Table 1.

Summary of key effects of nutrients and diet in skin aging.

Nutrients/Diet	Relationship with the Skin	References
Water	Maintain skin internal balance and tissue function (e.g., aging and inflammation)	[56,57]
Proteins	Constitution and repair of skin tissues (involved in protein synthesis and metabolism), mediation of skin physiological functions and supply of energy.	[74]
Trace Elements
Copper	Involved in extracellular matrix, synthesis and stabilization of skin proteins, and angiogenesis.	[63]
Zinc	Participates in the proliferation and differentiation of epidermal keratinocytes.	[60,61]
Iron	Closely related to the activity of antioxidant enzymes in skin cells.	[64,65]
Selenium	1. Essential for the development and function of skin keratinocytes.2. Related to skin antioxidant enzyme activity.	[67]
Vitamins
VA	Commonly used anti-aging ingredients prevent skin aging by regulating the expression of genes and matrix metalloproteinases.	[97,98]
VB	Associated with skin inflammation and pigmentation.	[99]
VC	Involved in skin collagen synthesis and elimination of intracellular reactive oxygen species.	[100]
VD	Reduces skin DNA damage, inflammation, and photocarcinogenesis.	[101]
VE	Prevent skin aging by inhibiting lipid peroxidation.	[102,103]
Diet
Fat	High fat is associated with skin inflammation, essential fatty acids are involved in skin lipid synthesis and metabolism.	[92,104]
Tobacco	Change skin cuticle thickness, accelerate skin pigmentation and skin necrosis.	[76,77,78,79]
Alcohol	Promote the proliferation of keratinocytes, change the skin permeability, destroy the barrier function of the skin, affect the skin lipid composition.	[81,82]
Sugar and baked goods	Associated with skin thickness, AGEs, autophagy, and inflammation.	[93,94,95,96]