乳腺癌与便秘

Breast Cancer & Constipation

乳腺癌与便秘

 

原文网址：https://nutritionfacts.org/video/breast-cancer-and-constipation/

 

原文作者：Michael Greger M.D.

 

 

Why do constipated women appear to be at higher risk for breast cancer? Results suggest a slight increased risk of breast cancer for both decreased frequency of bowel movements and firm stool consistency, whereas women who have three or more bowel movements a day—super poopers—appeared to cut their risk of breast cancer in half. This could be because constipation means a greater contact time between our waste and our intestinal wall, which may increase the formation and absorption of fecal mutagens—substances that cause DNA mutations and cancer—into the circulation, and they could end up in breast tissue.

为什么便秘的女人乳腺癌风险看起来更高？结果表明，排便频率低和大便燥结的人，乳腺癌风险都高，而每天排便不少于3次的女人——排便超级通畅者，乳腺癌风险似乎只有一半。这可能是因为，便秘意味着体内的垃圾跟肠壁接触时间更长，而这会让人体形成并吸收更多粪便诱变剂——造成DNA突变和癌症的物质，进入循环，而它们最终进入乳腺组织。 

This concept dates back more than a century where severe constipation, so-called chronic intestinal stasis, was sometimes dealt with surgically. Figuring the colon was an inessential part of the human anatomy, why not cure constipation by just cutting it out? What they noted, though, was that potentially precancerous changes in the breasts of constipated women seemed to disappear after the surgery.

这种想法，100多年前就有了。那个时候，严重的便秘，即所谓的慢性肠停滞，有时用手术来处理。认定结肠是人体结构中无关紧要的部分，何不把它切除掉，以此来治便秘？不过，它们发现：便秘的妇女，在手术后，有可能引发癌症的变化，似乎消失了。 

It would take another 70 years, though, before researchers followed up on the clues by those distinguished surgeons who claimed breast pathology cleared when constipation was corrected. So they investigated the relation between potentially precancerous changes in the breast and the frequency of bowl movements in nearly 1500 women. They found four times the risk in women reporting two or fewer bowel movements a week compared to more than once daily, who had the lowest risk.

然而，直到70年后，研究者才跟踪了那些杰出的外科医生提供的线索。这些医生宣称：纠正了便秘问题后，乳腺的病状也清除了。因此，他们调查了接近1500名妇女可能的癌前变化跟排便频率之间的关系。他们发现：一天排便不止一次的女人，乳腺癌风险最低；相比她们，报告说每周排便不多于2次的女人，风险高达4倍。

 

We know that even the non-lactating breast actively takes up chemical substances from the blood, so maybe substances originating in the colon might enter the bloodstream and reach the breast. We know there are mutagens in feces, so it is not unreasonable to suggest that potentially toxic substances derived from the colon have damaging or even carcinogenic effects upon the lining of the breast. And those toxic substances may be bile acids.

我们知道，即使不母乳喂养的乳腺，也会从血液中积极地吸收化学物质，因此，有可能，源于结肠的物质会进入血流，并到达乳腺。我们也明白，粪便中有诱变剂。因此，来自结肠、可能有毒的物质，对乳腺的内层有损伤或致癌作用，这种想法不无道理。而这些有毒物质可能是胆汁酸。

 

First shown to promote tumors in mice in 1940, subsequent experiments on rats led to the mistaken belief that bile acids just promoted existing cancers but couldn’t actually initiate tumors themselves. However, there is a fundamental difference between the rodent models and human cancer. Rats only live a few years, and so the opportunity for cancer causing mutations may be at least 30 times greater in humans. Now we have at least 15 studies that show that bile acids can damage DNA, strongly suggesting they can initiate new cancers as well.

1940年，首先有研究表明胆汁酸会催生小鼠体内的肿瘤。其后对大鼠的试验，导致了错误的认识，以为胆汁酸仅仅助长已有的癌症，而实际上不会激活肿瘤本身。然而，在大鼠模型与人体癌症之间，有着根本的区别。大鼠只能活几年，因此，造成突变的癌症几率，在人体内可能至少高30倍。迄今，我们已有至少15项研究表明，胆汁酸能损伤DNA，这强烈地暗示，它们也能引发新癌症。

 

Bile acids are formed as a way of getting rid of excess cholesterol. Our liver dumps bile acids into the intestine for disposal, assuming our intestines will be packed with fiber to trap it and flush it out of the body, but if we haven’t been eating enough whole plant foods, bile acids can be reabsorbed back into the body, and build up in the breast.

人体形成胆汁酸，以此作为一种清除过多胆固醇的方式。我们的肝脏将胆汁酸排入肠道，以便清理掉它。我们的肠道，原本会充满纤维来吸附它们，干干净净地把它们带出体外，但是，如果我们没吃够整全植物性食物，胆汁酸就会重新吸收进入体内，并在乳腺积聚。

 

Carcinogenic bile acids are found concentrated in the fluid of breast cysts at up to a hundred times the level found in the bloodstream. By radioactively tagging bile acids they were able to show that intestinal bile acids rapidly gain access to the breast, where they can exert an estrogen-like cancer-promoting effect on breast tumor cells. This would explain why we see 50% higher bile acid levels in the bloodstream of newly diagnosed breast cancer victims. These findings support the concept of a relationship between intestinally derived bile acids and risk of breast cancer. So how can we facilitate the removal of bile acids from our body?

在乳腺囊肿液中，可见致癌的胆汁酸浓度高达血流中所见水平的上百倍。通过对胆汁酸进行放射标记，他们得以显示出，肠道胆汁酸迅速进入乳腺，在这里，它们会对乳腺肿瘤细胞施加类似雌激素的促发癌症的影响。这可以解释，为什么在刚诊断出乳腺癌的患者的血流中，我们会看到胆汁酸高出50%。这些发现，有助于证实：源于肠道的胆汁酸和乳腺癌风险之间有相关性。因此，我们该怎么做，才能促使人体排出胆汁酸？

 

We can speed up the so-called oroanal transit time, the speed at which food goes from mouth to toilet, because slowed colonic transit can increase bile acid levels. We can do that by eating lots of fiber. A diet packed with plants greatly increases bile acid losses.

我们可以加速所谓的“口-肛门通行时间”——食物从入口到拉出所用的速度，因为结肠转运减缓会提高胆汁酸水平。吃大量的纤维，我们就能做到这一点（译者注：指加速通行时间）。

 

Fiber can bind up and remove toxic elements like lead and mercury, as well as cholesterol and bile acids. But plants can bind bile acids even independent of fiber. Vegan diets bind significantly more bile acid than lacto-ovo or non-vegetarian diets even at the same fiber intake, which could explain why it appears that individuals eating vegetarian might excrete less mutagenic feces in the first place.

纤维可以吸附并清除铅、汞、胆固醇和胆汁酸等毒素。不过，就算没有纤维，植物本身也能吸附胆汁酸。即使吃同样多的纤维，相比蛋奶素或非素食饮食，纯素饮食也能吸附多得多的胆汁酸，这也有助于解释：为什么看起来，一开始，吃素食的人排出的致诱变粪便会较少。