A new study says that you can lay some of the blame for your desire for dark roast on your parents.
The research, co-authored by Neil Caporaso of the Nation Cancer Institute, found that two genes already known to be responsible for the breakdown of caffeine in the liver also affect our drive to consume caffeine as well. The study is published in the journal PLoS Genetics
"You might think, 'I drink caffeine to feel good or not to fee bad,' but that is established by how fast your liver breaks down the caffeine," said Caporoso. "If your liver breaks it down very rapidly, they you likely drink more."
The genes CYP1A2 and AHR affect our caffeine cravings because they are directly related to how caffeine is tolerated by certain individuals. The more you can process, the more you can drink, according to the study. Researchers said all people carry these genes, but some are more active than others, and this determines the amount of caffeine one is driven to consume.
Caffeine content for:
Coffee (8 oz., brewed) — 95-200 mg.
Monster Energy (16 oz.) — 160 mg.
Full Throttle (8 oz.) — 144 mg.
Rockstar (8 oz.) — 80 mg.
Red Bull (8.3 oz.) - 76 mg.
Vault (12 oz.) — 71 mg.
Mountain Dew (12 oz.) — 54 mg.
Coca-Cola Classic (12 oz.) — 35 mg.
Lipton Iced tea (12 oz.) — 26 mg.