Harvard study shows filter coffee offers greatest health benefits

Researchers from the Harvard School of Medicine examined more than 500,000 coffee drinkers aged 20 to 79 over a 20‑year period. Their analysis concluded that coffee prepared with a paper filter provides the strongest health advantages, because the filter removes compounds such as cafestol and kahweol that can raise cholesterol. The study also found that drinking up to five cups of filter coffee daily is safe and may be linked to a longer lifespan, with antioxidants, magnesium, potassium and vitamin B3 largely retained.

A separate analysis of the UK Biobank data reported that consuming five or more cups of coffee each day was associated with a 32 % lower risk of severe liver disease, a 47 % reduction in liver‑cancer risk and a 42 % lower risk of death from liver‑related causes. Benefits were observed for coffee overall, but the strongest protective effect was seen with filtered coffee. The researchers cautioned that added sugar or high‑fat additives can diminish the positive impact.

Overall, the findings suggest that moderate intake of filtered coffee can support liver health, cardiovascular markers and overall longevity, while unfiltered methods such as French press or espresso may increase cholesterol‑raising substances.