Dietary adjustments, particularly those focusing on a lower glycemic load and potentially reducing dairy consumption, may offer benefits for individuals struggling with acne and psoriasis. While not a cure, these changes could contribute to clearer and healthier skin over time. Collagen supplements, however, have not demonstrated significant effectiveness in improving skin quality in rigorous studies.
Diet and Acne
Studies indicate that the overall glycemic load of a diet plays a role in managing acne. The glycemic load measures how quickly a food raises blood sugar and the quantity consumed. Research published in the American Journal of Clinical Nutrition found that young men who switched to a lower glycemic load diet experienced a significant reduction in inflamed acne spots over three months. This dietary shift involved replacing refined carbohydrates and sugary foods like sweetened cereals, biscuits, and pastries with options such as whole-grain bread, pasta, and fruits, complemented by protein-rich foods like lean meats, poultry, and fish.
A subsequent trial in Acta Dermato-Venereologica corroborated these findings. After ten weeks on a lower glycemic load diet, participants saw an approximate 30% decrease in inflamed acne spots, whereas those maintaining their usual diet saw no significant change.
The mechanism behind this improvement is thought to involve insulin levels. Foods that rapidly increase blood sugar can elevate insulin and IGF-1 (Insulin-like Growth Factor 1). IGF-1 can stimulate oil production in the skin and accelerate the multiplication of pore-lining cells, leading to blockages. These conditions can foster bacterial growth and inflammation, resulting in acne.
While not yet a formal treatment guideline, incorporating slower-release carbohydrates like oats, whole grains, and pulses, while minimizing intake of sugary and fast-releasing foods, is suggested as a potential trial for those with persistent acne.
Dairy Intake and Skin
Analysis of dietary habits involving nearly 80,000 young individuals, published in Nutrients, identified a potential, albeit vague, link between milk consumption and acne. Consuming two or more glasses of milk daily was associated with increased acne, while a few glasses per week had little impact. Notably, skimmed and low-fat milk showed a stronger association than full-fat milk. This could be attributed to milk proteins and sugars influencing insulin and IGF-1 levels, with skimmed milk containing the same amount of protein and sugar as full-fat milk but lacking the fat that slows digestion.
While a causal relationship cannot be definitively established, individuals with persistent acne who consume significant amounts of milk may consider reducing their intake for six to eight weeks to observe potential improvements. Ensuring adequate calcium intake from other sources, such as fortified plant-based milks, is important during this period.
Psoriasis and Diet
Individuals with psoriasis, an autoimmune condition causing rapid skin cell reproduction and scaly patches, might also benefit from dietary modifications. A small study in JAMA Dermatology indicated that a Mediterranean-style diet, rich in olive oil, vegetables, and oily fish, when combined with prescription creams, led to greater improvement in psoriasis symptoms compared to a general low-fat diet. Nearly half of the participants on the Mediterranean diet experienced a significant improvement in their psoriasis, a benefit not observed in the comparison group.
The Mediterranean diet is known for its anti-inflammatory properties, which are relevant as psoriasis is linked to inflammation. This dietary approach aligns with a lower glycemic load, emphasizing vegetables, fruits, beans, whole grains, and fish.
Collagen and Anti-Aging
Regarding concerns about wrinkles and skin aging, the efficacy of collagen supplements is questionable. A review in the American Journal of Medicine suggested that while pooled trial data indicates some benefit, this advantage diminishes when studies funded by collagen companies and lower-quality research are excluded.
Consuming foods rich in collagen, such as bone broth or chicken skin, is also unlikely to directly improve skin collagen levels, as the body breaks down collagen into amino acids before rebuilding its own collagen for various bodily functions, not solely for skin health.
However, the gut microbiome plays a role in anti-aging. Fiber consumed from fruits and vegetables is fermented by gut microbes into compounds that may reduce inflammation throughout the body, potentially including the skin. A diet that prioritizes fruits, vegetables, whole grains, beans, nuts, and seeds could contribute to long-term skin health.