Table 1 Summary of nutrients and food factors with prostate cancer

Carbohydrate [3-7]

Low carbohydrate slowed tumor growth.

Rare

On-going

Potential, awaits evidence from RCT

Protein [23-46]

Soy protein slowed tumor progression. Genistein inhibited PCa cell detachment, invasion, and metastasis.

Mixed results in total protein, dairy, soy intake.

Supplement of geneistein reduced PCa progression.

Soy products showed potential benefit, need more RCT to confirm.

Fat [47-84]

Low fat reduced PCa risk, high fat increased risk.

Mixed results. Saturated fat may increase and plant fat decrease PCa risk. W-3 PUFA may decrease risk.

Low fat plus w-3 PUFA reduced PCa proliferation and CCP.

Further research needed to clarify role of amount and type of total fat and fatty acids.

Vitamin A [85-90]

NA

Higher serum β-carotene associated with higher PCa risk.

β-carotene supplement increased PCa risk.

Supplement not advised.

Folate [91-98]

Folate depletion reduced tumor growth.

Higher circulation folate associated with higher PCa risk or lower PSA.

Supplement folate had no effect on PCa risk.

Potential dual role of folate in prostate carcinogenesis, needs further examination.

Vitamin C [89]

May slow tumor growth in vitro and in vivo.

Rare

Rare. One study showed no effect.

May act both as pro-oxidant and antioxidant. Needs clarification.

Vitamin D [100-114]

May slow PCa progression.

Serum vitamin D associated with a higher or lower risk.

No impact of vitamin D supplement on PSA or PCa risk.

A ‘U’ shaped relationship may exist between vitamin D status and PCa.

Vitamin E [115-125]

May slow PCa tumor growth.

Some show no association between vitamin E supplement and PCa risk.

400 IU supplement had no effect or increased PCa risk, but 75 IU supplement lowered risk.

Weak evidence of benefit, further research should consider dosage also.

Vitamin K [126,127]

Anti-tumor, chemo and potential radiosensitizers.

Inverse relationship between vitamin K and PCa incidence.

NA

Inadequate evidence

Calcium [128-130]

Rare

Calcium intake increased or decreased PCa risk.

A ‘U’ shaped relationship may exist.

Further research is needed to clarify if any association exists.

Selenium [123,125,131,132]

Inhibit angiogenesis, proliferation, inducing apoptosis.

Toenail selenium associated with reduced advanced PCa risk.

Selenium supplement had no effect for PCa chemoprevention, or increased high grade PCa risk among men with high selenium status.

Conflicting results, more research is needed.

Silibinin [133-135]

Inhibit PCa growth via EGFR, IGF-1R, NF-kB, TGFβ2, and CAF-like markers.

NA

NA

Potential as chemopreventive agent, awaits further research.

Curcumin [136,137]

Inhibited proinflammatory NF-B, induced apoptosis, slowed PCa growth.

NA

NA

Potential to slow PCa growth, awaits further research.

Pomegranate [137-141]

Inhibited PCa proliferation, angiogenesis.

Pomegranate juice increased PSA doubling time in one trial, but no controls included. Another trial showed no impact.

Weak evidence of benefit.

Green tea [131,137,142-145]

Inhibited PCa growth, induced apoptosis, decreased inflammation.

NA

Green tea catechin or EGCG supplement reduced PCa incidence or PSA.

Some evidence of benefit, more research needed.

Resveratrol [137,146-151]

Inhibited PCa growth in some but not all studies.

NA

NA

Potential, awaits further study.

Zyflamend [152-157]

Reduced PCa progression.

NA

Reduced risk among those with high grade PCa.

Potential to slow PCa growth.

Fruits and vegetables [158-163]

Allium vegetable reduced PCa risk.

Inverse relationship between total fruit and vegetable intake and PCa risk.

Supplement of pomegranate, green tea, broccoli, turmeric reduced PSA rise.

Moderate evidence, consistent with current dietary guideline to encourage rich intake.

Tomatoes and products [131,164-176]

Lycopene slowed PCa growth, progression.

Higher lycopene intake or serum level associated with lower PCa risk in some studies.

Supplement lycopene lowered PSA, PCa symptoms in some studies.

Moderate evidence, needs large RCT to confirm.

Coffee [177-183]

NA

Inverse between coffee consumption and PCa risk in some studies but not all.

NA

Potential benefit.

Dietary pattern [70,184-191]

NA

High HEI associated with lower PCa risk. Mediterranean diet may prevent PCa. Western diet associated with higher PCa risk and Asian diet opposite.

NA

Promising. RCT needed.