Coffee is one of the most (if not THE most) commonly used source of antioxidants within the western diet. It just goes to show how insignificant our general consumption of antioxidant-rich foods is. Especially considering the amount of damage we sustain from free radicals. Many regard coffee as an 'unhealthy' beverage owing to the fact that early research had linked it to disease; but (and this is a big BUT), early studies often failed to control for social behaviours associated with the drinking of coffee (think - smoking, stressful jobs...).

Like many other foods, coffee has its pros and cons, with more and more cons coming forward the more things we add to our cup of hot joe (think - processed dairy, sugar, caramel).

In more modern research, coffee has been shown to:

• Reduce the risk of heart disease
• Reduce the risk of dementia and Parkinson's
• Reduce the risk of liver, prostate and endometrial cancers
• Reduce the risk of early death, particularly in females
• Increase insulin production in people diagnosed with Type 2 Diabetes
• Improve athletic performance
• Improve sexual behaviour and performance (seriously!)

Conversely, it can also potentially raise increase production of certain stress hormones. Particularly - cortisol. A nasty bugger, at times, capable of disrupting our metabolic harmony (cortisol can spike blood sugar and blood pressure, for instance). On another note, coffee consumption (three cups and over) has also been associated with a... reduction in women's breast size (determined in a questionnaire-based study involving 300 women).

The positive effects of coffee are not seen in all persons.

Coffee, ultimately, is a bean (or a seed, if we're being nit-picky). So to some degree, we may acknowledge their worth in terms of the protective polyphenols found in all beans. But coffee isn't just "beans", it's caffeine too. And what does caffeine do? It promotes adrenaline secretion, for starters, but we have come to learn that this only happens if you are a "slow metabolizer" of coffee. Persons, who metabolize coffee quickly, do so in such fashion that they risk no increase in blood-adrenaline levels - even at four cups/day. The latter population is thus consuming a black-coloured beverage, which is nothing more than water mixed with polyphenols (which are good for you). This is why the benefits of coffee aren't always so clear cut.

Take blood pressure, for instance. We know that caffeine can raise your blood pressure, but we know that polyphenols can lower your blood pressure. If you are a rapid metabolizer of caffeine, then good news - coffee would actually be beneficial for your blood pressure.

Unfortunately, the decider here is the gene, which regulates the metabolism of caffeine. And you wouldn't really know if you're a fast or a slow metabolizer unless you test for this gene directly. But if you're the type of person who drinks a cup of coffee and acquires a seemingly everlasting surge of energy that does not subside, even up to 9 hours after consumption - then you can safely assume that you are a slow metabolizer.

This is why coffee and its effect on blood pressure are often debated; because even though the caffeine in coffee can potentially spike your blood pressure in the short-term, it doesn't seem to cause long-term changes in rapid metabolizers.

But there again, since coffee intake was associated with a lower risk of cardiovascular disease and mortality, while caffeine intake was not associated with risk of cardiovascular disease and mortality, it suggests (key word: "suggests") that the majority of folks among us may lean more towards the "rapid metabolizer" spectrum.

How many cups? I would say that a cup or two a day should be about right, veering more towards beverages like green tea as the day goes by. And also bearing in mind what kind of response you have. The protective polyphenols found in green tea are potentially superior to those found in coffee - coupled with the reduced consumption of caffeine within the beverage - it would make for better health gains. But if you can't live without coffee, then stick to black. Don't add dairy, don't add creamers (and especially fake creamers) and don't add sugars. If you can, it may also be worth investing in filtered coffee, which has shown to have a lesser impact on LDL cholesterol, particularly in low-carb dieters, who have often seen a rise in plasma triglycerides and LDL cholesterol with coffee consumption.

So what can we conclude?

1. For the majority of us who aren't basing our livelihoods on our sporting performance, stick to black coffee. Around 1 - 2 cups/day should be sufficient.
2. If you feel jittery after coffee consumption or if your blood pressure is spiked for a considerable amount of time after consumption, then maybe it's best to stick to green tea.
3. Black coffee over anything else. Coffee is only as unhealthy as we make it when we start adding milk, creamers, marshmallows and other things to it.
4. Skip coffee after 6pm (or less depending on how it affects you). Don't let caffeine disrupt your sleep!