Diet synergies and mortality--a population-based case-control study of 32,462 Hong Kong Chinese older adults.
BACKGROUND
Food and drink are not consumed in isolation and can have complimentary effects enhancing or blocking the overall uptake of nutrients. We investigated how combinations of foods, drinks, and smoking affected mortality. Method Adjusted logistic regression was used to assess the joint effect of healthy foods, less healthy foods, smoking, and alcohol use on mortality in a case-control study of all Chinese adults aged 60 or over who died in 1998; 21,494 dead cases (81% of all registered deaths) and 10,968 live controls were included.


RESULTS
There was a significant trend of increasing all-cause mortality risk with decreasing healthy food consumption (P < 0.001), and the increase in risk was significantly steeper for people with high intakes of less healthy food (P for interaction <0.001). There was a steeper risk from increasing less healthy food intake in ever-smokers and people not drinking tea regularly (P < 0.001), while the J-shaped relationship between alcohol and mortality differed in shape with level of less healthy food intake.


CONCLUSIONS
Intake of some dietary items may modify the effect of others. An analysis framework explicitly recognizing complementary and potentially synergistic effects of food, drinks, and smoking could enhance our understanding of dietary epidemiology.
Schooling
C Mary
CM
Department of Community Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China.
Ho
Sai Yin
SY
Leung
Gabriel M
GM
Thomas
G Neil
GN
McGhee
Sarah M
SM
Mak
Kwok Hang
KH
Lam
Tai Hing
TH
D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects / Q000401:mortality*; D016022:Case-Control Studies; D004032:Diet / Q000009:adverse effects* / Q000706:statistics & numerical data; D004812:Epidemiologic Methods; D005247:Feeding Behavior; D005260:Female; D005638:Fruit; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017747:Seafood; D012907:Smoking / Q000009:adverse effects / Q000401:mortality*; D045730:Soy Foods; D013662:Tea; D014675:Vegetables
D013662:Tea