The Victor crew came across an article* that seemed very interesting regarding the amounts of caffeine we are actually consuming is based on several factors.
One factor is what type of coffee you are brewing. Caffeine is actually a natural pesticide so it will vary in the beans dependent on where they are grown. If they are grown in regions where there are a lot of insects, the beans will adapt and produce more caffeine.
Another factor is the size you grind your coffee. The smaller the grounds, the more surface area they have. Different brewing methods use different sizes. Cold brew uses a larger grind while espresso uses a fine grind.
Water temperature can factor in as well. The higher the temperature the higher the extraction is. Cold brew would only extract about 75% of the coffee.
Brewing style matters as well. You completely cover the grounds with immersion brewing where you leave the grounds sitting as opposed to simple pour over.
Two former Googlers, Jake Knapp and John Zeratsky who worked on Gmail and YouTube, have some advice for handling your caffeine habit.
They suggest you not drink coffee first thing. Perhaps wait until after 9:30 am. Cortisol is highest before that so its not needed earlier.
They say that caffeine doesn’t give an energy boost but prevents energy from waning. “If you wait until you are tired, it’s too late.” Since energy level goes down after lunch, have your second coffee half hour in advance.
If you miss that second cup in time, they suggest you take a nap.
Instead of another big cup of coffee in the afternoon, switch to tea or espresso (small cup), which have less caffeine.
Use proper timing for your last cup. Caffeine half-life it 5-6 hours so if your last cup is 4pm, you will still have half the effect of the caffeine at bedtime.
According to a new study by BMJ (formerly British Medical Journal), three to five cups of coffee intake was found to be beneficial, except for pregnant women. They do not suggest that doctors should recommend coffee consumption, however.
The amount is maxxed out at five cups. Any more than that are of no benefit and may even reduce or reverse the benefit. In terms of caffeine that is less than 400mg of caffeine/day. Pregnant women should keep their intake to less than 200mg/day of caffeine.
Some of the health benefits believed to be from coffee include incidence of an mortality from cardiovascular disease, incidence of cancer, fatty liver disease (non-alcoholic), diabetes, and cirrhosis.
The Victor crew found an interesting article from the Huffington Post that talks about coffee interfering with your performance.
They state people start drinking caffeine to be more alert and get into a better mood. There are also studies that say that coffee improves memory and attention span, however, they don’t take into consideration each person’s actual caffeine habits. They claim that in one study they think the upsurge is due to having caffeine after going through withdrawal and that is giving the positive results. Caffeine withdrawal actually does negatively affect your mood and cognitive performance. So in other words, the caffeine is actually just bringing you back to your caffeine normal.
Caffeine releases adrenaline. In the fight-or-flight response this produces, you could be in a hyper-aroused state, allowing emotions to take over. Large doses of caffeine can also raise blood pressure, and deprive your brain of oxygen.
Caffeine can also affect sleep. You’ll want to stay away from it later in the day. Caffeine has a six-hour half life. It takes a full twenty-four hours to be depleted. If you drink it at 8:00 am, you still have 25% in your system at 8:00 pm. Caffeine also affects your REM sleep.
Caffeine withdrawal can cause headaches, fatigue, sleepiness. Some even go through depression and anxiety. It is better to taper off caffeine if you decide to stop drinking coffee (perish the thought.)
… drink more coffee! In a study released April 21, 2017 by ScienceDirect, it was determined to be safe for healthy adults to consume up to 400 mg of caffeine per day. Pregnant women should limit to under 300 mg per day. For children, they should keep their consumption to less than 2.5 mg per kg of weight per day. For us Americans, that would be approximately 1.14 mg per lb weight.
The problem is, there is a large gap in how much caffeine is in a cup. Brewed coffee has about 95-165 mg per 8 oz. cup. As a rule of thumb, if you measure the amount of cofee, each 10 grams of Arabica coffee has about 100 mg caffeine. So no matter how you brew, that amount of beans will yield no more than that much caffeine. Somebody from coffee.stackexchange.com did the research for this. This is not an entirely conclusive way to measure. Someone later on this page does say you would need to send about 4 samples of coffee brewed the same way from different batches to a testing facility to see what is really in your brews.
Just know it’s safe to drink about 4 cups coffee per day!