双语早读丨吃素一个月，身体会发生什么变化？
出于哲学或是健康原因，有些人打算不再吃肉食，而改吃纯素食。这一饮食方式戒绝所有的动物制品，包括肉类、鱼类、牛奶、鸡蛋，甚至蜂蜜。
Whether for philosophical or health reasons, some people are opting to stop consuming animals and are adopting a vegan diet. This approach to eating eschews all animal products, including meat, fish, milk, eggs and even honey.
对吃惯了奶制品和肉类的人来说，改吃纯素食是一种挑战，但是，吃纯素食对健康有一定益处，甚至能在某些方面改变你的身体。
Making the switch can be a challenge for people who are accustomed to incorporating dairy and meat in their diet, but it could offer some health benefits. It might even change your body in certain ways.
不过，身体如何改变取决于之前的饮食习惯，俄亥俄州立大学韦克斯纳医学中心注册营养师德娜·钱皮恩表示。该大学位于哥伦布市。
But how it might change depends on what you were eating before, says Dena Champion, a registered dietitian at the Ohio State University Wexner Medical Center in Columbus.
“当‘纯素食’指饮食习惯时，只意味着不吃任何动物制品。素食本身与有益健康并不等同，但它可以成为一种健康的日常饮食”，尤其是在之前的饮食习惯不太健康的情况下，她解释道。
“The term ‘vegan’ as it pertains to diet only means that one does not eat any animal products. It doesn’t inherently equal healthy, but it can be a healthy diet,” especially if you’re coming from a less healthful way of eating, she explains.
“如果日常饮食已经是以植物为主，只吃极少的动物制品，那么改吃纯素食带来的变化可能很小。”钱皮恩说。不过，“如果是由平时主要吃肉类、奶制品，改为吃大量水果、蔬菜和全谷物”，那你的身体也许会在若干方面发生变化。”
“If you’re already eating a diet heavy in plants with minimal animal products, you may see very few changes,” Champion says. But, “if you go from eating a diet heavy in animal meat and dairy and change to a diet consisting of high amounts of fruits, vegetables and whole grains,” you may see changes in several areas.
体重减轻
加利福尼亚州奥兰治县圣约瑟医院癌症防治中心的肿瘤学营养师凯莉·普罗克特说：“减少任何一大类食物的摄入量都会导致热量不足，这里说的是减少动物蛋白。”
“Eliminating any major food group, in this case animal proteins, can cause a calorie deficit,” says Kailey Proctor, an oncology dietitian with the Center for Cancer Prevention and Treatment at St. Joseph Hospital in Orange County, California.
很多美国人平时吃大量加工肉制品，这些肉制品脂肪含量高，热量和饱和脂肪含量也很高。普罗克特解释道，减少这些动物蛋白的摄入可能意味着热量的减少。
Many Americans consume a diet that’s heavy in processed, high-fat meats, which also tend to be high in calories and saturated fat. Removing those animal proteins can mean a reduction in calories, Proctor explains.
纯素食者摄入的蛋白质来自植物性食物，例如豆腐、豆豉、豆子、豆奶、豆类植物，而不是培根、牛肉这类食物中的高脂肪、高热量蛋白质。
Instead of high-fat and calorie-dense proteins like bacon and beef, vegans get their protein from plant-based sources such as: Tofu. Tempeh1. Beans. Soy milk. Legumes.
普罗克特表示：“这能使体重减轻。考虑到有三分之二的美国人超重或肥胖，吃纯素食对体成分和健康指标都有积极影响。”指标包括血压和血液中甘油三酸酯（一种脂肪）的水平。
“This can lead to weight loss, and considering that two-thirds of Americans are overweight or obese, this can have a positive impact on body composition2 and health markers,” such as blood pressure and triglyceride (a type of fat) levels in the blood, Proctor says.
心血管健康改善
普罗克特说：“以水果、蔬菜和全谷类为主的日常饮食能够降低甘油三酸酯和胆固醇水平，从而降低患心脏病的风险。”胆固醇是一种只存在于动物制品中的脂肪物质，会在血管系统中堆积，引起血管堵塞，从而导致心脏病发作或中风。像豆腐、豆豉这样富含植物蛋白的食物中不含胆固醇。不吃动物制品可以避免在日常饮食中摄入胆固醇，从而降低患心脏病的风险。
“Diets high in fruits, vegetables and whole grains can lower triglycerides and cholesterol thereby reducing the risk of heart disease,” Procter says. Plant-based protein sources such as tofu and tempeh have no cholesterol3 – cholesterol is a fatty substance that only comes from animal products. It can build up in the vascular system, leading to blockages that could trigger heart attacks or strokes. Eliminating animal products removes cholesterol from the diet, which could reduce your risk of heart disease.
此外，由于大多数水果和蔬菜的钠含量不高，纯素食的钠摄入量比其他饮食习惯更低。钠会使血压升高，所以少吃盐和钠也更加有益于心血管健康。
What’s more, a vegan diet tends to be lower in sodium than some other types of diets because most fruits and vegetables are low in sodium. Because sodium can increase blood pressure levels, lowering your consumption of salt and sodium may also contribute to better heart and vascular health.
血糖控制改善
由于引发糖尿病的一大危险因素是超重或肥胖，所以减肥能够降低患糖尿病的风险。例如，2018年《营养学》杂志上发表了一篇研究论文：在无糖尿病史的超重人群改吃纯素食后，研究人员对他们进行了为期16周的跟踪调查。研究发现，这群人的胰岛素敏感性上升，负责生产和释放胰岛素的胰腺细胞功能加强，血糖水平从而得到了改善。
Because being overweight or obese is a major risk factor for developing diabetes, losing weight can lower that risk. One study published in the journal Nutrients in 2018, for example, followed overweight people with no history of diabetes after they switched to a vegan diet for 16 weeks. Those people saw improvements in insulin4 sensitivity and better function of the pancreatic5 cells responsible for producing and releasing insulin. This led to improvements in blood sugar levels.
关节痛缓解
水果和蔬菜中含有某些叫作植物营养素的化合物，能够对抗细胞发炎。这些化合物又叫抗氧化物，能够帮助减轻关节炎和其他慢性关节病引起的关节疼痛、肿胀和压痛。
Fruits and vegetables contain certain compounds called phytonutrients6 that have an anti-inflammatory effect on cells. Also called antioxidants7, these compounds can help reduce the joint pain, swelling and tenderness associated with arthritis and other chronic conditions of the joints.
除此之外，如果超重，减肥能够帮助隐隐作痛的下肢关节减轻受力。臀部、膝盖和脚踝承受着整个身体的重量，体重减轻则意味着受力减轻，有时候能够为患炎症的关节减轻很大受力。
In addition, if you’re overweight, losing weight can help reduce stress on achy joints in the lower body. The hips, knees and ankles bear the weight of the whole body, so weighing less means less pressure – in some cases, a lot less pressure – on the arthritic joint.
肠道健康改善
由于健康的纯素食饮食强调吃水果、蔬菜和全谷类等高纤维食物，因而能够帮助改善肠道健康，增强肠道规律性。
Because a healthy vegan diet emphasizes consumption of high-fiber foods like fruit, vegetables and whole grains, that can lead to better gut health and regularity.
高纤维、全谷类食物中含有益生元，它是一种不可消化的天然化合物，能够促进肠道中有益细菌的生长。也就是说，你需要益生元来产生益生菌，即那些有益细菌。
High-fiber, whole grain foods contain prebiotics, which are natural, nondigestible compounds that help support the growth of helpful bacteria in the gut – i.e., you need prebiotics to form probiotics, which are those beneficial bacteria.
摄入的益生元和益生菌达到足够数量时，它们就能帮助调节肠道健康。越来越多的科学研究发现，这有益于整个机体的健康。高纤维食物还能增加粪便体积，从而促进规律排便，改善胃肠健康。
When you’re consuming prebiotics and probiotics in adequate amounts, that can help regulate gut health, which science is increasingly learning can contribute to overall good health. High fiber foods also add bulk to the stool, which can make for better regularity and improved gastrointestinal8 health.
癌症风险降低
普罗克特说，吃纯素食还有可能降低患癌的风险。“在搭配合理的纯素食饮食中，水果、蔬菜和全谷类的占比也很高。经证实，这些植物性食物由于富含抗氧化物和植物营养素，能够降低患癌的风险。”
There’s also the potential to reduce your risk of developing cancer, Proctor says. “Vegan diets, when planned correctly, are also very high in fruits, vegetables and whole grains. These plantbased foods have been shown to reduce the risk of cancer due to their high antioxidant and phytonutrient content.”
保证营养均衡
普罗克特表示，确保摄入充足的特定营养素非常重要，这对严格的纯素食者来说也许更难做到。
It’s important to make sure you’re getting adequate amounts of certain nutrients that may be more difficult to get when following a strict vegan diet, Proctor says.
“‘纯素食’一词与益于健康并不等同。”普罗克特提醒，比如“你可以吃一块全素饼干，但归根结底它仍然只是一块饼干”。
“The term ‘vegan’ doesn’t exactly mean healthy,” Proctor cautions. “You can have a vegan cookie,” for example, “but at the end of the day, it’s still a cookie.”
就像其他任何一种饮食习惯一样，应该始终注意尽可能吃天然、新鲜的食物。对于经过制作或加工的食物，要阅读其标贴，知道自己吃的是什么。
As with any other type of diet, the emphasis should always be on consuming whole, fresh foods as much as possible. Read labels on any prepared or processed foods so you know what you’re eating.
同时，钱皮恩建议，纯素食生活方式的转变要慢慢进行。“从每餐吃动物制品到突然一口不吃会让人非常不适应。要给自己时间寻找菜谱，制定方案。”
And Champion recommends transitioning to a vegan lifestyle slowly. “It can feel really overwhelming to go from eating animal products at every meal to eliminating them all overnight. Allow yourself time to find recipes and make a plan.”
普罗克特还建议“把含蛋白质食物混在一起吃，从而保证各类蛋白质摄入全面”。例如，大米和豆子一起吃，或者花生酱和果酱抹在全麦面包上一起吃，这能够为身体全面补充氨基酸，保持肌肉强壮。
Proctor also recommends “combining protein sources to make complete sources of protein.” For example, combining rice and beans, or peanut butter and jelly on wheat bread can provide the full complement of amino acids your body needs to keep muscles strong.
同样，可注意添加豆腐、豆豉、毛豆、豆奶和烘焙黄豆等豆类食物，来保证充足的蛋白质摄入。
你还需要确保自己摄入了充足的维生素B12。这对纯素食者来说可能是个问题，因为维生素B12“只存在于动物蛋白中”，普罗克特解释说，“维生素B12 对于红细胞的生成、DNA 和RNA 的合成，以及保持神经系统健康都具有重要意义。”
You also need to be sure you’re getting enough vitamin B12, which can be problematic for people who follow a vegan diet because vitamin B12 “is only found in animal proteins,” Proctor explains. “Vitamin B12 plays a role in red blood cell production, synthesis of DNA and RNA as well as keeping our nervous system healthy.”
来源：中国日报网英语点津