Caffeine Slow Metabolizers

[Bekegren]

Hi, Jordan. I have a question about caffeine, health, and exercise performance. I have read that “slow metabolizers” have increased risk of heart attacks, and actually have a decrease in exercise performance. Is this supported by the current evidence? I am currently following the 2018 physical activity guidelines, & the 2020 dietary guidelines.

thank you for your time.

[Jordan Feigenbaum]

Where did you hear this from? I have not come across this in any data set or published research.

In general, people who don't tolerate caffeine very well will not consume it due to the side effects. You would know if you were one of these people most likely and abstain from caffeine.

[Bekegren]

https://pubmed.ncbi.nlm.nih.gov/16522833/

https://pubmed.ncbi.nlm.nih.gov/19451835/

[Jordan Feigenbaum]

Thanks for providing those. They are certainly interesting, but I do think we need to put them into context.

Yes, this specific gene has been associated with higher ApoB and blood pressure levels along wtih other CVD risk factors independent of any effects on caffeine metabolism per se'. Additionally, the coffee-cyp1A2 relationships here aren't terribly impressive to me with respect to the odds ratios, confidence intervals, and using abstainers in the samples. There's also conflicting data even when using the same study design. Previous studies show short-term increases in HR and BP in caffeine naive individuals, but this goes away pretty quickly. Not sure that I'm really interested in what happens to people who don't take in caffeine via coffee regularly in the few hours after ingestion.

We know that coffee intake is neutral or health-promoting provided people don't add a bunch of stuff to it and/or tolerate caffeine well. I don't think that people should undergo genetic testing to see if they can drink coffee or otherwise abstain from it based on current data.