The role of diet and nutrition in COPD management

The goals of effective management of COPD are to prevent disease progression, relieve symptoms, improve exercise tolerance and health status, prevent and treat complications and exacerbations and reduce mortality.¹ Diet and nutrition support at all stages of this chronic disease can significantly impact on achieving these goals.

Nutrition needs vary depending on disease severity, nutritional status and whether the patient is stable or experiencing an acute exacerbation. Overall the aims of nutrition care for those with COPD are to provide adequate energy to minimise the risk of unwanted weight loss and/or gain, avoid loss of muscle mass and improve pulmonary and functional capacity. This article will present on the main nutrition challenges and needs of those with COPD including:

• Healthy eating for COPD 
• Key nutrition considerations in COPD: 

– Obesity 

– Osteoporosis

– Body composition and sarcopenia 

– Malnutrition: detection of risk and management care pathways

• Management of common problems compromising dietary intake. 

Healthy eating for COPD 

For stable COPD patients with a normal BMI (20-25kg/m2) who have not experienced weight loss, a diet based on healthy eating guidelines is recommended. Adequate intake of anti-oxidant rich fruits and vegetables and fibre should be highlighted and reduction of nitrate containing processed meats and potato products. These features of a healthy eating pattern are thought to have an anti-inflammatory effect and a protective role in lung function.²

Protein-rich foods

At least two portions of protein-rich foods should be consumed per day (2-3oz cooked meat/fish or 4-5oz of pulses/beans/lentils). Protein provides the essential amino acids to build and preserve muscle mass. Choose lean cuts of meat instead of cured or processed meats like sausage, salami, and cured bacon which contain preservatives such as nitrites that can generate reactive nitrogen species and amplify pulmonary inflammation.²

Oily fish

At least one serving of oily fish should be consumed per week. Studies have observed lower levels of the inflammatory marker TNF-α in COPD patients supplemented with omega-3 fatty acids.³ There is also potential to improve exercise performance via modulation of skeletal muscle oxidative capacity. One serving of salmon, mackerel, herring or trout provides the equivalent dose of approximately 450mg EPA and DHA per day. There is insufficient evidence to recommend routine omega-3 supplementation in this patient group

High-fibre starchy carbohydrates

Adequate energy intake should be met by consuming approximately three to five servings of high-fibre starchy carbohydrates per day. Increased resting energy expenditure is observed in patients with COPD. Including one to two servings of bread, cereals, potatoes, rice or pasta at each meal will help meet energy requirements. 

Fruit and vegetables

Five to seven portions of fruit and vegetables should be consumed per day. Ensuring adequate intake of antioxidant nutrients (vitamins A, C and E) found in this food group may enhance immune function and aid maintenance of pulmonary function.

Dairy foods

Three portions of dairy foods should be consumed per day. Dairy foods are a valuable source of calcium and protein for bone health. Choose a combination of cheese, milk and yogurts. Choose full fat options if BMI < 20kg/m2  to optimise energy intake. Calcium and vitamin D supplementation may be required (see section on osteoporosis). There is no evidence to support the claim that dairy foods increase mucus production.

Adequate fluid intake

Recommended fluid intakes are 2 litres a day for females and 2.5 litres a day for males, unless fluid restriction is indicated. Adequate hydration can thin mucus and make it easier to cough and clear, easing breathing. 

Key nutrition concerns in COPD 

Obesity 

Approximately 25% of people with GOLD stage 1 and 2 COPD are obese.⁴ Obesity in COPD is associated with a higher prevalence of metabolic syndrome and higher risk of cardiovascular disease and type 2 diabetes. Weight gain can occur due to reduced physical activity levels and increased appetite due to steroid treatment resulting in fat accumulation and redistribution around the abdomen.  Although the ‘obesity paradox’ is observed,  with  lower mortality rates within a BMI range of 26 to 31kg/m²,  it can significantly impact on increasing dyspnoea, exercise capacity and quality of life. Dietary changes and exercise as part of a pulmonary rehab programme can be effective in achieving weight loss but for many the most realistic aim may be to prevent further weight gain. If weight loss is an appropriate goal the following should be considered:

• If BMI of ≥ 30kg/m² refer to dietitian for individualised dietary and behaviour change intervention 
• Dietary goal: calorie restriction (~600kcal deficit) with sufficient protein intake of 1.2-1.5g/kg adjusted body weight/day, combined with resistance exercise programme to minimise muscle loss.
• Small dietary changes can make a significant difference in calorie intake reduction:

– Limit sugary foods, eg. cakes, biscuits, sweets, fizzy drinks

– Reduce fat intake through use of lower fat spreads, limit frying, deep fried foods and takeaways and choosing low-fat dairy products

– Aim to include five to seven portions of fruit and vegetables, use as a snack instead of chocolate, biscuits, crisps and other high-fat, high-sugar foods

– Portion control of starchy carbohydrates, use wholemeal varieties to help with satiety and slow energy release.

Osteoporosis 

A higher prevalence of osteoporosis has been reported in individuals with COPD.⁵ Immobility, reduced sunlight exposure, reduced capacity of ageing skin to synthesise vitamin D and medications such as glucocorticoids and inhaled corticosteroids all influence the osteoporosis risk in COPD. Vitamin D deficiency is common and correlates with disease severity.⁵ Although no guidelines have been developed specifically for COPD, it is prudent to recommend that individuals follow general lifestyle guidelines for preventing and treating osteoporosis, including participation in weight-bearing exercises as appropriate. Dietary guidelines for bone health:

• For the general population consuming adequate amounts of calcium and vitamin D (recommended daily intake for calcium 800mg and 10µg (400IU)/day for vitamin D⁶
• Long-term inhaler or oral glucocorticoid therapy patients are at higher risk of bone loss, therefore higher intake/supplementation is recommended of 1,200mg of calcium and 800-1,000 international units of vitamin D⁷
• Avoiding excess caffeine by limiting to 200mg/day, equivalent to two mugs of coffee/tea
• If dairy consumption is low, non-dairy calcium-rich foods include; tinned oily fish, almonds, dark green vegetables and fortified bread and cereals
• Limit alcohol (safe upper limit 11 units for a women and 17 units for men).

Body composition changes and sarcopenia 

Sarcopenia has been reported at a rate of 15-40% in the COPD population. It increases with disease severity and is present across all BMI categories.⁸ Sarcopenia is defined as a syndrome characterised by progressive and generalised loss of skeletal muscle mass and strength with a risk of adverse outcomes such as physical disability, poor quality of life and death. Potential catabolic triggers for inducing the sarcopenic process in COPD include; physical inactivity, oxidative stress, inflammation, use of glucocorticoids and hypoxia.

Measuring body composition:

• Dual-energy x-ray absorptiometry (DXA) has been proposed as the most appropriate method for body composition analysis in COPD because it combines screening for osteoporosis with assessment of total fat mass (FM) and fat free mass (total body mass – fat free mass = FFM)⁹
• Where DXA is unavailable, lower cost methods to assess body composition and muscle function include hand grip strength, mid-arm muscle circumference (MAMC) and bio-electrical impedance analysis.
• Assessment of body composition and BMI enables stratification of nutritional risk in COPD. 

Malnutrition 

In patients with COPD, 30-60% of inpatients and 21-45% of outpatients have been found to be at risk of malnutrition.^10,11 Malnourished patients have a reduced health-related quality of life and increased reliance on healthcare services. In the UK a two- to three-fold increase in healthcare costs is associated with low body weight (BMI < 20kg/m2) COPD admissions.^11,12 It may develop gradually over several years or accelerate during acute exacerbations. The causes are multifactorial and include:

• Disease effects, eg. breathlessness, anorexia, chronic inflammatory processes
• Increased nutritional requirements, eg. higher energy cost of breathing and physical activity
• Effects of medication, eg. taste changes negatively affecting dietary intake 
• Dietary intake problems (see Table 1)
• Psychological factors, eg. motivation, apathy, depression 
• Socio-economic factors, eg. social isolation, low income.

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Detecting malnutrition

Malnutrition screening tools are now imbedded into routine hospital admission assessments in the Irish acute and residential care settings¹³ and are currently being implemented in the community setting. Validated tools such as the ‘Malnutrition Universal Screening Tool’ (MUST) identify malnutrition (under-nutrition) based on weight changes and categorisation of BMI. 

As discussed muscle wasting, particularly of the extremities occurs in patients with COPD even in those with a normal BMI and therefore utilisation of body composition and muscle function tools are also useful.

In COPD those considered at high risk of malnutrition are:

• BMI of less than 20kg/m2 ¹⁴
• Unintentional weight loss of greater than 5% within the past three months or 10% in the past six months regardless of BMI^9,11
• Fat free mass index (FFMI):

– < 17kg/m2 in males,

– < 15kg/m2 in females (if equipment is available to assess body composition¹⁵

Treatment of high-risk/malnourished COPD patients

A care pathway for management of malnutrition in COPD has recently been developed in the UK to help guide clinicians in the community, this is available at
http://malnutritionpathway.co.uk/copd

Management of malnutrition can include dietary advice (eg. high protein, high calorie diet), assistance with eating, texture-modified diets and oral nutritional supplements (ONS) where indicated.¹¹ Dietary advice should aim to increase intake of all nutrients including energy, protein and micronutrients. 

Goals of nutrition intervention depend on disease status and prognosis:

• Stable COPD: depending on BMI, it may be appropriate to aim for an increase in body weight and fat-free mass. Amongst those who are malnourished a 2kg increase is suggested as a threshold at which functional improvements are seen¹¹
• Acute exacerbations: An acute exacerbation of COPD can lead to rapid deterioration of nutritional status and muscle wasting. The elevated resting energy requirements coupled with a deficit in energy and protein intakes as a result of the altered mechanics of breathing affecting chewing and swallowing and reduced appetite can lead to rapid weight loss. Overcoming infection while minimising weight and fat free mass loss through nutritional intervention (high protein high calorie diet (+/-) oral nutritional supplements) may be the most realistic goal¹¹
• Pulmonary rehabilitation: Nutritional intervention can support the effectiveness of exercise programmes in malnourished COPD patients. It is an opportunity to optimise nutritional status through education by a dietitian to meet energy demands of increased physical activity. Dietary advice and oral nutritional supplements should be considered for those at risk of malnutrition to ensure further weight loss is prevented.

Stepwise approach to nutrition care for high-risk patients in the community

• Record details of malnutrition risk (screening result/risk category, or clinical judgement) 
• If high risk refer to a community dietitian for specialist nutrition support. To view contact details for dietitian queries in your local area please use the following link
• www.hse.ie/eng/services/list/5/kerryhealthservices/kerryprimarycare/dietitian.html and download link at bottom of page under ‘contact us’
• Consider underlying symptoms and causes of malnutrition eg. nausea, infections and treat if appropriate 
• Troubleshoot any symptom related difficulties with dietary intake and advise on how to overcome them (see Table 1) 
• Consider social requirements, eg. social supports, ability to collect prescription, etc.
• Confirm individual is able to eat and drink and consider any physical issues, eg. dysphagia, poor fitting dentures/dentition and if speech and language referral is needed
• If BMI < 20kg/m2 and/or at high risk of malnutrition regardless of BMI – consider prescribing oral nutritional supplements. Increased compliance is achieved using higher energy (≥ 2kcal/ml) low volume (125ml) supplements, spread frequently throughout the day, especially in individuals with early satiety and/or breathlessness. 

The dietitian’s role in managing high-risk COPD patients

• Detailed assessment of nutritional status (psychosocial, physical, biochemical, physiological) 
• Educate patient and/or carer on a high protein, high calorie diet and food fortification techniques
• Agree an individualised meal plan eg. meal and snack timing and portion sizes etc.
• Recommend and advise on appropriate use of oral nutritional supplements
• Liaise and work with Respiratory Integrated Care Team, physiotherapist and clinical nurse specialist where available, to ensure multiple treatment goals are met.
• Monitor every three months or sooner if clinical concern, taking account of:

– Weight change

– Nutritional intake versus requirements and identification of deficits

– Strength (use of hand grip strength measurement)

– Physical appearance  (eg. muscle wasting in the extremities)

– Appetite

– Ability to perform daily activities, eg. food preparation, food shopping etc.

• If goals of nutrition intervention are not achieved at three to six months, the dietitian can discuss with patient, carer and doctor the options regarding more intensive specialist nutrition support measures. 

Dietary intake challenges in COPD

Individuals with COPD can experience a range of symptoms that are likely to impact on dietary intake and nutritional status. Dietitians can deliver targeted education on dietary strategies to help manage these issues. Table 1 outlines how these symptoms can be managed to optimise dietary intake and minimise the risk of developing disease- related malnutrition.

In conclusion, nutritional status is an important determinant of COPD outcome. The COPD population is heterogeneous in terms of the nutritional risks and variation in the nutritional intervention required. Ideally, overweight/obese patients should be given advice via a community dietitian to prevent further weight gain and support weight loss if indicated.

Early detection, intervention and monitoring of those at risk of malnutrition (BMI < 20kg/m² and/or at high risk of malnutrition regardless of BMI) can reduce hospital admissions. Nutrition interventions using oral nutritional supplementation can improve respiratory muscle strength, functional and exercise capacity. The importance of consideration of changes in body composition and muscle function in this patient group is highlighted due to the prevalence of sarcopenia across all BMI categories. 

Suzanne Seery is a senior dietitian in cardiology and obesity, Croi Heart and Stroke Centre, Galway and was formerly a senior dietitian specialising in respiratory and cardiology in St James’s Hospital, Dublin

References

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10. Collins PF, Stratton RJ, Elia M. et al. Nutritional support in chronic obstructive pulmonary disease: a systematic review and meta-analysis. Am J Clin Nutr. 2012;95:1385-95. 
11. Managing Malnutrition in COPD, expert panel UK. Available from: http://www.malnutritionpathway.co.uk/files/uploads/Managing_Malnutrition_in_COPD_document_-_final.pdf
12. Ferreira IM, Brooks D, White J, Goldstein R. Nutritional supplementation for stable chronic obstructive pulmonary disease. Cochrane Database Syst Rev. 2012 Dec 12;12:CD000998.
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14. National Institute for Clinical Excellence. Chronic obstructive pulmonary disease in over 16s: diagnosis and management. NICE, 2010.
15. Cederholm T, Bosaeus I, Barazzoni R. European Society for parenteral and enteral nutrition. Diagnostic criteria for malnutrition - An ESPEN Consensus Statement. Clin Nutr. 2015 Jun;34(3):335-40