DISSERTATION
Title: Exploring attitudes, beliefs and behaviours of cardiac/stroke support group members in relation
to a Mediterranean style diet.
Author: J.S.Bakkali
Student number: 1425339
Programme:MSc Public Health Nutrition
Submission date: 21st October 2016
Declaration:This dissertation is my own work.
TABLE OF CONTENTS
1 | LITERATURE REVIEW 4
1.1 | ABSTRACT 5
1.2 | DEFINITIONS AND ABBREVIATIONS 6
1.3 | BACKGROUND 8
1.4 | THE MEDITERRANEAN DIET 9
1.5 | MEDITERRANEAN DIET ADHERENCE 10
1.6 | BEHAVIOUR CHANGE THEORIES 12
1.7 | REPORTED BARRIERS TO FOLLOWING A HEALTHY DIET 16
1.8 | REPORTED BARRIERS TO FOLLOWING A MEDITERRANEAN DIET19
1.9 | REPORTED BARRIERS TO FOLLOWING A DIETARY PATTERN IN RELATION TO CARDIOVASCULAR DISEASE 20
1.10 | CONCLUSION 22
1.11| REFERENCES 24
2 | RESEARCH STUDY36
2.1 | PUBLICATION JOURNAL 37
2.2 | ABSTRACT37
2.3 | FIGURES AND TABLES 39
2.4 | DEFINITIONS AND ABBREVIATIONS 39
2.5 | INTRODUCTION 41
2.5.1| Aim 42
2.6 | METHODS43
2.6.1 | Participants and recruitment 43
2.6.2 | Data collection 44
2.6.3 | Analysis46
2.7 | RESULTS 47
2.7.1 | Participants 47
2.7.2 | Mediterranean diet scores 50
2.7.3 | Themes 52
2.7.3.1 | Limited Mediterranean diet awareness53
2.7.3.2 | Following a Mediterranean style diet would be difficult 53
2.7.3.3 | A Mediterranean style diet is inappropriate 54
2.8 | DISCUSSION 55
2.8.1 | Limited Mediterranean diet awareness55
2.8.2 | Following a Mediterranean style diet would be difficult 58
2.8.3 | A Mediterranean style diet is inappropriate 59
2.8.4 | Limitations of this study60
2.8.5 | Recommendations for future research61
2.9 | CONCLUSION61
2.10| ACKNOWLEDGEMENTS62
2.11| REFERENCES63
2.12| APPENDICES72
2.12.1 | Appendix 1 – Participant information sheet72
2.12.2 | Appendix 2 – Participant screening questionnaire74
2.12.3 | Appendix 3 – Participant consent form76
2.12.4 | Appendix 4 – Ethical approval 77
2.12.5 | Appendix 5 – Mediterraneandiet score questionnaire79
1 | LITERATURE REVIEW
Title: Exploring attitudes, beliefs and behaviours of cardiac/stroke support group members in relation
to a Mediterranean style diet.
Author: J.S.Bakkali
Student number:1425339
Assessment number:J17858
Submission date: 21st October 2016
Module: XN7066 Research Project
Declaration:This review is my own work.
Word count: 3667
1.1 | ABSTRACT
It is widely known that cardiovascular disease has a huge impact on health, and in the United Kingdom cardiovascular disease is reported to be responsible for about 27% of all deaths.
Four risk factors associated with cardiovascular disease are high blood pressure, diabetes, high cholesterol, and being overweight, and these factors are all modifiable via diet and nutrition.
A dietary pattern that has been recognised as cardioprotective is the Mediterranean diet, however, this dietary pattern is not widely adhered to, and even though some studies have reported an overall moderate adherence to the Mediterranean diet, they additionally reported that adherence to certain individual components of the Mediterranean diet is low.
This review consideredliterature on behaviour change theories, interventions, and barriers in relation to following a healthy diet, following a Mediterranean diet, and following a Mediterranean diet in relation to cardiovascular disease, in order to identify areas for further research.
Conclusion: There is ample research on barriers to following a Mediterranean style diet, and there is ample research into dietary behaviour changes for individuals who have experienced a cardiovascular condition or event, but there is a lack of research that combines the two, exploring the barriers to following a Mediterranean style diet for individuals who have experienced a cardiovascular condition or event.
1.2 | DEFINITIONS AND ABBREVIATIONS
primary prevention
of disease / Defined as follows: “Taking action to reduce the incidence of disease and health problems within the population, either through universal measures that reduce lifestyle risks and their causes or by targeting high-risk groups” (The King’s Fund, 2016b, para. 1).
secondary prevention
of disease / Defined as follows:“Systematically detecting the early stages of disease and intervening before full symptoms develop – for example, prescribing statins to reduce cholesterol and taking measures to reduce high blood pressure” (The King’s Fund, 2016a, para. 1).
Note that the distinction between secondary and tertiary prevention,
that is preventing deterioration after the disease has caused harm or disability (Gordon, 1983), is not always clear and consistent. For example Doyle, Fitzsimmons, McKeown, & McAloon (2012) studied dietary choices of myocardial infarction patients at a secondary prevention clinic, and prevention after a myocardial infarction would probably be classed as tertiary if using the definition by Gordon (1983).
Note that usage of the term ‘secondary’ in thiscurrent study encompasses tertiary prevention as defined by Gordon (1983).
Abbreviations
CVD / cardiovascular disease
MD / Mediterranean diet
UK / United Kingdom
1.3 | BACKGROUND
It is widely known that cardiovascular disease (CVD) has a huge impact on health, and it is repeorted that CVD is responsible for about 27% of all deaths in the United Kingdom (UK), almost a third of which are premature (age < 75 years) (British Heart Foundation, 2016), and globally CVD is responsible for approximately 17 million deaths per year (World Health Organisation, 2016).
CVD comprises all the diseases of the heart or circulatory system, such as heart attack or stroke (National Health Service, 2016), andthe main underlying cause of CVD is atherosclerosis, a chronic inflammation condition where fatty deposits cause plaque build-up in the large and middle sized arteries (British Heart Foundation, n.d.-a; Frostegård, 2013).The direct cause of CVD is reduced oxygenated blood flow to the heart or the brain caused by blood clots that are formed from ruptured plaque deposits (British Heart Foundation, n.d.-a; Frostegård, 2013).
Risk factors associated with CVD include high blood pressure, diabetes, high cholesterol, being overweight and smoking (British Heart Foundation, n.d.-b; Office for National Statistics, 2015). These risk factors are potentially modifiable lifestyle factors, and the first four can be changed via diet and nutrition (National Health Service, 2016; Rees et al., 2013).
A dietary pattern that has been widely studied in association with reducing CVD risk factors is the Mediterranean diet (MD) (de Lorgeril & Salen, 2011; Estruch et al., 2013; Gotsis et al., 2015; Martínez-González et al., 2015; Widmer, Flammer, Lerman, & Lerman, 2015). A meta-analysis, designed to assess the MD for the primary prevention of CVD, cancer, Alzheimer’s disease and Parkinson’s disease, reviewed twelve prospective cohort studies (subjects = 1,574,299) (Sofi, Cesari, Abbate, Gensini, Casini, 2008). The duration of the studies included in the meta-analysis ranged in length from three to eighteen years, and found that higher adherence to the MD showed a 9% reduction in CVD mortality (Sofi et al., 2008). A limitation of this meta-analysis was the lack of homogeneity amongst the studies, however the authors reported that the main characteristics of the MD were present in all twelve studies (Sofi et al.,2008).
The MD is also well established as a dietary pattern for the secondary prevention of CVD (de Lorgeril & Salen, 2011), and a randomised single-blind trial following individuals after a first myocardial infarction showed, that after an average of 46 months, endpoints, such as sudden cardiac death, and CVD events, such as coronary thrombosis, were significantly reduced (p = 0.001) (de Lorgeril et al.,1999).
1.4 | THE MEDITERRANEAN DIET
The MD consists of large amounts of olive oil, legumes, fruits, vegetables, whole grains, tree nuts, along with moderate amounts of fish and seafood, moderate amounts of dairy, eggs, poultry, wine with meals, and small amounts of red meat and sweets (Bach-Faig et al., 2011; Oldways, 2009), and of these, fruits, vegetables, tree nuts, legumes, wine, whole grains, fish oils and olive oil have, individually, been shown to be cardioprotective (Basu, Rhone, & Lyons, 2010; Guasch-Ferré et al., 2013; He, 2009; Oyebode,Gordon-Dseagu,Walker, & Mindell,2014; Schwingshackl,Christoph,Hoffmann, 2015; Souza,Gomes, Naves,Mota, 2015; Vilavalur, Otani, Singal, & Maulik, 2006; Wang et al., 2014; Zock, Blom, Nettleton, & Hornstra, 2016; Zong, Gao, Hu, & Sun, 2016). Furthermore, Grosso et al. (2015) suggested that the MD components, fruit, vegetables, legumes and olive oil were the greater contributors to the cardioprotective effect.
1.5 | MEDITERRANEAN DIET ADHERENCE
Advice to follow a MD is routinely given in the UK for the prevention of CVD (National Institute for Health and Care Excellence, 2016), however the consumption of some of the MD component foods is low in the UK, for example,in relation to bacon and red meat, oily fish, and fruit and vegetables (Public Health England, 2014). The National Diet and Nutrition Survey carried out by Public Health England (2014) reported that, on the four consecutive days of data collection, bacon and red meat were eaten by 60% of participants aged 65 years or over, that oily fish was consumed by 38% of participants aged 65 years or over and by 23% of participants aged 19 to 64 years, and that the recommendation to eat five fruit and vegetables a day was met by 30% of participants aged 19 to 64 years and by 41% of participants aged 65 years or over. A limitation reported in this survey is that the data on food consumption was self-reported, and self-reported data does not always reflect actual consumption (Public Health England, 2014). In addition, it is worth noting that self-reported figures can be affected by optimistic bias, where the belief is greater than the reality (Raats & Sparks, 1995).
The data from the National Diet and Nutrition Survey (Public Health England, 2014) highlights low adherence to selected components of the MD, as limited red meat consumption, higher oily fish consumptionand higher fruit and vegetable consumption are elements of the MD (Bach-Faig et al., 2011; Oldways, 2009).
Adherence to a MD is assessed by a Mediterranean diet score (National Audit of Cardiac Rehabilitation, 2013; Schröderet al., 2011), a tool widely used to assess adherence levels for the individual components within the MD (Bach et al., 2006; Papadaki, Wood, Sebire, & Jago, 2015), and a cross-sectional survey of healthy individuals (n = 590, mean age = 43.8 years, SD = 11.1, university education = 58.5%) at workplaces (n = 4) in the South West of England in fact reported an overall moderate adherence to the MD. The authors did, however, report mixed adherence levels for different MD components, withhigh adherence for fruit, vegetables, cereals and alcohol and low adherence for olive oil, red meat, poultry, dairy products, fish and legumes (Papadaki et al., 2015).
Overall moderate adherence (at baseline) was similarly reported in a 6 month intervention study in Scotland (female = 100%, n = 53, university education = 66%) (Papadaki & Scott, 2005). An additional cross-sectional survey in the North East of England (n = 206, mean age = 61 years, SD=7, university education = 47%) reported high adherence to the vegetables, poultry and carbonated beverage components of the MD, and low adherence to the alcohol, olive oil, red meat, alcohol, fish, and dairy components, with an overall mean Mediterranean diet score of 5.6 out of 14 (Lara, McCrum, & Mathers, 2014). Findings from these studies are useful, however they may not be fully representative of individuals at risk of CVD, as individuals at risk of CVD tend to be from lower socio-economic backgrounds and their lifestyles are likely to be significantly different from the lifestyles of the study participants (Maguire & Monsivais, 2015).
Benefits reported from following the MD, in relation to CVD, are from following the MD in its entirety (Widmer et al., 2015), asnutrients are not usually eaten in isolation, and the interaction between components is a key element (Sofi et al., 2008). It is therefore important to understand the barriers that prevent closer adherence to the MD, especially in respect of the less favoured components of the MD, such as red meat, oily fish, and fruit and vegetables.
1.6 | BEHAVIOUR CHANGE THEORIES
Changing a dietary pattern, in simplistic terms, requires two things, initial change and sustained repetition (Chapman & Ogden, 2009). However, in reality, both are complex processes and are affected by many factors (Barker & Swift, 2009; Kwasnicka, Dombrowski, White, & Sniehotta, 2016). Many behaviourchangetheories exist and they provide models of behaviour change mechanisms, identifyingbarriers, and how and why changes happen, in order to inform future health behaviour interventions.
Popular traditional theories on health behaviour change are identified in a scoping review by Davis,Campbell,Hildon, Hobbs and Michie (2015), and the three most used theories in studies from 1977 to 2012 are the transtheoretical model of change (Prochaska & DiClemente, 1983), the theory of planned behaviour (Ajzen & Madden, 1986), and social cognitive theory (Bandura, 1977).
The transtheoretical model of change (Prochaska & DiClemente, 1983), also known as the stages of change model, posits that there are sequential stages to a changed behaviour: pre-contemplation; contemplation; preparation; action; and maintenance. Behaviour change results from going through this process in this order can be used to overcome behaviour change barriers such as low perceived social support and low nutritional knowledge, as shown in a workplace intervention that was concerned with increasing vegetable consumption (Kushida & Murayama, 2012). The non-randomised control intervention provided nutritional information about vegetables in workplace canteens (n = 16), and reported that the intervention resulted in higher perceived social supportamongst the intervention group, as well as an increased number of participants from the intervention group in the action and maintenance stages of the trial compared to baseline figures (Kushida & Murayama, 2012).
The theory of planned behaviour (Ajzen, 1991) evolved from the theory of reasoned action (Ajzen & Madden, 1986) which states that if an individual has the intention to make a behaviour change then the change will follow (Fishbein, 2008). The theory of planned behaviour added a further dimension, an individual’s belief in being able to successfully carry out the behaviour, and states that behaviour results directly from intention (Ajzen & Madden, 1986). Ajzen & Madden (1986) list three antecedents to intention; firstly, perceived behavioural control which is an individual’s beliefs about capability regarding the outcome, and about being able to control the outcome; secondly, an individual’s attitude towards a behaviour; and thirdly, subjective norms, that is an individual’s level of motivation to comply, and the influence of significant people, and how they, in turn, perceive the outcome. A systematic review and meta-analysis by McDermot et al. (2015) identified studies based on this theory, and reported that, in relation to changed dietary behaviours, the greatest association with intention was attitudes, and the greatest association with behaviour was intentions. McDermot et al. (2015) also reported that the potential barrier to dietary behaviour change created by perceived behavioural control was a greater barrier for older participants (age > 17 years) than for younger participants (age < 18 years).
The third commonly used theoretical model is social cognitive theory (Bandura, 1977) which is concerned with levels of self-efficacy and posits that behaviour results from continuous cognitive learning gained by watching and observing others in social interactions and contexts, and that personal factors, for example perceived consequences, perceived goals and outcomes, and behavioural factors such as self-judging, are guided and shaped by social cognition. Authors of a systematic review and meta-analysis of behaviour change studies, based on social cognitive theory, reported that reducing the barrier of low self-efficacy was positively associated with dietary behaviour (Stacey, James, Chapman, Courneya, & Lubans, 2015), however, it is worth noting that as all the participants in the studies in this review were cancer survivors, the findings may not relate to wider populations.
In relation to change behaviour theories in general, it is widely recognised that health behaviour change interventions have not yielded health behaviour changes on the scale required (Kelly & Barker, 2016), and it is subsequently argued that the traditional behaviour change theories are no longer a good fit for today’s societies, as the traditional theories focus on the individual, and do not fully address barriers to behaviour change that are currently present in the wider social environment, for example advertising, and culture(Chapman & Ogden, 2010; Hollands, Marteau, & Fletcher, 2016; Kelly & Barker, 2016; Mielewczyk & Willig, 2007).In fact, Hollands et al. (2016), who described engagement as either conscious or non-conscious, argued that it is the influence of micro-environments, for example advertising and social norms, that people are not wholly conscious of, that often outweigh an individual’s capacity to self-regulate, and that can therefore have significant influence over their behaviour. The nature of the concept of conscious and non-conscious engagement means it places minimal demands on cognitive processes and could therefore be useful for behaviour change interventions in populations of mixed social-economic backgrounds (Hollands et al., 2016).
Furthermore, in addition to environmental influences as barriers to behaviour change, there is the barrier of sustaining behaviour change, which,unlike initial behaviour changes that result from extrinsic motivation, for example a health event such as a heart attack, result from an individual’s own motivations, and in order to maintain changed behaviour there needs to be constant and repeated rewards and satisfaction (Kwasnicka et al., 2016). Kwasnicka et al. (2016) carried out a systematic review of behaviour theories to better understand their use in behaviour maintenance, and reported five barriers that could hinder maintenance of behaviour change: motives; self-regulation; habits; resources; and the environment and social influences (Kwasnicka et al., 2016).
Theories and concepts relating to health behaviour are borne out of the work of theorists and practitioners and identify many potential barriers to changing dietary behaviours, for example knowledge, self-regulation, environments, and social pressures. The reality of barriers, perceived and genuine, will be considered next.
1.7 | REPORTED BARRIERS TO FOLLOWING A HEALTHY DIET
Considering firstly reported barriers to following a healthy diet as these may underlie barriers that are specific to following a MD.
A pan European Union study (n = 14,331) identified the main barriers as time issues, such as irregular working hours, busy lifestyle, and taste (Kearney & McElhone, 1999). The figures from the UK participants (n = 961) showed that giving up liked foods to be the most reported barrier, followed by willpower, irregular work hours, busy lifestyle and cost, which wasreported by 25% of the UK participants (Kearney & McElhone, 1999). Kearney and McElhone (1999) also reported that 71% of European Union participants, and 62% of UK participants, believed their diets to be healthy and balanced and did not need changing. This led Kearney and McElhone (1999) to report that the dietary evaluationsby the participants are lacking, as they were largely informed by three key health messages: eat less fat; eat more fruit and vegetables; and eat a balanced and varied diet.
It is worth noting here that perceived barriers do not necessarily translate into actual barriers. A study of data from the Scottish Health Survey 2008-11 (n = 8319, mean age = 52 years) found that although the cost of fruit and vegetables was a significant perceived barrier, cost did not actually affect fruit and vegetable consumption (McMorrow, Ludbrook, Macdiarmid, &, Olajide, 2016). A further perceived barrier was lack of willpower, but the analysis of the data showed it only to be a barrier for women, and even then it had little effect on their intake of fruit and vegetables (McMorrow et al., 2016). As a result Mc Morrow et al. (2016) proposed the explanation that willpower may relate to avoidance of less healthy foods rather than eating healthy foods. Additional perceived barriers noted, just by women, were cooking skills and lengthy food preparation (McMorrow et al., 2016). Perceived barriers noted by both men and women were the disliked taste of fruit and vegetables, and the fact that they found fruit and vegetables boring (McMorrow et al., 2016).