Dietary patterns and chronic diseases among Australian adults

Dr. Zumin Shi, The University of Adelaide, South Australia

Slide 2

Background

• High burden of chronic disease- globally

• Diet – disease link widely studied, but

– Single nutrient

– Single food

– Overall diet is of interest: interaction between nutrients and foods; cumulative effects

• Increasing number of studies on dietary pattern and disease-last decade

Approach in define dietary patterns

• Knowledge based – Health Eating Index

• Data driven methods – Factor analysis

– Cluster analysis

– Reduced Rank Regression

– Method review by Newby et al

Newby PK, Tucker KL. Empirically derived eating patterns using factor or cluster analysis: a review. Nutr. Rev. 2004; 62(5): 177-203.

Examples of dietary pattern studies

• Nurse Health Study

• Two dietary patterns (first published by FB Hu et al) – Prudent and Western patterns

– Obesity, diabetes, CVD, metabolic syndrome, depression etc.

– Inflammatory biomarkers

Hu FB. Dietary pattern analysis: a new direction in nutritional epidemiology. Curr. Opin. Lipidol. 2002; 13(1): 3-9.

Examples of dietary pattern studies

• Jiangsu Nutrition Study, China

• Four dietary patterns: traditional, macho, sweet tooth, vegetable rich – Anemia, obesity, weight gain, asthma, metabolic syndrome

– Vegetable rich pattern: obesity (+), weight gain

– Used as covariates

Imamura F et al. Confounding by Dietary Patterns of the Inverse Association Between Alcohol Consumption and Type 2 Diabetes Risk. Am. J. Epidemiol. 2009; 170(1): 37-45.

Slide 6

Objectives

• Using North West Adelaide Health Study data (wave 3):

– Identify dietary patterns

– Assess the association between dietary patterns and NCD

– Assess whether inflammatory biomarkers mediate the association between dietary patterns and NCD

Slide 7

Dietary pattern analysis

• Food intake- assessed by Food Frequency Questionnaire (Vitoria Cancer Council)

• Food intake collapsed into 40 food groups

• Factor analysis, varimax rotation

Results

• Participants: n=2503, age 57.7(SD 14.2) years

• Two dietary patterns identified

• Similar to Nurse Health Study

– Prudent

– Western

Slide 8

Factor loadings

Slide 9

Dietary patterns score by birth cohorts

Slide 10

-.3

-.2

-.1

0.1

.2

Pru

dent pattern

score

<=1946 Baby boomer >=1966

Birth cohort

-.2

-.1

0.1

.2.3

Weste

rn p

attern

score

<=1946 Baby boomer >=1966

Birth cohort

Birth cohort and Western dietary pattern

Quartiles of Western pattern Birth cohort (%) Q1 Q2 Q3 Q4 <=1946 29.6 26.5 23.6 20.3 Baby boomer 24.1 24.8 25.1 26.1 >=1966 17.8 22.4 27.8 32.0

Slide 11

Obesity

0

10

20

30

40

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

1 2 4

Odds ratio(95%CI)

Diabetes

0

10

20

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

Hypertension

0

10

20

30

40

50

60

70

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

Asthma

0

10

20

30

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

COPD

Slide 16

0

10

20

30

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

CVD

Slide 17

0

10

20

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

Mental health problem

Slide 18

0

10

20

30

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

Depression

Slide 19

0

10

20

30

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

Osteoporosis

Slide 20

0

10

20

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

High cholesterole

Slide 21

30

40

50

Q1 Q2 Q3 Q4

Pre

vale

nce

(%

)

Prudent

Western

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

Prudent pattern

Western pattern

.5 1 1.5 2

Odds ratio(95%CI)

Dietary patterns and inflammatory biomarkers

Slide 22

Prudent pattern

Western pattern

-.05 0 .05 .1 .15Beta(95%CI)

log CRP log IL6 log TNF log Selectin

Inflammation is a mediator

• The association between diet and NCD is mediated by inflammatory biomarkers

– e.g. 6.6% of the total effect of the Western dietary pattern on depression was indirectly via CRP

Slide 23

Slide 24

Conclusion

• Western dietary patterns was associated with a range of chronic disease, especially obesity.

• Western dietary pattern was related to increased level of inflammation

• The association between Western dietary pattern and chronic diseases was mediated by inflammation

Contact information

Doctor Zumin Shi, MD, MPhil, PhD

Population Research and Outcome Studies

Discipline of Medicine

The University of Adelaide, South Australia

( L3, 122 Frome Street ADELAIDE SA 5005)

Email: zumin.shi@adelaide.edu.au

Ph: 8313 11188

health.adelaide.edu.au/pros