今注目を集めている Will Blueberries Make Your Stool Blackについて、詳しいまとめをご紹介しています。

Did you know that the blackening effect is stronger with certain digestion conditions? If you have slower digestion (like after a big meal or if you’re a bit backed up), the anthocyanins have more time to react with stomach acid and bile. More time = darker color.

Also, the ripeness of the blueberry matters. Darker, riper berries have more pigment. So, if you ate a whole bag of dark, juicy blueberries, you’re basically painting your colon with a temporary tint.

Blueberries Make You Poop Black at Holly Stine blog

And here’s a fun fact: the same thing happens with beets, but they turn your pee pink or red. Blueberries are polite—they only mess with the exit. Beets? They’re overachievers.

The Big “Am I Dying?” Checklist

  • Did you eat blueberries in the last 24 hours? → Probably just the berries.
  • Did you also eat black licorice, dark chocolate, or take Pepto-Bismol? → Same party, different guests.
  • Is the black color uniform, not speckled or streaky? → Likely pigment.
  • Do you feel completely fine otherwise? → Celebrate your berry-fueled digestive art.

If you answered “no” to all of those, and you’re still seeing black, get a checkup. No shame in being cautious! But for 99% of you, it’s just blueberries showing off.