|Old macchinetta. Source: Rafiq Sarlie|
But...why coffee? The researchers then looked at the effects of coffee extracts on prostate cancer cells in the lab. Caffeinated extracts were able to reduce the ability of prostate cancer cells to grow, divide and spread, while decaffeinated extracts could not. This is most likely caused by a synergistic reaction between caffeine and other bioactive, antioxidant compounds in coffee.
Unfortunately, however, not all coffee is created equal. Most of the men in this study would have been drinking Italian-style coffee, which is prepared differently to coffee in countries like the USA. The use of filters is common in the USA, which can reduce the amount of beneficial nutrients and compounds that actually make it from the ground beans to what we drink. As you can see in these instructions, optimal extraction of compounds such as essential oils also requires high pressure and hot to boiling water. The most expensive macchinetta machines, found in espresso bars, produce about 9 atmospheres (900kPa) of pressure, but the more traditional ones for home use go to about 1.5 atmospheres (150kPa). Boiling the water causes it to rise through the coffee grounds, extracting the caffeine and other phytochemicals, and into an upper chamber. It is not as simple as pouring water on any old instant coffee, but whether you're drinking it for the flavour or health benefits, it's worth it!