SIMAR BAJAJ2026年6月2日Q: I’ve always heard that you need to drink milk to keep your bones healthy. Is that true?问：我经常听说要喝牛奶来保持骨骼健康。这是真的吗？For generations, Americans have been told — through school nutrition programs and advertising campaigns — that milk is an essential part of a healthy diet.几代人以来，美国人通过学校营养项目和广告宣传得知，牛奶是健康饮食中必不可少的一部分。Key to that narrative was that milk builds strong bones. Your bones are made of calcium, and one cup of whole milk contains about 300 milligrams of this nutrient. So drinking three cups per day, the thinking went, must make them resilient. But that message was built on short-term studies and pushed by the dairy industry, said Dr. Walter Willett, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health.这种说法的核心是牛奶能强健骨骼。骨骼由钙构成，而一杯全脂牛奶含有约300毫克的钙。因此，人们认为每天喝三杯牛奶一定能让骨骼更坚韧。但哈佛大学陈曾熙公共卫生学院的流行病学与营养学教授沃尔特·威利特博士表示，这种说法基于短期研究，且由乳制品行业推动。With over a third of people in the United States having trouble digesting lactose, nobody needs to drink cow’s milk, said Christopher Gardner, a nutrition scientist and professor of medicine at Stanford University. Getting enough calcium is still important, especially for some high-risk groups, but there may be better sources.斯坦福大学医学教授、营养学家克里斯托弗·加德纳称，美国有超过三分之一的人存在乳糖消化困难问题，其实没人非喝牛奶不可。摄入足够的钙仍然很重要，尤其是对一些高风险人群，但或许存在更好的钙来源。What does milk do to bones?牛奶对骨骼有什么作用？Calcium is an essential nutrient, critical for nerve, muscle and heart function, as well as bone and tooth health. However, as with most nutrients, your body needs only a certain amount. The U.S. dietary guidelines recommend that adults consume 1,000 to 1,200 milligrams of calcium per day, but this threshold is debated among experts — and other countries, like the United Kingdom, recommend only 700 milligrams.钙是一种人体必需的营养素，对神经、肌肉和心脏功能以及骨骼和牙齿健康至关重要。然而，和大多数营养素一样，人体所需的钙量是有限的。美国膳食指南建议成年人每天摄入1000至1200毫克钙，但这一标准在专家中存在争议——像英国等其他国家，推荐量仅为700毫克。Past clinical trials have found that when children and adults who weren’t eating enough calcium increased their consumption, whether via dairy foods or supplements, their bone densities increased by up to 3 percent. But those gains were too small to meaningfully reduce fracture risk, Dr. Willett said. And other studies have found that people must consume extra calcium every day to maintain those gains, which may not be worth the investment, he added.过去的临床试验发现，当钙摄入不足的儿童和成人增加摄入量（无论是通过乳制品还是补充剂），其骨密度最多增加3%。但威利特表示，这种提升幅度太小，不足以显著降低骨折风险。他还说，其他研究还发现，人们必须每天额外摄入钙才能维持这种提升效果，而这可能并不值得。“The idea that we need lot of calcium is based primarily on very short-term studies looking at calcium balance over a few weeks,” Dr. Willett said. And an analysis of 79 milk papers published between 1999 and 2003 found that over a third received funding from the dairy industry.“我们需要大量钙的观点主要基于对几周内钙平衡进行观察的极短期研究，”威利特说。此外，对1999年至2003年间发表的79篇牛奶相关论文进行的一项分析发现，超过三分之一的论文获得了乳制品行业的资助。There’s even evidence that people can have strong bones without drinking milk. According to one review published in 2020, people who live in countries with the lowest rates of hip fractures also tend to drink the least milk. And analyses of multiple studies have found that drinking more milk was not associated with lower fracture risk.甚至有证据表明，不喝牛奶也能拥有强健的骨骼。根据2020年发表的一篇综述，髋部骨折发生率最低国家的居民往往也是牛奶摄入量最少的群体。对多项研究的分析也显示，增加牛奶摄入量与降低骨折风险并无关联。Of course, studies like these can’t prove any link between milk consumption and bone health, said Dr. René Rizzoli, the former head of the bone diseases department at the University Hospitals of Geneva. To show that milk consumption prevents fractures, for instance, you would need clinical trials on the topic, which have not been done.当然，日内瓦大学医院骨病科前主任勒内·里佐利博士表示，像这样的观察性研究并不能证明牛奶消费与骨骼健康之间存在任何关联。例如，要证明喝牛奶能预防骨折，就需要针对该主题进行临床试验，而目前这类试验尚未进行。Ultimately, your exercise and broader diet may have more influence over your bone health. So don’t count on milk alone to eliminate your fracture risk, Dr. Rizzoli said.归根结底，锻炼和更广泛的饮食习惯可能对骨骼健康影响更大。因此，里佐利表示，不要指望单靠牛奶就能消除骨折风险。Do some people need milk more than others?有些人比其他人更需要牛奶吗？Experts say that children ages 9 to 18 need more calcium than any other age group to support their growth; as do older adults, since bone density tends to decrease after age 50.专家表示，九至18岁儿童比其他任何年龄段都需要摄入更多钙来支持生长发育；老年人也是如此，因为骨密度在50岁以后往往会下降。When a person’s calcium levels are low, the body can adapt by pulling more calcium from food and rejecting less as waste, Dr. Gardner said. But these mechanisms decline with age, and when the body isn’t getting enough, it pulls more calcium from bones, he added, weakening them.加德纳博士指出，当人体的钙水平较低时，身体可以通过从食物中吸收更多钙，并减少钙的排泄来适应。但他还说，这些机制会随着年龄的增长而衰退，当身体无法获得足够的钙，就会从骨骼中提取更多的钙，从而导致骨骼变脆弱。In a 2021 clinical trial, researchers assigned more than 7,000 older adults living in assisted care facilities in Australia to either maintain their usual two servings of dairy per day or increase their consumption to 3.5 servings per day. Over the two-year study, the higher-dairy group had an 11 percent reduced risk of falls and a 33 percent reduced risk of fractures. The researchers also found that they maintained more weight, muscle mass and bone density than the lower-dairy group, though the team couldn’t determine whether their lower risk of falls and fractures were because of stronger bones or something else, said Sandra Iuliano, a nutritionist at the University of Melbourne.在2021年的一项临床试验中，研究人员将7000多名居住在澳大利亚辅助护理机构的老年人分组，一组维持每天摄入两份乳制品的习惯，另一组则将摄入量增加到每天3.5份。在为期两年的研究中，高乳制品摄入组跌倒的风险降低了11%，骨折的风险降低了33%。墨尔本大学的营养学家桑德拉·尤利亚诺表示，研究人员还发现，与低乳制品摄入组相比，高乳制品摄入组在体重、肌肉量和骨密度保持方面情况更好，尽管研究团队无法确定跌倒和骨折风险的降低究竟是因为骨骼更强健还是出于其他原因。Regardless, milk can be one of the most convenient sources of calcium, along with other nutrients like protein, potassium and phosphorus, said Jeri Nieves, a nutritional epidemiologist at the Hospital for Special Surgery in New York City. Other foods — like tofu, bony fish, leafy vegetables and fortified orange juice or plant-based milks — are good sources too, Dr. Nieves said, even if they have less calcium per serving.纽约市特殊外科医院的营养流行病学家杰里·尼夫斯说，无论如何，牛奶都是最便捷的钙质来源之一，同时还能提供蛋白质、钾和磷等其他营养物质。尼夫斯表示，其他食物——如豆腐、带骨鱼、绿叶蔬菜以及强化橙汁或植物奶——也是很好的钙来源，尽管它们每份的含钙量相对较低。The best option for calcium, however, might be fermented dairy products like yogurt and cheese. They support the gut microbiome, tend to be better tolerated by people sensitive to lactose and are more strongly tied to lower fracture risk than milk, Dr. Rizzoli said. They’re also packed with calcium — a 1.5-ounce serving of Cheddar cheese, for example, has the same amount as a cup of whole milk.然而，获取钙的最佳选择可能是酸奶和奶酪等发酵乳制品。里佐利说，它们有助于支持肠道微生物群，往往更容易被乳糖敏感人群耐受，而且与牛奶相比，它们同降低骨折风险的关联更为密切。它们也富含钙——例如，约40克的切达奶酪与一杯全脂牛奶所含的钙量相同。“If you like milk, drink it. If you don’t like milk, or if you can’t tolerate it, use some other source,” Dr. Nieves said.“如果喜欢牛奶，那就喝。如果不喜欢牛奶或者无法耐受，那就选择其他来源，”尼夫斯说。Simar Bajaj报道健康和健康生活方式。翻译：晋其角点击查看本文英文版。