Some people thrive on spicy foods — eating the ghost pepper salsa or ordering the ‘nuclear’ hot wings. Are these people just tougher? stronger? superior? Or are they the genetic oddities? Personally, I say that there is no shame in being a spicy food wimp!
Capsaicin is the component of chili peppers that makes them taste hot. It binds to a specific receptor called the TRPV1 receptor, which gives us the perception of heat and pain from spicy foods.
Interestingly, birds don’t respond to capsaicin, so the hot pepper seeds don’t bother them, but most mammals avoid capsaicin due to the pain. This is an advantage for plants since seeds tend to pass on through birds, distributing the plants far and wide. Whereas mammals are more likely to destroy the seeds with their teeth not passing them on. [ref]
So why are some people less bothered by spicy foods? Repeated exposure to capsaicin turns down the TRPV1 receptor.
Who on earth would want to eat enough spicy food to have repeated exposure? People who have variants of the TRPV1 receptors that cause them not to feel as much pain.
TRPV1 stands for transient receptor potential vanilloid 1. This is the gene that codes for the receptor that is activated by capsaicin. This receptor is also involved in body temperature regulation.
TRPV1 is activated by:
- temperatures greater than 43 °C (109 °F),
- wasabi and mustard compounds (isothiocyanate),
- acidic conditions
- spider, centipede, and tarantula venom [ref]
- cannabidiol (CBD oil) at certain doses[ref]
The TRPV1 receptors are mainly found in the peripheral nervous system in the nociceptive (pain-sensing) neurons. [ref]
Capsaicin cause you to feel heat and pain through activating the pain receptors in the peripheral nervous system. But repeated exposure to capsaicin will decrease the TRPV1 receptor activity, causing you to be less sensitive to pain. This is why capsaicin can be used to decreasing the pain of arthritis.
Beyond just signaling pain, the TRPV1 receptor plays other important roles within the body. It is important in the cardiovascular system and in insulin release. [ref][ref] TRPV1 activation increases insulin sensitivity and is therefore involved in energy expenditure and diabetes.[ref]
TRPV1 Genetic Variants:
Genetic variants that decrease the amount of TRPV1 should give a greater tolerance to spicy foods. These variants are also linked to less sensitivity to tasting salt and a decreased risk of diabetes.
Check your genetic data for rs8065080 (23andMe v5; AncestryDNA):
Check your genetic data for rs222741 (23andMe v4; AncestryDNA):
- A/A: normal
- A/G: increased risk of migraine (more sensitive to pain?)
- G/G: increased risk of migraines [ref] (more sensitive to pain?)
Check your genetic data for rs222747 (AncestryDNA only):
- G/G: less TRPV1 protein,
- C/G: more TRPV1 protein
- C/C: more TRPV1 protein, lower levels of inflammatory cytokines in multiple sclerosis[ref]
*given here in the plus orientation to match AncestryDNA orientation.
Check your genetic data for rs161364 (23andMe v4 only):
- T/T: decreased risk of diabetes [ref] less TRPV1(should be better able to tolerate spicy foods)
- C/T: somewhat decreased risk of diabetes
- C/C: normal variant
Check your genetic data for rs224534 (23andMe v4, v5; AncestryDNA):
- A/A: less sensitive to capsaicin (skin sensitivity test) [ref]
- A/G: normal sensitivity to capsaicin
- G/G: normal sensitivity to capsaicin
What can you do if you are a spicy foods wimp?
- Casein, a protein in dairy, can help break the bond between capsaicin and the receptor. Yogurt has been shown to decrease the hotness of chili peppers. [ref][source] And full-fat dairy may help more than low-fat dairy.[ref]
- Capsaicin is an alkaloid oil, so drinking water doesn’t do much for the burn.
- Protons can sensitize TRPV1 receptors to capsaicin. Acids are proton donors. [ref] Some online resources say that acids will temporarily give a cooling sensation, only to have the burning from capsaicin return with a vengeance.
- Heat can also activate the TRPV1 channel, causing pain at 109 F. But capsaicin lowers the threshold for that activation. So drinking or eating something hot along with spicy chilis will potentially cause more pain.[ref]
- Sweets may decrease the pain intensity of eating foods with capsaicin. [ref] Combining this with dairy and cold makes ice cream a good bet for decreasing the burn from hot chilis.[ref]
- The tip of the tongue should have the most TRPV1 channels, so perhaps shoving the hot spices further back in your mouth will help. [ref]
In mice, capsaicin reduces obesity from a high-fat diet. It also helps with insulin sensitivity.[ref][ref][ref] The human studies aren’t all that impressive for weight loss or weight loss maintenance, but there may be minor benefits for some.[ref]
If you have ever started dripping with sweat after eating something spicy, there is a name for this — gustatory sweating – and it is caused by the thermoregulation by TRPV1. [ref] This thermoregulation is thought to be why eating spicy foods in a hot climate ends up cooling you off (theoretically). [ref]
Capsaicin creams have been shown to be effective for arthritis pain, shingles, and muscle pain. They work by repeated exposure to capsaicin causing a decrease in TRPV1. [ref]
Capsinoids are similar to capsaicin but without the hotness. Capsinoids are found in a type of chili pepper known as CH-19 Sweet. They give the metabolic benefits of capsaicin without the spice. [ref]
Cannabidiol (CBD oil) is a part of the cannabis plant that doesn’t get you high. It binds to the TRPV1 receptor as an agonist, and this is at least part of why it is effective for pain for some people.[ref] In theory, taking CBD oil before eating spicy foods should decrease the pain. There aren’t any studies on this, though, that I could find.