塔夫茨大学的研究正在仔细观察测试对象和他们吃的东西，以解开食物的奥秘
【中美创新时报2024 年 4 月 17 日编译讯】（记者温友平编译）目前，塔夫茨大学一个研究团队，正在仔细观察测试对象和他们吃的东西，以解开食物的奥秘。《波士顿环球报》记者Felice J. Freyer对此作了下述详细报道。
乔恩·哈姆多夫 (Jon Hamdorf) 是一位热爱冒险、追求自由的人。他的最新作品有点不同。
事情始于 1 月中旬，当时他入住了波士顿唐人街一栋土褐色砖砌建筑 12 楼的一个房间。70 岁的哈姆多夫没有永久地址，每天都在缅因州的船上旅行或居住。 但在这次短途旅行中，这个勇敢的灵魂受到了严格的时间表的约束，要求吃递给他的特定食物，并禁止在没有监护人陪同的情况下外出——所有这些都是为了科学。
“对我来说，这就像去尼泊尔或去以色列一样。这就像另一场冒险，”退休注册会计师哈姆多夫说。
他说，令人兴奋的是目标。 在为期三周的为期三周的工作中，哈姆多夫同意成为一个项目的研究对象，该项目旨在回答几乎所有将叉子放到嘴里的人所困扰的问题：吃完这种食物后，我的身体会发生什么？ 它会让我发胖、提高胆固醇、扰乱我的肠道微生物组——或者可能延长我的寿命吗？
精准健康营养研究是一项耗资 1.7 亿美元的国家研究项目，计划在全国范围内招募 10,000 人，旨在开发一种方法来为每个人确定最佳饮食。 该研究由全国六个临床中心进行，其中包括塔夫茨大学和马萨诸塞州总医院运营的新英格兰临床中心。
目前的营养建议是基于平均值，基于对大多数人来说最有效的营养建议。但国家研究项目主任霍莉·尼卡斯特罗 (Holly Nicastro) 解释说，在许多研究中，食用完全相同的营养素组合的人在血糖或血压等指标上有不同的反应。
这项研究将试图找出确切的原因，以便有一天——人们希望——能够食用适合其独特生物学的饮食。
该研究还试图克服长期困扰营养研究的挑战。 通常，营养数据依赖于询问人们记得吃过什么。但众所周知，记忆是不准确的，而且常常会因为吃掉整片奥利奥而感到尴尬而产生偏见。 Nutrition for Precision Health 正在测试其他记录人们消费情况的方法，包括使用应用程序、调查问卷或安装在眼镜上、通过咀嚼启动的微型摄像头。
“我们拥有真正摆脱对记忆的依赖的技术，”塔夫茨大学美国农业部人类营养衰老研究中心主任莎拉·L·布斯 (Sarah L. Booth) 说。 “这是这项研究令人兴奋的方面之一。 我们可能会彻底改变我们研究营养的方式。”
参与者首先完成一个“模块”，在该模块中他们遵循正常饮食 10 天并报告他们吃了什么。 如果他们想继续，他们要么选择购买预先包装好的饭菜在家吃，要么参加“居家饮食”模块，这是哈姆多夫选择的严格控制的逗留方式。通过将人们留在室内并受到监视，研究人员可以精确而确定地追踪人们吃什么，以及这些食物对全身的影响。
哈姆多夫是波士顿居家饮食阶段首届四名参与者之一。所有人此前都签署了美国国立卫生研究院的“我们所有人研究计划”，该计划旨在招募 100 万或更多参与者贡献他们的健康数据（包括遗传学），以建立一个可以为数千项研究提供信息的数据库。只有现有的“我们所有人”成员才会被邀请参加营养研究。
第一天，参与者提供了血液和唾液样本，扫描了他们的骨骼，测量了他们的代谢率，并记录了他们的脂肪与肌肉的比率。他们还在腰间配备了血糖监测仪，以持续跟踪血糖波动，还配备了跟踪活动和睡眠的腕带。
第二天，日常生活开始了：早上 6:30 测量体重和生命体征；早上8点早餐； 中午12点 午餐; 下午 3 点 小吃; 下午 6 点 晚餐; 晚上11点 熄灯。
哈姆多夫说，事实证明，严格的日程安排比限制更自由。 “这样的结构感觉非常好，”他说。 “你只需要吃饭就可以了，不需要去购物什么的。”
在用餐和测试之间，参与者可以自由使用13楼的健身器材，在瑜伽室的垫子上伸展身体，在游戏室聚会，或者在带观景窗的宽敞私人房间放松身心。他们喜欢与人类营养衰老研究中心办公室、实验室和厨房的 150 名工作人员进行互动。
偶尔，他们也会到外面散步，但前提是有工作人员陪同，以免有人想吃蛋卷冰淇淋； 研究人员必须能够证明参与者只吃了里面提供的食物。
他们提供什么服务？
就在中午，他们的第一个两周的工作即将结束时，四名参与者在临床研究经理保罗·J·福斯 (Paul J. Fuss) 的陪同下，成群结队地来到 11 楼的餐厅，后者在他们吃饭时留下来监视他们。
厨房工作人员给他们端来了用塑料包裹的盘子，上面贴着他们的名字。每顿饭都是根据个人的卡路里需求量身定制的；参与者不应增加或减轻体重。
每个都有一个小橡胶抹刀来舀起每一个面包屑。 “我们几乎要求你舔盘子而不是舔盘子，”营养师凯拉·艾拉吉(Kayla Airaghi)说。 如果他们吃不完，工作人员会对剩下的食物进行称重，将消耗量精确到十分之一克。
这一天，来自安多佛的 60 岁的洛里·马修斯 (Lori Mattheiss) 得到了汉堡、桃子和薯片；她的丈夫蒂姆·卡特 (Tim Carter)，63 岁，享用了两个汉堡包。克林顿的简·卡谢尔 (Jane Cashell) 75 岁，吃西兰花、鸡块、通心粉和奶酪。 哈姆多夫买了西班牙米饭、玉米卷调味鸡肉和切达干酪。
“这不是我们通常吃的食物，”马修斯说。 “我吃的是从小到大就没吃过的东西。” 其他日子她会喝 Yodel、Kool-Aid、罐装水果鸡尾酒、Fritos。
在为期两周的课程中，参与者食用了他们所谓的传统美国饮食。然而，研究人员拒绝给它贴上标签。官方仅根据其含量来描述，精制谷物和含糖饮料的含量较高，而水果、蔬菜、全谷物和鱼类的含量较低。
在第二次和第三次为期两周的访问中——两次访问之间至少相隔两周——参与者吃了高脂肪和高蛋白质的食物，最后，饮食中富含水果、蔬菜、豆类、坚果、 全谷物和鱼（四个人最喜欢这个）。
该中心的高级科学家、该研究新英格兰分部的首席研究员 Sai Krupa Das 表示，选择这三种饮食并不是因为推荐，而是因为它们是美国最常见的饮食模式。 “它们反映了我们作为一个国家的消费方式，”她说。
我们的目标不是确定哪种饮食最好，而是衡量个体对不同成分的不同反应。
研究人员承认，很难吸引不同的人群参与该项目的这一阶段。 有多少人可以一次将自己的生活搁置两周？在线交易股票的卡特和马蒂斯在逗留期间工作，其他远程工作人员也许也能做同样的事情。但公交车司机呢？ 餐馆老板？ 年幼孩子的父母？ 即使完成所有三个为期两周的课程的 6,200 美元津贴也可能不足以弥补工作损失。
尽管面临挑战，美国国立卫生研究院的尼卡斯特罗表示，“我们确实有雄心勃勃的多样性目标”，他们希望至少通过“模块 1”来实现这一目标，其中参与者吃他们平常吃的东西并记录下来。 但即使对于要求更高的模块——预先包装的膳食或生活饮食——研究机构也在与教堂、理发店、社区中心和其他地方合作，让人们报名参加“我们所有人”，然后招募他们参加营养研究 ，尼卡斯特罗说。
耶鲁大学公共卫生学院教授拉斐尔·佩雷斯-埃斯卡米拉（Rafael Pérez-Escamilla）没有参与这项研究，他认为“精准健康营养”可能会回答一些令人着迷的科学问题，但他说，这对改善健康没有多大作用。人们的健康或影响那些因不良饮食而受到最严重影响的人。
“我们生活在一个大约 70% 的成年人超重或肥胖的国家，他们 70% 或更多的卡路里来自超加工食品或垃圾食品，包括含糖饮料，”他说。 “问题主要集中在穷人身上。”
佩雷斯-埃斯卡米拉更希望看到类似的投资，以增加获得健康食品的机会，例如提供借记卡购买新鲜水果和蔬菜的“生产处方计划”。
斯坦福大学教授克里斯托弗·加德纳（Christopher Gardner）研究了膳食成分对健康的益处，但没有参与精准健康营养研究，他称这是一个“极其雄心勃勃”的项目。 他预测研究人员将确定肠道中关键的好细菌和坏细菌，以及哪些食物会促进它们的生长。
加德纳在私人公司 Zoe 的科学顾问委员会任职，该公司根据生物信息提供个性化营养建议。 人们在家进行测试，并根据结果得到关于吃什么的指导。
这正是美国国立卫生研究院研究最终希望提供的结果，但波士顿首席研究员达斯表示，结果将有更强有力的科学支持。当被问及佐伊时，她说：“市场总是领先于科学。”
在两周的停留结束后，参与者将面临整整两天的测试，对他们生物学的各个方面进行测量。 最后一天，他们喝两杯香草安素，然后从早上 8 点到下午 1 点坐在椅子上，每隔一段时间抽取血样，以测量营养物质的代谢情况。
“居家饮食”课程预计将于 2026 年中期结束。然后，利用每个人的大量数据，乘以数千名参与者，该项目将部署人工智能，提出算法来确定谁应该吃什么。但这还不是结束：必须进行一系列研究来验证这些算法。
尼卡斯特罗渴望了解哪些因素驱动个人反应。 “这可能是遗传因素，可能是微生物组，也可能是环境因素，或者可能是很多因素混合在一起，”她说。 最终目标是让医生或营养师能够测试某些因素，然后制定个性化的饮食计划。
与此同时，前四名参与者带着柠檬绿色的纪念品水瓶回到家中，已经发现自己正在改变饮食习惯。卡谢尔非常喜欢第三种饮食，她试图在厨房里重新制作食谱。 哈姆多夫注意到，在实验过程中，他从未感到饥饿，但对每顿饭都充满期待，并意识到他需要吃更多的东西，喝更多的水。 马蒂斯和卡特试图在晚上少吃一点，多吃水果和坚果。
所有人都很高兴能够参与这项研究。
“你没有太多机会为重要的科学研究做出贡献，”卡特说。 “我很幸运能够做到这一点。”
题图：研究参与者有半小时的时间在人类衰老营养研究中心享用定制午餐。JONATHAN WIGGS/GLOBE STAFF
附原英文报道：
Study at Tufts is taking a close look at test subjects and what they eat to unlock the mysteries of food
By Felice J. Freyer Globe Staff,Updated April 13, 2024
Jon Hamdorf is a free spirit who lives for adventure. His latest was a little different.
It started in mid-January when he checked into a 12th-floor room in a drab brick building in Boston’s Chinatown. At age 70, Hamdorf has no permanent address and spends his days traveling or living on his boat in Maine. But for this jaunt, this intrepid soul was confined to a rigid schedule, required to eat specific meals that were handed to him, and forbidden to go outside without a chaperone — all in the service of science.
“This, to me, is like going to Nepal or going to Israel. It’s like another adventure,” said Hamdorf, a retired CPA.
The thrill, he said, lay in the purpose. For three two-week stints, Hamdorf had agreed to become a study subject in a project seeking to answer questions that have troubled nearly every person who brings fork to mouth: What will happen in my body after I eat this food? Will it make me fat, raise my cholesterol, mess up my gut microbiome — or perhaps extend my life?
The Nutrition for Precision Health Study, a $170 million national research project seeking to enroll 10,000 people nationwide, aims to develop a way to pinpoint the optimal diet for every person. The study is being carried out by six clinical centers across the country, including the New England Clinical Center, run by Tufts University and Massachusetts General Hospital.
Current nutrition advice is based on averages, on what seems to work best for most people. But in many studies, people eating the exact same mix of nutrients have differing responses in measures like blood glucose or blood pressure, explains Holly Nicastro, the national study’s program director.
The study will try to find out exactly why, so that someday — it is hoped — people will be able to consume a diet tailored to their unique biology.
The study is also seeking to overcome the challenges that have long dogged nutrition research. Typically, nutrition data relies on asking people what they remember eating. But memories are notoriously inaccurate, and often biased by, say, embarrassment over having eaten that entire sleeve of Oreos. Nutrition for Precision Health is testing other methods of documenting what people consume, including with an app, a questionnaire, or a tiny camera mounted on eyeglasses that is activated by chewing.
“We have the technology to actually get away from the reliance on memory,” said Sarah L. Booth, director of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. “This is one of the exciting aspects of this study. We may be completely revolutionizing how we study nutrition.”
Participants first complete a “module” in which they follow their normal diet for 10 days and report what they ate. If they want to continue, they choose either to pick up prepackaged meals to eat at home or to enroll in the “live-in diet” module, the tightly controlled sojourn that Hamdorf selected. By keeping people inside and under watch, researchers can track — with precision and certainty — what people eat, and what effects those foods have throughout the body.
Hamdorf was among an inaugural group of four participants in the live-in diet phase in Boston. All had previously signed up for the All of Us Research Program of the National Institutes of Health, which aims to enroll 1 million or more participants to contribute their health data, including genetics, to build a database that can inform thousands of studies. Only existing All of Us members are invited to take part in the nutrition study.
On the first day, the participants gave blood and saliva samples, had their bones scanned, their metabolic rates measured, and their fat-to-muscle ratio documented. They were also equipped with blood-glucose monitors attached at the waist to continuously track fluctuations in blood sugar, and wrist bands that tracked activity and sleep.
The next day, the daily routines kicked in: 6:30 a.m. weight and vital signs taken; 8 a.m. breakfast; 12 p.m. lunch; 3 p.m. snack; 6 p.m. dinner; 11 p.m. lights out.
The strict schedule proved more liberating than confining, Hamdorf said. “It feels very good to be structured like this,” he said. “You just show up for the meals, and you don’t have to go shopping or anything.”
Between meals and tests, participants were free to use the exercise equipment on the 13th floor, stretch on the mats in the yoga room, gather in the game room, or relax in their spacious private rooms with picture windows. They loved interacting with many of the 150 people working in offices, laboratories, and the kitchen at the Human Nutrition Research Center on Aging.
Occasionally, they took a stroll outside, but only when a staff member could accompany them, lest anyone get an urge for an ice cream cone; the researchers must be able to attest that the participants ate only what they were served inside.
And what were they served?
Precisely at noon near the end of their first two-week stint, the four participants trooped to the 11th-floor dining room, accompanied by Paul J. Fuss, clinical research manager, who stayed to keep an eye on them as they ate.
The kitchen staff brought them plates wrapped in plastic and labeled with their names. Each meal is tailored to the individual’s calorie needs; participants are not supposed to gain or lose weight.
Each also has a tiny rubber spatula to scoop up every crumb. “We’re pretty much asking you to lick the plate without licking the plate,” said Kayla Airaghi, a dietitian. If they can’t finish, the staff will weigh the leftovers, tracking consumption down to a 10th of a gram.
On this day, Lori Mattheiss, 60, of Andover got a hamburger, peaches, and potato chips; her husband, Tim Carter, 63, was served two hamburger sliders. Jane Cashell, 75, of Clinton, ate broccoli, chicken nuggets, and mac and cheese. Hamdorf got Spanish rice, chicken with taco seasoning, and cheddar cheese.
“It’s not the food we normally eat,” Mattheiss said. “I’m eating things I haven’t eaten since I was a kid.” On other days she’s had a Yodel, Kool-Aid, canned fruit cocktail, Fritos.
In this two-week session, participants consumed what they called the traditional American diet. The researchers, however, resist labeling it; officially it’s described only by its contents, high in refined grains and sugar-sweetened drinks and low in fruits, vegetables, whole grains, and fish.
In the second and third two-week visits — which were spaced apart with at least two weeks in between — the participants ate high-fat and high-protein fare, and, finally, a diet replete with fruits, vegetables, beans, nuts, whole grains, and fish (the four liked this one best).
The three diets were chosen not because they’re recommended but because they are the most common diet patterns in the United States, said Sai Krupa Das, a senior scientist at the center and principal investigator for the New England branch of the study. “They are reflective of what we consume as a nation,” she said.
And the goal is not to determine which diet is best, but rather to measure individuals’ varying response to the different components.
The researchers acknowledge that it will be difficult to attract a diverse population to this phase of the project. How many people can put their lives on hold for two weeks at a time? Carter and Mattheiss, who trade stocks online, worked during their stays, and other remote workers might be able to do the same. But bus drivers? Restaurant owners? Parents of young children? Even the $6,200 stipend for completing all three two-week sessions may not be enough to compensate for lost work.
Despite the challenges, the NIH’s Nicastro said, “We do have ambitious diversity goals,” which they expect to achieve at least with “Module 1,” in which participants eat what they normally do and record it. But even for the more demanding modules — the prepackaged meals or the live-in diet — research sites are working with churches, barbershops, community centers, and other places to sign people up for All of Us, and then recruit them into the nutrition study, Nicastro said.
Rafael Pérez-Escamilla, a professor at the Yale School of Public Health, who is not involved in the study, believes the Nutrition for Precision Health will probably answer some fascinating scientific questions — but, he said, it won’t do much to improve people’s health or reach those suffering the worst effects of a poor diet.
“We live in a country where about 70 percent of adults are either overweight or obese, and 70 percent or more of their calories are coming from ultraprocessed or junk foods, including sugar-sweetened beverages,” he said. “The problem is heavily concentrated among the poor.”
Pérez-Escamilla would much prefer to see a similar investment in efforts to increase access to healthy foods, such as “produce prescription programs” that supply debit cards to purchase fresh fruits and vegetables.
Christopher Gardner, a Stanford professor who has studied the health benefits of dietary components but is not involved with the Nutrition for Precision Health study, called it an “incredibly ambitious” project. He predicted that the researchers would identify the key good and bad bacteria in the gut, and which foods promote them.
Gardner serves on the scientific advisory board for a private company, Zoe, that is offering personalized nutrition advice based on biological information. People take at-home tests and get instructions on what to eat based on the results.
This is exactly what the NIH study eventually hopes to offer, but Das, the principal investigator in Boston, said the results will have stronger scientific backing. “The market’s always ahead of the science,” she said, when asked about Zoe.
At the end of their two-week stay, the participants face two full days of testing, every aspect of their biology measured. On the last day, they drink two cups of vanilla Ensure and then sit in a chair from 8 a.m. to 1 p.m., giving blood samples at set intervals to measure how nutrients are metabolized.
The “live-in diet” sessions are expected to wrap up in mid-2026. Then, with a trove of data from each individual, multiplied across thousands of participants, the project will deploy artificial intelligence to come up with proposed algorithms for determining who should eat what. But that’s not the end: A series of studies will have to be conducted to validate those algorithms.
Nicastro is eager to learn what factors are driving individual responses. “It could be genetics, it could be microbiome, it could be something about the environment, and or probably a lot of these things mixed together,” she said. The ultimate goal is to enable doctors or dietitians to test for certain factors and then produce a personalized eating plan.
Meanwhile, the first four participants, settled back at home with their lime-green souvenir water bottles, are already finding themselves making changes in their diet. Cashell loved the third diet so much she’s trying to re-create the recipes in her kitchen. Hamdorf noticed that during the experiment he never felt hungry, yet looked forward to each meal — and realized he needed to eat more, and drink more water. Matthiess and Carter are trying to eat less in the evening and include more fruits and nuts.
All were gratified to have been part of the study.
“You don’t have many opportunities to contribute to important scientific research,” Carter said. “And I feel lucky that I am able to do that.
