帮人也是护脑：三万多人队列显示常助人者认知衰退少15%–20%
The Best Thing You Can Do for Your Brain This Week Might Actually Help Someone Else
想让大脑老得慢一点，研究者给出的建议之一是去帮别人。一项发表在《Social Science & Medicine》的研究分析了美国健康与退休研究（HRS）中三万多名成年人长达 20 年的数据，发现经常做志愿服务、或日常帮邻居亲友搭把手的人，与年龄相关的认知衰退比不常助人的人少 15% 到 20%；其中每周助人约 2 到 4 小时的人获益最明显。研究负责人、得克萨斯大学奥斯汀分校的 Sae Hwang Han 认为，助人同时调动身体与大脑，带来社交连接、目标感和认知刺激，可能还帮助降低压力与炎症；面对面的帮助可能效果更强，但远程志愿服务同样有价值，不必非得报名正式项目——帮邻居浇花、取快递、给术后朋友做顿饭都算。需要说明证据等级：这是观察性队列研究，显示的是统计关联而非因果证明——也可能是认知状态更好的人本来就更愿意、也更有能力助人；「少 15%–20%」是群体平均差异，不是对个人的效果保证，更不能理解为助人可以预防或治疗痴呆。把它当作一条低成本、可持续的生活方式线索即可。
- A study of 30,000 adults found that those who volunteered or offered informal help regularly had 15 to 20 percent less age-related cognitive decline.
- People who spent around two to four hours a week helping others saw the biggest benefit.
- Experts say helping in person may be the most potent, as doing so strengthens the social and psychological rewards that help promote cognitive health.
Living a long, physically healthy life isn’t enough—you want to be mentally sharp along the way, too. There are many everyday habits that can improve your brain health, but there's one that benefits you as well as those around you: helping others.
Both volunteering and offering informal help to neighbors and friends may slow down cognitive aging, which can impact your ability to think, learn, remember, and make decisions, suggests one study published in the journal Social Science & Medicine.
Here’s what the researchers found, plus how to put this knowledge to work for your gray matter.
Meet the experts: Sae Hwang Han, PhD, is the lead study author and associate professor in the Department of Human Development and Family Sciences at The University of Texas at Austin. Faye Begeti, PhD, is a neuroscientist at Oxford University Hospitals.
What did the study find?
For the study, researchers analyzed data from more than 30,000 U.S. adults over 20 years using data from the Health and Retirement Study.
The researchers discovered that people who volunteered their time or regularly offered less formal help to neighbors, relatives, or friends had 15 percent to 20 percent less cognitive decline linked with aging than those who didn’t help others.
When they dove a little deeper into the data, they discovered that people who spent around two to four hours a week giving back saw the biggest benefit.
Why might volunteering be linked with slower cognitive decline?
There are likely a few things going on here. “Volunteering and helping others engage both the brain and body in ways that protect against cognitive aging,” says Sae Hwang Han, PhD, lead study author and associate professor in the Department of Human Development and Family Sciences at The University of Texas at Austin. “These activities provide social connection, a sense of purpose, and often an environment that can be cognitively stimulating—all of which are linked to better cognitive health.”
Mental stimulation is paramount, says Faye Begeti, PhD, a neuroscientist at Oxford University Hospitals. “The key factor to prevent cognitive decline is to continue challenging our brains throughout life,” she says. “I often see people who slow down after retirement, and I always encourage them to stay cognitively active. Volunteering is a wonderful way to do that.”
Helping others may even reduce stress and inflammation, two factors that are linked with cognitive decline, Han adds.
What kind of volunteering is best?
In-person seems to be the ideal way to go, Han says. Think: offering a hand at a soup kitchen or reading to kids. “Face-to-face engagement likely strengthens the social psychological rewards that help promote cognitive health,” he says. “That said, remote or virtual volunteering could still offer benefits if it’s cognitively stimulating or provides a meaningful human connection.”
And don't forget, you don't necessarily have to sign up for a formal volunteer opportunity—the study found that offering informal help to others was just as effective. So, why not agree to water a neighbor's plants or pick up their mail while they're out of town? Or if cooking is more your thing, making a lasagna for a friend recovering from a surgery could be your way of showing love and support. (And, while not scientifically proven, we'd imagine you'd get bonus brain points for dining together, too!)
Ultimately, Han recommends doing what you can. “Even modest levels of helping—about two to four hours a week—can make a real difference for long-term cognitive health,” he says. And really, any amount of helping is better than none, according to research. "There’s just robust evidence that around two to four hours a week is the sweet spot where the benefits become most pronounced," Han says.
At the end of the day, a small time investment has potentially large returns, especially compared to how much time many of us spend in front of screens each day, Han says. "The key message is that meaningful engagement with others isn’t just good for the community—it’s good for your brain.”
来源：颜如玉编辑台 · womenshealthmag.com