Your morning cups of coffee and tea could be associated with lower risk of stroke and dementia
The cup of coffee or tea you reach for in the morning -- OK, maybe it's a few -- may be associated with a lower risk for stroke and dementia, according to a new study.
Among more than 360,000 participants studied over a period of 10 to 14 years, those who drank 2 to 3 cups of coffee, 3 to 5 cups of tea, or a combination of 4 to 6 cups of coffee or tea a day had the lowest risk of stroke and dementia, according to researchers from Tianjin Medical University in Tianjin, China.
"Our findings suggested that moderate consumption of coffee and tea separately or in combination were associated with lower risk of stroke and dementia," the authors of the study said in a release.
Around the world, 10% of deaths are caused by stroke, according to a 2017 study published in The Lancet. Dementia refers to a general decline in brain function, but it can set in after a stroke.
Drinking coffee or tea alone also was associated with lower risk for both conditions, but people who had 2 to 3 cups of coffee and 2 to 3 cups of tea daily -- 4 to 6 cups total -- faired the best, with a 28% lower risk of dementia and 32% lower risk of stroke than those who didn't drink either, according to the study.
The participants' information came from the UK Biobank, a database of anonymous health information from around half a million volunteers in the United Kingdom gathered between 2006 and 2020. The study looked at health participants between ages 50 and 74 who self-reported their consumption of coffee and tea.
Over the course of the study period, 5,079 participants developed dementia and 10,053 experienced at least one stroke, according to the study, which was published in PLOS Medicine.
There have been many studies suggesting health benefits may be associated with drinking coffee and tea, but it is important to note that the researchers could only say the two were linked -- not that the beverages necessarily offered protection.
There are limitations to the accuracy of the data because the participants reported their own tea and coffee drinking, and their estimates could be influenced by their own bias, Dr. Lee H. Schwamm, chair of the American Stroke Association Advisory Committee and chair in Vascular Neurology at Massachusetts General Hospital, said via email.
"We cannot impute causality, and say 'drinking more coffee or tea is good for your brain.' What we can only say is that in this study, people who reported moderate coffee/tea drinking were less likely to have a stroke or dementia occur in the 10 years of follow-up," Schwamm said.
Is it time to start drinking coffee?
Past research has suggested that coffee may be beneficial to brain health.
Another 2021 study that utilized the UK Biobank showed that for people with no diagnosis of heart disease, regular coffee consumption of 0.5 to 3 cups of coffee a day was associated with a decreased risk of death from heart disease, stroke and early death from any cause when compared to non-coffee drinkers.
Several studies have also shown that three cups of coffee a day can decrease the risk for Alzheimer's Disease.
Caffeinated coffee can help the brain in several ways by increases production of granulocyte-colony stimulating factor, according to the UK Alzheimer's Society. Called G-CSF, it helps protect and repair neural brain cells.
Neither decaffeinated coffee nor caffeine alone was shown to help in this way, "suggesting that there could be a combination effect between caffeine and an unknown compound in coffee," the society said.
More is not always better when it comes to coffee. People drinking more than 6 cups a day were at an increased risk of dementia and smaller total brain volumes, according to a study published in June in the journal Nutritional Neuroscience.
The results of the most recent study may point to some benefits of drinking coffee and tea, but that doesn't necessarily mean that everyone should start to brew more cups across the day.
"A word of caution, one man's cappuccino is another man's expresso," Schwamm said. "Not all coffee beverages have the same amount of caffeine, and people estimate a cup's worth of coffee or tea differently, so we should keep in mind that most things are best consumed in moderation."
If you avoided caffeinated beverages in the past, there may have been a good reason, and there isn't evidence yet that there is a benefit to starting a coffee or tea habit, he added. For most things, moderation is the best approach, Schwamm said.
"Enjoy your morning cup of coffee, and don't swear off additional cups if you enjoy them," he concluded.
早上喝咖啡和茶可能会降低中风和痴呆症的风险
一项新的研究表明，你早上伸手去拿的一杯咖啡或茶——好吧，也许是几杯——可能与中风和痴呆症的风险降低有关。
在为期 10 至 14 年的研究期间，超过 360,000 名参与者中，那些每天喝 2 至 3 杯咖啡、3 至 5 杯茶或 4 至 6 杯咖啡或茶的人的风险最低据中国天津市天津医科大学的研究人员称，中风和痴呆症。
“我们的研究结果表明，分别或同时适量饮用咖啡和茶与中风和痴呆症的风险较低有关，”该研究的作者在一份新闻稿中说。
根据 2017 年发表在《柳叶刀》上的一项研究，在世界范围内，10% 的死亡是由中风引起的。痴呆症是指大脑功能普遍下降，但它可以在中风后出现。
单独喝咖啡或茶也与这两种情况的风险较低有关，但每天喝 2 到 3 杯咖啡和 2 到 3 杯茶的人——总共 4 到 6 杯——表现最好，有 28%根据这项研究，与不喝酒的人相比，他们患痴呆症的风险更低，中风的风险也降低了 32%。
参与者的信息来自英国生物银行，这是一个匿名健康信息数据库，该数据库收集了 2006 年至 2020 年英国约 50 万志愿者的匿名健康信息。该研究调查了 50 至 74 岁的健康参与者，他们自我报告了咖啡和茶。
根据发表在 PLOS Medicine 上的研究，在研究期间，5,079 名参与者患上了痴呆症，10,053 人至少经历了一次中风。
有许多研究表明，喝咖啡和茶可能对健康有益，但重要的是要注意，研究人员只能说两者是相关的——并不是说这些饮料一定能提供保护。
美国中风协会咨询委员会主席兼血管学主席 Lee H. Schwamm 博士说，数据的准确性存在局限性，因为参与者报告了他们自己喝过的茶和咖啡，而且他们的估计可能会受到他们自己的偏见的影响马萨诸塞州总医院的神经病学通过电子邮件说。
“我们不能归因于因果关系，并说'多喝咖啡或茶对你的大脑有益。'我们只能说，在这项研究中，报告适度饮用咖啡/茶的人在 10 年的随访中不太可能发生中风或痴呆症，”施瓦姆说。
是时候开始喝咖啡了吗？
过去的研究表明，咖啡可能有益于大脑健康。
2021 年的另一项利用英国生物银行的研究表明，对于没有被诊断出心脏病的人，每天定期喝 0.5 至 3 杯咖啡可以降低因心脏病、中风和全因过早死亡的风险与不喝咖啡的人相比。
多项研究还表明，每天喝三杯咖啡可以降低患阿尔茨海默病的风险。
根据英国阿尔茨海默氏症协会的说法，含咖啡因的咖啡可以通过增加粒细胞集落刺激因子的产生来以多种方式帮助大脑。称为 G-CSF，它有助于保护和修复神经脑细胞。
该协会表示，无论是脱咖啡因咖啡还是单独的咖啡因都没有显示出以这种方式提供帮助，“这表明咖啡因和咖啡中的未知化合物之间可能存在组合效应”。
说到咖啡，更多并不总是更好。根据 6 月份发表在营养神经科学杂志上的一项研究，每天喝超过 6 杯水的人患痴呆症的风险增加，总脑容量更小。
最近的研究结果可能指出喝咖啡和茶的一些好处，但这并不一定意味着每个人都应该在一天中开始冲泡更多的杯子。
“请注意，一个人的卡布奇诺是另一个人的浓缩咖啡，”施瓦姆说。 “并非所有的咖啡饮料都含有相同量的咖啡因，人们对一杯咖啡或茶的估计价值也不同，所以我们应该记住，大多数东西最好适量饮用。”
他补充说，如果你过去避免喝含咖啡因的饮料，这可能是有充分理由的，而且目前还没有证据表明养成喝咖啡或喝茶的习惯有好处。施瓦姆说，在大多数情况下，适度是最好的方法。
“享受你早上的咖啡，如果你喜欢的话，不要发誓再喝一杯，”他总结道。
