Ken Riedl

We hypothesized that soy phytochemicals may have immunomodulatory properties that may impact prostate carcinogenesis and progression. A randomized, phase II trial was conducted in 32 prostate cancer patients with asymptomatic biochemical recurrence but no measurable disease on standard staging studies. Patients were randomized to 2 slices of soy bread (34 mg isoflavones/slice) or soy bread containing almond powder daily as a source of β-glucosidase. Flow cytometry and bioplex assays were used to measure cytokines or immune cell phenotype in blood at baseline (day 0) and following intervention (day 56). Adequate blood samples were available at enrollment and day 56 and evaluated. Multiple plasma cytokines and chemokines were significantly decreased on Day 56 versus baseline. Subgroup analysis indicated reduced Th1 (p=0.028) and MDSC-associated cytokines (p=0.035). Th2 and Th17 cytokines were not significantly altered. Phenotypic analysis revealed no change in CD8+ or CD4+ T cells, bu...

Epidemiological associations suggest populations consuming substantial amounts of dietary soy exhibit a lower risk of prostate cancer. A 20-week randomized, phase II, cross-over trial was conducted in 32 men with asymptomatic prostate cancer. The crossover involved 8 weeks each of soy-bread and soy-almond bread. The primary objective was to investigate isoflavone bioavailability and metabolite profile. Secondary objectives include safety, compliance and assessment of biomarkers linked to prostate carcinogenesis. Two distinct soy breads were formulated to deliver ~60 mg aglycone equivalents of isoflavones/day. The isoflavones were present as aglycones (~78% as aglycones,) in the soy-almond bread (SAB) while in the standard soy bread (SB) predominantly as glucosides (18% total isoflavones as aglycones). Compliance to SB (97%±4%) and SAB (92%±18%) was excellent, toxicity was rare and limited to grade I gastrointestinal complaints. Pharmacokinetic studies between SB and SAB showed modes...

UVB exposure, a major factor in the development of skin cancer, has differential sex effects. Tomato product consumption reduces the intensity of UVB-induced erythema in humans, but the mechanisms are unknown. Four week old SKH-1 hairless mice (40 females, 40 males) were divided into two feeding groups (control or with 10% tangerine tomatoes naturally rich in UV-absorbing phytoene and phytofluene) and two UV exposure groups (with or without UV). After 10 weeks of feeding, the UV group was exposed to a single UV dose and sacrificed 48 hours later. Blood and dorsal skin samples were taken for carotenoid analysis. Dorsal skin was harvested to assess sex and UV effects on carotenoid deposition, inflammation (skinfold thickness, myeloperoxidase levels) and DNA damage (cyclobutane pyrimidine dimers, p53). Females had significantly higher levels of both skin and blood carotenoids relative to males. UV exposure significantly reduced skin carotenoid levels in females but not males. Tomato co...