Stomachs on legs are proud to present

Soy milk, a bit of sugar, a cigarette and maybe - just maybe - grapefruit juice - may enhance the drug-like effects of your 3pm cup of joe.

And while you're at it, you cigarette-smoking health fiend, bear in mind that evil black brew may actually help prevent Alzheimers and Parkinsons.

(note: Kaffee Klatsch is a German term for when people get together in a coffee shop for a nitter-natter)

Excerpt from article:

Play to caffeine's strengths.

Caffeine's effects can be maximized or minimized depending on what else is in your system at the time.

The beneficial effects of caffeine may be most pronounced in conjunction with sugar. For example, one factor analytic study has shown caffeine-glucose cocktails provide benefits to cognition not seen with either alone.

Some flavonoids (such as soy) may act in the same way as caffeine - i.e., through adenosine receptor antagonism - in particular galangin, genistein, and hispidol. Evidence showing that markers of caffeine metabolism are slowed by flavonoids might suggest that ingestion of flavonoids would enhance the effects of caffeine - some studies show grapefruit juice might keep caffeine levels in the bloodstream high for longer, though others have found no such effect.

Similarly, nicotine may speed the metabolism of caffeine.

More on the science of caffeine.