You are what you eat: the importance of nutrition in wound healing

Normal wound healing is a complex biological process that involves four overlapping phases – inflammation, proliferation, epithelisation, and remodelling, also known as maturation (Bishop, 2021).

Malnutrition adversely affects the physiological response to infection through the loss of immune function, predisposes people to skin infections by rendering the skin thin and friable so more susceptible to wound development, increases the likelihood of pressure wound development through loss of subcutaneous fat over pressure points, and increasing immobility through a lack of energy reserves, and reduces the collagen synthesis essential to healing (Ghaly et al 2021).

Both intrinsic and extrinsic factors can affect wound healing, for example:

• Extrinsic factors include – smoking, medication and nutrition.
• Intrinsic factors include – age, genetic factors, and diseases such as diabetes. (Simmons 2022)

This clinical blog will explore how adequate nutrition supports wound healing.

The British Association of Parenteral and Enteral Nutrition (BAPEN 2024a), defines malnutrition as a: “state where there is an imbalance (either deficiency or excess) of energy, protein, and other nutrients that adversely affects tissue and bodily functions and clinical outcomes.”

The National Institute for Health and Care Excellence (NICE 2017) defines a person as being malnourished if they have:

In the UK, estimates suggest 1.3 million people over 65 suffer from malnutrition, and the vast majority (93%) live in the community (BAPEN 2024b). 

The use of malnutrition screening tools, such as the ‘Malnutrition Universal Screening Tool’ (MUST) can help to identify those at risk of malnutrition. It consists of three parts:

• Measuring Body Mass Index (BMI) – this is calculated from an individual’s weight and height. A BMI of less than 18.5kg/m² suggests a significant risk of malnutrition.
• Considering any history of recent weight loss that has occurred without any intention to lose weight. The unintentional loss of more than 10% of normal body weight in the last 3-6 months suggests a significant risk of malnutrition.
• Identifying an “acute disease effect” associated with being acutely ill and being unable to eat adequate amounts for more than five days.

‘MUST’ identifies people as being at low, medium or high risk of malnutrition and guides the user to develop individualised care plans for management or further monitoring (BAPEN 2024b).

How can we help to improve nutrition?

Protein deficiency is widely held to be a major problem in malnourished people and has been linked to an increased risk of pressure ulcers and slow wound healing in several studies (Litchford et al 2014).

Inadequate protein intake has been shown to significantly delay wound healing by prolonging the inflammatory phase (Grada and Philips, 2022). A minimum protein intake of 1–1.5 g/kg/day is recommended for people with chronic wounds producing high exudate volumes (Clark et al, 2004). Based on this guidance a person weighing 65kg (10 stone) with an exuding, chronic wound would require a minimum of 97.5 grams of protein daily (using the higher value of 1.5g/kg/day). This is the equivalent to:

• 7.5 eggs
• 1 250g steak
• 24 avocados
• 4 salmon fillets
• 2 big, cooked chicken breasts

Achieving the recommended protein intake by eating extra food can be extremely challenging, especially during periods of illness and for people living with dementia (PLWD). The British Dietetics Association (BDA 2024) gives the following advice to support a person to achieve a balanced diet:

• eat ‘little and often’ – 3 small meals a day with 2-3 snacks in-between meals.
• include protein like meat, fish, chicken, eggs, beans or lentils in each meal.
• add high calorie ingredients like full cream milk, cheese, butter, ghee, olive oil and cream to meals and drinks.
• include puddings after lunch and dinner like creamy yoghurts, custards, rice pudding, milk puddings, or ice-cream.
• try ready meals if you don’t feel like cooking.
• choose nourishing milky drinks like malted drinks, hot chocolate, milky coffee and milkshakes.
• choose high sugar drinks like fruit juice, smoothies, fizzy drinks or squash (you can also add egg powder to juice to increase its nutrients).
• try including 1 pint of full cream milk each day – you can fortify (add extra nutrients to) this by adding 4 tablespoons of dried milk powder – and use this in drinks, cooking, cereals and puddings.

Treatment for malnutrition will depend on a person’s general health and how severely malnourished they are. NICE (2024) guidance states that management of a person with, or at risk of, malnutrition should include:

• Providing a nutritional care plan, including nutrition support such as dietary advice.
• Managing underlying conditions, causes, risk factors, and/or complications of malnutrition.
• Setting individualised treatment goals.
• Providing sources of information and support.
• Prescribing oral nutritional supplementation if clinically indicated and stopping when appropriate.
• Referring to a Dietitian, Speech and Language Therapist (SALT), Occupational Therapist (OT), Physiotherapist, Mental Health Team, or adult social care if indicated.
• Monitoring progress; the frequency depending on clinical judgement.

This clinical blog has highlighted the need for all healthcare professionals to encourage patients to achieve an adequate nutritional state, and how protein is a key factor in ensuring a good quality wound healing process. Carrying out a standardised assessment such as the ‘MUST Tool’ to identify a person’s risk of malnutrition will ensure an individualised care plan and relevant support can be implemented in a timely manner to help reduce the risk of developing pressure ulcers and to also optimise wound healing.

References

1. Ayman Grada, Tania J. Phillips, (2022) Nutrition and cutaneous wound healing. Clinics in Dermatology, Volume 40, Issue 2, Pages 103-113.
2. BAPEN (2024a) How is malnutrition recognised? available at How is malnutrition recognised? | BAPENaccessed August 2024.
3. BAPEN (2024b) Introduction to Malnutrition, available at How is malnutrition recognised? | BAPEN accessed August 2024 .
4. Bishop A. (2021) Wound assessment and dressing selection: an overview. British Journal of Nursing. Vol 30 (5). S12-S20.
5. British Dietetics Association (BDA) (2024) available at Spotting and treating malnutrition – British Dietetic Association (BDA) accessed September 2024.
6. Clark M, Schols JM, Benati G, Jackson P, Engfer M, Langer G, Kerry B, Colin D; (2004) European Pressure Ulcer Advisory Panel. Pressure ulcers and nutrition: a new European guideline. J Wound Care. Vol 13 (7), Pg 267-72.
7. Ghaly P, Iliopoulos J and Ahmed M (2021) The role of nutrition in wound healing: an overview British Journal of NursingVol. 30, No. 5, accessed September 2024.
8. Litchfield M Dorner B and Posthauer ME  (2014) Malnutrition as a Precursor of Pressure Ulcers (2014) Adv Wound Care (New Rochelle).Vol 3 (1) Pg 54–63.
9. NICE (2017a) Nutrition Support for Adults, Section 1.3, NICE guidelines, available at https://www.nice.org.uk/guidance/cg32, accessed August 2024.
10. NICE (2024b) Adult Malnutrition: Summary, available at Adult malnutrition | Health topics A to Z | CKS | NICE, accessed August 2024.
11. Simmons J. (2022) Wound Healing and Assessment. Journal of the Dermatology Nurses’ Association 14(5):p 197-202. Accessed September 2024.