By Dan Murphy, D.C.
A hot topic within the profession is the use of cold lasers. Today’s
Chiropractic asked an authority on the subject, Dr. Dan Murphy, to tell us how
this technology works. His response is featured below:
In 1997, Douglas Wallace1 wrote an article for Scientific
American titled “Mitochondrial DNA In Aging and Disease.” In this
article, he notes that an intracellular organelle, the mitochondria, is the
power plant of cells because it produces ATP energy.
“Mitochondria provide about 90 percent of the energy that cells, and thus
tissues, organs and the body as a whole, need to function.” Every cell
in the body contains hundreds of mitochondria that produce the energy that the
body requires.
Each mitochondria contains many copies of DNA, called mitochondrial DNA, or
mtDNA. Mitochondrial DNA is separate and distinct from the cell’s copy
of nuclear DNA. Our mtDNA comes from our mother and is identical to our mother’s
mtDNA. Mitochondrial DNA (mtDNA) codes for 13 proteins (enzymes) required for
the production of ATP energy.
A simplified image (after Audesirk) of the mitochondrial production of ATP energy
follows:
Note that the primary producer of ATP energy is the “electron transport
system” of the mitochondria. This is important in the understanding of
laser physiology.
Wallace further notes, “Anything able to compromise ATP production in
mitochondria could harm or even kill cells and so cause tissues to malfunction
and symptoms to develop.”
The inner membrane of the mitochondria contains four protein complexes called
the respiratory chain. Electrons from food pass through these protein complexes
with the help of Coenzyme Q10, interacting with oxygen and hydrogen to produce
water and ATP energy.
“As the respiratory chain participates in energy production, toxic by-products
known as oxygen free radicals are given off. These oxygen derivatives, which
carry an unpaired electron, are highly reactive and can attack all components
of cells, including respiratory chain proteins and mitochondrial DNA. Anything
that impedes the flow of electrons through the respiratory chain can increase
their transfer to oxygen molecules and promote the generation of free radicals.”
Importantly, anything that improves the flow of electrons through the respiratory
chain will increase the production of ATP while reducing the generation of free
radicals. As we will learn, this is the key to low-level laser therapy.
Wallace notes: “The mitochondrial theory of aging holds that as we live
and produce ATP, our mitochondria generate oxygen free radicals that inexorably
attack our mitochondria and mutate our mitochondrial DNA.” The accumulation
of mitochondrial DNA mutations reduces ATP energy output below needed levels.
“In doing so, the mutations and mitochondrial inhibition could contribute
to common signs of normal aging, such as loss of memory, hearing, vision and
stamina.”
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In support of the writings of Wallace is the 2004 book edited by Rainer Straub
and Eugenio Mocchegiani2. These authors
note: “One of the most accepted theories of ageing is the free radical
theory of aging. “The overproduction of free radicals can induce cell
death. Aging, as stated in free radical theory of aging is characterized by
an increased production of free radicals in several tissues or a decreased antioxidant
defense leading to chronic oxidative stress.” The mitochondria are the
major source for the production of free radicals.
Tiina Karu wrote “Low-Power Laser Therapy” in the Biomedical Photonics
Handbook, in 20033. He notes that low-level laser therapy
works because the laser light is absorbed by the mitochondria photoreceptors,
which enhances cellular metabolism. This means the mitochondria produce more
ATP as a result of exposure to laser light. He notes that the primary reaction
of laser light is in the mitochondria, which results in increased APT energy.
“The mechanism of low-power laser therapy at the cellular level is based
on the increase of oxidative metabolism of mitochondria, which is caused by
electronic excitation of components of the respiratory chain.”
Karu states: “It is known that even small changes in ATP levels can significantly
alter cellular metabolism.” The elevated levels of ATP energy increase
the rate of DNA synthesis.
Consequently, the increased levels of ATP energy and DNA synthesis will benefit
acute and chronic musculoskeletal aches and pains, inflamed oral tissues, help
to heal skin and mucosal ulcerations; treat edema, burns and dermatitis; relieve
pain and treat chronic inflammation, as well as autoimmune diseases. Laser therapy
is also used in sports medicine and rehabilitation clinics (to reduce swelling
and hematoma, relieve pain, improve mobility and to treat acute soft-tissue
injuries). It was shown in the 1980s that laser radiation altered the firing
pattern of nerves, which is connected with pain therapy.
Possibly, the most authoritative text on low-level laser therapy is the 2002
book by Jan Turner and Lars Hode, titled “Laser Therapy Clinical Practice
and Scientific Background4.” This book contains 1,281
references. These authors note:
A recent representative article regarding low-level laser therapy was published
October 2004 in the American Journal of Physical Medicine & Rehabilitation5.
Researchers injured the knees of 42 rats giving them arthritis. Twenty-one of
the rats were given 632 nm low-level laser, applied over the arthritic knee
for 15 minutes, three times per week, for 8 weeks; the other 21 rats were not
similarly exposed. The results showed a marked repair of arthritic cartilage
in the lased rats, but not in the non-lased group. The authors concluded that
the 632 nm low-power laser enhances protein production in arthritic joints and
repairs the arthritic cartilage.
These authors also note: Laser is “thought to cause electronic excitation
of the photoacceptor molecules, which are thought to be various cytochrome enzymes
that are terminal electron carriers in the respiratory chain.” This is
thought to accelerate electron transfer. “Electron transport in the mitochondrial
membrane is one of the main fueling mechanisms underpinning metabolism and proliferation
of cells, including generation of adenosine triphosphate (ATP).” Low-level
laser mediated increase in efficiency of the electron carriers in the respiratory
chain would increase generation of adenosine triphosphate, which could manifest
itself as increased DNA and protein synthesis and result in cell proliferation,
as shown in the present study.” Thus, their explanation of the physiology
of low-level laser therapy is consistent with Karu3 and Turner4 above.
Turner4 notes: “any wavelength will have a biological effect.” Karu3
notes, “The 632.8 nm and the 820 nm are the most common wavelengths used
in therapeutic light sources.” Turner4 and Baxter6
both note, “Shorter wavelengths have higher energy.” Baxter6 even
gives the mathematical formula used to calculate energy based upon wavelength
differences. Based upon the formula Baxter6 uses, a 632.8 nm laser has more
energy than an 820 nm laser.
Turner states: “The first company to receive a 510(k) from the Federal
Drug Administration (FDA) was Majes-Tes Innovations in the USA and its Erchonia
laser.” Review of the FDA’s website notes that the evidence Erchonia
used to achieve the FDA 510(k) status shows that its laser was 60 percent greater
at improving pain and range of motion as compared to the placebo group. Turner
also states: “All laser treatment should be preceded by a system-stimulating
irradiation of the vertebrae that innervates the damaged area.” This is
consistent with the chiropractic concept of spinal neurology influencing the
health and physiology of peripheral tissues. Consequently, the Erchonia laser
is a 635nm wavelength line-laser (as opposed to dot laser) with dual heads,
one for the spine and one for the peripheral tissue. The spinal head is pre-set
to the neurological tissue, while the other head is programmable to the specific
peripheral pathology. Each head has four separate laser beams. Erchonia’s
low-level lasers range in price between $4,500 and $12,900.
In summary, mitochondria present a paradox. They are the major producer of ATP
energy, but they are also the major producer of free radicals. As the mitochondria
produce the ATP energy that our bodies require to function, the mitochondria
also produce the free radicals that damage and age our bodies. Lasers increase
the mitochondrial production of ATP without increasing the production of free
radicals. Anything that increases the production of ATP energy will speed healing
and improve symptoms. Since lasers can achieve this without side effects or
risks, low-level laser therapy is here to stay.
References
1) Douglas Wallace, Scientific American, Mitochondrial DNA In Aging and Disease,
Scientific American, August 1997.
2) Rainer Straub and Eugenio Mocchegiani, Editors, Neuroimmune Biology, The
Neuroendrocrine immune Network In Ageing, Elsevier, 2004.
3) Tiina Karu, “Low-Power Laser Therapy” Chapter 48 in Biomedical
Photonics Handbook, Tuan Vo-Dinh CRS Press, 2003.
4) Jan Turner and Lars Hode, Laser Therapy Clinical Practice and Scientific
Background, Prima Books, 2002
5) Lin, Yueh-Shuang MS; Huang, Mao-Hsiung M.D., Ph.D.; Chai, Chee-Yin MD, Ph.D.;
Yang, Rei-Cheng M.D., Ph.D., Effects of Helium-Neon Laser on Levels of Stress
5 Protein and Arthritic Histopathology in Experimental Osteoarthritis. American
Journal of Physical Medicine & Rehabilitation. 83(10):758-765, October 2004.
6) G. David Baxter Therapeutic Lasers, Theory and Practice, Churchill
Livingstone, 1999.
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