“For the first time you can achieve essential protection from dangerous sun exposure in a pill”
– LifeExtension advertisement for Fernblock
“Heliocare works to turn back the sun”
– Advertisement for Heliocare
If only it were that easy.Unfortunately, statements like this might make you think that Fernblock and Heliocare are alternatives to sunscreens. But if you put your trust in oral sunscreens, you may end up burned.
Up here in the Great White North, it seems summer is just getting started. And when the sun shines, those prone to sunburn get into a familiar routine: Applying sunscreen to all exposed areas of our bodies before we spend any prolonged time outside. It’s a smart practice: Blocking ultraviolet-A (UVA) and UVB rays prevents an array of skin damage. Immediate effects of UV exposure include skin irritation (red skin) and inflammation (swelling). A microscopic analysis will reveal “sunburn cell” appearance. There is also a reduction in cells that support the skin’s immunity (Langerhans and mast cells). Longer-term effects of sun exposure include skin wrinkling, sagging, DNA damage, liver spots, and even cancer. With a single blistering sunburn said to double the riskof sunburn, wouldn’t it be easier to just take a pill that would boost our skin’s resistance to UVA and UVB rays?
Protecting your skin from UV damage is the claim with the products Heliocare and Fernblock. Both contain extracts of Polypodium leucotomos, (cabbage palm fern), a native plant of Central America. The active ingredient is in the rhizome (rootstalk), and like many plants there’s some interesting biological compounds inside. They include calagualine, ecdysone, ecdysterone, and polypodaureia. Plant extracts appears to have antioxidant properties, and may reduce oxidative damage caused by UV light. In animal models that have looked at simulated UV radiation, inflammation and irritation were reduced. 
“In over a decade of clinical trials, FernBlock® has shown remarkable effectiveness in shielding skin against dangerous ultraviolet exposure” [source]
Not quite. Let’s look for evidence to answer the following question: In typical users, does consuming Polypodium leucotomos provide UVA and UVB skin protection that is comparable to sunblock?
A search of the literature identified only three semi-relevant published trials that study the active ingredient in Fernblock and Heliocare and its ability to prevent sunburn.
Middelkamp-Hup studied Polypodium leucotomosin the prevention of sunburn. In this small open-label (unblinded) study, nine volunteers were given different doses of UV radiation, and then the radiation was repeated after two days of taking Fernblock. A small sample (biopsy) was taken of the skin before and after Fernblock, and the samples were compared. They found less evidence of skin damage, and concluded that Fernblock protected the skin from inflammation and the effects of sunburn. This was an interesting preliminary study, but not one to draw broad conclusions from. The study was not blinded – that is, both the researchers and the patients knew that a treatment was being given. The effects were modest. Long-term effects were not studied. 
Another study by the same author studied the effect of Polypodium leucotomos in volunteers that were given sensitiziers that accelerate UV damage. Ten patients were studied. There was no blinding. Volunteers received simulated sun exposure before and after 7.5mg/kg of Polypodium leucotomos. The author concluded that Polypodium leucotomos was an effective skin protector against the simulated sun exposure. As this study examined the products effectivenss in patients given UVA sensitizers, it’s difficult to draw conclusions about its usefulness in normal patients receiving regular sun exposure. 
González studied both topical and oral forms of Polypodium leucotomos in 21 people. Some patients were given sensitizers to accelerate UVA damage, some were untreated. All received Polypodium leucotomos. Skin was evaluated to measure the protective impact of the product. The product was administered before sun exposure. He observed that the time to initial reddening increased significantly, and reduced other initial signs of skin damage. He concluded that both versions offered some degree of skin protection. This was a small study, with no blinding. No comparison was made to sunscreen. 
That’s the extent of the research that’s relevant to our question. There have been no double-blind trials and no direct comparisons to sunscreen. There are some other trials, that are suggestive, but not conclusive, that Polypodium leucotomos may provide some benefit to people who have abnormal skin reactions to sunshine. Without double-blind trials, we are left with examining the results of studies that are prone to bias. That doesn’t mean we ignore the results, but we should remain skeptical, and look for confirming evidence.
The most common side effect reported in the limited research reported is stomach upset. Based on these very small trials, Fernblock and Heliocare seems to be safe when taken for up to two days. There is no published information showing either is safe if taken for a longer period.  Another brand of the same ingredient appears to be safe when taken for up to five months, however.  In light of the small studies that have been conducted, the full safety profile may not yet be well understood. There’s no information about the product’s safety in pregnancy, or in breastfeeding women, so it should be avoided.
The consequences of unprotected exposure to UV light can be severe. Sunscreen in the forms of creams and other physicial barriers have been demonstrated to reduce UV light exposure and the long-term risks of skin damage. Oral sunscreens, like Heliosun and Fernblock, appear to slightly reduce some of the severity of a sunburn. One of the key researchers has suggested it offers an SPF of about 3 – insufficient for most people that need sunblock. Most importantly, there is no evidence yet that this product protection against the most serious, long-term effects of sun exposure. Importantly, both manufacturers recommend that you apply sunscreen creams in combination with the product. Given most sunscreens offer an SPF of 15 or more, these products do not offer much additional protection.
Topical sunscreen products remain the protection of choice against sun exposure. Fernblock and Heliosun have not been well studied, and have not been compared to topical sunscreens. It is good to see that longer-term, larger trials appear to be ongoing. Until better effectiveness and longer-term safety data emerges, these products are not recommended for use, or for sale in the science-based phamacy.
For more information
The Healthy Skeptic from the LA Times.
University of Montana’s Drug Information Service: “Oral Sunscreen: Take One Tablet Daily? August 2006. [PDF]
Natural Medicines Comprehensive Database [database on the Internet]. Stockton (CA): Therapeutic Research Faculty; 1995-2009 [cited 17 August 2009] Available from: http://www.naturaldatabase.com. Subscription required to view.
Middelkamp-Hup MA, Pathak MA, Parrado C, Goukassian D, Rius-Díaz F, Mihm MC, Fitzpatrick TB, González S. Oral Polypodium leucotomos extract decreases ultraviolet-induced damage of human skin. J Am Acad Dermatol. 2004 Dec;51(6):910-8.
Middelkamp-Hup MA, Pathak MA, Parrado C, Garcia-Caballero T, Rius-Díaz F, Fitzpatrick TB, González S. Orally administered Polypodium leucotomos extract decreases psoralen-UVA-induced phototoxicity, pigmentation, and damage of human skin. J Am Acad Dermatol. 2004 Jan;50(1):41-9.
González S, Pathak MA, Cuevas J, Villarrubia VG, Fitzpatrick TB. Topical or oral administration with an extract of Polypodium leucotomos prevents acute sunburn and psoralen-induced phototoxic reactions as well as depletion of Langerhans cells in human skin. Photodermatol Photoimmunol Photomed. 1997 Feb-Apr;13(1-2):50-60.