Soybean products and reduction of breast cancer risk: a case–control study in Japan

Components of the Japanese diet, which might contribute to the relatively low breast cancer incidence rates in Japan, have not been clarified in detail. Since soybean products are widely consumed in Japan, a case–control study taking account of the menopausal status was conducted using data from the hospital-based epidemiologic research program at Aichi Cancer Center (HERPACC). In total, 167 breast cancer cases were included and 854 women confirmed as free of cancer were recruited as the control group. Odds ratios (OR) and 95% confidence intervals (95% CI) were determined by multiple logistic regression analysis. There were reductions in risk of breast cancer associated with high intake of soybean products among premenopausal women. Compared with women in the lowest tertile, the adjusted ORs for top tertile intake of tofu (soybean curd) was 0.49 (95% CI, 0.25–0.95). A significant decrease in premenopausal breast cancer risk was also observed for increasing consumption of isoflavones (OR=0.44; 95% CI, 0.22–0.89 for highest vs lowest tertile; P for trend=0.02). The present study found a statistically inverse association between tofu or isoflavone intake and risk of breast cancer in Japanese premenopausal women, while no statistically significant association was evident with the risk among postmenopausal women

Presence of Caffeic Acid in Flaxseed Lignan Macromolecule

Phenolic compounds were extracted from defatted flaxseeds using ethanol-dioxane (1:1, v/v). The crude extract obtained was purified using Amberlite XAD-16 column chromatography with water and methanol as mobile phases. RP-HPLC and SE-HPLC showed a lignan macromolecule (LM) as a dominant phenolic compound in the purified extract. After the alkaline hydrolysis of LM caffeic acid glucoside (CaAG) was isolated using a semi-preparative HPLC and its structure was confirmed by LC-ESI-MS. In LM of the investigated flaxseed, one molecule of caffeic acid corresponded with five molecules of p-coumaric acid and two molecules of ferulic acid. The presence of caffeic acid in the lignan molecule might be very beneficial due to its high antioxidant activity

Whole grain consumption and risk of colorectal cancer: a population-based cohort of 60 000 women

We examined prospectively the association between whole grain consumption and colorectal cancer risk in the population-based Swedish Mammography Cohort. A total of 61 433 women completed a food-frequency questionnaire at baseline (1987–1990) and, through linkage with the Swedish Cancer Registry, 805 incident cases of colorectal cancer were identified during a mean follow-up of 14.8 years. High consumption of whole grains was associated with a lower risk of colon cancer, but not of rectal cancer. The multivariate rate ratio (RR) of colon cancer for the top category of whole grain consumption (⩾4.5 servings day−1) compared with the bottom category (<1.5 servings day−1) was 0.67 (95% confidence interval (CI), 0.47–0.96; P-value for trend=0.06). The corresponding RR after excluding cases occurring within the first 2 years of follow-up was 0.65 (95% CI, 0.45–0.94; P-value for trend=0.04). Our findings suggest that high consumption of whole grains may decrease the risk of colon cancer in women

A prospective cohort study of soy product intake and stomach cancer death

The relationship between intake of soy products and death from stomach cancer was examined in a community-based prospective study of Japanese men and women in Takayama, Japan. Over 7 years of follow-up, 121 deaths from stomach cancer (81 men and 40 women) occurred among 30 304 (13 880 men and 16 424 women) participants who were at least 35 years of age. Diet including the intake of soy products and isoflavones was assessed by a validated semiquantitative food–frequency questionnaire at the beginning of the study. In men, the highest compared to the lowest tertile of total soy product intake was significantly inversely associated with death from stomach cancer after controlling for covariates (hazard ratios=0.50; 95% confidence intervals (CIs) 0.26-0.93, P for trend=0.03). Decreased hazard ratios for the highest compared to the lowest tertiles of total soy product intake (hazard ratios=0.49; 95% CI 0.22–1.13) was observed in women, although this association was of marginal significance. These data suggest that soy intake may reduce the risk of death from stomach cancer

One year soy protein supplementation has positive effects on bone formation markers but not bone density in postmenopausal women

BACKGROUND: Although soy protein and its isoflavones have been reported to reduce the risk of osteoporosis in peri- and post-menopausal women, most of these studies are of short duration (i.e. six months). The objective of this study was to examine if one year consumption of soy-containing foods (providing 25 g protein and 60 mg isoflavones) exerts beneficial effects on bone in postmenopausal women. METHODS: Eighty-seven eligible postmenopausal women were randomly assigned to consume soy or control foods daily for one year. Bone mineral density (BMD) and bone mineral content (BMC) of the whole body, lumbar (L1-L4), and total hip were measured using dual energy x-ray absorptiometry at baseline and after one year. Blood and urine markers of bone metabolism were also assessed. RESULTS AND DISCUSSION: Sixty-two subjects completed the one-year long study. Whole body and lumbar BMD and BMC were significantly decreased in both the soy and control groups. However, there were no significant changes in total hip BMD and BMC irrespective of treatment. Both treatments positively affected markers of bone formation as indicated by increased serum bone-specific alkaline phosphatase (BSAP) activity, insulin-like growth factor-I (IGF-I), and osteocalcin (BSAP: 27.8 and 25.8%, IGF-I: 12.8 and 26.3%, osteocalcin: 95.2 and 103.4% for control and soy groups, respectively). Neither of the protein supplements had any effect on urinary deoxypyridinoline excretion, a marker of bone resorption. CONCLUSION: Our findings suggest that although one year supplementation of 25 g protein per se positively modulated markers of bone formation, this amount of protein was unable to prevent lumbar and whole body bone loss in postmenopausal women