Dietary patterns

• CVD


  Cardiovascular disease
• Affects ~ 7M people UK
• Accounts for more than a quarter of deaths in England; 1 death every 4 minutes
• Accounts for > 15% of total disability adjusted life years in England
• Costs of CVD


  • ~£15.8 billion per year (non-healthcare costs)
  • £7.4 billion per year (healthcare costs in England)
• People living in the most deprived areas of England are almost 4 times more likely to die prematurely from CVD than those in least deprived areas
• CVD risk factors


  • age
  • gender
  • overweight / obesity
  • diet (main modifiable factor)
  • smoking
  • being physically inactive
  • excessive alcohol
  • hypertension
  • high cholesterol levels
  • diabetes
  • dyslipidaemia
  • insulin resistance
• Behavioural risk factors


  • diet
  • smoking
  • physical inactivity
  • excessive alcohol consumption
• Medical risk factors


  • hypertension
  • high cholesterol
  • high fasting plasma glucose
  • high BMI
• Dietary risk factors


  • sodium
  • low whole grains
  • low fruit
  • low vegetables
  • low nuts and seeds
  • low omega 3
  • low poly-unsaturated fatty acids
  • low fibre
  • high trans fat
  • high processed meat
• Of the four behavioural risk factors, dietary factors made the largest contribution to the population-level CVD mortality burden in both sexes in 2015
• Dietary pattern assessment


  Using data-driven methods
• Increased consumption of dietary fat, esp trans + sat fats

  Increases atherosclerosis risk
• Cluster analysis


  1. Collect data

  2. Statistically analyse data to determine clusters

  3. Identify groups of individuals (clusters) with similar dietary patterns

  4. Describe/define groups in terms of dietary patterns

  5. Examine relationships between dietary patterns and health outcomes
• Increased sodium diets


  Increase risk of hypertension
• Consumption of F&V and dietary fibre

  Have a protective effect
• Cluster analysis


  • Groups are mutually exclusive and relatively homogenous - no overlap between groups
• Dietary pattern assessment


  Using specified dietary patterns
• Dietary fat and sat fat

  Implicated in increased CHD risk
• Dietary pattern assessment - limitations

  • Dietary assessment methods (e.g. food frequency questionnaires FFQs; 24 hr dietary recalls, etc) introduce bias and error
  • Dietary patterns are not universally nor consistently defined by researchers, there is no specific number or specification
  • Researchers determine clusters
• Factor analysis


  1. Consider dietary intakes

  2. Determine foods that are correlated and group together

  3. Identify elements of the diet and develop factors

  4. Describe/define dietary patterns in terms of the elements within them

  5. Examine relationships between dietary patterns and health outcomes
• When considering evidence between studies, be aware that:
• Specified diets


  • Categorising individuals based on having specified diets or not
  • Individuals asked to tick their dietary pattern
  • Considering intakes and preferences of individuals
• Mediterranean Diet - MeDiet

  Traditional dietary pattern observed in Mediterranean populations
• Dietary fat associated with meat, processed meat; inc sat fat from meat

  Increased LDL
• Relationships between dietary patterns and health outcomes are examined in both cluster analysis and factor analysis, independent of the outcome
• Processed meat


  Implicated in increased CVD risk
• Specified diets are typically based on self-reported patterns, rather than dietary assessment and on what foods are excluded
• Greece, Italy, Spain


  1950/60s
• Red meat and CVD

  Contrasting results (difference between processed meat and red meat due to sat fat & cholesterol amounts)
• Interest in MeDiet grew from initial observations of substantially lower rates of heart attack among population compared with northern European countries/US and potentially attributed to different dietary habits
• Specified diets


  • Vegan (no meat, fish, eggs, or dairy)
  • Lacto-ovo vegetarian (includes eggs and dairy)
  • Pescatarian (fish, but no meat)
• Dietary pattern


  Quantities, proportions, variety or combinations of different foods and beverages in diets, and the frequency with which they are habitually consumed
• Groups


  • Control
  • Med diet + extra virgin oil
  • Med diet + nuts
• MeDiet


  Mediterranean Diet
• MeDiet


  Mediterranean Diet
• Background to the MeDiet

  1. Review this short film and consider the following questions:

  2. What was the 'New American plague'?

  3. What were the risk factors identified as affecting heart attack rates/longevity of executives?

  4. What was the name of the study examining cross cultural comparison of populations?

  5. Who were the participants?

  6. How were meats, fish and dairy products used?

  7. Differences found?
• Plant-based diets


  Diet with an emphasis on fruit, vegetables, pulses, grains & nuts and smaller amounts of animal products (meat, chicken, fish, dairy & eggs) and an emphasis on whole foods and a reduced amount of highly refined foods (not a universally accepted definition)
• The Seven Countries study, 1950/60s


  • Criticism on whether all data was included in the study
  • Aim: explore associations of diet and lifestyle and disease rates between populations and among individuals, particularly looking at coronary disease
  • At the time heart disease was considered an inevitable consequence of aging
• Data collected


  MeDiet score, FFQ, biomarkers (allows to test for p. compliance) for EVOO (urinary hydroxytirosol) and nuts (plasma α-linolenic acid) in subsamples