The Little Spaceman: Humph's adventures with red light (near-infrared) therapy

In the past couple of weeks, Humphrey has had a few inquiries about the red light/near-infrared therapy he's been undergoing. 

This is the $35 bulb Humphrey is currently using.

NASA developed red light technology (also see this) to help plants - and eventually people - while in space when they do not have access to sunlight. Basically, NASA discovered that the long wavelengths of LED red light penetrate deep into body tissue, stimulating cell activity. Because fo that, it can treat various injuries, wounds, burns, neuropathy – all areas where large body areas are involved. Red light also simulates hair growth.

In the past twenty or so years, the effects of read light (also called near-infrared) have been extremely well researched in the medical community, and results for certain benefits to the human (and animal) body have been well-documented. You may recall that we consulted research for dog alopecia not long ago (there's not a lot on dog hair loss to date, but the research so far is promising).

The most popular commercial use of red light therapy to date appears to be for its anti-aging properties. Shining the right red LED frequency stimulates collagen production in older cells, leaving skin looking plump and reducing wrinkles. It also has been effective in treating acne. The technology resulted in all kinds of products for the face. Many small products that have frequencies that only penetrate the top layer of the skin are available for anywhere from $50 to several hundred dollars. At the time of writing, the Silk'n is probably the most popular at-home option (though one of the pricier ones). A cheaper option that works the same way is the Tanda. Similarly, commercial devices in the shape of caps to stimulate hair growth are available.

Some advocate for using dermatologist-quality devices, which are larger, stronger (because they usually contain more LEDs) and some use longer wavelengths to penetrate deeper. This is a great, plain-language article about cosmetic/face use.

The more important uses for red light therapy are not cosmetic. Red light therapy benefits cancer patients and diabetics who suffer from neuropathy (must be 800-900 nm wavelength to be effective).
It also aids in healing tissue injuries, including muscle injuries.  It seems to be routinely used in dogs with knee (CCL) injuries to speed the healing. I don't have the research at my fingertips, but will update at some point. Red light therapy will not cure anything, but will help the body heal faster by feeding the cells so that they do their work.

So far, decades of research show no damaging effects. LEDs are low temperature, so the lamps do not heat up, there is no chance of burning. They do not contain and UVA or UVB, so no threat of cancer or burn exist.

In terms of devices - the important thing is to obtain a device that has the RIGHT wavelength for what you want to achieve. For example, Silkn or Tanda for the face might not have the correct wavelength for a deep tissue injury. Once you have the right wavelength, the strength of the device also has to do with how many individual LEDs make up the lamp. More LEDs mean more strength. More strength means less time you need to devote to it. Similarly, the distance from the affected area affects how much time you need with the red light. The farther away from the body and injury, the more time you need.

When a decent strength red light is used at a close distance, the length per session (even for a deep tissue injury) is usually not more than 15 minutes at the site of the injury. However, a weaker lamp or a distance that's not right against the skin might require 30 minutes per session. The facial devices recommend only about 2 minutes when the device is right up against the skin.

Humphrey usually naps while receiving light therapy.

An inexpensive way to try red light therapy is a bulb - the least expensive options are on Amazon, for example, this one in the $30 range (pictured above). Of course, you need a base for the bulb (it screws into a standard socket), and then you need to set it up accordingly. This one has 2 wavelengths: Deep Red 660nm (surface) and Near Infrared 850nm (deeper tissue). If you are buying online, read the specs carefully so you get the correct wavelength, and that it's a bulb or device for human (not plant) use. The inexpensive lamp does not have all that many LEDs, so it requires more than a couple of minutes of contact time to make a difference. We have used this one for a dog (hair), and a human (chemo neuropathy). At least at first, daily for a minimum of 15 minutes per spot is necessary, then the frequency can be reduced to a couple of times a week. If he had unlimited funds, Humphrey would probably purchase the Joov (which is a commercial/consumer product with greater strength, but very pricey).

UPDATE "BRAIN PHOTO-BIO-MODULATION":

Some studies are showing that red light use MIGHT offer some modest help with people who suffer from various dementias - Major Cognitive Impairment (MCI, which is a  general dementia, and affects the front of the brain)  and Alzheimer's Disease (AD, which seems to affect the back of the brain). The red light (near infrared frequencies) appears to help with oxygenation in the brain. The therapeutic approach is called "photobiomodulation", and involves exposing the brain to near infrared.

In 2015, a study on mice found that near infrared helped mitigate loss of oxygen, affected the "tangles" associated with dementia, and offered some general protection. For reference, mice with dementia received 90 seconds of 670nm frequency, 5 days a week for 4 weeks and then the results were analyzed.

A 2018 "narrative review" explains how near infrared works with respect to the brain, also discusses the challenges of delivery (that is, to get deep into the tissue). 

A small 2017 study which applied red light through the nose (!!!) for 12 weeks found that outcomes for people with moderate to severe dementia improved. The methods of this study are not ideal (it's not an RCT) but nonetheless promising.

Finally, this 2019 paper summarizes research to date on photobiomodulation for dementias  (also this 2019 paper and this one as well)- noting what I found which is that studies on humans are small and not great methodologically, but there's a pretty robust literature with animal trials that is very promising. 

THE VERDICT: early research, especially on animal brains, is very promising; the poorly designed studies on humans support what researchers have already found with animals. Given no side effects and relatively low cost, it's probably worth it for dementias.

SUGGESTIONS GLEANED FROM THE PUBLISHED LITERATURE TO DATE:

• Generalized dementia: frontal cortex; Alzheimers, back of head, though for humans nasal route has been used because it's difficult to penetrate very deeply through bone and tissue. This may or may not be the same for animals who presumably have much less tissue.
• Frequency should be in the 670 range (at least) to penetrate (that is what they used for mice)
• The amount of time in studies varies - but probably 5 days a week, for at least 5 minutes would make sense; minimum 4 weeks, probably more like 12 weeks.