Skin health from the inside out: acne, aging and gut

Chronic skin problems are often treated by suppressing symptoms with steroids, antibiotics or biologics. In a conversation with Dr. Mark Hyman, an integrative dermatologist describes a different approach: skin health comes from the inside out, and many conditions trace back to the gut, hormones and insulin. This guide summarizes the key ideas on chronic skin disease and skin aging.

Find the root cause, not only the symptom

The dermatologist grew up with a Japanese mother who exposed her to holistic healing. After conventional training she noticed that suppressing inflammation does not solve the underlying trigger. With patients she now looks at diet, sleep, stress, hormones, environment, exercise and gut health before she builds a plan.

Gut and hormones are the two biggest drivers she sees in acne, eczema, psoriasis, rosacea and hair loss. Rosacea is linked to higher rates of SIBO and Helicobacter pylori. For acne she checks insulin and the ratio of insulin to fasting glucose. Hyman adds that optimal fasting insulin is under 5, yet 65% of more than half a million Function Health members have high insulin.

What the evidence says about diet

Most evidence supports a Mediterranean style pattern: adequate protein and healthy fats, low sugar and plenty of fiber, fruits and vegetables. For acne the strongest links are dairy, especially skim milk, and sugar, and low fiber also plays a role. For psoriasis, the Mediterranean pattern plus omega 3s and vitamin D helps, and gluten avoidance matters mostly when antibody tests are positive. For chronic conditions she suggests a short elimination diet of gluten, dairy, sugar and processed food. Hyman shares a patient with psoriatic arthritis, migraines, depression and reflux who improved on his 10 day detox diet plus treatment for gut overgrowth.

Omega 3s are the nutrient with the best clinical results for skin, hair and nails, and the omega 3 index should be above 8%. Hyman also takes Perfect Amino for protein.

Hormones and skin aging

Estrogen activates fibroblasts that build collagen and supports hydration and skin thickness, so its drop in the first five years of menopause leads to dry, crepey skin. Thyroid problems cause dry skin, brittle nails and hair loss, and insulin resistance accelerates aging. She is a big fan of hormone replacement therapy for skin, though skin specific studies are still lacking.

Aging also slows cell turnover, makes pigment cells unpredictable, reduces lipids and breaks down collagen, elastin and hyaluronic acid. Alcohol, smoking, pollution, sedentary habits and sugar speed all of this up, because sugar forms advanced glycation end products that make collagen brittle.

Mitochondria, urolithin A and collagen

UV damage worsens mitochondrial function and oxidative stress. Mitophagy clears damaged mitochondria, and sleep, strength training, less stress, omega 3s, polyphenols and urolithin A support it. Hyman uses Timeline Mitopure daily. The dermatologist favors collagen peptides, noting they send signals to build collagen, but only after sleep, sun protection and stress are handled.

A small study of midlife women found that strength training gave a thicker dermis than aerobic exercise.

The highest value skin routine

1. Sun protection is number one. Avoid peak UV between 10 a.m. and 2 p.m., and consider UPF clothing. Skin cancer risk is tied to intermittent burns and chronic exposure, but low vitamin D also raises melanoma risk, so seek balance.
2. Vitamin C in the morning and a retinoid at night. Retinol is slower and gentler than tretinoin.
3. Cleanser, moisturizer and sunscreen as a minimum.
4. Add peptides, growth factors, PDRN or niacinamide only after the basics.

Topical copper peptides have decent data, while injectable GHK Cu, exosomes and stem cell products lack safety evidence. Mineral sunscreens are classified as generally recognized as safe, while chemical filters absorb more into the bloodstream. Beef tallow is not a miracle moisturizer.

Are skincare ingredients safe?

Hyman asked about parabens found in a patient's urine and about the EWG Skin Deep database. The dermatologist respects the database but notes that much of its data comes from very high doses in animal models, so she would not panic over a bit of paraben exposure. Skin is a good barrier, yet some compounds do cross it, such as nitroglycerin paste or fentanyl patches. If given a choice, she would pick products with fewer industrial ingredients after checking the safety data.

In rapid fire answers, she said UV is the biggest driver of premature aging, exercise matters more if you want to live longer while skincare matters more for smooth skin, and mitochondria rate at least a nine out of ten.

Conclusion

The top driver of premature skin aging is UV, and the best foundation is sunscreen, vitamin C, a retinoid, sleep, strength training and a low sugar whole food diet. For acne, eczema and psoriasis, look at gut, insulin and hormones with your clinician.