Drink 3 to 4 cups of coffee a day, keep total caffeine under 400 mg, and don't add sugar or milk foam

Cost

About 1 to 2 CNY a day if you make it yourself. Making a cup takes a few minutes and costs you almost no time. If you buy large cups, keep track of how many milligrams of caffeine you have had in a day.

What you get

A review pooled the results of 201 meta-analyses again; the original studies under those meta-analyses were all observational, only recording and not assigning groups. For total mortality, the review cited one of them, a meta-analysis of the dose-response relationship. People who drank 3–4 cups of coffee a day had 17% lower risk of death than people who didn't drink it (relative risk 0.83, 95% CI 0.79–0.88, the plausible range). At 7 cups a day the reduction narrowed to 10% (relative risk 0.90, 95% CI 0.85–0.96), and no rebound in risk was seen. A study in the U.S. National Health and Nutrition Examination Survey (NHANES) followed 40,725 adults, half of them for 9.8 years, and also only recorded without assigning groups. The study split coffee drinkers into two types. The morning type drank their coffee between 4:00 and 11:59 a.m. and almost none in the afternoon or evening; they were 36% of the drinkers. Compared with people who didn't drink coffee, their risk of death from any cause was 12% lower (hazard ratio 0.88, 95% CI 0.81–0.96). After also adjusting for short sleep and trouble sleeping, it was 16% lower (hazard ratio 0.84, 95% CI 0.74–0.95). Their risk of death from cardiovascular disease was 19% lower (hazard ratio 0.81, 95% CI 0.70–0.94), and 31% lower after adjusting for sleep (hazard ratio 0.69, 95% CI 0.55–0.87). The all-day type drank coffee in the morning, afternoon and evening, and made up 16%. Their risk of death from any cause showed no difference (hazard ratio 0.99, 95% CI 0.90–1.10). Neither type showed a difference in risk of death from cancer. The daily caffeine limit has an official basis. The European Food Safety Authority (EFSA) and Health Canada both set the limit for healthy adults at 400 mg a day. That is the total from all sources; tea, cola and energy drinks count too. EFSA also asks that it be spread through the day, with no more than 200 mg at a time. The amount in a cup of coffee varies a lot. In EFSA's table, a 200 mL cup of filter coffee has about 90 mg. In Health Canada's table, an 8-ounce (237 mL) cup of brewed coffee averages 135 mg. In the U.S. Food and Drug Administration (FDA) table, 12 ounces (about 355 mL) of brewed coffee has 113–247 mg. So the FDA converts 400 mg to about 2 to 3 cups of 12-ounce coffee, and the review converts it to about 4 cups.

Notes

The dispute: the review's authors state that most of the evidence comes from studies that only follow and record, and that reliable randomized controlled trials are needed to tell whether the link is causal. Drinking it in the morning being better rests on a single U.S. study, so it is not in the title. Its authors state that the result cannot be read as causal; people who drink coffee in the morning may simply live healthier lives overall. In another U.S. study that included only people with diabetes, people who drank coffee from dawn to morning had 25% higher risk of death and people who drank it from morning to noon had 20% lower, the opposite result. None of these studies compared noon (12:00) with 2 p.m. (14:00). §3.4 (no caffeine after 2 p.m.) is about sleep, and you count back from your own bedtime, so it doesn't conflict with this item. 400 mg is a safe upper limit, not a beneficial dose. Decaffeinated coffee has similar benefits, only slightly smaller, so there is no need to drink more to reach an amount. Pregnant women should have no more than 200 mg a day (EFSA) or 300 mg (Health Canada). Women at high risk of fractures should not follow this item. Neither should people with anxiety or insomnia; that is this book's judgment, and the review has no conclusions for these two groups. People with atrial fibrillation do not all have to give up coffee. In one trial, people with persistent atrial fibrillation who drank about 1 cup of coffee a day after electrical cardioversion had fewer recurrences than those who gave it up (47% versus 64%). The 2023 U.S. atrial fibrillation guideline also does not recommend giving up coffee to prevent episodes, but people who get symptoms from drinking it should cut back. For other arrhythmias there is no evidence; listen to your doctor. For death rate, no cancelling-out of the benefit by added sugar was seen. But syrup and milk-foam drinks haven't been studied and contain a lot of sugar, so we still recommend leaving them out.

Evidence grade

A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.

Sources

1. Poole R, Kennedy OJ, Roderick P, et al. (2017). Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ, 359, j5024. https://doi.org/10.1136/bmj.j5024，含更正 BMJ (2018), 360, k194. https://doi.org/10.1136/bmj.k194（摘要里总死亡率的可信范围由 0.83–0.88 改为 0.79–0.88）
2. Wang X, Ma H, Sun Q, et al. (2025). Coffee drinking timing and mortality in US adults. European Heart Journal, 46(8), 749-759. https://doi.org/10.1093/eurheartj/ehae871
3. Yang R, Lei Q, Liu Z, et al. (2024). Relationship between timing of coffee and tea consumption with mortality (total, cardiovascular disease and diabetes) in people with diabetes: the U.S. National Health and Nutrition Examination Survey, 2003–2014. BMC Medicine, 22, 526. https://doi.org/10.1186/s12916-024-03736-x
4. EFSA Panel on Dietetic Products, Nutrition and Allergies (2015). Scientific Opinion on the safety of caffeine. EFSA Journal, 13(5), 4102. https://doi.org/10.2903/j.efsa.2015.4102
5. EFSA 咖啡因专题页（每份含量表）https://www.efsa.europa.eu/en/topics/topic/caffeine
6. FDA. Spilling the Beans: How Much Caffeine Is Too Much? https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much
7. Health Canada. Caffeine in foods. https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/caffeine-foods.html
8. 加糖：Liu D, Li ZH, Shen D, et al. (2022). Association of Sugar-Sweetened, Artificially Sweetened, and Unsweetened Coffee Consumption With All-Cause and Cause-Specific Mortality. Annals of Internal Medicine, 175(7), 909-917. https://doi.org/10.7326/M21-2977
9. Treskes RW, Clausen J, Marott JL, et al. (2023). Use of sugar in coffee and tea and long-term risk of mortality in older adult Danish men. PLOS ONE, 18(10), e0292882. https://doi.org/10.1371/journal.pone.0292882
10. 房颤：Wong CX, Cheung CC, Montenegro G, et al. (2026). Caffeinated Coffee Consumption or Abstinence to Reduce Atrial Fibrillation. JAMA, 335(4), 317-325. https://doi.org/10.1001/jama.2025.21056
11. Joglar JA, Chung MK, Armbruster AL, et al. (2024). 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation. Circulation, 149(1). https://doi.org/10.1161/CIR.0000000000001193

Translated from the Chinese original. Original book, section 2, tip 26. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer