茶是继水之后世界上最受欢迎的饮料；红茶占消费量的三分之二以上，而在宣称更健康的背景下，全球绿茶销量近年稳步上升。证据之一是《Molecules》在2019年的一项对3,349名50岁及以上人群的分析：在对吸烟、咖啡及其他因素进行调整后，喝绿茶者在“成功老龄化”指数上的得分高于喝红茶者。

一项2016年的研究发现，绿茶每杯的L-茶氨酸含量比红茶高近28%，且益处会随每日剂量增加而上升，至少可达约200mg（约八杯）。在《Nutrients》（2019年）中，30名日本成年人每日服用200mg持续四周，然后再服用安慰剂四周，睡眠和焦虑/抑郁显著改善，且言语流利度与认知功能更好；在《Journal of Medicinal Food》（2021年）中，26名50至69岁的日本志愿者服用仅一半剂量后，单次服用就在记忆和反应速度测试中优于安慰剂。

绿茶所含抗氧化物大约比红茶多五分之一，而《International Journal of Molecular Sciences》在2020年的论文将一种绿茶抗氧化物与降低炎症及清除受损细胞联系起来，可能降低心血管以及呼吸与消化系统癌症风险。红茶仍富含茶黄素和茶红素，它们可降低胆固醇吸收并对抗氧化与炎症损伤，因此证据的整体指向是两者优势重叠但各有侧重。

Tea is the world’s most popular drink after water, with black tea making up over two-thirds of consumption. However, green tea sales have been increasing due to perceived health benefits. A 2019 analysis highlighted that older adults who drink green tea score higher on a successful aging index compared to those who prefer black tea. Additionally, a 2016 study showed that green tea contains nearly 28% more L-theanine per cup, with benefits increasing with daily intake up to about 200mg.

In a 2019 study from Nutrients, 30 Japanese adults taking 200mg of L-theanine daily for four weeks experienced significant improvements in sleep, anxiety, depression, verbal fluency, and cognitive function. Additionally, a 2021 Journal of Medicinal Food study found that 26 volunteers aged 50–69 taking a lower L-theanine dose performed better in memory and reaction-speed tests than those on a placebo.

Green tea has about 20% more antioxidants than black tea, which are linked to reduced inflammation and lower cancer risks. Meanwhile, black tea is richer in theaflavins and thearubigins, offering its own health benefits.

Source: Is a matcha latte better for you than a builder’s brew?

Subtitle: We spill the tea

Dateline: 2月 05, 2026 04:18 上午