Love it or loathe it, caffeine pops up all over the place; some swear by it and others don’t touch caffeine if they can help it. This review paper looks at studies on caffeine – you’ll see a summary of the findings and a link to the full paper.
Summary of findings on caffeine

1. Coffee is a complex mixture of chemicals , some of which are healthful and some of which interfere with nutrient absorption
2. Unfiltered coffee is a significant source of cafestol and kahweol which have been implicated in the cholesterol-raising effects of coffee. (Does this matter? See cholesterol in the glossary.)
3. Coffee consumption may help prevent several chronic diseases, including type 2 DM, Parkinson’s disease and liver disease.
4. Most studies have not found that coffee consumption is associated with significantly increased risk of CHD or stroke.
5. BUT some trials have found coffee consumption is associated with increases in several cardiovascular disease risk factors, including blood pressure and plasma tHcy.
6. At present, there is little evidence that coffee consumption increases the risk of cancer.
7. Up to three cups a day (300 mg/d of caffeine) in older adults who consume enough calcium, mineral density and hip fracture does not seem to increase in older adults but may do if more is drunk.
8. Data on the effects of caffeine during pregnancy are conflicting, but they raise concern regarding the potential for high intakes of coffee or caffeine to increase the risk of spontaneous abortion and impair fetal growth. (This means, it’s best to avoid, or keep to a minumum, caffeine consumption when preganant.)
9. Serious adverse effects from caffeine at the levels consumed from coffee are uncommon, but there is a potential for adverse interactions with a number of medications.
10. Regular consumers of coffee and other caffeinated beverages may experience withdrawal symptoms, particularly if caffeine cessation is abrupt.
Overall, there is little evidence of health risks and some evidence of health benefits for adults consuming moderate amounts of coffee (3–4 cups/d providing 300–400 mg/d of caffeine), but more research is needed to determine whether long-term caffeine consumption has adverse effects on the health of children and adolescents.