What is caffeine? How much a day is normal? What does coffee have to do with caffeine?

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Caffeine plays an important role in the busy life of modern people. many people wake up with a cup of coffee in the morning. when their blood sugar rises after lunch and their heads feel dizzy, many people want to have another cup of caffeine to refresh themselves. at this time, coffee, tea, carbonated drinks or energy drinks are common choices for Chinese people. Do you know how much caffeine you eat at the end of the day? What is the maximum amount of caffeine that can be consumed every day in order not to cause health hazards? is there a reference criterion?

How much do you know about caffeine?

Caffeine belongs to purine alkaloids. At present, more than 60 kinds of plants are known to contain caffeine, such as coffee beans, tea, cocoa beans, Kola nut (once one of the raw materials for cola beverage extraction), Madai leaves, Guarana and so on. These edible natural raw materials themselves or their extracts are often used in beverage production. The use of caffeine compounds in the food industry is regarded as a flavoring agent in food additives and must comply with the norms for the use of food additives. at present, caffeine compounds can only be added to seasoned drinks in Taiwan. Caffeine intake will stimulate the human central nervous system, cardiovascular, respiratory system, gastrointestinal, muscle and so on, but also increase the speed of cell metabolism, diuresis and so on. For ordinary people, its action time can be up to 3-4 hours.

The "advantages" and "disadvantages" of caffeine on the health of ordinary people have been widely discussed in different literatures, including boosting spirit, increasing alertness, concentration and responsiveness, reducing cardiovascular and neurodegenerative diseases, and even longevity; "disadvantages" include palpitations, sleep disorders, anxiety, irritability, bone health and gastrointestinal function, and may affect fetal health in pregnant women. However, due to the different strength of the literature evidence, professionals are needed to evaluate the validity of these conclusions and their applicability to individuals. The health risk assessment information section of the Food and Drug Consumer knowledge Service Network of the Ministry of Health and Welfare also has a special chapter on caffeine.

The most talked about caffeine research report in the world is the review of caffeine safety assessment written by Nawrot et al in 2003 and peer-reviewed (peer-review), which is the most widely cited internationally and is also used by Health Canada as the basis for recommendations for maximum caffeine intake. Although more than 10,000 caffeine-related papers have been published in the more than 10 years since its publication, there has been no comment on caffeine since it was published.

In view of this, ILSI North America decided to update the classic literature and invited 15 experts, including epidemiology, clinical medicine and systematic review, to conduct a systematic review (systematic review) of the potential adverse effects of caffeine published from 2001 to June 2015. The subjects were adults, pregnant women, adolescents and children. The results of acute toxicity, cardiovascular toxicity, effects of bone and calcium, behavior, development and reproduction were compared with the current version of non-adverse effect caffeine intake of Health Canada.

When clarifying and evaluating causality, scientific research pays great attention to the classification of the strength of scientific evidence. If the conclusions of scientific research only come from expert opinions (not supported by empirical data), the intensity of such scientific evidence is the weakest; the credibility of integrated analysis, systematic review and randomized controlled trials located in the upper half of the pyramid is higher because they can provide high intensity of scientific evidence, but the resources required for such research, such as funds, manpower and time, are also relatively high.

ILSI verifies caffeine security code

The rigorous caffeine systematic Review of ILSI North America, published in the Journal of Food and Chemical Toxicology (Food and Chemical Toxicolog) in April 2017, reaffirmed the benchmark conclusion established by Nawrot et al in 2003 that there was no adverse effect or no change in acceptable caffeine intake, 400mg / day for adults (lethal dose of 10g) It is 300mg / day for pregnant women (including those preparing for pregnancy) and 2.5mg / kg / day for 12-year-old 19-year-old and 3-year-old 12-year-old children. These data are simplified to 400mg / kg / day for adults)-300mg / day for pregnant women (pregnant women)-2.5mg / day for teenagers and children (BW is the abbreviation for Body Weight) because they are not yet fully developed and their weight varies greatly. This 400-300-2.5 BW is the security password for caffeine. However, when interpreting this data, people should note that this series of figures are only used as a reference value for ordinary people. Because there are too many variables among individuals, no data can be fully applied to the safe dose of the whole population. Practical application should be considered according to their own conditions, and this data should not be regarded as the upper limit of caffeine intake or iron law.

The report's conclusions on the recommended daily intake of 400mg caffeine for healthy adults are consistent with the US dietary guidelines for 2015-2020 to drink 3-5 cups of coffee per day (240ml per cup), the caffeine intake limit of 400mg per day, and the EU Food Safety Agency (EFSA) recommendation of 400mg per day in 2015. Taiwan's current recommendation for caffeine intake is that it is best not to exceed 300 mg a day.