Fish oil is a rich source of the omega-3 fatty acids, which are among the most comprehensively studied nutrients currently available on the market. Omega-3 fatty acids are believed to possess wide-ranging and remarkable health benefits, including:
Improving insulin sensitivity
Reducing symptoms of depression and anxiety
Reducing pain and inflammation associated with arthritis
Preventing asthma exacerbations in children and young adults
Supporting healthy brain development in babies and children
Reducing the risk of Alzheimer's disease and other dementias
Indeed, fish oil has many tricks up its sleeve, and it would be a remarkable silver-lining if it can actually halt hair loss.
What we know so far about Androgenetic Alopecia
Affecting 60 to 70% of the world population, including 50% of Caucasian men in their 50s, Androgenetic Alopecia (AGA) is characterized by miniaturization of the hair follicles.
Dihydrotestosterone (DHT), thought to be a major contributor to AGA, is a potent sex hormone derived from testosterone with the help of the enzyme 5-alpha-reductase. It is believed that DHT shortens the growth phase of the hair cycle, and as a result, hair becomes progressively shorter and follicles stop functioning.
Compared to people with a head full of hair, the balding counterparts have higher free androgens, higher free testosterone, higher 5-alpha reductase, and lower sex hormone binding globulin (SHBG). In addition, people with AGA have abnormally high androgen receptors (AR), making the follicles more sensitive to DHT, which enjoys a high affinity to AR.
Testosterone is an androgen responsible for turning boys into men, and making men more manly. That we can grow hair at all, is thanks to the androgens. However, androgens have different effects at different hair follicles.
At the facial hair follicle, androgens stimulate growth factors, leading to hair growth. At the scalp, DHT stimulates pro-inflammatory cytokines, causing the follicle to shrink. Prostaglandin D2 (PGD2) is one of these cytokines, and is elevated in the balding scalp, according to one study by Cotsarelis and colleagues.
There are at least 16 classes of prostaglandins; some of them are harmful to hair follicles (PGD2), while others are known to boost hair growth and be healthy for hair in general (e.g prostaglandin E2 and prostaglandin F2 alpha). Prostaglandins are now believed to be a major player in hair regulation; they have to be in balance to prevent follicles from shrinking and encourage hair growth.
It also turns out that DHT may increase levels of the cyclooxygenase (COX)-2 enzyme, which is important in the synthesis of prostaglandins from fatty acids.
What is Fish Oil?
Fish oil is literally what it sounds like: oil squeezed out of fish. But when we talk about fish oil, we are really referring to the two omega-3 fatty acids eicosapentanoic acid (EPA) and docosahexanoic acid (DHA). EPA and DHA are almost exclusively found in marine sources. Generally, the oilier the fish, the more omega-3's it contains. Fish do not make these fatty acids themselves; they get the omega-3's from the primary source- the planktons- which they eat.
Much of the interest in fish oil started with the groundbreaking study of the Eskimos of Greenland by Bang and Dyerberg. In their research, they found that Eskimos had a high fat diet, and yet they had lower rates of heart disease.
Along with their cousins, the omega-6 fatty acids (e.g Arachidonic acid), the omega-3's are also called essential fatty acids and polyunsaturated fatty acids. They are called "essential" because they cannot be made by the body, and must be obtained from the diet. Aside from marine sources, omega-3's can also be obtained from plant oils as alpha-linolenic acid (ALA), which is converted EPA, then into DHA.
Fatty acids have two important functions. First, they provide structural integrity to cells. Second, fatty acids are precursors to eicosanoids, proteins that regulate the body's inflammatory processes, like prostaglandins, thromboxanes and leukotrienes. Generally, the metabolites of omega-6 fatty acids are more inflammatory.
Omega-3's and 6's compete for the COX-1 and COX-2 enzymes to create their respective proteins. So, if there's more omega-3's there will be less chance for the omega-6's to produce their more inflammatory proteins. Unfortunately, the standard western diet has 10 times more omega-6 than omega-3, at the least.
How does Fish Oil work for hair loss?
Despite being known to regulate prostaglandins, which are involved in hair regulation, there is surprisingly little in the literature that links fish oil and hair. In theory, though, omega-3's disrupt several processes necessary in the development of alopecia.
Inhibits 5-alpha-reductase
As you already know, 5-alpha-reductase is overexpressed in individuals with AGA. 5-alpha-reductase is an enzyme present in high levels in the prostate and the scalp and catalyzes the metabolism of testosterone into DHT.
Finasteride and dutasteride are two of the medications we have that can inhibit 5-alpha-reductase., but they come with many risks, like impotence and depression. A study by Pham and Ziboh found that EPA inhibited 5-alpha-reductase conversion of DHT by 55%.
In the same study, a fatty acid called gamma-linolenic acid (GLA) inhibited 5-alpha-reductase by 80%. GLA is an omega-6 fatty acid. Although an omega-6 fatty acid, GLA has anti-inflammatory properties.
What is the connection between GLA and EPA? Well, EPA enhances the conversion of GLA into prostaglandin E1 (PGE1). PGE1 is a potent vasodilator, like Minoxidil. EPA also prevents the conversion of GLA into Arachidonic acid.
Inhibits Prostaglandin D2
In the Cotsarelis and Garza study, the researchers found that it's not only DHT that destroys the follicles. They found that PGD2 and the enzyme prostaglandin D2 synthase are elevated in the balding scalp in men with AGA. PGD2 is believed to cause hair to stop growing by inducing the catagen stage and death of follicular cells.
So, it would make sense to inhibit the synthesis of PGD2. A study published in the Journal of British Society for Allergy and Clinical Immunology found that EPA inhibited PGD2 by blocking the COX-2 pathway.
Suppresses androgen receptor expression
The AR is overexpressed in people with prostate cancer and AGA, which increases sensitivity to the effects of androgens. In a study by Friedrichs, researchers found that at the molecular level, omega-3 fatty acids significantly decreased expression levels of AR by inducing protein instability.
Although the study was on prostate cancer, the results may also be applied to AGA as they have a similar pathologic basis.
Lowers testosterone and SHBG
High free testosterone and low SHBG are a glaring problem in AGA. In women with polycystic ovary syndrome, specifically, omega-3 fatty acids have been found to significantly decrease testosterone and raise SHBG.
In another study, women with female pattern hair loss were supplemented with omega-3's, omega-6 (in the form of GLA) and antioxidants for 6 months. At the end of the study, 88.9% of the subjects reported a reduction in hair loss.
Getting and using Fish Oil
The best way to get omega-3 fatty acids is by eating whole food, like fatty fish at least twice a week. Not just any fish, either; it should be the fattiest and oiliest fish available in the market.
Fish rich in omega-3's include:
Herring
Pacific 1.81
Atlantic 1.71
Salmon
Chinook 1.48
Sockeye or pink 1.05
Coho 0.91-1.09
Atlantic 1.09-1.56
Tuna 0.26-1.28
Sardines 0.98-1.70
Mackerel 0.34-1.57
Anyway you choose to cook, you have to remember that fish cooks quickly. The best way to cook fish and preserve its health benefits is to cook it with water by steaming, baking, poaching or boiling rather than frying.
If for some reason you are unable to get enough fish, the second best way to get your omega-3's is through fish oil supplements.
Fish oil supplements
Fish oil supplements come in two forms: natural and processed. Natural fish oil comes from the fatty tissue of fish, and is the closest thing you can have to whole fish. Fish oil is about 30% omega-3 and 70% other fatty acids that can enhance absorption.
Not only does fish oil provide omega-3's, it contains vitamin A and D, as well. And if it is fermented, it can contain vitamin K2.
Processed fish oil is the concentrated ethyl ester form, which may contain up to 90% of omega-3's. It is cheap, and very popular with consumers, but it is not absorbed as well as natural fish oil. It is also more vulnerable to oxidation.
Choosing a supplement
When choosing a fish oil supplement, search the label for FFA (free fatty acids), PLs (phospholipids), or TG (triglycerides) for better absorption. Do not choose EE (ethyl ester).
Also important in choosing a fish oil supplement is to make sure it's fresh and not rancid. Always check the date and see if the supplement has an added vitamin E.
Dosage
So far, there has not been an official recommended daily allowance for omega-3's. The FDA considers doses up to 2, 000 mg per day safe, while the EFSA has set a maximum dose of 5, 000 mg per day.
The Bottom line
While theory strongly suggests that fish oil and omega-3's could be a significant step towards curing AGA, current evidence of a direct association or correlation between the two is sorely lacking at best. What we know now is just the tip of the AGA ice berg, er, follicle.