Greetings from Berlin,
This is not a typical newsletter you read to learn about what happened in the world of cryptocurrencies or digital medicine nor it is about my last trip to Spain and the lovely scenery. It is about avoiding the noise!
We are confronted daily with news on all possible aspects of life. Mostly from people pretending to be experts and narrating their side of the story. But in most cases, all of this information is just noise. It is loud and insignificant.
I spend a lot of time reading books, science papers and articles or listening to podcasts about subjects that interest me (philosophy, social sciences, medicine, machine learning, and dermatology) -that’s how I came up with the word “noise” (shout out to Daniel Kahneman)-. Of course I do my best to avoid wasting my time with pseudo-experts or pseudo-knowledge, but unfortunately, they are too viral. So I decided to create a newsletter “noiseless insights”. Where I share with you information, that I found accurate and insightful. I hope this newsletter helps you to learn something new and live a more noiseless life.
How hard can it be to have a healthy diet?
The answer is: pretty hard. But not because of obvious reasons like your willingness to avoid milk chocolate or oversugared beverages nor it about your bad consciousness after a guilty snack while watching a movie. It turners out, it is a lot more complicated to define a healthy diet, since it’s more personlized than you think.
Last Friday I had an appointment at the gym that I wasn’t looking forward to. It was a so called “Body scan”. I never did a “body scan” before, because I knew it was a big waste of time. I am a 28 year old young man, non-skmoker, without any previous conditions, who goes to the gym 5 times a week and… I am a doctor. What on earth can a body scan tell me that, I don’t already know about myself. But the gym coerced me to do it, since they booked the costs for this “body scan” directly from my bank account. It was obligatory they said. But I don’t have to do it, if I didn’t want to. However they will keep charging me for it every six months either ways. So I decided to make an appointment. In the room there a was a machine with electrodes that will be wired to my body. The machine then determines my puls, stress levels, water, muscle and fat perecntages. On the wall there was a sign. It said: if you have a heart condition or are pregrenant, then you can’t do the test. I understand why pregnant women couldn’t take the test. Due to the heart rate of the fetus, and how the machine is constructed, it might not be able to detect the puls of the mother or the right percentages of water, muscle and fat in the body. But heart conditions? So in other words you can only take part of the test if you are a healthy person, in order to tell you, that you are healthy!
After I finished the body scan, the instructor told me that my values were pretty good. My stress level – whatever this is- was 9%. “Very good, you have very low stress levels” the instructor said. This test couldn’t get worthless than it already is I thought to myself. Two hours ago my stress levels were through the roof, how is the test telling me now my stress levels were “very good”?. There is more. The muscle-fat ratio was also fine. “You should include protein in every meal” the instructor said. “If you want to lower your fat and increase your muscle mass, eat more protein, less sugar, less beverages. An occasional diet coke or energy drink is just fine”. I told the instructor about this paper I read the other week, but he didn’t seem interested. I noticed this after I used the word “hyperglycamic”. He started staring at me, as if I was talking japanese. We hear this sort of advice all the time. There seem to be a general consensus about what makes a healthy diet. Less fat, less sugar, more green, more fibers. A diet coke is better than a normal one. Or doctors favorit “a mediterranean diet”. I must be honest, until a few weeks ago, I also fell for this advice. But then I read two papers in “Nature” and “Cell” that completely changed my views about diets.
The two papers are from Eran Segel, a computational biologist at the Weizmann Institute in Israel. Both of these papers are linked at the end. [1], [2]
It will take too long to explain every aspect of these papers and I will definitely come back to them in future “noiseless insights”. For today there are two important facts, I wish to present you:
- Sugared beverages or nutritions are better than artificial sweetened ones:
In a study conducted at the the Weizmann Institute, researches compared mice drinking water with non-caloric artificial sweeteners (NAS), with mice drinking normal water and water supplemented with glucose or sucrose (a disaacchrid comprising of glucose and fructose, also known as table sugar). The non-caloric artificial sweeteners (NAS) included saccharin (also known in the EU as E954), sucralose (E955) and aspartame (E951). What they found was, that all 3 NAS induced glucose intoleranz compared to the other mice who consumed normal water and glucose or sucrose sweetend water, which still had adequate glucose toleranz.
So what is glucose intorleranz? And why is it so important?
Glucose intorleranz is a condition that results in higher blood sugar levels than normal. If persisted, glucose intoleranz results in a pre-diabetic or a diabetic condition.
Non-caloric artificial sweeteners (NAS) aren’t normally absorbed by the gut. That’s why they are called non-caloric. They don’t lead to a cloric intake and hence don’t result in energy production. That’s why we would assume, that NAS shouldn’t lead to any changes in our metabolic response and especially not in our blood glucose. So how could NAS change the metabolic response in the body?
Well the researches at the the Weizmann Institute didn’t just study the glucose blood levels, but also analyzed the gut microbiome of these mice. What they found was that mice who have been consuming NAS for a period of 11 weeks had significant alterations in their microbiota compared to mice which didn’t consume NAS. These changes lead to overrepresentation of certain species (Baceteroides vulgatus) and underrepresentation of certain others (Akkermansia muciniphila). Some of these overrepresented bacteria are linked to conditions like diabetes mellits or obesity. And these changes are also transferabel to normal healthy mice after having a facecal transplant from the mice which consumed NAS.
But this is not the whole story. The glucose intolranz we talked about, it went away after the researchers gave the mice antibiotics.
- A healthy diet for one person might completely contradict a healthy diet for another person.
The same guys at the the Weizmann Institute also presented another study this time in “Cell”. The study showed, that depending on the microbiome of individuals, people could have different postprandial glucose responses to the same meal. Postprandial means after consuming food and postprandial glucose response is the blood suagr measured after consuming a meal. High postprandial glucose response is a major risk factor for metabolic disorders such as diabetes mellits type 2. The study found, that the same meal which is healthy for some indiviuals, i.e lead to a low postpranidal glucose response, is bad for others, i.e. leading to a high postprandial glucose response. For some participants Schnitzel and Pizza were in fact healthy diet options, since they induced a lower postprandial glucose response in them. While Hummus and potatoes were bad to other participants becuase they induced a higher postpranidal glucose response.
Of course this not everything about this study. After we talked about NAS in the previous section and how it changed the microbiome of the mice, you have to assume that we will talk about microbiome changes in this study and how the guys at the the Weizmann Institute were able to predict metabloic responses in 100 people. But since this newsletter is getting too long, we will talk about the rest next time. Until then, stay safe, be happy and enjoy your week!
Best regards,
Yesser
[1] “Artificial sweeteners induce glucose intolerance by altering the gut microbiota | Nature.” https://www.nature.com/articles/nature13793.