Some fascinating factoids edited from Interesting Facts.com.

1. Why does cilantro taste like soap?

While some people enjoy sprinkling this herb on guacamole and tacos, others can’t stand its “soapy” flavor. The reason? Genetics. According to a 2012 study, people with certain olfactory receptor genes — about 20% — are more likely to detect cilantro’s aldehydes, compounds also found in common household cleaning agents and perfumes. Feel strongly? You’re not alone: Facebook’s I Hate Cilantro page has more than 26,000 likes.

2. Why does OJ tastes horrible after you brush your teeth?

Blame the toothpaste ingredient sodium lauryl sulfate (SLS) which produces the foam created during brushing. SLS temporarily blocks the tongue’s sweet receptors, while also destroying compounds in saliva that suppress our bitter receptors. The result? A double-whammy for sensitive taste buds, leaving us to taste only citric acid without the oranges’ natural sweetness.

3. Why does spinach make your mouth feel strange?

Does your mouth ever feel coated or “chalky” after eating these nutritious greens? The effect, known as “spinach tooth,” results from the vegetable’s oxalic acid and calcium; combined as we chew, they produce easily detectable crystals of calcium oxalate, which could cause problems for anyone susceptible to kidney stones. Boiling, steaming, or adding lemon juice to spinach helps offset the unpleasant mouthful that accompanies the benefits of iron, fiber, and vitamin C.

4. Why does asparagus cause stinky pee?

Think twice before serving asparagus to company! An acid found solely in this particular vegetable breaks down into sulfur byproducts upon digestion and surfaces in urine as soon as 15 minutes after eating. Not everyone detects this aroma: A 2016  study found that roughly 60% of participants didn’t smell anything funky.

5. Why do salty foods cause swelling?

Ever overindulged in too many chips or fries? Besides feeling guilty, you may also notice swollen fingers, toes, or lips, a condition known as edema. The puffiness results from our body’s response to excess sodium: it pumps more water into our bloodstream, resulting in fluid-bloated tissue. Drinking lots of water, eating high-potassium foods, and sweating it out in the gym can help flush out bloat.

6. Why do pine nuts taste metallic?

After enjoying pesto, have you experienced a metallic aftertaste that can linger for up to two weeks? After reports of “pine nut syndrome” or “pine mouth” first surfaced in Belgium, investigators followed the trail to the Far East, where seeds of the Chinese white pine (Pinus armandii) appeared to be the source of this unusual but harmless affliction. The cause is still unclear, although one professor at the University of Idaho suggested that the seeds stimulate a hormone that increases the production of bitter-tasting bile.

7. Why do citrus and sunshine cause a rash?

This isn’t the result of consuming a specific food, but a possible outcome of residue lingering on hands and arms. Lemons, limes, and other citrus fruits contain chemicals called furanocoumarins which can produce poison ivy-like effects of discoloration, inflammation, and blistering when exposed to the sun’s ultraviolet rays. Technically called phytophotodermatitis, the condition is also known as “bartender dermatitis”, a reference to preparing citrus-infused cocktails in tropical locations. While prevention isn’t as simple as wiping off the juice — more thorough soap-and-water scrubbing is required — the rashes are usually treatable with cold compresses and topical creams.

And now we know!