I love my morning cup of coffee. I drink it black for all the antioxidant benefits. It wakes me up
and sharpens my mind. Coffee has many benefits such as enhancing energy, mental clarity and
physical performance. Are you a caffeine enthusiast or someone trying to manage their caffeine
intake for better health?
Caffeine is a beloved psychostimulant found naturally in various plants. Coffee and tea are the
most used sources. It’s also present in kola nuts, cocoa beans, yerba mate, and guarana berries.
We all know it as the energy boost, we get from our morning coffee or tea, but caffeine can be
found in various other forms, including energy drinks, soft drinks, and even chocolate.
While caffeine has many benefits, there are also some downsides and precautions to take when
drinking any caffeinated beverage. We’re here to explore the world of caffeine, how it affects
our bodies, and its impact on hormones and overall well-being.
Genetics and Variability: One fascinating aspect of caffeine is its varied effects on individuals.
Some people can consume high levels without issue, while others are more sensitive.
- Genetics play a role, with certain enzymes like CYP1A2 responsible for metabolizing
caffeine. Genetic studies have shed light on how our bodies process caffeine and its
impact on sleep, anxiety, and even neurological, cardiovascular and psychiatric
Hormones and Caffeine: Caffeine can influence hormones, especially in specific situations.1
- During pregnancy, caffeine metabolism changes. Its half-life is prolonged. Most people
have a half-life of 2.5 to 5 hours, and it takes 5 half-lives to be completely out of your
system. In the third trimester of pregnancy, the half-life increases up to 11.5 to 18
hours and daily consumption leads to caffeine accumulation in the fetus. Therefore, it’s
advisable to limit intake.
- Oral contraceptives can also affect caffeine metabolism and doubles the half-life.
- Women may experience fluctuations in caffeine half-life during their menstrual cycle.
Caffeine metabolism slows in the luteal phase just after ovulation and prior to our
Factors Affecting Caffeine Clearance: Several factors can influence how our bodies handle
caffeine. Diet plays a role and so does the enzyme CYP1A2 found in the liver. Foods and
supplements affect this enzyme which clears caffeine from your system. 1
- Speeds clearance of caffeine: Brassica vegetables such as broccoli, cauliflower, kale,
brussels sprouts, mustard greens, arugula, watercress, bok choy, collard greens,
cabbage, turnips, radishes, wasabi and horseradish, kohlrabi, rutabaga and vitamin C-
rich foods, increase caffeine clearance. This gets caffeine out of your system faster.
Apiaceous vegetables such as carrots, celery, parsley, caraway, fennel and parsnips, also
slow caffeine clearance. However, an interesting phenomenon is that Apiaceous
vegetables can mitigate the effects of exposure to air pollution. These vegetables
protect the body from accumulation of acrolein, an irritant to the lungs and skin with a
strong unpleasant odor, abundantly found in cigarette smoke and automobile exhaust. 2
- Slow caffeine clearance: Interestingly, South Asians may have lower caffeine
metabolism due to their culinary practices of using curries with curcumin and turmeric.
Flavonoids such as quercetin also slows caffeine metabolism and has been used in
people fighting viruses, allergies and mast cell disorders.
- Alcohol’s Impact: If you enjoy the occasional alcoholic beverage, it’s essential to know
that alcohol can affect caffeine metabolism. It can increase caffeine half-life and reduce
clearance, leading to extended caffeine effects. Alcohol significantly increases caffeine
half-life by 72% and reduces clearance by 36%. If you take caffeine to wake up and stay
alert during the day and alcohol to relax and slow down at night, this often interrupts
sleeps leaving you tired and creating a viscous cycle of dependency.
Drug Interactions: Although regarded safe in small quantities, caffeine can interact with many
medications both prescription and over the counter medications. 3
- Many drugs, including certain selective serotonin reuptake inhibitors (particularly
fluvoxamine), antiarrhythmics (mexiletine), antipsychotics (clozapine), psoralens,
idrocilamide and phenylpropanolamine, bronchodilators (furafylline and theophylline)
and quinolones (enoxacin), affect and inhibit the CYP1A2 enzyme and prolong the half-
Toxic Effects: The most serious caffeine-related CNS effects include seizures and delirium.
Other symptoms affecting the cardiovascular system range from moderate increases in heart
rate to more severe cardiac arrhythmia. an excessive dietary intake of caffeine has also been
observed in psychiatric patients), gastrointestinal, infectious, respiratory and skin disorders.
Finding Your Balance: Understanding how caffeine interacts with your body is crucial for
maintaining a healthy balance. Whether you’re a coffee lover or just looking to manage your
caffeine intake, knowledge is power. Be mindful of your unique response to caffeine and
consider factors like genetics and diet.
Adults are advised to limit their caffeine consumption in one sitting to 200 mg (about two
regular 125 ml cups of coffee) and to 400 mg over a daytime period. Pregnant women should
not go over 200 mg caffeine per day, and for children and adolescents, the safe limit is set at 3
mg/kg per day. Sensitive people should have a lower dose or eliminate it completely.
However, if you have anxiety, panic attacks, palpitations, a racing heart and difficulty falling or
staying asleep, it is best to try a trial of being off caffeine. Many people report relief from these
Remember, we’ re here to support you on your wellness journey. If you have questions or
concerns about caffeine, hormones, or overall health, visit The Feel Good AgainInstitute.com.
It’s your one stop source for education, group and individual coaching, live, group and DIY
courses and referrals to medical care. Your well-being is our priority, and together, we can find
the right path to optimal health and vitality.
1.Nehlig A. Interindividual Differences in Caffeine Metabolism and Factors Driving Caffeine
Consumption. Pharmacol Rev. 2018;70(2):384-411. doi:10.1124/pr.117.014407
2.Redding MC, Pan JH, Kim YJ, et al. Apiaceous vegetables protect against acrolein-induced
pulmonary injuries through modulating hepatic detoxification and inflammation in C57BL/6
male mice. J Nutr Biochem. 2022;101:108939. doi:10.1016/j.jnutbio.2022.108939
3.Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary
caffeine and medications. Clin Pharmacokinet. 2000;39(2):127-153. doi:10.2165/00003088-
Lorraine Maita, MD, CEO & Founder of The Feel Good Again Institute and Vibrance for life and widely known as “The Hormone Harmonizer”, has helped thousands of people ditch fatigue, brain fog, mood swings, lose weight, and achieve balanced hormones so they Feel Good Again.
She is a recognized and award-winning triple board certified, holistic, functional, integrative and anti-aging physician, speaker and author, and has been featured in ABC News, Forbes, WOR Radio and many media outlets to spread the word that you can live younger and healthier at any age.