Measurement of caffeine in beverages: you might take too much without noticing!
The production volume of beverages such as green tea, black tea, and coffee has increased in Japan since 2000 and many people drink them on a daily basis. However, these beverages contain caffeine from ingredients. It is said that the intake of a moderate amount of caffeine stimulates the brain and helps you stay awake, while the intake of an excessive amount of caffeine causes dizziness, increased heart rate, shivers, diarrhea, nausea and other health problems. When a pregnant woman takes too much caffeine, her fetus may become underweight. According to the results of questionnaire survey among mothers with infants, on the other hand, they are scarcely aware that roasted green tea and brown rice tea contain caffeine. Incidentally, some manufacturers sell decaf beverages (e.g. coffee, tea-based beverage, black tea) targeting caffeine-conscious consumers.
In about five years from FY2016 through the end of September 2021, PIO-NET* received 69 caffeine-related inquiries. Some consumers asked about energy drinks containing much caffeine as food additive. Some other consumers said: "It's not good that the caffeine content is not labeled on coffee beverage products."
It is left to manufacturers' discretion whether or not to indicate the caffeine content in beverages. There are quite a few beverage products not indicating the caffeine content on product labels. It appears that consumers might take too much caffeine by drinking beverages unintentionally. Therefore, NCAC has measured the caffeine content in 78 beverage products on the market (32 brands of tea-based beverages, 9 brands of black tea beverages, 28 brands of coffee beverages, and 9 brands of fizzy beverages) to share relevant information with consumers.
- * PIO-NET is a database that collects information on inquiries concerning consumer affairs by linking NCAC with local consumer affairs centers and similar organizations across Japan via an online network.
- All the tea-based beverages except for those claiming to be caffeine free contain caffeine. The caffeine content ranges from 5 to 40 percent of the caffeine content in coffee infusion (60 mg per 100 g) shown in the Standard Tables of Food Composition in Japan 2020.
- The caffeine content in tea-based beverages claiming to be low caffeine is not always less than the caffeine content in other similar beverages.
Black tea beverages
- The caffeine content in black tea beverages ranges from 10 to 30 percent of the caffeine content in coffee infusion shown in the Standard Tables of Food Composition in Japan 2020. Black tea with milk contains more caffeine than straight black tea and fruit flavored black tea.
PET bottled or canned coffee
- Coffee beverages with the product name "coffee" contain more caffeine than those with the product name "coffee beverage" or "liquid coffee", and some of them contain 20-40 percent more caffeine than the caffeine content in coffee infusion shown in the Standard Tables of Food Composition in Japan 2020.
Instant coffee sticks, portion packs, etc.
- The caffeine content in a solution diluted as indicated is less than the caffeine content of coffee infusion shown in the Standard Tables of Food Composition in Japan 2020.
- The caffeine content in fizzy beverages indicating the caffeine content on ingredients labels ranges from 10 to 20 percent of the caffeine content in coffee infusion shown in the Standard Tables of Food Composition in Japan 2020.
Labeling and representation
Indication of the caffeine content
- The caffeine content is labeled on: 10 out of 32 tea-based beverages, 10 out of 28 coffee beverages and 5 out of 9 fizzy beverages. The caffeine content is not labeled on any of the 9 black tea beverages.
- The caffeine content of some beverages is shown on sellers' websites although it is not indicated on product labels.
Indication of low or zero caffeine
- The caffeine content of some of the beverages claiming to be low caffeine is not shown anywhere.
Advice for consumers
- If you have a health problem (e.g. dizziness, increased heart rate, shivers, etc.) after drinking much coffee, tea-based beverage, black tea, fizzy beverage or others containing caffeine, replace those beverages with decaf or low caffeine beverages. Be cautious about caffeine intake.
- The caffeine content may be shown on seller's website in addition to product labels.
Request to businesses
- Properly inform consumers of the caffeine content in beverages so that consumers can easily access the information.