Plant-based diets: a fad or the future of medical nutrition therapy for children with chronic kidney disease?

植物性飲食：慢性腎臟病兒童醫(yī)學(xué)營養(yǎng)治療的“時(shí)尚”還是未來？

Pediatric Nephrology, 2023

兒科腎病學(xué)，2023

????Plant-based diets are growing in popularity worldwide due to the importance of reducing the population’s ecological footprint as well as an emerging role in the prevention and treatment of chronic human diseases. In adults, plant-based diets have been shown to be beneficial for preventing and controlling conditions that are common? in patients with chronic kidney disease (CKD), such as obesity, hypertension, type 2 diabetes, dyslipidemia, and metabolic acidosis. Emerging evidence suggests that the higher fiber content of plant-based diets may help to modulate production of uremic toxins through beneficial shifts in the gut microbiome. The effects of the plant-based diet on progression of CKD remain controversial, and there are no data to support this in children. However, knowledge that the bioavailability of potassium and phosphorus from plant-based foods is reduced has led to recent changes in international kidney-friendly diet recommendations for children with CKD. The new guidelines advise that high potassium fruits and vegetables should no longer be automatically excluded from the kidney-friendly diet. In fact, a plant-based diet can be safely implemented in children with CKD through building the diet around whole, high fiber foods, avoiding processed foods and using recommended cooking methods to control potassium. The health benefits of the plant-based diet compared to omnivorous diets in children with CKD need investigation.

????由于減少人口對(duì)生態(tài)影響的重要性以及在預(yù)防和治療人類慢性疾病方面的新作用，植物性飲食在世界范圍內(nèi)越來越受歡迎。在成年人中，植物性飲食已被證明有利于預(yù)防和控制慢性腎臟疾病（CKD）以及常見的疾病，如肥胖、高血壓、2型糖尿病、血脂異常和代謝性酸中毒。新出現(xiàn)的證據(jù)表明，植物性飲食中較高的纖維含量可能有助于通過腸道微生物的變化來調(diào)節(jié)尿毒癥毒素的產(chǎn)生。植物性飲食對(duì)CKD的影響仍然存在爭議，沒有數(shù)據(jù)支持兒童疾病的這一觀點(diǎn)。然而，由于植物性食物中鉀和磷的生物利用度降低，最近國際上對(duì)兒童CKD友好的飲食建議發(fā)生了變化。新指南建議，高鉀水果和蔬菜不應(yīng)再被自動(dòng)排除在腎臟友好型飲食之外。事實(shí)上，植物性飲食可以安全地在兒童CKD中實(shí)施，方法是使用全高纖維食物構(gòu)建飲食，避免加工食品，并使用推薦的烹飪方法來控制鉀攝入。與雜食性飲食相比，植物性飲食對(duì)兒童CKD的健康益處需要進(jìn)一步調(diào)查。

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????A plant-based diet is defined as a diet that predominantly contains nutrients from plant-based sources such as fruits, vegetables, nuts, seeds, whole grains, legumes, and plant oils, with limited animal-based products such as low-fat dairy, poultry, and fish.

????植物性飲食是指主要含有來自植物性來源的營養(yǎng)素的飲食，如水果、蔬菜、堅(jiān)果、種子、全谷物、豆類和植物油，以及有限的動(dòng)物性產(chǎn)品，如低脂乳制品、家禽和魚類。

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????Plant-based diets include proteins derived from plant sources, as well as complex carbohydrates and a higher proportion of unsaturated fats compared to traditional non-plant-based diets. Additionally, plant-based diets typically contain lower amounts of total, saturated, and trans fats. Plant-based diet also contain modest amounts of phytosterols (plant sterols and stanols structurally related to cholesterol) which form the structural components of plant membranes. The plant-based diet also contains bioactive plant-derived compounds called phytonutrients and is rich in dietary fiber, both of which are associated with positive health effects. Plant-based diets are growing in popularity due to their role in preventing several chronic diseases in adults. Their role in children with chronic diseases is less well defined. Almost no data exist on the role of plant-based diets in children with CKD, and therefore, benefits have been extrapolated from adult studies.

????與傳統(tǒng)的非植物性飲食相比，植物性飲食包括來源于植物的蛋白質(zhì)，以及復(fù)雜的碳水化合物和更高比例的不飽和脂肪。此外，植物性飲食通常含有較低量的總脂肪、飽和脂肪和反式脂肪。植物性飲食還含有適量的植物甾醇，它們形成了植物膜的結(jié)構(gòu)成分。植物性飲食還含有一種名為植物營養(yǎng)素的生物活性衍生化合物，并富含膳食纖維，這兩種物質(zhì)都對(duì)健康有積極影響。植物性飲食因其在預(yù)防成人幾種慢性疾病方面的作用而越來越受歡迎。他們?cè)诨加新圆〉膬和械淖饔眠€不太明確。幾乎沒有關(guān)于植物性飲食在兒童CKD中的作用的數(shù)據(jù)，因此，從成人研究中推斷其益處。

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????In the general population, scientific data support the use of plant-based diets to improve cardiovascular disease (CVD), obesity, type 2 diabetes (T2D), hypertension, dyslipidemia, and osteoporosis. Many of these chronic diseases are interrelated.

????在普通人群中，科學(xué)數(shù)據(jù)支持使用植物性飲食來改善心血管疾?。–VD）、肥胖、2型糖尿病（T2D）、高血壓、血脂異常和骨質(zhì)疏松癥。這些慢性病中有許多是相互關(guān)聯(lián)的。

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????Plant-based diets can help with lowering blood pressure via promotion of weight loss due to the close relationship between adiposity and blood pressure. A large meta-analysis showed that a decrease of approximately 4 mmHg in both systolic and diastolic blood pressure was achieved by losing 5kg of weight in adults, and additional reductions in systolic and diastolic blood pressures were observed in those with more than 5-kg weight loss. Furthermore, a diet rich in fruits and vegetables and low in saturated fats has been shown to effectively lower blood pressure, even in the absence of weight loss. A lower urine sodium to potassium ratio observed in those consuming plant-based proteins may be responsible for the lower blood pressure in these individuals.

????由于肥胖和血壓之間的密切關(guān)系，植物性飲食可以通過促進(jìn)減肥來幫助降低血壓。一項(xiàng)大型薈萃分析顯示，成年人體重減輕5公斤可使收縮壓和舒張壓降低約4毫米汞柱，體重減輕5千克以上的人可觀察到收縮壓和舒張壓進(jìn)一步降低。此外，富含水果和蔬菜、低飽和脂肪的飲食已被證明可以有效降低血壓，即使在沒有減肥的情況下也是如此。在食用植物蛋白的人中觀察到的尿鈉鉀比較低可能是這些人血壓較低的原因。

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????The gut microbiome, a microcosm composed of trillions of highly complex communities of microorganisms, is known to affect human health and well-being and can be manipulated to attenuate the risk of obesity, T2D, cancer, and CVD. Diet has a significant impact upon the gut microbiota composition and function, and plant-based diets rich in fiber can help to promote a more favorable profile, as gut microbes help with fermentation of nondigestible carbohydrates and dietary fiber to increase production of butyrate and other short-chain fatty acids. Plant foods also contain polyphenols, flavanols, and phytochemicals, including carotenoids and phytosterols, which undergo microbial metabolization. The resulting bioactive compounds have anti-inflammatory and antioxidant activity, as do the short-chain fatty acids. Phytochemicals also increase beneficial bacteria in the gut such as Lactobacilli and Bifidobacterium. In those consuming a typical Western diet low in fiber, increased penetration of the intestinal barrier and a shift from fiber-degrading to mucus-degrading bacteria with the production of pro-inflammatory metabolites was observed. However, more studies are needed to elucidate the relationship between plant-based diets, the gut microbiome, and associated metabolic responses.

????腸道微生物組是由數(shù)萬億高度復(fù)雜的微生物群落組成的微觀世界，已知會(huì)影響人類健康，并可利用以降低肥胖、T2D、癌癥和心血管疾病的風(fēng)險(xiǎn)。飲食對(duì)腸道微生物群的組成和功能有重大影響，富含纖維的植物性飲食有助于促進(jìn)更有利的狀況，因?yàn)槟c道微生物有助于發(fā)酵不易消化的碳水化合物和膳食纖維，以增加丁酸和其他短鏈脂肪酸的產(chǎn)生。植物性食品還含有多酚、黃烷醇和植物化學(xué)物質(zhì)，包括類胡蘿卜素和植物甾醇，它們經(jīng)過微生物代謝產(chǎn)生的生物活性化合物具有抗炎和抗氧化活性，短鏈脂肪酸也是如此。植物化學(xué)物質(zhì)還會(huì)增加腸道中的有益細(xì)菌，如乳酸桿菌和雙歧桿菌。在那些食用典型的低纖維西方飲食的人中，觀察到腸道屏障的滲透增加，并且隨著促炎代謝產(chǎn)物的產(chǎn)生，細(xì)菌從纖維降解轉(zhuǎn)變?yōu)檎骋航到?。然而，還需要更多的研究來闡明植物性飲食、腸道微生物組和相關(guān)代謝反應(yīng)之間的關(guān)系。

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????Dietary fiber can increase gastric motility by increasing the consistency and volume of the stool. The water-soluble dietary fiber contains pectin, beta-glu-cans, gums, and psyllium. These water soluble fibers form viscous gels in the gut and hence reduce the adsorption of carbohydrates, fats, and cholesterol from the diet. Soluble fiber is present in vegetables, legumes, fruits, and cereals, and insoluble fiber is present in vegetables, nuts, and whole grains.

????膳食纖維可以通過增加糞便的稠度和體積來增加胃動(dòng)力。水溶性膳食纖維含有果膠、β-葡聚糖和樹膠。這些水溶性纖維在腸道中形成粘性凝膠，從而減少對(duì)飲食中碳水化合物、脂肪和膽固醇的吸收?？扇苄岳w維存在于蔬菜、豆類、水果和谷物中，不溶性纖維存在于植物、堅(jiān)果和全谷物中。

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????There is some evidence in the literature that higher dietary fiber intake is associated with lower risk of CVD, T2DM, and obesity since they decrease the caloric and fat absorption form the diet. An intake of 25~30gm dietary fiber intake is recommended in adults to have a beneficial effect on bowel health, and reduce risk of T2DM and coronary heart disease and obesity.

????文獻(xiàn)中有一些證據(jù)表明，較高的膳食纖維攝入量與較低的CVD、T2DM和肥胖風(fēng)險(xiǎn)有關(guān)，因?yàn)樗鼈儠?huì)減少飲食中的熱量和脂肪吸收。建議成年人每天攝入25~30克的膳食纖維，對(duì)腸道健康有有益影響，并降低患T2DM、冠心病和肥胖的風(fēng)險(xiǎn)。

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????Observational studies such as the Atherosclerosis Risk in Communities Study indicated a significant increase in incidence of CKD in individuals who consumed more red and processed meat whereas there was decreased incidence of CKD in those with higher intake of legumes, nuts, and low-fat dairy products. This is in line with a meta-analysis of 7 studies of over 15000 adults with CKD, which similarly reported an association of increased red meat consumption with increased risk of developing kidney failure. High-quality data showing clear benefits of plant-based diet in adults are lacking, and low-protein diets are not recommended for children with CKD due to the adverse effects on their growth and development.

????社區(qū)動(dòng)脈粥樣硬化風(fēng)險(xiǎn)研究等觀察性研究表明，攝入更多紅肉和加工肉的人CKD的發(fā)病率顯著增加，而攝入更多豆類、堅(jiān)果和低脂乳制品的人則CKD的發(fā)生率降低。這與一項(xiàng)針對(duì)15000多名CKD成年人的7項(xiàng)研究的薈萃分析一致，該研究同樣報(bào)告了紅肉消費(fèi)量增加與腎衰竭風(fēng)險(xiǎn)增加之間的關(guān)系。目前缺乏顯示植物性飲食對(duì)成人有明顯益處的高質(zhì)量數(shù)據(jù)，并且由于對(duì)CKD兒童的生長發(fā)育有不利影響，因而不建議對(duì)他們使用低蛋白飲食。

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????As kidney function declines, uremia can lead to modification of the gut microbiome, denoted as “uremic dysbiosis”. This imbalance favors pathobiont overgrowth over symbiont growth. Uremic dysbiosis can be caused increased urea levels or by medications such as antibiotics, phosphate binders, and chemotherapy agents. This dysbiosis of gut microbiome can lead to detrimental effects in production of microbiota-derived metabolites and therefore could contribute to accumulation in uremic retention solutes observed in CKD.

????隨著腎功能的下降，尿毒癥會(huì)導(dǎo)致腸道微生物組的改變，稱為“尿毒癥微生態(tài)失調(diào)”。這種不平衡傾向于病理生物的過度生長而不是共生體的生長。尿素水平升高或抗生素、磷酸鹽結(jié)合劑和化療藥物等藥物可導(dǎo)致尿毒癥生態(tài)失調(diào)。腸道微生物組的這種微生態(tài)失調(diào)會(huì)對(duì)微生物群衍生代謝產(chǎn)物的合成產(chǎn)生不利影響，因此可能導(dǎo)致CKD中觀察到的尿毒癥滯留溶質(zhì)的積累。

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????A meta-analysis of multiple studies including a total of 630108 adult participants revealed that healthy diets focused on fruits, vegetables, fish, legumes, whole grains, and fiber may lower mortality in CKD patients. Those who consumed the highest quartile of vegetable proteins had decreased risk of CKD.

????一項(xiàng)對(duì)包括630108名成年參與者在內(nèi)的多項(xiàng)研究的薈萃分析顯示，以水果、蔬菜、魚類、豆類、全谷物和纖維為重點(diǎn)的健康飲食可以降低CKD患者的死亡率。

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????Prebiotics are indigestible food additives that support growth of beneficial gut bacteria and limit growth of deleterious bacteria. In pre-dialysis patients, multiple studies report that supplementation of Arabic gum and fermentable carbohydrates had the ability to decrease serum urea concentrations and increase nitrogen in stool. Studies for investigating this novel therapy in CKD are limited and largely remain inconclusive. Studies are needed to further characterize the intestinal microbiome profile in CKD to identify beneficial and deleterious bacteria.

????益生元是不易消化的食物，支持有益腸道細(xì)菌的生長，限制有害細(xì)菌的生長。在透析前患者中，多項(xiàng)研究報(bào)告稱，補(bǔ)充阿拉伯樹膠和可發(fā)酵碳水化合物能夠降低血清尿素濃度并增加糞便中的氮。研究這種新型CKD治療方法的研究是有限的，并且在很大程度上仍然沒有結(jié)論。需要進(jìn)一步研究CKD的腸道微生物組特征，以確定有益和有害細(xì)菌。

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????Beans (such as black, pinto, red, garbanzo), lentils, peas, tofu, tempeh, unsalted nuts, and natural nut butters are not only excellent sources of protein, but also contain potassium and phosphorus. To lower the potassium content in legumes, one cup of dried legumes can be soaked in six cups of water for 12h, then cooked in fresh water for 30 min on the stovetop or 15 min in a pressure cooker. Canned legumes are inherently lower in phosphorus and potassium than cooked dried beans, so using the canned product is a good strategy to reduce preparation time. However, it should be noted that canned legumes often contain added sodium, so it is recommended to look for products canned with “no added salt” and/or check the nutrition facts label for the sodium content. Canned products with added sodium should be rinsed and drained prior to use to reduce sodium content.

????豆類（如黑、花、紅、鷹嘴豆）、扁豆、豌豆、豆腐、豆豉、無鹽堅(jiān)果和天然堅(jiān)果黃油不僅是蛋白質(zhì)的極好來源，而且含有鉀和磷。為了降低豆類中的鉀含量，一杯干豆類可以在六杯水中浸泡12小時(shí)，然后在爐灶上在淡水中煮30分鐘或在高壓鍋中煮15分鐘。罐裝豆類的磷和鉀含量天生低于煮熟的干豆，因此使用罐裝產(chǎn)品是節(jié)約準(zhǔn)備時(shí)間的好方法。然而，需要注意的是，罐裝豆類通常含有額外添加的鈉，因此建議使用“不添加鹽”的罐裝產(chǎn)品和/或查看營養(yǎng)標(biāo)簽中的鈉含量。添加了鈉的罐頭產(chǎn)品在使用前應(yīng)沖洗并瀝干水分，以減少鈉含量。

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????Brown or wild rice, whole grain pasta and breads, oats, quinoa, couscous, or farro are examples of whole grain starches that can provide a healthy source of carbohydrates as part of a plant-based diet. Whole grain products are now preferred over those made with white refined flour, which are more highly processed and contain fewer nutrients, less fiber, and more preservatives.

????糙米或野生大米、全谷物意大利面和面包、燕麥、藜麥、蒸粗麥粉或二粒小麥都是全谷物的食物，它們可以作為植物性飲食的一部分，提供健康的碳水化合物。全谷物產(chǎn)品現(xiàn)在比用白色精制面粉制成的產(chǎn)品更受歡迎，后者經(jīng)過高度加工，營養(yǎng)成分更少，纖維更少，防腐劑更多。

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????Potatoes are known to be one of the richest sources of natural dietary potassium. One medium baked potato contains 926 mg of potassium. Subsequently showed that the “double boiling method” is more effective, reducing the potassium content of various types of potato by approximately 50%. As suggested by the name, the “double boiling” method involves first boiling peeled, diced potato in a pot of fresh water for 10-15 min, draining, then adding the potatoes to a new pot of fresh water and boiling for an additional 10-15 min. Alternatively, cauliflower is a vegetable that is significantly lower in potassium and can be used as a substitute for mashed potato in recipes.

????眾所周知，土豆是天然膳食鉀最豐富的來源之一。一個(gè)中等大小的烤土豆含有926毫克的鉀。隨后表明，“雙煮法”可使各種類型馬鈴薯的鉀含量降低約50%。正如名字所暗示的，“雙煮”方法包括首先將去皮的土豆丁放在一壺淡水中煮10-15分鐘，瀝干水分，然后將土豆加入一壺新的淡水中，再煮10-15分鐘?；蛘?，花椰菜是一種鉀含量明顯較低的蔬菜，可以在食譜中用作土豆泥的替代品。

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????Some of the most challenging aspects in the care of children with kidney disease include controlling hyperphosphatemia and hyperkalemia. In the past, it was thought that many of the plant-based foods that are traditionally regarded as “healthy” should be avoided by patients with kidney disease due to their objectively higher potassium and phosphate contents. However, according to the recent Pediatric Renal Nutrition Taskforce (PRNT) guidelines, plant-based foods can now be included in the kidney-friendly diet, given the lower bioavailability of potassium and phosphorus from plant sources. Because the potassium in plant foods is mostly intracellular, a significant proportion of dietary potassium is not absorbed and is excreted in feces. Similarly, naturally occurring phosphorus in plant-based foods is bound to phytate, which is not easily absorbed, since humans lack the enzyme (phytase) required to digest this compound. As such, the bioavailability of phosphorus and potassium from whole plant foods is reduced, and these foods contain other nutrients and fiber that provide additional nutritional benefits.

????腎病兒童護(hù)理中一些最具挑戰(zhàn)性的方面包括控制高磷血癥和高鉀血癥。過去，人們認(rèn)為，許多傳統(tǒng)上被視為“健康”的植物性食物，由于其客觀上鉀和磷酸鹽含量較高，腎病患者應(yīng)該避免食用。然而，根據(jù)最近的兒科腎臟營養(yǎng)工作組（PRNT）指南，鑒于植物來源的鉀和磷的生物利用度較低，植物性食物現(xiàn)在可以被納入腎臟友好型飲食。因?yàn)橹参镄允澄镏械拟浿饕羌?xì)胞內(nèi)的，所以飲食中很大一部分鉀沒有被吸收，而是通過糞便排出。同樣，植物性食物中天然存在的磷與不易吸收的植酸酶結(jié)合，因?yàn)槿祟惾狈ο@種化合物所需的酶，因此，全植物食品中磷和鉀的生物利用度降低，這些食品含有其他營養(yǎng)素和纖維，可提供額外的營養(yǎng)益處。

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????Overall, the bioavailability of potassium and phosphorus is lowest from plant-based sources (40-60%), higher from animal sources (70%), and highest from inorganic additives to processed foods (100%). Processed foods, whether plant-based or not, are often laced with such inorganic sodium, potassium, and phosphorus preservatives. The used of additives and preservatives are continuing to increase with the creation of ultraprocessed foods, and this phenomenon presents a hidden danger to patients with kidney disease. Added potassium may be disguised within products that are promoted as “healthy” and “l(fā)ow in sodium” because the sodium has been replaced with potassium chloride. The key is to choose a plant-based diet that is focused on whole, high-fiber foods, avoid processed foods, and use recommended cooking methods.

????總的來說，植物來源的鉀和磷的生物利用度最低（40-60%），動(dòng)物來源的磷和鉀的生物利用率較高（70%），加工食品的無機(jī)添加劑的生物利用性最高（100%）。加工食品，無論是否以植物為基礎(chǔ)，通常都含有無機(jī)鈉、鉀和磷防腐劑。隨著過度加工食品的出現(xiàn)，添加劑和防腐劑的使用量不斷增加，這一現(xiàn)象對(duì)腎病患者構(gòu)成了隱患。添加的鉀可能被偽裝在被宣傳為“健康”和“低鈉”的產(chǎn)品中，因?yàn)殁c被氯化鉀取代。關(guān)鍵是要選擇以植物為基礎(chǔ)的飲食，重點(diǎn)是完整的高纖維食物，避免加工食品，并使用推薦的烹飪方法。