[3] Two reviews of clinical studies on people recovering from abdominal, colorectal, and gynecological surgery found that coffee consumption was safe and effective for enhancing postoperative gastrointestinal function.
[11] Additional meta-analyses corroborated these findings, showing that higher coffee consumption (2–4 cups per day) was associated with a reduced risk of death by all disease causes.
[20] A large 2024 study,[21] involving close to two hundred thousand participants using the UK Biobank, indicated that a habitual caffeine intake, at moderate levels of 200 mg - 300 mg of caffeine per day "was associated with a lower risk of new-onset CM [Cardiometabolic multimorbidity] and could play important roles in almost all transition phases of CM development."
By contrast, a 2011 review had found that drinking one to three cups of coffee per day may pose a slightly increased risk of developing hypertension.
[22] The 2021 European Society of Cardiology Guidelines on Cardiovascular Disease Prevention in Clinical Practice state: "Non-filtered coffee contains LDL-C-raising cafestol and kahweol, and may be associated with an up to 25% increased risk of atherosclerosis (ASCVD) mortality by consumption of nine or more drinks a day.
[2] In a systematic review and meta-analysis of 28 prospective observational studies, representing over one million participants, every additional cup of caffeinated and decaffeinated coffee consumed in a day was associated, respectively, with a 9% and 6% lower risk of type 2 diabetes.
[2][37][38] Long-term preliminary research, including assessment of symptoms for dementia and cognitive impairment, was inconclusive for coffee having an effect in the elderly, mainly due to the poor quality of the studies.