Nutrition to support skin integrity

Requirements of the skin barrier/ nutrients for a healthy skin
The effective structure and functioning of healthy skin is dependent on an adequate level of nutrition. It is evident from the deficiency of certain essential nutrients that certain diseases may arise. This includes, for example, vitamin deficiency such as scurvy due to vitamin C deficiency, which can lead to bleeding gums, easy bruising and sometimes purpura, and pellagra (including dermatitis) due to nicotinic acid (niacin or vitamin B₃) deficiency, which include signs such as dermatitis to sun exposed sites, scaly erythema and hyperpigmentation (Mackie, 2003). Another condition is kwashiorkor that is due to protein malnutrition and leads to dry skin, erythematatous eruption and dry brittle hair. Table 4.2 summarises the key nutrients related to skin health, based on Allen (2000), Dealey (2005) and Patel (2005).

Table 4.2 Key nutrients related to skin health.   Nutrient   Relevant function   Good sources   Carbohydrate   Energy for fibroblast, macrophage, leucocyte function and collagen synthesis   Wholegrain cereals, potatoes, wholemeal bread   Essential fatty acids (EFAs)   Formation of new cells (cell wall phospholipids), energy formation, skin barrier function   Dairy products, vegetable oil, oily fish, nuts   Minerals           Zinc   Enzymatic activity – intermediary in metabolism, cell proliferation and epithelisation, collagen synthesis   Meat, wholegrain cereals, cheese   Iron   Collagen synthesis   Meat, eggs, dried fruit   Copper   Collagen synthesis   Shellfish, liver, meat, bread   Protein   Collagen synthesis (about a third of the body’s protein), fibroblast proliferation, angiogenesis, immunity   Meat, fish, eggs, cheese, pulses, wholegrain cereals   Vitamin A   Membrane stability, normal growth and differentiation of the epidermis   Leafy vegetables (broccoli, spinach), carrots, apricots, liver   Vitamin B complex including           B3 (niacin)   Collagen cross-linking, Enzymatic activity – intermediary in metabolism   Cereal grains, meat, nuts and some fruit and vegetables   B2 (riboflavin)   Deficiency can cause fissuring and inflammation around the lips/mouth and tongue       B6 (pyridoxine)   Amino acid metabolism       Vitamin C   Enzymatic activity, collagen synthesis, blood vessel maintenance, immunity   Citrus fruit and fresh vegetables   Vitamin D   Cell signalling, keratinocyte proliferation   Solar irradiation of Vitamin D3 (cholecalciferol) in the skin and some fish (mackerel, tuna and salmon); Cheese, eggs, beef, liver

Malnutrition remains a significant problem among outpatients (Neelemaat et al., 2008) and indeed may occur when patients are hospitalised (O’Flynn et al., 2005). Other common forms of malnutrition, such as obesity, are responsible for changes in skin barrier function, sebaceous glands and sebum production, sweat glands, collagen structure and function, wound healing and the microcirculation and are implicated in a wide spectrum of dermatological diseases (Yosipovitch et al., 2007).

When the skin is under stress the demand for nutrients will alter and specific items play an important role in countering disease, such as essential fatty acids (EFA) in eczema and psoriasis and zinc in wound healing (Allen, 2000). Extensive skin inflammation increases its requirements for energy and fluid and for specific nutrients such as folic acid and protein.

Nutritional support is required for the healing of wounds (Dealey, 2005) and may help protect against pressure ulcer development and improve the rate of healing (Houwing et al., 2003). However, a systematic review suggests that more evidence is required to identify effective dietary interventions (Langer et al., 2003). Nutrition guidelines for pressure ulcers have been developed (Schols and de Jager-v d Ende, 2004).