Table 1.
Characteristics of the included studies.
| References | Study design | Country | Type of cancer | Gender | Participants (case/control) | Mean age (year) | Follow-up time | Food intake assessment tool | DAL assessment indicators | Confounders considered in the analysis | Outcomes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Jafari et al. (19) | Case–control | Iran | Colorectal | Both | 499 (259/240) | 50 | - | FFQ | PRAL | Age, comorbidity, CFH, salt intake, physical activity, and Ca supplement | PRAL↑ → risk of CRC and CRA↑ |
| Mehranfar et al. (20) | Case–control | Iran | Prostate | Men | 120 (60/60) | Not indicated | - | FFQ | PRAL & NEAP | Age, BMI, TEI, smoking, physical activity, race, job, education, and drug usage | PRAL↑ → risk of prostate cancer↑ NEAP↑ → risk of prostate cancer↑ |
| Mousavi et al. (31) | Case–control | Iran | Glioma | Both | 366 (123/243) | 42 | - | FFQ | NEAP | Age, sex, TEI, marital status, smoking, CFH, physical activity, supplementation, BMI, X-ray exposure, head trauma, allergy, duration of illness, micronutrient intake, and comorbidity | NEAP↑ → developing glioma among adults ↑ |
| Park et al. (21) | Cohort | US and Puerto Rican | Breast | Women | 43570 | 54.5 | 7.6 y | FFQ | PRAL | Race, education, household income, BMI, physical activity, smoking, alcohol, CFH, breastfeeding, TEI, and parity | PRAL↑ → risk of breast cancer ↑ |
| Ronco et al. (22) | Case–control | Uruguay | Colorectal | Both | 3005 (611/2394) | 64 | - | FFQ | PRAL & NEAP | Age, sex, residence, education, CFH, BMI, smoking, alcohol, TEI, total fiber, micronutrient, and total heterocyclic amines | PRAL ↑ → risk of colorectal cancer ↑ NEAP↑ → risk of colorectal cancer ↑ |
| Ronco et al. (23) | Case–control | Uruguay | Lung | Men | 2309 (843/1466) | 65 | - | FFQ | PRAL & NEAP | Age, residence, CFH, BMI, smoking, alcohol, TEI, total fiber, micronutrient, and total heterocyclic amines | PRAL↑ → was not significantly associated with lung cancer risk NEAP↑ → risk of lung cancer ↑ |
| Ronco et al. (32) | Case–control | Uruguay | Breast | Women | 1461 (572/889) | 65 | - | FFQ | PRAL & NEAP | Age, residence, education, age at menarche, menopausal status, number of live births, age at menopause, CFH, BMI, smoking, alcohol, and TEI | PRAL↑ → risk of breast cancer ↑ NEAP↑ → risk of breast cancer ↑ |
| Safabakhsh et al. (33) | Case–control | Iran | Breast | Women | 300 (150/150) | 46.5 | - | FFQ | PRAL & NEAP | Age at first menarche, BMI, education, marital status, menopause status, socioeconomic status, alcohol, smoking, supplementation, comorbidity, number of Child, breast feeding, CFH, and TEI | PRAL↑ → was not significantly associated with breast cancer risk NEAP↑ → was not significantly associated with breast cancer risk recurrence |
| Shi et al. (24) | Cohort | US | Pancreatic | Both | 95708 | 64.5 | 8 y | FFQ & DHQ | PRAL | Age, sex, smoking, diabetes, alcohol, BMI, CFH, TEI, and dietary fiber | PRAL↑ → risk of pancreatic cancer ↑ |
| Wu et al. (30) | Cohort | US | Breast | Women | 2950 | 44 | 7.3 y | 24-h food recall | PRAL & NEAP | Age at diagnosis, race, education, menopausal status at baseline, TEI, alcohol, physical activity, BMI, number of comorbidities, radiotherapy, and chemotherapy. | PRAL↑ → was not significantly associated with breast cancer recurrence NEAP↑ → was not significantly associated with breast cancer recurrence |
DAL, dietary acid load; FFQ, food frequency questionnaire; DHQ, diet history questionnaire; PRAL, potential renal acid load; NEAP, net endogenous acid production; CFH, cancer family history; CRC, colorectal cancer; CRA, colorectal Adenoma; TEI, total energy intake.