There are many urban myths about ways people can improve their high while using marijuana. This can be anything from eating a mango to drinking orange juice. While many of these ways are probably untrue (although eating a mango could be), there's a way with actual scientific backing: Consuming more Omega-3.
A recent post on the weed-related subreddit r/trees suggested that taking Omega-3 supplements lowered one user's tolerance to weed. And while the Reddit poster was mostly going on anecdotal evidence, there's actually scientific research to back it up. In 2011, researchers found that a lack of Omega-3 fats in a person's body lowered the medical effects of cannabis. American diets are high in Omega-6 fats, not Omega-3 fats. Without Omega-3 fats, the receptors in a person's brain that absorb the compounds in cannabis don't function properly. Therefore, a lack of Omega-3 fats means a person won't receive the full effects from marijuana.
So the poster saying that taking Omega-3 supplements "lowered their weed tolerance" is sort of correct. It definitely made his brain more susceptible to the effects of marijuana, which meant he could get a stronger high while consuming less cannabis.
Two of the most common sources of Omega-3 fats is fish oil and flax seeds. Another good source is ground up hemp seeds. So you can actually improve your high on marijuana by consuming products that make marijuana!
The receptors that are affected by Omega-3 supplements can also prevent conditions such as Huntington's, Parkinson's, Alzheimers and more. So even if you're not a marijuana user or want to lower your weed tolerance, increasing your Omega-3 intake is still a good idea to improve overall brain health.
So next time your hippie friend proposes some bizarre way to improve your marijuana experience, listen to them. They might be steering you towards a more healthier way of living!