Which is it? Well, coffee, a morning staple in the UK, but they've only recommended a certain amount.
Whether it's a flat white on the way to work or a strong morning espresso at home, coffee has become a daily ritual for millions.
Loved for its rich flavour and reliable caffeine kick, it's the go-to beverage to kickstart most of our days.
But what if your morning cup could be doing more than just waking you up?
Bean Signal has now highlighted a major new Harvard study which suggests that coffee may help support healthier ageing.
What are the pros? It could potentially be boosting your chances of reaching later life in better physical and mental shape.
According to the research, women who regularly consumed caffeinated coffee were up to 30% more likely to reach age 70 in what researchers defined as "exceptional health" - avoiding major chronic illnesses, staying mentally sharp, and maintaining physical function.
The findings come from the Nurses' Health Study, one of the world's largest and longest-running health research projects, which followed 47,513 women over more than 30 years.
Participants' caffeine intake was assessed from 1984 to 2002, and their health outcomes were tracked until 2016.
The most striking results were found in women who consumed around 315mg of caffeine per day - this is roughly two to three cups of regular coffee.
This group had the highest chance of achieving what the study classifies as "healthy aging", a measure that excluded participants with 11 major chronic diseases and required high levels of both mental and physical wellbeing.
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This study adds to a growing body of evidence which suggests that coffee may offer protective health benefits that extend well beyond short-term alertness. Moderate, consistent intake of brewed coffee could play a small but meaningful role in promoting better aging.
The study's lead researchers recommend two to three cups of black coffee per day as a safe and potentially beneficial level for most people, though they caution that individuals with caffeine sensitivity or certain medical conditions should consult their doctor.