Tomatoes or lycopene versus prostate cancer: is evolution anti-reductionist?

Occasionally, but not often, positive things happen in the field of cancer prevention science to popular, good-tasting foods. Cruciferous vegetables have been the subject of intense study, but these foods might be—to modify the expression—an easy pill but a hard food for the public to swallow. By contrast, tomatoes (scientifically classified as a fruit) have overcome their earlier reputation as an inedible and possibly toxic food to become one of the most heavily consumed fruits or vegetables in the Western diet—mostly in the form of pizza, salsa, chili, pasta sauce, and ketchup.

Effects of carotenoids on aflatoxin B1-induced mutagenesis in S. typhimurium TA 100 and TA 98.

The effects of beta-carotene, canthaxanthin, and extracts of tomato paste (containing lycopene) and orange juice (containing cryptoxanthin) onaflatoxin B1 (AFB1)-induced mutagenesis in S. typhimurium TA 100 and TA 98 were investigated. Inhibition of mutagenesis was studied during and following completion of AFB1 metabolism (i.e., after the addition of menadione), thereby permitting separate examination of the metabolic activation and phenotypic expression phases. Each experimental carotenoid, except lycopene, inhibited AFB1-induced mutagenesis in both tester strains.

Intake of carotenoids and retinol in relation to risk of prostate cancer.

Several human studies have observed a direct association between retinol (vitamin A) intake and risk of prostate cancer; other studies have found either an inverse association or no association of intake of beta-carotene (the major provitamin A) with risk of prostate cancer. Data regarding carotenoids other than beta-carotene in relation to prostate cancer risk are sparse.

We concluded a prospective cohort study to examine the relationship between the intake of various carotenoids, retinol, fruits, and vegetables and the risk of prostate cancer.

Antioxidant activity of fresh apples.

Vitamin C is used as a dietary supplement because of its antioxidant activity, although a high dose (500 mg) may act as a pro-oxidant in the body1, 2. Here we show that 100 g of fresh apples has an antioxidant activity equivalent to 1,500 mg of vitamin C, and that whole-apple extracts inhibit the growth of colon- and liver- cancer cells in vitro in a dose-dependent manner. Our results indicate that natural antioxidants from fresh fruit could be more effective than a dietary supplement.

Hormones and diet: low insulin-like growth factor-I but normal bioavailable androgens in vegan men.

Mean serum insulin-like growth factor-I was 9% lower in 233 vegan men than in 226 meat-eaters and 237 vegetarians (P = 0.002). Vegans had higher testosterone levels than vegetarians and meat-eaters, but this was offset by higher sex hormone binding globulin, and there were no differences between diet groups in free testosterone, androstanediol glucuronide or luteinizing hormone.

Low-protein diet suppresses serum insulin-like growth factor-1 and decelerates the progression of growth hormone-induced glomerulosclerosis.

A low-protein (LP) diet has been associated with amelioration of renal function in glomerulosclerosis (GS). However, the mechanisms involved are still unclear. We have used a mouse transgenic for bovine growth hormone (GH), which develops progressive GS and exhibits consistently elevated levels of circulating GH and insulin-like growth factor (IGF)-1, to study the effect of dietary protein restriction. LP (6% protein) and normal-protein (NP, 20% protein) diets were maintained for 30 weeks in mice with established GS of mild/moderate degree.

Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 as predictors of advanced-stage prostate cancer.

BACKGROUND: Plasma levels of insulin-like growth factor-I (IGF-I) have been associated with the risk of prostate cancer. However, the association ofIGF-I with specific tumor stage and grade at diagnosis, which correlate with risk of recurrence and mortality, has not been studied rigorously. To determine whether plasma levels of IGF-I and its main circulating binding protein, IGF binding protein-3 (IGFBP-3), predict more aggressive forms ofprostate cancer, we investigated the association between plasma levels of each and specific stages and grades of prostate cancer.


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