Your veins have a natural safety system that helps prevent them from squeezing too tight when a powerful tightening chemical is present; if you block this system with aspirin, the veins squeeze much harder—showing that this safety system is really important.

45

Pro

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Against

Evidence from Studies

Supporting (1)

45

Community contributions welcome

45

Endothelium-dependent modulation of responses to endothelin-I in human veins.

Randomized Controlled Trial

Human

1993 Apr

When people took aspirin, their veins tightened much more when exposed to a chemical that makes blood vessels shrink — proving that their bodies normally make a natural substance (prostacyclin) to keep that tightening in check.

Contradicting (0)

0

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No contradicting evidence found

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

Endothelium-dependent modulation of responses to endothelin-I in human veins.

Score: 45

DOI: 10.1042/CS0840427

Similar Assertions

Prostacyclin works better than a common heart medication called glyceryl trinitrate to relax veins that have been tightened by another substance, making the veins open up more — it reduces tightening to just 12% instead of 33%.

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85%

A natural substance in the body called endothelin-1, given in a tiny amount, causes veins to tighten up slowly and stay that way for a long time—up to two-thirds narrower—showing it’s a powerful and lasting way to control blood vessel size.

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78%