Most startups have free coffee as a perk because its a well-known productivity booster, but its lesser-known positive effect on employee health may be even more important. This is especially true when health concerns are of primary concern for employers and employees alike, as they obviously are today.

According to research published in JAMA Internal Medicine and summarized in Popular Science magazine, on average coffee drinkers have fewer illnesses than non-coffee drinkers, reducing absenteeism and presenteeism. Specifically, drinking coffee:

  • Reduces risk of cancer by 20 percent.
  • Reduces risk of Type 2 diabetes by 20 percent.
  • Reduces risk of Parkinson's disease by 30 percent.
  • Reduces risk of heart disease by 5 percent.

How can coffee have so many positive effects? Simple. It increases the efficiency of your metabolism. According to a 2018 study conducted by the Finnish National Institute for Health and Welfare and published in the prestigious Journal of Internal Medicine:

"coffee contains many bioactive compounds, any of which may impact pathways related to disease development... A total of 115 metabolites (i.e. substances that affect your metabolism ed.) were significantly associated with coffee intake. We observed a significant enrichment of metabolite members of five which coffee may be exerting its health effects."

Increasing the efficiency of your metabolism increases your general immunity to disease, according to research presented at the Keystone Symposia of Molecular and Cellular Biology at Dublin in 2017. This is why coffee reduces the risk of contracting so many different types of diseases.

However--and this is really important so listen up--you only get the immunological value of coffee if you drink it:

  1. Without whole milk, cream, sugar, or chemical additives. The extra sugar and fat counteracts the beneficial effects of coffee's bioactive compounds.
  2. In quantities less than six to eight cups a day. Drinking too much coffee can create stress (aka the "jitters") and insomnia, both which lower your immunity.

There's also one special case: pregnant women should not drink coffee because it might affect fetal development. That's not an immunological issue; it's just important to know.

Takeaway: According to the latest scientific research, drinking a moderate amount of black coffee each day can significantly increase your immunity to disease. Because of this, companies are well-advised to offer free coffee as an in-office perk.

The Extra Mile: If your employees are working from home, consider sending them some coffee to brew at home, or maybe a gift card to a local coffee shop. This "remote perk" is a great way to keep your team healthy and remind them that you appreciate their contributions.