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系列之2：蔬果昔對你有壞處嗎？ 請看 Michael Greger 醫(yī)生制作的小視頻：
蔬菜和水果是地球上營養(yǎng)密度最高的食物，而深綠色的蔬菜則是王中之王。 Fruits and vegetables are the most nutrient-dense foods on the planet, and dark green leafy vegetables lead the pack. 被稱作“像發(fā)電廠一樣的蔬菜和水果”中最有營養(yǎng)的前5名是綠葉蔬菜。 Each of the top five so-called “power house fruits and vegetables” were greens. 中國白菜（美國超市名字Bok Choy，跟漢語拚音 Bai Cai差不多） （譯者注：營養(yǎng)密度100分的綠葉蔬菜除 Watercress（西洋菜）外，還有另外三種： Kale（羽衣甘藍(lán)） Collard Greens（芥藍(lán)菜葉） Mustard Greens（芥菜） 2017年3月16號 Joel Fuhrman 醫(yī)生制作了最新ANDI食物評分表，感興趣的可參考以下鏈接： https://www./library/eat-to-live-blog/128/andi-food-scores-rating-the-nutrient-density-of-foods ） 如果把這些蔬菜用攪拌機(jī)攪碎（或者做成湯或醬），攪拌破壞細(xì)胞壁使?fàn)I養(yǎng)最大限度被釋放出來，這些釋放出來的營養(yǎng)物質(zhì)就會快速進(jìn)入血液。 And so, if we blend them up in a smoothie (or soup or sauce),we’re taking the food with the most nutrition and breaking all the cell walls to dump that nutrition into our blood stream.
從消化和營養(yǎng)吸收的的效率來看，咀嚼是好的，但攪拌的效果更好。 Chewing is good, but blending is better, in terms of digestive efficiency and absorbing nutrients. 如果我們（的消化道上段）快速吸收了營養(yǎng)，造成沒有營養(yǎng)到達(dá)結(jié)腸，會不會使結(jié)腸內(nèi)的菌群挨餓呢？ But if we suck up all that nutrition such that none of it makes it down to our colon, might we be starving our microbial selves? 完整的谷物、豆類和堅(jiān)果比面包、鷹嘴豆泥和堅(jiān)果泥好的原因是因?yàn)闊o論我們怎么咀嚼，完整的食物碎片會到達(dá)結(jié)腸，它們會提供“自助餐”給結(jié)腸內(nèi)的益生菌。 The reason intact grains, beans, and nuts are better than bread, hummus, and nut butters is that no matter how well we chew, intact food particles make it down to your colon where they can offer a smorgasbord for your good bacteria. 圖中箭頭所指顯示的是糞便中谷物被細(xì)菌消化后的侵蝕部分。
但如果谷物、豆類和堅(jiān)果被攪拌的非常碎，即在你吃之前就成為面粉和泥狀，可能會使你的腸道菌群缺乏食物。 But if your grains, beans, and nuts are finely ground up into flour or paste before you eat it, you may be leaving your gut flora high and dry.
對于蔬菜和水果也會是一樣的嗎？ Would the same be true for fruits and vegetables?
蔬菜和水果有特別種類的微量營養(yǎng)素會保護(hù)結(jié)腸免生癌癥。蔬果昔逃過了胃和小腸的消化和吸收直接到達(dá)結(jié)腸，作用就像是益生菌一樣。無論我們?nèi)绾尉捉溃@些東西都與纖維附著在一起。 There are special classes of phytonutrients in fruits and vegetables that appear to protect against colon cancer. They can escape digestion and absorption in our stomach and small intestine, and end up in our colon to act as prebiotics. No matter how much we chew, they stay attached to the fiber. 上圖：高達(dá)90%的植物多酚逃過了消化道上段的消化和吸收，直接到達(dá)結(jié)腸。在那里接觸腸道微生物，作為腸道微生物的培養(yǎng)基，例如小的酚酸和SCFA，確實(shí)，對腸道微生物的種類和新陳代謝行為有一定影響。
但如果用攪拌機(jī)會不會讓這些營養(yǎng)物質(zhì)提前脫離出來呢? But if we use a blender, might we prematurely detach these nutrients?
答案是：不會的。即使用最高速的攪拌機(jī)攪拌5分鐘，這些營養(yǎng)物質(zhì)還是附著在纖維上，一起被運(yùn)送給結(jié)腸的細(xì)菌。 No. Even if you blend in a high-speed blender for five minutes, they remain bound to the fiber for transport down to your colon bacteria. 對有回腸造口袋的人取出小腸內(nèi)容物進(jìn)行蔬果昔試驗(yàn)結(jié)果顯示，那些多酚植物營養(yǎng)素大部分都完好無損地可到達(dá)結(jié)腸。所以當(dāng)攪拌蔬菜和水果時(shí)，不用擔(dān)心搶劫一方去補(bǔ)另一方的問題。 You can do smoothie experiments on people with ileostomy bags that drain the contents of the small intestine, and show that most of the polyphenol phytonutrients make it out intact. So we don’t have to worry we may be robbing Peter to pay Paul when we blend fruits and vegetables. 圖中比較原蘋果昔中幾種營養(yǎng)素含量與從回腸造口袋中取出物中營養(yǎng)素含量 那么蔬果昔有沒有不好的一面呢？ Is there any downside to smoothies, then?
對于蔬果昔，只是因食物顆粒小會增加消化和吸收效率，對谷物或許也一樣。但對谷物的顧慮則是攪拌會促使淀粉更容易消化和吸收而引起血糖波動。 Well, just as smaller particle size may improve digestive efficiency and gastrointestinal absorption of nutrients from fruits and vegetables, the same may be true for grains. But the concern is that this could boost starch availability and cause a blood sugar spike.
例如：這是吃半杯糙米后4小時(shí)血糖的升高和下降，誘發(fā)胰島素緩慢波動來應(yīng)對血糖的變化。并沒有超過禁食期血糖變化范圍。 For example, here’s the rise and fall in our blood sugar in the four hours after eating a half cup of brown rice, eliciting a nice gentle bump in our insulin levels to take care of it. Doesn’t even go above normal fasting blood sugar levels. 如果吃同樣多的糙米，但吃糙米前先把糙米打成粉，再做成幼滑的糙米粥對血糖的影響會怎樣呢？ But what if we ate the same amount of brown rice, but first ground into brown rice flour, so like a cream of brown rice hot cereal? 血糖和胰島素的波動就會加倍。等量的食物，只是形式不同。這就是完整形式的全谷物比用粉狀全谷物做的產(chǎn)品好的原因。 You get twice the blood sugar, twice the insulin spike. Same amount of food, just in a different form. Another reason why intact whole grains are better than whole grain flour products.
即使只是仔細(xì)咀嚼谷物也會增加血糖和胰島素的反應(yīng)。這就是普通咀嚼與仔細(xì)咀嚼的區(qū)別。 Even just chewing really well can boost the glycemic and insulin response. Here’s if you just chew rice regularly and here’s if you chew really well.
下面是正常咀嚼情況下血糖和胰島素反應(yīng)圖：
下圖中較高的曲線是仔細(xì)咀嚼情況下血糖和胰島素反應(yīng)圖：
較小的糙米顆粒會縮短胃排空時(shí)間，造成較大的血糖和胰島素反應(yīng)。 The smaller rice particles empty out of your stomach faster, producing greater blood sugar and insulin responses.
諷刺的是，有位狂熱的健康專家大力提倡仔細(xì)咀嚼食物以更好消化。但如果是仔細(xì)咀嚼含5種奶酪的披薩呢？也許咀嚼的不太仔細(xì)還更好。 It’s ironic that there were health crusaders pushing people to chew more to digest their food better, but if what you’re chewing is a five-cheese pizza, maybe it’s better not to digest so well. 下圖中這位先生提倡咀嚼食物50 – 100次成為液體后再吞下：
下圖：含5種奶酪的披薩仔細(xì)咀嚼后造成血糖波動大
有人還建議肥胖和糖尿病人不要咀嚼食物太多。不經(jīng)過咀嚼地吞下切成塊的食物，不僅會失去吃的樂趣，而且還可能會噎著。 Some have even suggested that diabetics and obese persons not chew their food so much. Swallowing diced food without chewing would not only reduce the pleasure of eating, though, but people could choke on it.
然而，他們建議有個(gè)簡單可接受的方法可以讓病人降低血糖的波動而不需做不可思議的事（囫圇吞），就是多吃高纖維食物，例如豆類，已證實(shí)可以使血糖波動平緩。 Still, though, they suggest it could be a simple way to allow patients to reduce their blood sugar levels without fundamentally altering their diets and may thus prove more acceptable than having to do the unthinkable — eat high fiber foods like beans, which have been shown to blunt blood sugar spikes.
甚至是打成糊的豆類，象鷹嘴豆泥之類的（也可降低血糖波動嗎）？ Even blended beans, like hummus?
答案是肯定的，豆類跟谷物不一樣，攪碎豆類不會影響血糖反應(yīng)。 Yes, unlike grains, blending legumes does not affect their glycemic response.
所以又回到蔬果昔的問題了，水果是更像是谷類還是更像豆類？ So, circling back to the smoothie question, is fruit more like grains or more like beans? 如果用水果做蔬果昔，會不會有血糖波動太大的風(fēng)險(xiǎn)？ If you liquefy fruit in a blender to make a smoothie, do you risk spiking your blood sugar too high?
請聽下回分解。 We’ll find out next. |
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