 I hear from lots of people every day who are concerned about how their diet is affecting their health. They need answers based on facts, in other words, from the peer-reviewed medical literature, and that is what I'm here for. Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Greger. Today we have the second in our two-part series on anti-aging creams, and we start with a look at niacinamide, also known as nicotinamide, in a form of vitamin B3. I've talked about sunscreen and topical retinoids. What are their skin-crean components have been shown to help with skin aging? While placebo-controlled trials are the standard in most medical research, they're still all too rare for cosmetic products. This raises efficacy questions. Many are left with simply buying hope in a jar, as well as safety concerns. Cosmetics to this day contain an array of toxic chemicals, of the more than 12,000 synthetic chemicals used in cosmetics fewer than 20% have been recognized as safe. Of course this doesn't mean natural ingredients are necessarily harmless, poison ivy is as natural as you can get, but you wouldn't want to rub it on your face. However, there are some relatively safe natural options with varying degrees of efficacy. In contrast to retinoic acid, a form of vitamin A that can be irritating, topical niacinamide, also known as nicotinamide, is a form of vitamin B3 that is non-irritating and found to be effective. It's been described as one of the best-studied cosmeceutical ingredients for anti-aging. But it looks like there are only two placebo-controlled human studies, which gives you an idea of the state of cosmeceutical science. Skin photoaging is largely mediated by UV-induced free radical formation. One of the consequences of excess sun exposure is the oxidation of sugars and proteins in the skin into yellow-brown pigments that give aging skin a yellowing, sallow appearance. Since niacinamide is a precursor to two potent antioxidants, the hope is that this process could be interrupted and indeed the first published study was entitled Topical Niacinamide Reduces Yellowing, Wrinkling, Red Blotchyness, and Hyperpigmented Spots in Aging Facial Skin. It was a 12-week double-blind placebo-controlled randomized clinical split-face study of middle-aged women In a split-face study, each woman is her own control, rubbing the active formulation, in this case 5% niacinamide and moisturizer, on one side of her face, and the placebo, straight moisturizer, on the other half, though neither she nor the researchers know which side is which until the code is broken at the end. This controls for skin type and administration technique, and different people apply facial products differently, but participants often use the same hand for applying the creams to both sides so unless specified that different gloves be worn or hands washed in between, there can be cross-contamination. Anyway, at the end of 12 weeks, there was a small 5% reduction in wrinkles and fine lines and a slowing the development of blotchiness, spots, and salinus, a subsequent publication noted an improvement in skin elasticity as well. The magnitude of these effects may only be one-third to one-fifth as good as retinoic acid, but there were no reports of excess skin irritation. But, used a 4% concentration and the application was limited to crow's feet wrinkles around the eyes. Significant reductions in wrinkles by both subjective and objective measures were noted by the end of the 8-week study. 64% of the niacinamide side eye wrinkles unwent moderate or market improvement compared to 0% on the placebo side eyes. Finally today, we look at the pros and cons of alpha hydroxy acid, lotions, chemical peals, and topical antioxidants in reversing the signs of aging. There is a reason why there's a long historical use of fruit purees as facial masks, and perhaps why Cleopatra was said to be than sour milk. Alpha hydroxy acids, also known as fruit acids, are natural acids found in foods. They include citric acid from citrus, glycolic acid from sugarcane, lactic acid from fermented fruits, malic acid from a variety of fruits, and tartaric acid from grapes. High strength concentrations are used for chemical peals. Concentrations over 40% can only be used by medical doctors. Professionals in salons can give more mild peals with 10-40% acid solutions, but concentrations under 10% are sold over-the-counter as exfoliants. Alpha hydroxy acids are thought to work by weakening cell-to-cell bonds to hasten the shedding of dead cells off the skin surface. Three placebo-controlled studies of over-the-counter strengths have been published. The first compared an 8% glycolic acid lotion to an 8% lactic acid lotion to a placebo lotion applied daily on face and forearms for 22 weeks. Both the acids work similarly, producing visible improvements in facial photo damage and more than 70% of the acid groups versus only 40% of the placebo group. All of the participants were advised to wear protective clothing and regularly use sunscreen, which may explain the benefits even in the placebo group. Overall forearm photo damage and salinists also improved significantly in the acid versus placebo groups. About one in three participants experienced transient redness, but only one out of 74 left to study due to facial irritation. The second trial found a 5% glycolic acid lotion for three months beat out placebo on lessening skin roughness and model discoloration on the face and neck, but failed to significantly reduce wrinkle scores. The irony of alpha hydroxy acids is that while they can help with past photo damage, they can make future damage worse by increasing skin photosensitivity. So taking precautions is recommended. The FDA recommends that all alpha hydroxy products be labeled with a prominent warning sunburn alert. This product may increase your skin sensitivity to the sun, and particularly the possibility of sunburn, use a sunscreen where protective clothing and limit sun exposure while using this product and for a week afterwards. What about ascorbic acid, also known as vitamin C? If niacinamide works by turning into antioxidants, why not just apply antioxidants directly? Topical application can lead to vitamin E levels in the skin 10 times, what is achieved by oral dosing, and vitamin C up to 40 times higher, at least in mouse and big skin, respectively. According to a review on topical anti-aging skincare by a prominent Beverly Hills plastic surgeon, at a minimum, patients should be encouraged to use daily sunscreen, with retinoid every night, and a topical antioxidant daily. But there's only one antioxidant that's been clearly shown to work. Despite its ubiquity in skin care products, there is no evidence to support any role for topical vitamin E in skin aging, whether for wrinkles, discoloration, or texture. The one study on topical CoQ10 also failed to work significantly better than placebo, but there is one type of vitamin C that has been shown to help. One biopsy study showed that the topical application of a 5% solution of elascorbic acid, also known as just ascorbic acid, the type of vitamin C found in food, significantly increases the expression of collagen in human skin, compared to placebo, suggesting functional activity of the skin cells is not maximal in post-menopausal women and can be increased. A split face study involving the application of three drops of a 10% elascorbic solution for three months found significant improvements over the placebo side of the face in fine and coarse wrinkles, sourness, and skin tone or firmness. Not knowing which side was which, 16 out of 1984 percent of patients correctly identified the vitamin C side as the one showing improvement. Unfortunately, elascorbic acid is unstable in creams, turning an unsightly ground when it oxidizes, limiting its shelf life. So instead, the skin care industry uses more stable vitamin C esters or derivatives, such as ascorbic palmitate, magnesium ascorbic phosphate, ascorbic acid sulfate, ascorbic stearate, etc. Unfortunately, there is no evidence that these compounds have comparable effects, likely because they're poorly absorbed and only minimally convert to the active form. The good news is that you can make your own. Although vitamin C concentration is lowest 3% or 5% have been shown to have anti-wrinkle effects in split face or split neck and arm studies, 10% is recommended. The 10% solution used in this study retails for a ridiculous $127 per ounce. You can make a DIY solution more than 2,000 times cheaper simply by buying elascorbic acid in bulk and mixing 3 grams into 30 grams of water at a cost of about a nickel per ounce. You can mix it in an eyedropper and drip 4-5 drops on the palm of your hand and use your fingertips to apply over your face, neck, and upper chest daily. Now, just be careful to not get any in your eyes. We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to nutritionfacts.org slash testimonials. We may be able to share it on social media to help inspire others. If you see any graphs, charts, graphics, images, or studies mentioned here, please go to the Nutrition Facts podcast landing page. There you'll find all the detailed information you need plus links to all the sources we cite for each of these topics. My latest book, How Not to Age, is out now, premiering at No. 2 on the New York Times best sellers list. Check it out at your local public library. Of course, all the proceeds of the sales of all my books goes directly to charity. NutritionFacts.org is a nonprofit science-based public service where you can sign up for free daily updates on the latest nutrition research with bite-sized videos and articles, and everything on the website is free there. No ads, no corporate sponsorships, no kickbacks, strictly non-commercial. I'm not selling anything and just put up as a public service as a labor of love as a tribute to my grandmother, whose own life was saved with evidence-based nutrition.