Free Radical Damage Can Cause Hair Loss
Like most people, you've probably heard of free radicals—dangerous compounds in our bodies that wreak havoc in the form of oxidative stress and cause disease. They can damage cell structures and DNA and even destroy cells—including hair follicles. But what exactly are free radicals?(18)
Molecules are atoms of elements joined together with orbiting electrons around them that are most stable when these electrons are paired. Free radicals are actually one of two types of molecules that are collectively referred to as reactive oxygen species, or ROS for short:(56, 61)
- Free radicals are ROS molecules that contain an unpaired electron in its outer orbit.
- The other ROS molecules are called non-radical ROS and have paired electrons, but they are reactive and convert to free radicals.
Just as the name implies, ROS (both free radicals and non-radicals) are molecules that contain oxygen and are likely to react with other molecules.(56, 61)
For the purposes of simplification and familiarity, we will call all ROS free radicals.
The Making of a Free Radical
Our bodies experience many natural reactions all the time as a result of bodily function. These including oxidation-reduction reactions that result in the transfer of electrons from one molecule to another:(56)
- Adding one electron (typically in the form of a hydrogen atom) to an oxygen-containing molecule is referred to as reducing that molecule.
- Taking an electron away from a molecule oxidizes it.
These oxidized molecules are referred to as free radical reactive oxygen species (ROS) or free radicals for short. Highly unstable, free radicals create a cascade of oxidative reactions by stealing electrons from other molecules. This happens because the free radicals naturally seek to stabilize themselves, but in the process create more free radicals.(56)
Antioxidants are molecules that can stop these reactions from cascading out of control and causing cell damage. They do so by donating an electron without becoming free radicals themselves.(56)
Under normal healthy conditions the body reacts to the presence of free radicals by activating antioxidant defense mechanisms. These defenses include antioxidant enzymes and anti-apoptotic proteins (e.g., Bcl-2, which protect against cell death and damage by reducing free radicals.(57)
Some of the antioxidant enzymes known to protect hair follicles include:(57)
- Superoxide dismutase
- High catalase
- Glutathione peroxidase
- Methionine sulfoxide reductase
Research suggests that as we age our naturally-produced antioxidants can't keep up with neutralizing free radicals. These include naturally-occurring free radicals as well as those that caused by environmental factors (such as cigarette smoke and UV radiation). Certain dietary deficiencies found in older age adults may also lead to decreased production of natural antioxidants. That's because many vital nutrients (e.g., copper, manganese, selenium, and zinc) are needed to produce them. In fact, one of the symptoms of these nutrient deficiencies is often thinning hair.(18, 32, 47, 58)
Free Radicals and Hair
When free radicals are not regulated by antioxidants oxidative damage accumulates. This cell damage contributes to and causes effects of aging and also causes further impairment of the antioxidant defense system. Research shows that this happens in hair follicles and cells that produce hair pigment as well, which can promote hair loss (whether temporary or permanent).(18, 58, 59)
In otherwise healthy women with diffuse hair loss, antioxidant supplements can increase hair growth rate. These supplements might also prove useful for those suffering from conditions linked with both free radical stress and hair loss, such as polycystic ovary syndrome (PCOS).(18, 60)
In PCOS, research shows excess free radicals directly contribute to the increased levels of androgen hormones produced by the ovaries. This is likely the main cause of the high rates of androgenetic hair loss seen in women of all ethnicities who have PCOS.(60)