Chlorophyll psychological effects

[Loren Booda]

I believe that chlorophyll's pigment can act as an antidepressant, most activated during spring plant growth (re seasonal affective disorder). A lamp may be designed which utilizes the stimulation of chlorophyll's red, lower energy states to higher energy green states in suspension. Chlorophyll's spectrum, I conjecture, activates efficiently brain metabolism via the optic nerve by encouraging ATP production.

 

[Moonbear]

Seasonal affective disorder doesn't have to do with chlorophyll. People don't have chlorophyll, plants do. Seasonal affective disorder is believed to be related to shortening daylengths and the increased production and release of melatonin during the long nights. Simple exposure to a full-spectrum light to mimic longer daylengths seems to work well in treating SAD.

 

[Loren Booda]

Moonbear,

The Sun is effectively a green star, whose spectrum maximizes at the frequency where chlorophyll in plants activates. Directly or indirectly, the color of chlorophyll stimulates the brain like the sun does.

The radiance of chlorophyll in an environment usually corresponds inversely to the incidence of SAD. (An exception may be in the Pacific Northwest.) Have you experienced any connection between the absence of chlorophyll and SAD's occurrence? There is even a type of SAD that occurs in the dead of summer, when desert conditions predominate.

The chlorophyll-stimulated lamp I speculated would be more efficient than a full-spectrum light, and give an effect much like being in a greenhouse.

I tend to agree more with your review of the brain chemistry involved. Full-spectrum lamps can actually cause mania in individuals subject to that condition.

 

[Moonbear]

Loren, I really don't think I'm understanding what you're getting at when you talk about a chlorophyll-stimulated lamp. There are old studies in rodents (ground squirrels I think) that suggest photoperiodism is affected not only by duration of light exposure, but also by the wavelengths of the light (blue light was more effective than red light in inducing photoperiodic shifts). It could be true in humans as well that symptoms of SAD could be alleviated by a narrower range of light wavelengths rather than requiring the full spectrum. Whatever wavelengths they are, they are not present in regular incandescent lighting.

As for photopigments, there was a big deal made a few years ago about melanopsin, which is a photopigment in the retina that may be the pigment we use for photic entrainment (it's not required for vision). In mammals, all photic signals are processed via the retina, there is no direct effect of light on the brain. In birds, their skulls are thin enough that photic cues can directly reach the pineal gland to entrain melatonin release, so a direct pathway as well as the retinal pathway are functioning.

 

[Loren Booda]

Moonbear,

Thanks for your learned reply. I guess I first got stuck on this problem while leaching "chlorophyll" from leaves in benzene, noting the reflected light from the flask was green, and the transmitted light red. I thought it possible to create a laser with this solution to pump the red state to maintain the green state. Then there was the romantic notion of the first greenery of spring, and its possible alleviation of Seasonal Affective Disorder, or depression in general, by providing a similar, but artificial source of chlorophyllic emission.

The exact psycho-physiological mechanism, I would hazard, involves pigments like melanopsin. The sensitivity of the human retina matches well the visual spectrum of the Sun, so it may be suggested that the (green) peak corresponds to both chlorophyll and its visual analog.