"Impaired sleep-wake cycle, the most robust output rhythms of the circadian system, is significantly affected by neurodegenerative disorders, may precede them by decades, and may also impact their progression" (Videnovic and Zee, 2015).
^^^ that's the 'safe' way of saying circadian disruptions likely cause neurodegenerative disorders. And if you have one or more of these disorders, addressing circadian rhythms should be first line therapy.
Sleep loss itself is a risk factor for cerebrovascular events, likely due to alterations in autonomonic nervous system or immune homeostasis, and sleep disorders are common in stroke victims.
The robust circadian variation in cortisol declines in aging adults, and the degree it is lost is associated with cognitive impairments and crappy sleep.
Parkinson's Disease: circadian variation in symptoms -- it's almost always worse in the evening regardless of when dopaminergic medications are administered. Dopamine itself is a circadian hormone. All of these suggest circadian rhythms should be part of the treatment program. Indeed, 90% of patients report impaired sleep and reduced daytime alertness.
Alzheimer's Disease: one of the big ones. Circadian dysregulation has a major impact on quality of life and represents a major reason for institutionalizing these patients. That's expensive. Preclinical studies have suggested this is a function SCN atrophy (the master clock) and impaired pineal function (source of melatonin). Those two observations argue largely for the role of circadian dysregulation in the pathology of Alzheimer's disease. No one is talking about light therapy and blue blockers for Alzheimer's patients. No one.
Morning sunlight awakens diurnal animals and sunset evokes sleep. Or at least it should. Circadian clocks are present in nearly every cell in our body. It is thought that the central clock (SCN in hypothalamus) and food regulate peripheral clocks but peripheral clocks don't really regulate the central clock.
Light is the main zeitgeber for the SCN:
As mentioned previously, vasopressin plays a weird role in the regulation of circadian rhythms and we may even see drugs targeting vasopressin receptors to treat certain circadian-regulated disorders or influence performance output, for example, when sports teams fly long distances longitudinally.
Speaking of which, the timing of circadian reorganization during travel occurs in different speeds in different tissues. For example, the liver clock is rapidly re-entrained because it is highly dependent on food intake (which usually switches rapidly to the new time zone). Heart and lungs take quite a bit longer, which may be why sports teams try to get out to new locations as far in advance as possible.
Which nutrients or food factors, specifically? NOBODY KNOWS. It was briefly thought to be related to insulin (eg, Oike, 2017) because insulin can induce the expression of circadian genes, although the maintenance of normal circadian rhythms type 1 diabetes pretty much rules this out. It just seems to be 'calories.' Some hormones are secreted from the gut upon calorie ingestion which have been demonstrated to entrain liver clock (eg, oxyntomodulin).
On the other hand, a ketogenic diet appears to advance the circadian phase which may be good if you have trouble falling asleep at night and are sleepy in the morning. May also do well to eat breakfast in the morning and not have a big nighttime meal. Given the first half of this article, I'd start asap.
That's all for now!
If you’re interested in setting up consultations with me, reach out: [email protected].
Affiliate links: Still looking for a pair of hot blue blockers? TrueDark is offering 10% off HERE and Spectra479 is offering 15% off HERE. If you have no idea what I’m talking about, read this then this.
If you want the benefits of ‘shrooms but don’t like eating them, Real Mushrooms makes great extracts. 10% off with coupon code LAGAKOS. I recommend Lion’s Mane for the brain and Reishi for everything else.