Voedsel rijk aan isoflavonen gecombineerd met misosoep zou kans op borstkanker met 40% verminderen aldus tienjarige Japanse studie onder ca. 22.000 vrouwen. Artikel geplaatst juni 2003.

Actuele ontwikkelingen over therapeutische behandelingen van borstkanker zijn te lezen onder kankersoorten-borstkanker

Voedsel rijk aan isoflavonen gecombineerd met twee tot drie koppen misosoep zou de kans op borstkanker met 40% verminderen, aldus een Japanse studie naar het effect bij kanker en hartziektes. De studie begon al in 1990 en in tien jaar tijd zijn ca. 22.000 vrouwen in de leeftijd van 40 tot 59 jaar gevolgd. De resultaten zijn gecorrigeerd naar leeftijd, erfelijkheid, rookgewoontes enz. Van de 22.000 vrouwen ontwikkelden 179 vrouwen borstkanker. Hierbij het abstract van de studie en een persbericht van Reuters en een bericht van Nutra Ingredients daaronder. Beide persberichten gaan over dezelfde studie gepubliceerd in The Journal of the National Cancer Institute, Vol. 95, No. 12, 906-913, June 18, 2003:

S. Tsugane, Epidemiology and Biostatistics Division, National Cancer Center Research Institute, East, Kashiwa, Japan.

Correspondence to: Seiichiro Yamamoto, Ph.D., Cancer Information and Epidemiology Division, National Cancer Center Research Institute, 5–1-1, Tsukiji, Chuo-ku, Tokyo, Japan (e-mail: siyamamo@ncc.go.jp).

Background: Although isoflavones, such as those found in soy, have been shown to inhibit breast cancer in laboratory studies, associations between consumption of isoflavone-containing foods and breast cancer risk have been inconsistent in epidemiologic studies. We evaluated the relationship between isoflavone consumption and breast cancer risk among women in the Japan Public Health Center-Based Prospective Study on Cancer and Cardiovascular Diseases (JPHC Study). Methods: In January 1990, 21 852 Japanese female residents (aged 40–59 years) from four public health center areas completed a self-administered questionnaire, which included items about the frequency of soy consumption. Through December 1999 and 209 354 person-years of follow-up, 179 women were diagnosed with breast cancer. Cox proportional hazards regression was used to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for breast cancer in relation to consumption of miso soup, soyfoods, and estimated isoflavones. All statistical tests were two-sided. Results: Consumption of miso soup and isoflavones, but not of soyfoods, was inversely associated with the risk of breast cancer. The associations did not change substantially after adjustment for potential confounders, including reproductive history, family history, smoking, and other dietary factors. Compared with those in the lowest quartile of isoflavone intake, the adjusted RRs for breast cancer for women in the second, third, and highest quartiles were 0.76 (95% CI = 0.47 to 1.2), 0.90 (95% CI = 0.56 to 1.5), and 0.46 (95% CI = 0.25 to 0.84), respectively (Ptrend = .043). The inverse association was stronger in postmenopausal women (Ptrend = .006). Conclusion: In a population-based, prospective cohort study in Japan, frequent miso soup and isoflavone consumption was associated with a reduced risk of breast cancer.

Bron: Reuters: 18 juni 2003:

TOKYO, June 18 — Women who eat three or more bowls of miso soup each day may
cut their breast cancer risk by up to 40 percent, Japanese researchers said
on Wednesday.

Women who had three or more bowls of miso soup daily reduced their risk of
getting breast cancer by about 40 percent ...

MISO SOUP — a concoction of fermented soybean paste dissolved in
broth flavored with seaweed and bonito that usually includes bean curd and
vegetables — appears on most Japanese tables at least once a day.
Researchers at Japan’s National Cancer Center said they found that
the health benefits from the soup were due to the presence in soybeans of
isoflavones, a powerful phytochemical, or compounds found only in plants.
They tracked the eating habits of 21,852 women aged between 40 and 59
for 10 years from 1990, according to an abstract of their findings published
in the online edition of the U.S.-based Journal of the National Cancer
Institute.

Women who had three or more bowls of miso soup daily reduced their
risk of getting breast cancer by about 40 percent compared with those who
had only one bowl, while women who had two bowls daily cut their risk by 26
percent.
Isoflavones are also a type of plant hormone whose chemical structure
resembles estrogen, albeit a weaker version. They are found in a number of
legumes, such as chickpeas, but are most concentrated in soybeans.
Isoflavones are believed to provide numerous health benefits besides
reducing breast cancer, including helping prevent coronary heart disease, by
mimicking the effects of estrogen on various parts of the body. With breast
cancer, they are believed to block the cancer-causing effects of estrogen.

Other soy food products, such as tofu and natto — fermented whole
soybeans — also have a beneficial effect, the researchers were quoted by the
daily Mainichi Shimbun as saying.
Seiichiro Yamamoto, head of the group, was quoted by the paper as
saying that due to miso’s high salt content, people should try to balance
their soy intake by eating a number of different foods.

© 2003 Reuters Limited. All rights reserved. Republication or
redistribution of Reuters content is expressly prohibited without the prior
written consent of Reuters.

Bron: Nutra Ingredients

Eating foods rich in isoflavones may reduce the risk of breast cancer, especially in postmenopausal women, suggests Japanese research. Frequent consumption of soy-rich miso soup was found to be particularly effective.

Although isoflavones, such as those found in soy, have been shown to inhibit breast cancer in laboratory studies, researchers have found associations between consumption of isoflavone-containing foods and breast cancer risk to be inconsistent.
Led by Seiichiro Yamamoto, researchers from the National Cancer Center Research Institute in Japan evaluated the relationship between isoflavone consumption and breast cancer risk among women as part of the Japan Public Health Center-based prospective study on cancer and cardiovascular diseases (JPHC Study).

The study concentrated on the incidence of breast cancer in relation to consumption of soy foods, miso soup - a soy-filled staple of Japanese cuisine - and overall estimated isoflavone intake.

The study began in 1990, when nearly 22,000 Japanese female residents, aged 40–59 years, from four public health centre areas completed a self-administered questionnaire, which included items about the frequency of soy consumption. Ten years later 179 of these women had been diagnosed with breast cancer.

The scientists found that while soyfoods alone did not have a significant effect, both consumption of miso soup and overall isoflavone intake reduced the risk of breast cancer.

The participants were divided into four categories according to isoflavone intake. On comparison with those in the lowest quartile of isoflavone intake, the adjusted reduced risk for breast cancer for women in the second, third, and highest quartiles were 0.76, 0.90 and 0.46 respectively.

In addition the researchers reported that the inverse association was found to be stronger in postmenopausal women.

These associations did not change substantially after adjustment for reproductive history, family history, smoking, and other dietary factors, according to the researchers.

Due to increasing evidence of the benefits of isoflavones, including strengthening the heart and bones and possibly preventing prostate cancer, an EU-funded project, called the Isoheart project, has recently been established to explore the physiological effects from eating foods with added soy-derived isoflavones.

One of the project's aims is to establish the presumed health benefits of phytoestrogens on reducing the risk of heart disease in postmenopausal women as well as studying the consumer acceptability of foods enriched with isoflavones.

Full details of the study can be found in the Journal of the National Cancer Institute or alternatively for further information contact the lead researcher Seiichiro Yamamoto.

Source: Journal of the National Cancer Institute, Vol. 95, No. 12, 906-913, June 18, 2003