Caffeine overconsumption alert: CASE warns against mixing drinks for faster effects

Mixing coffee with energy drinks to stay awake for examinations or assignment?

While that may give an extra kick, youngsters may end up exceeding the recommended limit of 100mg of caffeine per day, the Consumer Association of Singapore (CASE) warned after it ran tests on six mixed drink combinations.

In a media release on Tuesday (Sept 22), the consumer watchdog said it conducted tests to provide consumers with objective information on caffeine levels in commonly mixed caffeinated drink combinations.

The move comes after media reported in 2024 that some youths have taken to mixing caffeinated drinks , including energy drinks and coffee, to stay alert or achieve a stronger caffeine effect.

Meanwhile, the British Government in July announced that it will ban the sale of high-caffeine energy drinks — containing over 150mg of caffeine per litre — to those under 16 from April next year, subject to parliamentary approval.

While there is currently no internationally recognised health-based guidance on daily caffeine intake, the Health Promotion Board (HPB) advises healthy adults to consume caffeine in moderation, with a general guide of 400mg per day.

The American Academy of Pediatrics also recommends caffeine intake of no more than 100mg daily for youths aged 12 to 18 years old.

How CASE ran the tests

CASE said the combinations tested were prepared using common caffeinated beverages such as matcha, energy beverages, and espresso, under standardised reconstitution ratios to ensure consistency.

Samples were extracted using boiling water, after which a portion of the extract was injected into a high-performance liquid chromatography system equipped with an ultraviolet-visible detector.

Caffeine content was then quantified against standards of known concentration, before each mixed beverage was analysed to determine its caffeine concentration (mg/100g) and total caffeine content per serving.

All six combinations tested exceeded the recommended daily caffeine amount of 100mg for persons below 18 years old, CASE said.

Four combinations, each with a single energy beverage, were found to contain between 100.45mg and 106.4mg of caffeine per 350g serving.

Of the two remaining combinations, one was found to contain 282.1mg of caffeine per 350g serving, or nearly three times the recommended maximum daily caffeine amount for persons below 18.

Following its findings, CASE advised youths and their parents to be mindful of total caffeine intake, adding that prioritising quality sleep, balanced meals and adequate hydration can support concentration and performance.

It also advised individuals to watch for symptoms of excessive caffeine intake such as headaches, rapid heart rate, anxiety, tremors and insomnia.

Those who exhibit such symptoms should reduce their caffeine intake and seek medical advice if symptoms persist, CASE said.

CASE president Melvin Yong, who is also MP for Radin Mas SMC, noted that the tests have shown how easily youths can exceed 100mg of caffeine per day when they mix caffeinated drinks.

He added that with the examination period approaching, some may turn to caffeinated drinks to stay alert, but they should be careful not to overconsume caffeine or mix multiple caffeinated products.

"Excessive caffeine intake can affect sleep and well-being, which in turn may affect concentration and school performance.

"We urge youths and parents to be mindful of total caffeine intake and to avoid mixing multiple sources of caffeine in a single drink," Yong said.

为了考试或作业保持清醒，会把咖啡和能量饮料混在一起喝吗？

新加坡消费者协会 (CASE) 在对六种混合饮料进行测试后警告说，虽然这可能会带来额外的提神效果，但年轻人最终可能会超过每天 100 毫克咖啡因的推荐摄入量。

周二（9 月 22 日），消费者权益保护机构在一份媒体声明中表示，他们进行了测试，旨在为消费者提供有关常见含咖啡因饮料组合中咖啡因含量的客观信息。

此前有媒体在 2024 年报道称，一些年轻人为了保持清醒或获得更强的咖啡因效果，开始将含咖啡因的饮料（包括能量饮料和咖啡）混合饮用。

与此同时，英国政府在 7 月份宣布，从明年 4 月起，将禁止向 16 岁以下的人出售每升咖啡因含量超过 150 毫克的高咖啡因能量饮料，但需经议会批准。

虽然目前国际上还没有关于每日咖啡因摄入量的健康指导意见，但新加坡健康促进局 (HPB) 建议健康成年人适量摄入咖啡因，一般指导原则是每天 400 毫克。

美国儿科学会也建议 12 至 18 岁青少年每日咖啡因摄入量不超过 100 毫克。

CASE如何运行测试

CASE表示，测试的组合是使用常见的含咖啡因饮料（如抹茶、能量饮料和浓缩咖啡）按照标准化的还原比例制备的，以确保一致性。

使用沸水提取样品，然后将部分提取物注入配备紫外可见检测器的高效液相色谱系统中。

然后，根据已知浓度的标准对咖啡因含量进行定量，再对每种混合饮料进行分析，以确定其咖啡因浓度（mg/100g）和每份的总咖啡因含量。

CASE表示，测试的所有六种组合的咖啡因含量均超过了18岁以下人群每日推荐摄入量100毫克。

经研究发现，四种组合（每种组合都包含一种能量饮料）每 350 克含有 100.45 毫克至 106.4 毫克的咖啡因。

在剩下的两种组合中，发现其中一种每 350 克含有 282.1 毫克咖啡因，几乎是 18 岁以下人群每日推荐最大咖啡因摄入量的三倍。

根据调查结果，CASE建议青少年及其家长注意咖啡因的总摄入量，并补充说，重视优质睡眠、均衡饮食和充足水分有助于提高注意力和表现。

它还建议人们注意过量摄入咖啡因的症状，例如头痛、心跳加速、焦虑、颤抖和失眠。

CASE表示，出现此类症状的人应减少咖啡因摄入量，如果症状持续，应寻求医疗建议。

CASE主席、同时也是拉丁马士单选区国会议员的杨明文指出，测试表明，青少年在混合饮用含咖啡因的饮料时，很容易每天摄入超过100毫克的咖啡因。

他还补充说，随着考试临近，有些人可能会喝含咖啡因的饮料来保持清醒，但他们应该注意不要过量摄入咖啡因或混合多种含咖啡因的产品。

“摄入过量咖啡因会影响睡眠和身心健康，进而影响注意力集中和学习成绩。”

“我们敦促青少年和家长注意咖啡因的总摄入量，避免在一杯饮料中混合多种咖啡因来源，”Yong说道。