The Evidence For (and Against) Health Supplements: a Visualisation

After col­lat­ing the res­ults of over 1,500 stud­ies and meta-stud­ies (only “large, human, ran­dom­ized placebo-con­trolled tri­als” were included), Inform­a­tion is Beautiful’s Dav­id McCand­less col­lab­or­ated with Andy Per­kins to pro­duce a com­pre­hens­ive data visu­al­isa­tion map­ping the the effect­ive­ness (or not) of a wide range of health sup­ple­ments (there’s a stat­ic image and inter­act­ive Flash ver­sion avail­able).

Some of the find­ings:

  • Green tea has been shown to lower cho­les­ter­ol in a large num­ber of stud­ies, but there’s no sign of can­cer pre­ven­tion prop­er­ties.
  • There’s strong evid­ence show­ing Omega 3’s cho­les­ter­ol-lower­ing abil­it­ies and good evid­ence indic­at­ing it can help improve some ADHD beha­viour and lower blood pres­sure. In terms of pre­vent­ing arth­rit­is and can­cer, and in reliev­ing depres­sion, the evid­ence is con­flict­ing.
  • Fish oil has been shown to help lower blood pres­sure and the risk of sec­ond­ary heart dis­ease, but the evid­ence for it improv­ing gen­er­al health isn’t strong (but is prom­ising).
  • Vit­am­in D is fant­ast­ic: great for all-round gen­er­al health and can­cer pre­ven­tion.
  • Vit­am­ins A and E aren’t bene­fi­cial for much at all, while Vit­am­in C stud­ies are some­what con­flict­ing.
  • Beta carotene’s pos­i­tion sur­prised me: there is little-to-no evid­ence of any health bene­fits. The same goes for acai and goji ber­ries, ginkgo biloba and cop­per.

The raw data used to gen­er­ate the visu­al­isa­tion is available–along with citations–in a Google doc­u­ment that is occa­sion­ally being updated.