*if you’re going to carb, that is
The Sofer study was uniquely insightful in that they compared 3 carb-rich meals per day with the same amount of carbs but restricted to 1 meal. Both groups ate 3 times per day. Tl;dr: one carb meal is modestly better than three even when total carbs are controlled. Since the carb-meal happened to be dinner, #fakenews reported that “carbs at night” are superior… but we saw right through that – the real conclusion was carb frequency not carb timing.
Posted in Advanced nutrition, angiotensin, Bromocriptine, Cabergoline, chronopharmacology, circadian, diet, Dietary fat, Dopamine, fertility, melatonin, Protein, sex, sleep, Sun, Vitamin D
Tagged calories proper, carbs, circadian rhythm, diet, melatonin, Paleo
Polish Mayor @jmmajchrowski takes steps to protect citizens from rising electromagnetic radiation; wifi, smartmeters https://t.co/Ywg0Jr7Xqw
— Dr Maryanne Demasi (@MaryanneDemasi) January 12, 2017
I was bored and had a stronger-than-usual espresso, saw the above Tweet, so obviously I decided to read the Health & Safety Guide that came with my cell phone.
The Federal Communications Commission (FCC) set specific limits to Radio Frequency (RF) that any given electronic device can emit. Theoretically, at or below this level is “safe.” The actual number comes from the National Council on Radiation Protection and Measurement (NCRP) and Institute of Electrical and Electronics Engineers (IEEE). The overall tone of this document is grave, ie, they take this RF limit very seriously.
The limit: 1.6 W/kg (Specific Absorption Rate [SAR]) or 0.0016 W/g.
I checked online at www.fcc.gov/oet/ea, and my phone is rated 0.3 Watts (W) at around 1.5 cm – distance is important: in this case, it’s the difference between squashing the phone between your face and your hand vs. holding it a finger tip’s distance away.
So, is my brain safe? Hard to say; how many grams of brain are within 1.5 cm from my brain? If we’re talking whole head exposure, ~4 kg, that’d be ~6 W. But I’m more concerned about the 4 grams of brain closest to my ear, within that 1.5 cm range, because brain cancer is pretty scary at any level of brain cancer (ie, whether it affects whole brain or just the 4 grams closest to my ear).
I can’t figure out these maths so I’m sticking with earbuds until I can.
Posted in chronopharmacology, circadian, Dopamine, melatonin, sex, Sun
Tagged circadian rhythm, melatonin
Humans are incredible omnivorous beasts that can thrive on a great variety of diets, but crumble if you mess with their sleep.
Circadian arrhythmia is thought to be a driving force behind a few types of cancer. But how, exactly, does seemingly harmless things like artificial light, skipping breakfast, or jet lag actually promote tumorigenesis? There are many potential mechanisms, and I’d bet different circadian disruptions promote different cancers in different #contexts.
In some cell types, circadian disruptions which dampen amplitude increase proliferation. This has led to some researchers to believe a robust circadian rhythm per se is tumor-suppressive. In agreement with this, many tumor suppressors are direct targets of circadian transcription factors. As was observed in some skin cancers, you may want suppressed proliferation at some times of the day but not others, so the tissue can renew properly. But you don’t want, for example, skin cells to be proliferating while they’re being exposed to UV light, so this process happens at night (in circadian fashion).
Circadian transcription factors also directly interact with endogenous antioxidant systems.
Cancer clocks out for lunch: disruption of circadian rhythm and metabolic oscillation in cancer (Altman, 2016)
Posted in angiotensin, Bromocriptine, Cabergoline, chronopharmacology, circadian, Dopamine, melatonin, sex, sleep, vasopressin, Vitamin D
Tagged circadian rhythm, dopamine, melatonin, mortality
T.S. Wiley wrote a lot about the protein-rich breakfast; here’s my understanding of her take on it.
N.B. I highly recommend her book, Lights out: sleep, sugar, and survival.
Quotes are mainly taken from the text. I’ve tracked down some of the cites; the rest are in the back of the book, albeit somewhat unorganized :/
Part 1. We naturally have a cortisol spike first thing in the morning, known as the Cortisol Awakening Response (CAR). This peak, which can be screwed up by artificial light at night or a big evening dinner, helps support morning light-induced dopamine.
Dopamine is great, but may induce impulsivity if it’s unfettered.
Enter: the protein-rich breakfast. It provides tryptophan and a bit of insulin to promote serotonin synthesis (eg, Manjarrez-Gutierrez et al., 1999).
Not enough serotonin to make you crazy, just enough to balance the dopamine = impulse control.
~ circadian balance achieved ~
Posted in Advanced nutrition, angiotensin, Bromocriptine, Cabergoline, chronopharmacology, circadian, diet, Dopamine, fat, Fish, insulin, Leptin, melatonin, Protein, sex, sleep, Sun, TPMC, Vitamin D
Tagged carbs, circadian rhythm, diabetes, energy balance, fat, insulin, ketosis, leptin, melatonin, muscle, nutrition, Paleo, protein
It is known. Carbohydrate restriction improves (lowers) testosterone in women with PCOS. It works for men, too… but by “works” I mean “increases.”
Decrease of serum total and free testosterone during a low-fat high fibre diet (Hamalainen et al., 1982)
Intervention pseudo-crossover study: 30 healthy Finnish men in their 40’s were studied on their habitual high fat diet (40% fat), then put on a low-fat (25%) high fibre diet for 6 weeks, then switched back to high fat. The high fat diet was also higher in saturates, P:S ratio 0.15 vs. 1.25.
Free testosterone levels declined on the low fat diet, but they recovered after 6 weeks of going back to their high [saturated] fat dieting (p < 0.01).
Some observational data: Testosterone and cortisol in relationship to dietary nutrients and resistance exercise (Volek
…fat, and in particular saturated fat, is associated with increased testosterone levels [in men]:
Posted in Advanced nutrition, clamp, diet, Dietary fat, fertility, insulin, sex, testosterone
Tagged calories, carbohydrates, carbs, diet, fat, insulin, testosterone
There are enough connections here to suggest it’s an interesting rabbit hole. Besides the effects of ARBs & desmopressin on mood and cognition, blood pressure regulation is not interesting <– fact. But if it ties into fertility, circadian biology, and seasonal changes in how we should be doing things…
Way back in 1998 when I was graduating high school, Murphy and colleagues were screwing with “light-entrainable” and “food-entrainable” oscillators of circadian rhythmicity (1998). They did this in two lines of rats, one with intact vasopressin signaling and one without. With little mechanistic work, they showed vasopressin mediates circadian effects driven by light; and rats without vasopressin were more entrainable by meal timing. N.B. in addition to the posterior pituitary, vasopressin is also found in the famous circadian light-regulated SCN neurons (Rosving 2010).
While it is speculated to play a role in social behaviors and sexual motivation, vasopressin is primarily known for its anti-hypotensive effects. When plasma volume drops, vasopressin is secreted to decrease urinary water loss and increase blood pressure. This is antagonized by alcohol, which is thought to be one reason why alcohol can dehydrate you.
Posted in Advanced nutrition, angiotensin, circadian, fertility, melatonin, sex, vasopressin, wine
Tagged angiotensin, circadian rhythm, fertility, vasopressin
Kisspeptin was discovered in Hershey, Pennsylvania, and was named after Hershey’s Kisses. It has 776 pubmed citations going back to 2001, and may (or may not) play a key part integrating circannual reproduction patterns and seasonal thyroid function.
Kisspeptin
Exhibit A. TSH restores a summer phenotype in photoinhibited mammals via the RF-amides RFRP3 and kisspeptin (Klosen 2013)
In this study, TSH infusion in short-day adapted hamsters (who are in winter non-breeding mode) induced summer phenotype & kisspeptin. It also fattened them up a bit. These TSH secreting neurons express melatonin receptors, but not those for TRH or T3 (Klosen 2002), so it is said to go something like this:
Posted in circadian, Dopamine, fertility, sex
Tagged calories proper, circadian rhythm, dopamine, energy balance, fertility, kisspeptin, Paleo, prolactin, thyroid
I’ve adapted much of this chart from Howell-Skalla (2002) and Tsubota (1998).
Canadian polar bears: bona fide seasonal breeders.
The light cycle increases until June, then decreases until December. Melatonin goes in the exact opposite direction. Testosterone peaks around the onset of breeding season (springtime, April/May), coinciding with LH (as expected). There is also a lot of bear-on-bear violence at this time due to: 1) testosterone-induced aggression; and 2) the high female:male ratio –-> females rear their cubs and are thus out of the game for about 3 years, but males like to breed every year.
Females followed a similar pattern, with estrogen peaking around breeding season and prolactin following the light cycle.
The authors mentioned that prolactin levels mirrored day length, and according to Wiley this would be the prolactin peak that normally occurs when you’re sleeping, but has spilled over into the daytime due to short sleep / long light cycle… not total prolactin levels (24h AUC?), which should be highest in winter (see below).