アブラナ科野菜を食べることにより乳がん患者の生存率が向上する

中国においてアブラナ科野菜摂取と乳がん生存率上昇とに関連が認められた

Cruciferous vegetable consumption linked to improved breast cancer survival rates in China

中国人女性において乳がんの診断後にアブラナ科野菜を摂取することにより生存率が上昇したと2012年AACR学会で発表された。研究者らは、2002～2006年にステージ1～4の乳がんと診断された中国人乳がん患者4,886人の前向きスタディであるShanghai Breast Cancer Survival Studyにおいてアブラナ科野菜の効果を調査した。人口動態、患者背景および生活習慣因子で補正した結果、乳がん診断後最初の36か月間のアブラナ科野菜摂取により総死亡、乳がん死亡および再発のリスクが摂取量依存的に減少することが示された。アブラナ科野菜摂取量4分位の増加に伴い、総死亡率は27%低下し62%に、乳がん死のリスクは22%低下し62%に、そして再発は21%低下し35%になった。野菜の摂取習慣が中国と異なる文化の女性に一般化することには注意が必要であると筆者らは述べている。中国で一般的に摂取されているアブラナ科野菜はカブ、中国キャベツ/青梗菜および青菜などである。

Eating cruciferous vegetables after breast cancer diagnosis was associated with improved survival among Chinese women, according to results presented at the AACR Annual Meeting 2012, held March 31 - April 4.

"Breast cancer survivors can follow the general nutritional guidelines of eating vegetables daily and may consider increasing intake of cruciferous vegetables, such as greens, cabbage, cauliflower and broccoli, as part of a healthy diet," said Sarah J. Nechuta, M.P.H., Ph.D., a postdoctoral research fellow at Vanderbilt University in Nashville, Tennessee.

She and her colleagues investigated the role of cruciferous vegetables in breast cancer survival in the Shanghai Breast Cancer Survival Study, a prospective study of 4,886 Chinese breast cancer survivors diagnosed with stage 1 to stage 4 breast cancer from 2002 to 2006.

After adjusting for demographics, clinical characteristics and lifestyle factors, the researchers found cruciferous vegetable intake during the first 36 months after breast cancer diagnosis was associated with a reduced risk for total mortality, breast cancer-specific mortality and recurrence in a dose–response pattern. Across increasing quartiles of cruciferous vegetable consumption, risk for total mortality decreased by 27 percent to 62 percent, risk for breast cancer-specific mortality decreased by 22 percent to 62 percent, and risk for recurrence decreased by 21 percent to 35 percent.

Nechuta noted that cruciferous vegetable consumption habits differ between China and the United States and suggested this fact be considered when generalizing these results to U.S. breast cancer survivors.

"Commonly consumed cruciferous vegetables in China include turnips, Chinese cabbage/bok choy and greens, while broccoli and brussel sprouts are the more commonly consumed cruciferous vegetables in the United States and other Western countries," she said. "Second, the amount of intake among Chinese women is much higher than that of U.S. women. The level of bioactive compounds such as isothiocyanates and indoles, proposed to play a role in the anticancer effects of cruciferous vegetables, depend on both the amount and type of cruciferous vegetables consumed."

She suggested that future studies with direct measurements of bioactive compounds such as isothiocyanates and host factors that influence the effects of these biological compounds be conducted to better understand the association of cruciferous vegetable intake with breast cancer outcomes.