托福阅读：“纯素食主义”的风险

　　近几年，素食主义悄然流行，越来越多的人加入了素食者的行列。不过，近日发布在自然母亲网络的一篇文章指出，纯素食也有潜在的健康风险，比如，纯素食者患肠癌的几率更高、骨矿物密度偏低，以及更容易缺乏维生素B12等等。营养专家表示，加入纯素食者行列意味着你要花更多的时间来规划饮食结构以保证各类营养摄入均衡。如果没有精力和时间详细规划，营养专家建议不妨做一个“弹性素食者”，即大部分时间吃素，偶尔吃点肉补充动物蛋白。

　　Thinking of giving up meat from your diet? The potential health benefits ofa green diet are well established, but a story by the Mother Nature Network(MNN) says there are also some potential side effects and health risksassociated with a vegetarian lifestyle.

　　Could low cholesterol kill you? A study by the Honolulu Heart Program foundthat elderly people with a "low cholesterol concentration" had a "significantassociation with mortality." In addition, a 2009 review published in theAmerican Journal of Clinical Nutrition found that while vegetarians have anoverall lower rate of cancer compared with meat eaters, vegetarians do have a 39percent higher rate of colorectal cancer.

　　Other health concerns associated with vegetarianism cited by MNN includedlower bone mineral density and lower levels of vitamin B12. However, thepublishers of the bone density study said the "magnitude of the association isclinically insignificant," at just around 5 percent.

　　Going vegetarian appears to have gained popularity in recent years. Arecent Yahoo Sports article even examined the diet of Mixed Martial Arts (MMA)fighter Jake Shields. Though much of the media's focus has been on a worldwidetrend toward bigger diets, whether that's Pizza Hut offering strange fast foodmashups or yet another customer at the Heart Attack Grill proving that there istruth in advertising.

　　The lesson in these potential risk-factors seems to be that if you're goingto become a vegan or vegetarian, you'll need to spend more time planning yournutritional choices to help ensure a balanced intake of vitamins and othernutrients. Though if you don't have the time or inclination for such efforts,there may be another option. University of Idaho nutritionist Katie Minor saysthat a "flexitarian" diet may be a viable third way.

　　"Flexitarians are people who are vegetarian most of the time, but once in awhile will consume an animal protein," Minor told MNN. "The more restrictive youare with your diet, the more you'll have to closely monitor what you'reconsuming and the more likely your need will be to supplement. Work with aregistered dietician to make sure you're not at risk for dietarydeficiencies."