This is my free weekly newsletter covering 5 interesting points from the week. Subscribe (if you haven’t already) if you’d like to get it in your inbox each week!
1. Why I stopped tracking my sleep
For a while I had been pretty diligently tracking my sleep with my Oura ring. Sometimes I would wake up feeling refreshed, but would be quite frustrated when the Oura app gave me a suboptimal score. I came across this paper Manipulating sleep duration perception changes cognitive performance – An exploratory analysis that found that people’s cognitive performance was straight up worse if you told them they slept 5 hours when they had really slept 8. The perception of having had poor sleep actually affected their performance. The reverse was true as well - telling people who slept 5 hours that they actually slept 8 hours improved their cognitive performance.
Sixteen healthy individuals [8F; mean age (± SD): 24.2 ± 3.0 years)] received an 8-h sleep opportunity followed by a 5-h opportunity on two consecutive nights. Upon waking, they were randomized to being informed that they received either an 8-h or 5-h sleep opportunity, via a clock that ran either fast, slow or normally. Cognitive performance was assessed using 10-min auditory psychomotor vigilance tests and subjective sleepiness ratings.
Results…Reaction time was significantly quicker when individuals thought that they had slept for 8 h but given a 5-h sleep opportunity. Conversely, reaction times were significantly slower when individuals thought they had 5 h of sleep but given an 8-h sleep opportunity.
I thought I would continue using the Oura ring and then just take a look at my sleep at the end of the week. However, the app wouldn’t actually record the previous night’s sleep data unless I opened it in the morning. So, for a while I would open the app in the morning, deliberately not look at the screen and then close it. This apparently was annoying enough for me to eventually forget about it and I stopped using it.
2. Gut issues? Don’t eat so much sugar and carbs
Here’s a 2019 study titled A Dietary Intervention with Reduction of Starch and Sucrose Leads to Reduced Gastrointestinal and Extra-Intestinal Symptoms in IBS Patients :
In epidemiological studies, an association has been found between IBS and irregular meal intake, fast food, and sweets]. It has recently been found that many patients with IBS have poor dietary habits, with irregular meal intake and high intake of cereals, sweets, and soft drinks, and a low intake of vegetables, fruits, and fish, with correlations between the intake of soft drinks and gastrointestinal (GI) symptoms. Dietary sugar contributes to low-grade inflammation and increased gut permeability, characteristics often described in IBS.
The study took 105 patients with irritable bowel syndrome and randomized them to a starch- and sucrose-reduced diet.
“After the intervention, one-third of the patients did not fulfill the criteria for IBS/functional gastrointestinal disorder. Half of the participants changed from moderate/severe disease to no/mild disease according to IBS-SSS.”
A whole third of the patients with irritable bowel syndrome, this nefarious and mysterious (“of unknown etiology”) syndrome, had their symptoms completely resolve by reducing starch and sugar in their diet. Another half drastically reduced the severity of their issues. A bonus was that their cravings for sweets reduced.
“In conclusion, [a starch- and sucrose-reduced diet] improves both GI and extra-intestinal symptoms in IBS.”
P.S. When I was in high school, I often had gas and stomachaches. My Mom said I should stop eating so much sugar. I adamantly said “it’s not the sugar!” and continued to have gas and stomachaches. I rarely eat sugar now, but when I do, I get gas.
3. Men: Skip the Flaxseed, eat Ginger?
Two points on from the Effects of Lifestyle on Men’s Health textbook from Elsevier Science:
Flax seed, a food that has been renowned due to its high omega-3 fatty acid content, has been shown to decrease total testosterone levels in men [101, 102]. This is primarily due to the high concentration of lignans in flax seed, a compound that is suggested to bind testosterone in the enterohepatic circulation and lead to its excretion [102]. Lignans have also been cited to increase SHBG in some studies leading to a consequent decrease in free testosterone [103]. Current research has focused on using flax seed as a potential treatment for polycystic ovarian syndrome in women due to its androgen-suppressing effects.
SHBG, sex hormone binding globulin, binds testosterone. So, in some cases, men may have normal total testosterone but low free testosterone due to elevated SHBG.
[Ginger] has antiinflammatory properties due to its main constituent, gingerol [110], which will enhance HPG axis activity. In a study of Iraqi men, supplementation with ginger was shown to increase testosterone by 17% from baseline [111]. Other components of the HPG axis like LH and FSH increased significantly as well.
LH, luteinizing hormone, and FSH, follicle stimulating hormone are released by the brain and act on the testes to produce testosterone.
4. Why does Harvard persist with ridiculous anti-meat claims?
Here’s a great thread by Nina Teicholz about Walter C. Willett, fervent champion of a vegetarian diet and Chair of the Harvard T.H. Chan School of Public Health, and why Harvard has been anti-meat for 30+ years despite overwhelming evidence against their claims.
5. Do or Die Meditation (Turning Alarm into Focus)
A couple months back, I read Shinzen Young’s The Science of Enlightenment. When he was becoming a monk in Japan, he was to do a 100-day ‘retreat’ in isolation in winter as part of his training. One of his tasks every morning was to go outside carrying pails, find a body of water where the surface was usually frozen over, break the ice, fill up the pails with the just-before-freezing water and dump it on his head. While this may sound like some form of unnecessary masochism, he understood it actually had a purpose. The intense cold gave him two options: (1) panic, shiver, grit his teeth, tense his muscles and be very uncomfortable or (2) maintain a deep state of focus that prevented him from reacting to the cold.
This was really interesting for me to read because I had noticed something similar when I was doing cold showers in winter a few years back. Though the water wasn’t nearly as cold as Shinzen’s, it was cold enough to force me into becoming really focused in a way that made me disassociate with the cold. The less focused I was, the more painful the experience.
Lately I’ve been doing Ice Baths every day before going to the gym, and maintaining the focus is something like Tony Hawk’s Pro Skater’s balance indicator. With the right finesse of gently tapping on the left and right arrow buttons, you can maintain the balance in the center, but once it starts to go off center it very quickly slides off to the side and you fall down. The cold in a way, teaches you to learn to balance your focus into the sweet spot between intensity and calmness.
About 5. It is so good to go for a swim in the sea in colder months, it shakes you and focuses you , and then you are even more receptive to nature around you, of course you have to go to a nice place/beach outside city, it can be really good experience. Very little people appreciate this, and they wonder why I do it. But I live. at Mediterranean climate, so it is not so cold, but still. Even now sea temp is 20 C , but it will go to 13 C, and keep that temp to may. This 20 C is remaining heat from summer.
Really appreciate this newsletter. Keep it up. Always look forward to it.