Dietary Patterns and Cardiovascular Disease (CVD) Outcomes: An evidence summary Professor Clare Collins PhD, BSc, Dip Nutr&Diet, Dip Clin Epi, advapd, FDAA Director of Research, School of Health Sciences, Faculty of Health & Medicine Co-Director, Priority Research Centre in Physical Activity and Nutrition, UON NHMRC and UON Brawn Senior Research Fellow @ProfCCollins
Acknowledgement Collins CE, Burrows TL, Rollo ME. Dietary Patterns and Cardiovascular Disease Outcomes: an Evidence Check rapid review brokered by the Sax Institute (www.saxinstitute.org.au) for the National Heart Foundation of Australia, 2017 Co Authors: Associate Prof Tracy Burrows AdvAPD, Dr Megan Rollo, APD Research Assistants: APDs - Dr Alecia Leonard, Dr Amy Ashman, Daisy Coyle, Provisional APDs - Erin Clarke, Janelle Skinner, Chelsea Carle Funded by the National Heart Foundation of Australia
Objectives of report 1. What is the evidence re. dietary patterns and risk of CVD? 2. What are the characteristics of dietary patterns associated with reduced risk of CVD? 3. What is the evidence re. dietary patterns and CVD outcomes in pts with existing CVD? 4. What are the characteristics of dietary patterns associated with improved CVD outcomes in pts with existing CVD? 5. What is the evidence re. advantages and disadvantages of giving dietary pattern advice vs nutrient-based advice? 6. What is the evidence re. which dietary pattern leads to better CVD outcomes?
What do we mean by primary and secondary prevention? Primary prevention Secondary prevention Combined primary and secondary Individuals without a CVD Focus on lifestyle changes to prevent first CVD event Individuals with a CVD Aimed at reducing progression of disease and preventing CVD event recurrence Reviews that contained both primary and secondary studies, where results could not be separated
Grading the evidence - NHMRC Body of Evidence Matrix
Inclusion criteria and article retrieval - Data sourced from CINAHL, Cochrane Reviews, Cochrane Other Reviews, Cochrane Trials, Embase, Medline and Scopus databases. - Search restricted from January 2010 to November 2016. - Systematic literature reviews and meta-analyses only
What are the characteristics of included dietary patterns? Dietary Patterns Healthy/prudent diet Mediterranean diet Nordic diet Tibetan diet DASH diet Portfolio diet Vegetarian diet Key Features Regular intake of fruits, vegetables, whole grains, fish, low-fat dairy, poultry, soy, olive oil High intake: fruit, vegetables, whole grains, beans/legumes, nuts/seeds, olive oil Moderate intake: Red wine, fish and dairy Low intake: Concentrated sugars and red meat Regular intake of whole grains, fruits, vegetables, nuts, fish, rapeseed oil, reduced-fat dairy Regular intake of whole grains/cereals, meat, fruits, vegetables and beans Regular intake of fruits, vegetables, whole grains, legumes, nuts/seed, fish, poultry, reduced-fat dairy and foods rich in Potassium, Magnesium and Calcium Low intake: Saturated fat, total fat and foods high in sodium Largely Vegetarian diet with aim to lower plasma cholesterol. Low intake saturated fat High intake of fruits, vegetables, whole grains, nuts, plant sterols, fibre and soy protein High intake of Fruits, Vegetables, Grains/Legumes Little to no Meat consumption
Data extraction and evaluation of evidence 1. Characteristics + outcome data of included studies was extracted 2. Evidence was evaluated by dietary pattern and CVD outcomes and summarised into Evidence Statements 3. An overall Grade of Recommendation established for each dietary pattern and CVD outcome. A total 4 CVD outcome groups investigated: 1. Blood lipids 2. Blood pressure 3. Weight status/body composition 4. CVD events and/or mortality
Example Evidence Statement DASH diet
Example Evidence Statement DASH diet
EVIDENCE GRADE Dietary patterns and primary CVD prevention Blood pressure Lipids Weight or body composition CVD events and/or mortality A DASH X X DASH B X X X Healthy/prudent C X Mediterranean Low GI/GL Mediterranean D X X X X
Dietary patterns and primary CVD prevention recommendations Blood pressure: Grade A - DASH diet: In adults (>18 yrs) following a DASH dietary pattern for 8-14 wks is effective in lowering systolic and diastolic blood pressure compared to usual diets. Plasma lipids: Grade C - Mediterranean diet: In adults, Mediterranean-style dietary interventions lasting from 12 wks - 48 mths lead to a greater reduction in total cholesterol and LDL-C compared to control interventions Grade C - Greater alignment between the Mediterranean-style dietary interventions with key elements of the traditional Mediterranean diet is associated with a greater reduction in total cholesterol. Risk of CVD events and/or mortality: Grade A - DASH diet: The DASH diet is associated with ~20% reduced risk of mortality and incidence from CVD, CHD, heart failure and stroke in adults (>18 yrs) in periods of time up to 24 yrs. Grade B - Healthy/prudent diet: Greater adherence is associated with a lower risk of CVD events and CVD mortality Grade C - Mediterranean diet: Greater adherence is associated with a reduced risk of all-cause mortality and combined CVD incidence and CVD mortality. Body weight and/or body composition: Grade C - Low Glycaemic Index /Glycaemic Load (Low GI/GL) diet: A Low GI/GL diet is more effective in reducing fat-free mass over 6-17 mths than a high GI/GL diet. However, it was not more effective in reducing fasting plasma cholesterol.
EVIDENCE GRADE Dietary patterns and secondary CVD prevention Blood pressure Lipids Weight or body composition CVD events and/or mortality A X X X X B X Portfolio X X C DASH Weight loss or Calorie-restricted X Weight loss or Calorie-restricted X D X X X X
Dietary patterns and secondary CVD prevention recommendations Blood pressure: Grade C - DASH diet: In hypertensive adults (>18 yrs), following a DASH diet for 2-26 wks is effective in lowering systolic and diastolic blood pressure compared to usual diets. Grade C - Weight loss or Calorie-restricted diet: Energy-restricted diets of a duration of >24 wks in adults with primary hypertension resulted in reductions to systolic and diastolic blood pressure and body weight. It is unclear what amount of energy restriction is optimal for this effect. Plasma lipids: Grade B - Portfolio diet: In adults aged >18yrs with hyperlipidaemia, following a Portfolio dietary pattern, for periods of time from 4 wks - 1 yr leads to modest improvements in total cholesterol and LDL cholesterol levels. Risk of CVD events and/or mortality: No recommendations Body weight: Grade C - Weight loss or Calorie-restricted diet: Energy-restricted diets of a duration of >24 wks in adults with primary hypertension resulted in reductions of body weight. However, the amount of energy restriction for optimal results is inconclusive.
EVIDENCE GRADE Dietary patterns for combined primary and secondary prevention A Blood pressure Lipids Weight or body composition CVD events and/or mortality X X X X B Vegetarian DASH Low Carbohydrate Weight loss or calorie restricted (diastolic only) DASH Low-Fat Weight loss or calorie restricted DASH X C Mediterranean Nordic Mediterranean Low GI High Protein Nordic diet X Mediterranean D Weight loss or calorie restricted (systolic only) X X X
Dietary patterns for combined primary and secondary prevention recommendations Blood Pressure: Grade B - Vegetarian diet: Vegetarian diets are associated with lower systolic and diastolic blood pressure compared with omnivorous diets in adults who are taking hypertensive medication and those not taking medication. Grade B - DASH diet: In normotensive and hypertensive adults (>18 years), following a DASH diet for 1 to 48 mths is effective in lowering systolic and diastolic blood pressure compared to usual, healthy, calorie-restricted, low-fat or low antioxidant diets. Grade B - Low CHO diet: A low CHO diet ( 120gm/day) is more effective in lowering systolic blood pressure than a low-fat diet in interventions lasting 8 wks - 2 yrs. Grade B - Weight loss or Calorie-restricted diet: Diets that adjusted caloric intake to reduce weight by at least 4.5kg (or 5% of body weight) of a duration of 6-36 mths in adults with/without hypertension resulted in decreases in diastolic blood pressure. Grade C - Mediterranean diet: Adherence to a Mediterranean dietary pattern is associated with lower systolic and diastolic blood pressure compared with control diets, in both healthy adults and those with existing CVD or CVD risk factors. Grade C - Nordic diet: Adherence to a Nordic dietary pattern resulted in decreases in systolic blood pressure and diastolic blood pressure in hypertensive and normotensive populations. Grade D - Weight loss or Calorie-restricted diets: Diets with adjusted caloric intakes to reduce weight by at least 4.5kg (or 5% of body weight) of a duration of 6-36 mths in adults with/without hypertension resulted in decreases in systolic blood pressure.
Dietary patterns for combined primary and secondary prevention recommendations Plasma Lipids: Grade B DASH diet: In normotensive and hypertensive adults (> 18 yrs), following a DASH diet for periods of time from 2 24 wks leads to modest improvements in total cholesterol and LDL-C. Grade B - Low-Fat diet: In adults aged >18 yrs, following a low-fat dietary pattern (fat intake 30% of total daily energy) for 2 wks - 4 yrs, leads to modest improvements in total cholesterol, LDL-C and HDL-C levels compared to usual dietary intakes. Grade B Low Carbohydrate diet: A low CHO diet (120gram/day or less) is more effective in lowering triglycerides than a lowfat diet in interventions lasting from 8 wks - 2 yrs. However, a low-fat diet (<30% Cals from fat/day) is more effective in lowering total and LDL-C. Grade C - Low Glycaemic Index (GI) diet: A low GI diet is more effective than a high GI diet in lowering fasting plasma cholesterol in interventions lasting from 1-20 mths. Grade C - Mediterranean diet: Compared with control diets, adherence to a Mediterranean diet may be associated with improvements in lipid profiles in adults from healthy populations and in adults with existing CVD or CVD risk factors. Grade C - High Protein diet: Consumption of a high protein diet (>25% daily energy intake from protein) is associated with improvements in triglyceride levels in adults with and without CVD risk factors. Grade C - Nordic diet: Adherence to a Nordic dietary pattern including consumption of whole grains, fish, and berries resulted in decreases in systolic blood pressure and diastolic blood pressure in hypertensive and normotensive populations.
Dietary patterns for combined primary and secondary prevention recommendations Risk of CVD events and/or mortality Grade C - Mediterranean diet: Adherence to a Mediterranean dietary pattern may be associated with a relative reduction in CVD risk between 13 38%, compared with control diets, in adults from healthy populations and in adults with existing CVD or CVD risk factors. Body weight and/or composition Grade B - DASH diet: Following a DASH diet (with or without energy restriction) in intervention from 8-52 wks leads to weight loss, and reductions in BMI and waist circumference, with greater effects in overweight/obese participants.
What are the similarities of the included dietary patterns? Dietary Patterns Healthy/prudent diet Mediterranean diet Nordic diet Tibetan diet DASH diet Portfolio diet Vegetarian diet Key Features Regular intake of fruits, vegetables, whole grains, fish, low-fat dairy, poultry, soy, olive oil High intake: fruit, vegetables, whole grains, beans/legumes, nuts/seeds, olive oil Moderate intake: Red wine, fish and dairy Low intake: Concentrated sugars and red meat Regular intake of whole grains, fruits, vegetables, nuts, fish, rapeseed oil, reduced-fat dairy Regular intake of whole grains/cereals, meat, fruits, vegetables and beans Regular intake of fruits, vegetables, whole grains, legumes, nuts/seed, fish, poultry, reduced-fat dairy and foods rich in Potassium, Magnesium and Calcium Low intake: Saturated fat, total fat and foods high in sodium Largely Vegetarian diet with aim to lower plasma cholesterol. Low intake saturated fat High intake of fruits, vegetables, whole grains, nuts, plant sterols, fibre and soy protein High intake of Fruits, Vegetables, Grains/Legumes Little to no Meat consumption
Similarities between the dietary patterns 100% recommended Fruits, Vegetables, Whole grains 85% recommended Beans/Legumes Other similarities: 60% of dietary patterns recommended Fish and Reduced-fat Dairy, 50% recommended regular consumption of Nuts/Seeds, 40% recommended regular consumption of Poultry and Olive oil as main cooking oil and 25% recommended low intake of Red Meat and Processed Meat Products.
Similarities between the dietary patterns Olive Oil Nuts/Seeds Beans/Legumes Reduced-fat Dairy Fruits Vegetables Whole grains Fish Poultry DASH was the only approach to specifically recommend a sodium reduction
Differences between the dietary patterns Mediterranean diet Encouraged a low-moderate consumption of Red Wine Encouraged a low consumption of refined, concentrated sugars e.g. Honey. Tibetan diet Encouraged the regular consumption of Meat DASH diet Encouraged consumption of Potassium, Magnesium and Calcium Only diet that encouraged low intake of Sodium Vegetarian diet Only diet that encouraged little to no consumption of meat Portfolio diet Only diet that specifically encouraged fibre intake
Key findings Majority of diets promoted consumption of: Fruits, Vegetables, Whole grains, Beans/legumes, Nuts/Seeds, Fish and Reduced-fat Dairy Primary prevention: The DASH diet appears to have the strongest evidence base for benefit in reducing CVD risk factors and CVD risk Secondary prevention: The Portfolio diet, followed by weight loss/calorierestricted and DASH diet have the strongest evidence base for benefit Combined: The DASH diet had the most consistent evidence with improvements in blood pressure, blood lipids and body weight