Fish and shellfish are commonly cited as beneficial for nail health, primarily due to their rich content of high-quality protein, omega-3 fatty acids, and essential micronutrients such as zinc, selenium, and biotin. Scientific studies support the idea that adequate dietary protein and specific micronutrients are necessary for normal nail growth and strength. Fish, in particular, provides all essential amino acids, which are the building blocks of keratin—the primary protein in nails. Additionally, omega-3 fatty acids found in fatty fish (like salmon, sardines, and mackerel) have anti-inflammatory properties that may help prevent nail bed inflammation and promote healthy nail growth.

Shellfish such as oysters are among the richest dietary sources of zinc, which has been shown in studies to play a key role in nail health, with deficiency sometimes leading to brittle nails or white spots. Likewise, selenium, present in seafood, is important for the synthesis of antioxidant enzymes that protect nail cells from damage. Although robust clinical trials specifically focusing on fish consumption and direct improvements in nail health are limited, the overall nutritional profile of fish and shellfish aligns well with nutrients known to support nail structure and appearance. As such, their use is scientifically justified and commonly recommended by nutritionists and dermatologists as part of a balanced diet for optimal nail health.