something that lowers the inflammation in the body. And if we can do that, we will have an open door for preventing lifestyle diseases, right? So for type diabetes, but actually also for some mental diseases as well. So as known as depression and anxiety and also Alzheimer’s disease, which are all associated in research, also newer research showing that inflammation increases the risk of depression, anxiety, and Alzheimer’s disease, neurological diseases. So if we can decrease inflammation in the body, we will decrease our modern lifestyle diseases, but also these increasing mental diseases that we see in these modern lifestyle times.

It’s just exposure to temperature, actually just a cold or to heat that is gonna trick our body into a natural state again and reset it where the homeostasis, the balance is lost a bit. So the body is gonna repair itself in that way. And I think it’s beautiful that we can do that just by changing the temperature of our body. 

Conclusion

Cold exposure is a safe and effective way to improve health. If you are considering trying cold exposure, be sure to talk to your doctor first and follow any safety tips. 

I will incorporate cold baths into my health routines :

  • Tuesday, after cardio session – 4 minutes total time (2 x 2 min dip)
  • Thursday, after cardio session – 4 minutes total time (2 x 2 min dip)
  •  Saturday, after cardio session – 4 minutes total time (2 x 2 min dip)

Thanks for reading

CGM experiment continues – Part 2

I wrote about my first two weeks with the CGM here, and here is a short update with new data. The overview of the data below, the new dates marked in yellow:

I wanted to try some things to reduce the average fasting glucose (FG), so here’s what I did.

Experiment 1 – keto diet

On Saturday May 5th I started a ketogenic diet , and as I’ve already been doing intermittent fasting, and generally I don’t eat a whole lot of carbs, I figured this would be easy to try. Here the results for three days:

Ok, that didn’t go as planned at all 🙁 The massive spike on Sat May 6th is from having one tiny slice of cake… 

Apparently there is something called ‘adaptive glucose sparing’ which essentially means that since your muscle cells prefer fat when you are doing a low carb/keto diet, there will be more glucose floating around in your bloodstream. 

I lost two pounds over the 3-4 days this lasted, and I generally feel leaner. The FG was very stable, but I don’t want to have FG that high in general. There are ‘extenuating circumstances’ (e.g insulin could still be low), but I would’ve needed a blood measurements of fasting glucose and fasting insulin to verify this, so I have try something else..

Experiment 2 – regular, smaller meals

After this I thought “hey maybe I’d just introduce smaller amounts of carbs, eat some breakfast and smaller portions”. This would allow my cells adjust to having carbs again, and with the smaller portions I don’t get as large spikes, here the next four days:

Ouch, not good either. And I wasn’t feeling too great this time, I could really feel sluggish and a bit more tired than usual.

Experiment 3 – back to intermittent fasting

So after this I thought I need to get back at least to where I was before. Here the next four days:

It’s really cool to see that after ONLY one day back to intermittent fasting, my FG normalizes again. I honestly don’t know any other health related measurement where one can see the results this quickly!!

Again I’m not worried about the higher readings around 16-17 as that is where I train, and interesting to note that movie night + salty popcorn does raise FG overnight -as can be seen on 05/15.

Conclusion

Overall I’m learning a lot re: how my body processes glucose/carbs, how intermittent fasting is really helpful for me – and it does make me want to try out some longer fasts (e.g. OMAD – one meal a day) style. Stay tuned.

Lessons from two weeks with a CGM

I received a CGM (Continuous Glucose Monitor) about two weeks ago via the Levels start-up. The package arrived a few days after ordering, and the initial setup was relatively easy and painless. I was able to easily export the data from the Levels website.

So how do the results look? The easiest way I can think of to show you the results are using Python (pandas, matplotlib, seaborn libraries) so here we go: (I’m skipping some data wrangling bits here..)

Glucose level distribution as a histogram

Glucose Level Time Series with rolling statistics

Honestly this data has me a bit worried because generally doctors, Peter Attia MD and the Levels program all suggest that fasting glucose should be less than 100/mg/dl…

Also, I wanted to correlate the glucose readings with the time of day, so we can do that eg with a heatmap:

Glucose Levels by Day, Hour in a Heatmap

This chart is really interesting to me because here a number of things stand out to me:

  • I was in Austin from April 26th to April 28th for a conference, and those days I did a light workout in the morning, and had a light lunch. So clearly a lighter lunch, moving around in the afternoon leads to lower fasting glucose.
  • I slept really badly Fri-28th-Sat 29th due to a late flight, and clearly a bad night sleep results in a bad fasting glucose.
  • I generally workout in the afternoon – between 4PM and 6PM, and so higher readings there are not alarming to me. 
  • What strikes me as odd is the differences in the morning fasting glucose -say 5AM to 10AM – varies between 66 mg/dl to 120 mg/dl…The mean is still around 100 mg/dl (which is not great), but I’m surprised about the high variability.
  • Since I do intermittent fasting (lunch is my first meal) I had generally thought that my morning glucose would be lower. 
  • There is a missing block on May 2nd as I switched the old sensor to the new one – as you have to do that every 10 days. The most painful thing was tearing the Levels patch off my hairy arms 🙂

All in all I’m very happy to have all this data from the CGM/Levels to explore, giving a lot of actionable intelligence – so I will try some life-style, diet modifications soon.