Have you ever wondered which anti-aging ingredients are proven to work? This week we review the science behind 5 of the top ingredients. Plus, find out why Germany wants to ban retinol!

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SHOW NOTES

Beauty Science News: Will retinol be banned from skin care?

We discuss an article from Colin’s Beauty Pages.

Question of the week: Which anti-aging products work the best?

Terri asks…Which anti-aging products or brands actually work the best? I’m over 50 and always trying to purchase the latest great and best thing.

Here is our version of the three “Kligman questions” that you should ask about any anti-aging ingredient.

1. Based on the chemistry of the ingredient, is there any scientific mechanism that could explain why it would work?

2. Does it penetrate to the part of the skin where it needs to be in order to work?

3. Are there peer reviewed, double blind, placebo controlled studies demonstrating the ingredient really works when applied to real people?

Retinol

What’s the story? It’s a vitamin A derivative which smooths skin, unclogs pores, lightens age spots and improves skin texture.

Can science explain how it works? Yes. It fades dark spots by reducing the contact time with pigment creating cells; reduces fine lines/wrinkles by stimulating synthesis of collagen and glycosaminoglycan. May also inhibit enzymes that breakdown collagen. Smooths skin by modulating genes involved in epidermal cell turn over.

Can it penetrate skin to get to where it needs to be in order to work? Yes. Retinol has the right chemical structure to penetrate skin and this has been confirmed two ways: In vivo by measuring the level of a skin enzyme induced by presence of retinoic acid. (Also confirms metabolism to active version.) In vitro by measuring retinol metabolites on skin biopsies and cell cultures. There are some unresolved questions about how much bio-converts, however.

Is there proof it does anything when I rub it on my skin? Yes. Retinoic Acid has undergone extensive clinical testing. Fewer studies have been on the over the counter versions. Retinol shown to be effective vs placebo but not as effective when compared to retinal for wrinkle reduction.

How do we rate it? “A” The mechanism and effects of retinoic acid are well understood and it appears that other retinoids have a similar, work the same way just to a lesser extent however the OTC versions are not as well substantiated as the prescription form.

Kinetin (N-furfuryladenine growth factor)

What’s the story? It’s a plant growth hormone that supposedly promotes cell division and acts as an antioxidant. It nourishes skin cells to keep them healthy longer/ Boosts skin’s energy for increased radiance

Can science explain how it works? Sort of. Testing on cultured human skin cells (lab testing aka in vitro testing) has shown kinetin can impact cell growth factors which cause age related changes, however the mechanism is not understood. Multiple studies have shown kinetin to be an effective antioxidant; it acts like Superoxide Dismutase, an natural free radical scavenger in skin. There are no reported mechanisms for how it helps wrinkles, age spots, or barrier properties.

Can it penetrate skin to get to where it needs to be in order to work? Unknown. No studies have been done on skin absorption of kinetin.

Is there proof it does anything when I rub it on my skin? Inconclusive. There’s very limited research on topically applied kinetin. One study showed it can partially improve photo-damaged skin and increase skin’s ability to retain moisture. Another showed that when combined with niacinamide it works synergistically to reduce hyper-pigmentation.

How do we rate it? “C” because it needs penetration studies, better mechanistic understanding, and additional studies to document efficacy.

Niacinamide

What’s the story? It’s a version of vitamin B3 (Niacin) which can brighten the complexion, erase wrinkles, reduce transepidermal water loss, improve elasticity, and fight inflammation.

Can science explain how it works? Yes, partially. The mechanisms for ALL these proposed benefits are not fully understood. However, Niacinamide’s ability to increase the antioxidant capacity of skin is well studied. It works by reducing (the opposite of oxidizing) NADP. Niacinamide may reduce water loss by increasing production of lipids and ceramides and by increasing cell turn over. It may reduce wrinkles by increasing collagen production. Finally, it lightens age spots by reducing the amount of pigment transferred from melanocytes to keratinocytes.

Can it penetrate skin to get to where it needs to be in order to work? Yes, penetration has been proven directly at sufficient levels in one study. In addition several studies indirectly proved penetration by measuring increased NAD in cells after topical application (which increases due to the skin metabolizing vitamin B3.)

Is there proof it does anything when I rub it on my skin? Yes. Skin brightening has been proven in several half-face studies. Some of the studies also measured niacinamide’s ability to reduce photo-aging.

How do we rate it? “A.” Although further mechanistic understanding is required, niacinamide is one of the best studied anti-aging ingredients.

Soybean extract

What’s the story? Consists of two active ingredient types (isoflavones and protease inhibitors) which neutralize free radicals, stimulate collagen production, increase skin moisture, and reduce hyperpigmentation.

Can science explain how it works? Sort of. For antioxidancy: One study shows soy isoflavones work 4 ways to fight oxidation in skin. They MAY work as cell signaling molecule but no conclusive proof. Even though mechanisms are unconfirmed, evidence shows they are antioxidants. For collagen production/skin thickening: Only data on collagen is in vitro. Specific components of soy (genistein and daidzein) MAY have sufficient estrogenic activity to counter act thinning skin. For moisture increase: Appears to boost hyaluronic acid production but we don’t know how. For depigmenation: appears to reduce pigment production and block transfer of pigment between cells.

Can it penetrate skin to get to where it needs to be in order to work? Not known for sure. There is little direct evidence the primary soy isoflavones penetrate skin. However, there is evidence that similar compounds can reach the epidermis and dermis. It is also known that penetration depends on the formula from which the isoflavone is delivered and its pH.

Is there proof it does anything when I rub it on my skin? Yes, partly. Preliminary in vivo tests confirm skin lightening benefits (undenatured only). However, anti-aging benefits related to antioxidancy are unconfirmed in large scale tests on humans.

How do we rate it? “B-“ It gets high marks for skin lightening as long as the ingredient is properly processed. But it gets a lower score for unconfirmed anti-oxidant anti-aging effect.

Green Tea

What’s the story? It’s an extract containing polyphenols which are known to be potent antioxidants that may protect against UV damage and help photo-aged skin.

Can science explain how it might work? Yes. There’s no doubt that green tea extract is an effective antioxidant which works by quenching several reactive oxygen species. It is also capable of limiting enzymes which cause collagen breakdown and to increase synthesis by fibroblasts, but again in in vitro testing.

Can it penetrate skin to get to where it needs to be in order to work? Probably not. The active component EGCG is water soluble so it is not well suited for skin penetration. Also, It’s difficult to stabilize green tea extract long enough for it to penetrate skin. To make things worse there is little standardization about which components are contained in extracts and how much of them.

Is there proof it does anything when I rub it on my skin? Maybe, for UV prevention. At least two studies indicate at high concentrations of the active components can prevent the damaged caused by UV exposure. However there is no comparison to indicate if it as good as conventional sunscreens. The only randomized, double-blind, controlled, clinical trial involving topical green tea extract showed no improvement in photo damaged skin from topical application of green tea extract after 8weeks. There were some trends in the data which indicate that a longer questing period might have yielded better results. But so far the ingredient remain unproven.

How do we rate it? “C” The active component is is unstable and it’s not easy to get the ingredient to where it needs to be work. Also, there are no clear studies proving that it does what it’s capable of. In addition, there is little standardization to document the type and concentration of antioxidants present in the extract, not to mention in any finished products.

The Beauty Brains Bottom line

For us to believe that an anti-aging ingredient really works, it must pass the test of the three Kligman questions. Of the 5 ingredients reviewed in the paper we found, Retinol and Niacinamide get an “A” for anti-aging. The others have gaps in their data which make them suspect.

References

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2921764/

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