CR/F-F/etc

[Guest guest]

Good news... Mark Mattson, Chief of the Laboratory of Neurosciences at the

National Institute on Aging, in Baltimore, MD, is planning HUMAN studies of the

effect of fasting/feasting (20hrs and 4 hrs) on the issues studied in the mice

study.

Ori makes a good point in his new book on why chronic undereating is probably

a bad idea. According to him, the body needs to cycle between the production

of cAMP and cGMP, the former which is produced during undereating and the

latter which is produced during overeating, specifically by the consumption of

carbohydrates or anything that stimulates insulin. cAMP stimulates the use of

fat for protein synthesis and stimulates growth potential, while cGMP is

necessary for the realization of the growth potential stimulated by cAMP, which

stimulates the deposition of material in the body. I guess it'd be necessary in

incorporating protein into muscle. It's also necessary for libido and erection

in males (Viagra works by inhibiting cellular reuptake of cGMP).

sexual arousal (in males i guess) is the one time where both cGMP and cAMP

are stimulated together, with cGMP dilating the blood vessels to allow flow into

the erectile chamber and cAMP restricting the blood vessels to trap the blood

in the erectile chamber.

Chronic stimulation of cGMP would lead to a sluggish metabolism, fat storage,

etc.

But chronic stimulation of cAMP has its drawbacks too. " Overall, cGMP is

critical for potency and virility. Men who crhonically undereat may be able to

live longer but may have to live life with a diminished libido and an inability

to perform. "

This makes a lot of sense to me. I think there are other hormonal cycles

that are similar. For example, calcitonin and parathyroid hormone. Chronic

stimulation of parathyroid hormone would be disastrous for the skeletal system,

since it supports osteoclasts and raises blood calcium by leaching it from the

bones. However, the active form of vitamin D cannot be created in the absence

of parathyroid hormone. So I think modern folks primarily have the problem

that decreased UV exposure, use of sunglasses, indoor jobs, etc, causes us to be

chronically stimulating parathyroid. But naturally you don't secrete

calcitonin all day. The natural cycle of light during the day and darkness at

night

secretes calcitonin during the day to help build up your bones, and creates

cholacaliciferol from cholesterol in your skin, and then the darkness allows you

to secrete parathyroid and turn the cholacaliciferol into calcitriol (the

active form of vitamin D).

cAMP and cGMP seems like a similar cycle and there are probably others.

Chris