This Is Why 99% of Skin Conditions Don't Heal — And What Dermatologists Won't Tell You

Dr. Mia repeatedly ranks sun protection as the single highest-value intervention for skin aging. She explains that intermittent intense sunburns — like a week on a beach vacation — are more associated with melanoma, while chronic daily exposure drives basal and squamous cell carcinoma and accelerated aging. She recommends UPF clothing, hats, and avoiding peak UV hours, and notes UV penetrates ordinary clothing.

Dr. Mia gives a minimalist framework because the skin-care world is noisy. The three non-negotiables are cleanser, moisturizer, and sunscreen. Once those are stable, add vitamin C in the morning and a retinoid at night. If that routine is well established, an additional serum with peptides or growth factors can be layered. She calls retinoids the most evidence-backed topical anti-aging ingredient and vitamin C the most studied antioxidant.

Dr. Mia says the evidence for acne points most strongly to dairy and sugar, with fiber being underrated. For psoriasis, the evidence supports a Mediterranean-style diet, omega-3s, vitamin D, and gluten elimination if antibody-positive. Hyman adds that standard antibody tests miss the innate immune system's reaction to gluten, so a short trial is a useful diagnostic.

Dr. Mia explains that aerobic exercise and strength training both improved skin hydration and barrier function in the study, but only strength training increased dermal thickness. Hyman connects this to his own functional-medicine framework: muscle building improves insulin sensitivity and mitochondrial health, which changes how skin cells behave.

Dr. Mia says she often collaborates with functional-medicine doctors for gut testing because conventional dermatology does not provide this workup. Hyman describes his Cleveland Clinic functional-medicine data where psoriasis and psoriatic arthritis patients treated with lifestyle and gut protocols did better on standard rheumatology rating scales than patients treated with immunosuppressants in the world-class rheumatology department.

Dr. Mia says she is a big fan of HRT and it does wonders for skin, but admits there are not many large studies dedicated to skin health. Estrogen and testosterone both decline in menopause. Estrogen loss lowers fibroblast activity, so collagen production and skin thickness decrease; skin also loses hyaluronic acid and lipids, becoming drier and thinner. Hyman adds that perimenopause creates a soup of dysfunctional hormones — insulin, thyroid, sex hormones, and cortisol — that deserves a full workup.

The skin diet is a Mediterranean-style, well-balanced diet: adequate protein, healthy fats, low sugar, and plenty of fiber. Dr. Mia highlights omega-3s and vitamin D for psoriasis, and colorful polyphenol foods for oxidative stress. Hyman calls omega-3s the most clearly clinically effective skin nutrient he has used for skin, hair, and nails, and notes that Function Health tests the omega index because most people are low.

Both speakers describe the same clinical shift. Dr. Mia went through dermatology residency and private practice where the core model was suppressing inflammation with topicals, oral steroids, or biologics. She says those treatments help people get through the day but do not address why the skin is inflamed. She now takes a broader history: diet, sleep, stress, hormones, environmental exposures, exercise, and menopause status.

For Hyman, insulin resistance is a big skin-health blind spot. He says high insulin in women raises testosterone, which worsens acne, and that sugar is a major unrecognized acne trigger. Dr. Mia says she tests insulin level and fasting glucose ratio for acne patients because it gives a more accurate picture of insulin sensitivity. Nicholas Perricone gets credit for popularizing the inflammation/oxidative-stress link to wrinkles.

Dr. Mia says gut and hormones are the two biggest root-cause categories she sees. She collaborates with functional medicine doctors for stool/microbiome testing and examines for yeast overgrowth, SIBO, and H. pylori. Hyman describes a severe psoriatic arthritis patient whose whole inflammatory symptom cluster resolved after treating SIBO and fungal overgrowth plus an elimination diet. Both caution this requires detective work and a practitioner willing to go beyond conventional testing.

Dr. Mia describes a study of about 60 midlife women comparing aerobic exercise with strength training. Both groups improved hydration and barrier function, but only strength training increased dermis thickness — the layer where collagen sits. She says the finding makes biological sense: strength training improves insulin sensitivity, decreases inflammation, and optimizes mitochondrial function, which helps dermal cells build more collagen.

Dr. Mia says UV radiation causes localized oxidative stress and DNA damage in skin cells. With enough hits, repair capacity is overwhelmed, mitochondrial function declines, and skin cells produce more oxidative stress, leading to collagen breakdown. Mitophagy clears damaged mitochondria, and optimizing it means reducing oxidative stress — less processed food, less chronic UV, adequate sleep, stress management, and exercise, which also increases mitochondrial number.