TABLE 2.
Evidence grades and main findings from the systematic literature reviews on postdiagnosis diet, nutrition, physical activity and survival in women with breast cancer
| All‐cause mortality | BrCA mortality | BrCA recurrence | Second primary BrCA | Non‐BrCA mortality | CVD mortality | |
|---|---|---|---|---|---|---|
| Exposure |
RR (95% CI) Studies I 2 |
RR (95% CI) Studies I 2 |
RR (95% CI) Studies I 2 |
RR (95% CI) Studies I 2 |
RR (95% CI) Studies I 2 |
RR (95% CI) Studies I 2 |
| Strong evidence (Convincing) | — | — | — | — | — | — |
| Strong evidence (Probable) | ||||||
| BMI (per 5 kg/m2) |
1.07 (1.05‐1.10) 64 studies I 2 = 56% |
1.10 (1.06‐1.14) 39 studies I 2 = 60% |
— |
1.14 (1.04‐1.26) 11 studies I 2 = 66% |
— | — |
| Waist circumference (per 10 cm) |
1.18 (1.07‐1.31) 5 studies I 2 = 55% |
1.12 (1.03‐1.22) 3 studies I 2 = 0% |
— | — | — | — |
| Waist‐hip‐ratio (per 0.1 unit) |
1.30 (1.20‐1.40) 8 studies I 2 = 0% |
1.21 (1.08‐1.35) 6 studies I 2 = 6% |
— | — | — | — |
| Limited evidence (Limited suggestive) | ||||||
| BMI (per 5 kg/m2) | — | — |
1.05 (1.03‐1.08) 63 studies I 2 = 54% |
— |
1.06 (0.94‐1.19) 10 studies I 2 = 78% |
1.16 (0.96‐1.41) 2 studies I 2 = 0% |
| Waist circumference | — | — | No MA a | — | — | — |
| Waist‐hip‐ratio (per 0.1 unit) | — | — | No MA a | — | — | — |
| Recreational physical activity (per 10 MET‐h/week) |
0.85 (0.78‐0.92) 12 studies I 2 = 87% |
0.86 (0.77‐0.96) 11 studies I 2 = 65% |
0.97 (0.91‐1.05) 6 studies I 2 = 68% |
— | — | — |
| Predefined healthy dietary and lifestyle patterns | No MA b | — | — | — | No MA b | — |
| Soy foods (isoflavones per 2 mg/day) |
0.96 (0.92‐1.02) 5 studies I 2 = 66% |
0.83 (0.64‐1.07) 3 studies (pooled analysis) |
0.75 (0.61‐0.92) 3 studies (pooled analysis) |
— | — | — |
| Dietary fibre (per 10 g/day) |
0.87 (0.80‐0.94) 4 studies I 2 = 0% |
— | — | — | — | — |
| 25(OH)D (per 10 nmol/L) |
0.93 (0.89‐0.97) 6 studies I 2 = 63% |
0.94 (0.90‐0.99) 5 studies I 2 = 24% |
— | — | — | — |
| Limited evidence (Limited—no conclusion) | ||||||
| Weight/BMI change | No MA a | |||||
| Other diet b | No MA a | |||||
Abbreviations: 25(OH)D, 25‐hydroxy vitamin D concentrations; BMI, body mass index; BrCA, breast cancer; CI, confidence interval; CVD, cardiovascular disease; MA, meta‐analysis; MET, metabolic equivalent of task; RR, summary relative risk.
Studies were descriptively synthesised, as the data was not sufficient for conducting meta‐analysis.
Other diet comprises low/high fat dietary patterns, healthy dietary patterns (for breast cancer‐specific mortality and recurrence), alcoholic drinks, fruit and vegetables, dietary fibre (for breast cancer‐specific mortality and recurrence), wholegrains, red and processed meat, fish, eggs, milk and dairy products, nutrients (fats, carbohydrate, animal protein, plant protein), supplements, vitamin D (blood levels on recurrence).