The odds for depression rise sharply after 300mg of caffeine. Let’s look at how that safe upper limit translates to in daily metric cups for different beverages (“cups” refers the measuring cups used in baking).
||Max metric cups/day
|Latte or mocha
|Brewed black tea
|Brewed green tea
(calculations based on caffeine contents gathered by the Mayo Clinic)
Drinking any caffeine after 2pm can worsen mood by disrupting sleep, but the brain benefits of tea hold up even with decaffeinated options.
Other Health Benefits
This data comes from associational studies, which means that cause and effect cannot be concluded despite the large number of people studied. Research from animal studies suggest the brain benefits described here may be real, and we know that coffee and tea have physical health benefits as well. Both lower the risks of diabetes, dementia, cancer, liver problems, and cardiovascular disease.
Sweeteners, whether in the form of sugar, honey, or artificial sugars, can reverse those health benefits. Xylitol, a plant-based sweetener, appears to be one of the healthier options.
When it comes to physical health, coffee may also be a two-edged sword, while tea is a safer route. The higher caffeine content of coffee can worsen some heart conditions, and eve decaffeinated coffee contains acids that can worsen heartburn. In contrast, “There doesn’t seem to be a downside to tea,” concluded the American Dietetic Association spokeswoman Katherine Tallmadge, MA, RD, LD.