Table 4.
Association between quintiles (Q)/tertiles (T) of low-, medium-, and high-glycaemic index (GI) foods (servings/week) in relation to overall adiposity-related cancers and site-specific cancers (Hazard ratios (HR) and 95% confidence intervals)
| Adiposity-related cancers*†‡ |
Breast cancers§†‖ |
Prostate cancers¶†** |
Colorectal cancers†††‡‡ |
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age adjusted |
Multivariable adjusted*† |
Age adjusted |
Multivariable adjusted§† |
Age adjusted |
Multivariable adjusted¶† |
Age adjusted |
Multivariable adjusted††† |
|||||||||
| Carbohydrate-containing foods | HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI | HR | 95% CI |
| Low-GI foods§§ | ||||||||||||||||
| Category 1 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | ||||||||
| Category 2 | 0·91 | 0·71, 1·18 | 0·95 | 0·73, 1·23 | 0·61 | 0·40, 0·93 | 0·59 | 0·38, 0·92 | 1·15 | 0·78, 1·71 | 1·14 | 0·75, 1·71 | 0·44 | 0·24, 0·81 | 0·52 | 0·27, 0·99 |
| Category 3 | 0·79 | 0·61, 1·03 | 0·80 | 0·61, 1·06 | 0·56 | 0·37, 0·87 | 0·51 | 0·32, 0·83 | 1·16 | 0·78, 1·73 | 1·16 | 0·75, 1·81 | 0·57 | 0·32, 1·00 | 0·76 | 0·38, 1·51 |
| Category 4 | 0·85 | 0·65, 1·10 | 0·85 | 0·65, 1·12 | – | – | – | – | – | – | ||||||
| Category 5 | 0·80 | 0·61, 1·04 | 0·80 | 0·59, 1·08 | – | – | – | – | – | – | ||||||
| Ptrend | 0·08 | 0·11 | – | – | – | – | – | – | ||||||||
| Medium·GI foods‖‖ | ||||||||||||||||
| Category 1 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | ||||||||
| Category 2 | 0·89 | 0·68, 1·15 | 0·94 | 0·72, 1·22 | 0·99 | 0·64, 1·53 | 1·04 | 0·66, 1·63 | 1·20 | 0·81, 1·79 | 1·17 | 0·77, 1·76 | 0·95 | 0·54, 1·65 | 1·19 | 0·66, 2·15 |
| Category 3 | 0·82 | 0·63, 1·08 | 0·85 | 0·64, 1·12 | 1·08 | 0·70, 1·67 | 1·26 | 0·77, 2·04 | 1·15 | 0·78, 1·69 | 1·13 | 0·73, 1·75 | 0·65 | 0·36, 1·19 | 1·03 | 0·48, 2·24 |
| Category 4 | 0·89 | 0·69, 1·16 | 0·89 | 0·67, 1·18 | – | – | – | – | – | – | ||||||
| Category 5 | 0·86 | 0·67, 1·12 | 0·87 | 0·64, 1·17 | – | – | – | – | – | – | ||||||
| Ptrend | 0·32 | 0·33 | – | – | – | – | – | – | ||||||||
| High·GI foods¶¶ | ||||||||||||||||
| Category 1 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | 1·00 | ||||||||
| Category 2 | 0·85 | 0·65, 1·10 | 0·93 | 0·70, 1·23 | 0·75 | 0·49, 1·14 | 0·72 | 0·45, 1·16 | 1·24 | 0·84, 1·85 | 1·28 | 0·83, 1·99 | 0·89 | 0·51, 1·55 | 1·14 | 0·61, 2·13 |
| Category 3 | 0·83 | 0·64, 1·09 | 0·90 | 0·67, 1·22 | 0·70 | 0·45, 1·08 | 0·64 | 0·34, 1·24 | 1·26 | 0·84, 1·88 | 1·40 | 0·78, 2·53 | 0·65 | 0·35, 1·21 | 0·95 | 0·39, 2·31 |
| Category 4 | 0·97 | 0·75, 1·26 | 1·04 | 0·75, 1·43 | – | – | – | – | – | – | ||||||
| Category 5 | 0·91 | 0·70, 1·18 | 0·99 | 0·66, 1·49 | – | – | – | – | – | – | ||||||
| Ptrend | 0·88 | 0·85 | – | – | – | – | – | – | ||||||||
Models were adjusted for age, sex, smoking, alcohol and energy.
Additional adjustment for BMI, waist circumference, height, pre-existing conditions (diabetes and CVD), antioxidant supplement use, education and physical activity did not change these findings and mutual adjustment of low-, medium-, and high-GI for each other did not change these findings.
The quintile cut-offs for adiposity-related cancerswere: low-GI foods (servings/week): Q1: <15·7, Q2: 15·7–22·8, Q3: 22·8–29·4, Q4: 29·4–39·5, Q5: >39·5; for medium-GI foods: Q1: <5·5, Q2: 5·5–8·7, Q3: 8·7–11·9, Q4: 11·9–16·8, Q5: >16·8; for high-GI foods: Q1: <33·7, Q2: 33·7–45·2, Q3: 45·2–57·6, Q4: 57·6–75·0, Q5: >75·0.
For breast cancer, models were adjusted for age, smoking, alcohol, energy (multivariable method), menopausal status, hormone therapy use, age at menopause and number of live births.
Thetertile cut-offsfor breast cancerwere: low-GI foods (servings/week):T1: <21·9, T2: 21·9–33·8, T3: >33·8; for medium-GI foods (servings/week):T1: <7·8, T2: 7·8–13·4, T3: >13·4; high-GIfoods: T1: <40·6, T2: 40·6–59·8, T3: >59·8.
For prostate cancer, models were adjusted for age, smoking, alcohol and energy (multivariable method).
The tertile cut-offs for prostate cancer were: low-GI foods (servings/week): T1: <18·8, T2: 18·8–30·7, T3: >30·7; for medium-GI foods: T1: <7·4, T2: 7·4–13·3, T3: >13·3; for high-GI foods (servings/week): T1: <43·3, T2: 43·3–66·6, T3: >66·6.
For colorectal cancer, models were adjusted for age, sex, smoking, alcohol, energy (multivariable method), red and processed meat intake and fibre intake.
The tertile cut-offs for colorectal cancerwere: low-GI foods (servings/week): T1: <20·2, T2: 20·2–32·3, T3: >32·3; for medium-GI foods: T1: <7·5, T2: 7·5–13·4, T3: >13·4; for high-GI foods (servings/week): T1: <41·6, T2: 41·6–62·7, T3: >62·7.
Low-GI foods included most fruits, non-starchy vegetables and carrots, legumes and certain whole grain and dairy products.
Medium-GI foods included certain fruits (e.g. bananas and blueberries), whole grain products (e.g. popcorn and cereal), desserts and baked goods and sugary drinks (e.g. juice and soft drinks).
High-GI foods included certain fruits (e.g. cantaloupe and watermelons), fast foods (French fries and doughnuts), potatoes, white bread, cold cereal and candy.