If you are drinking your morning coffee at 8 AM is that really the best time? The circadian rhythm of cortisol production would suggest not.
Neuroscience PhD student Steven Miller explains that in the mornings (between the hours of 8 am and 9 am) our cortisol levels are at their highest. Cortisol isn't just the "stress hormone"--it's also correlated with our alertness levels.
So if we drink coffee at the same time our alertness is already at its peak, we're wasting the potential alertness boost we get from the caffeine:
"One of the key principles of pharmacology is use a drug when it is needed (although I’m sure some scientists might argue that caffeine is always needed). Otherwise, we can develop tolerance to a drug administered at the same dose. In other words, the same cup of morning coffee will become less effective"
When you drink coffee-or anything else that has caffeine as an ingredient-your central nervous system gets a mild jolt. The presence of caffeine in your system does a number of things. It 'wakes up' your brain, gets your digestive tract going, speeds up your metabolism and raises the brain levels of serotonin, a neurotransmitter that affects mood. Because caffeine is known to help release additional free fatty acids for energy, some people will drink a cup of coffee or take caffeine pills before they workout. That's the good news, but here are some of the negative side effects of too much caffeine consumption.
Caffeine is a known stimulant which increase the cortisol production in the body and also enhances the aging process. It This dehydrates the skin and even leads to wrinkling. In addition, caffeine is a diuretic which further increases the risk of dehydration. So having it the morning is a poor choice for several reasons:
Coffee leads to dehydration. When we are dehydrated the body has a strong need to replenish water but our brains often seem to mistake this signal for the feeling of being hungry so may think you are hungry a lot earlier than you actually are. Since a cup of coffee removes up to a cup of water from the body, it's important to have at least one glass of filtered water before every cup of coffee.
Having coffee in the morning can cause heartburn (acid reflux) by relaxing the esophageal sphincter muscle. Caffeine is known to have an effect on this muscle but the problem occurs even with decaffeinated coffee.
3) Increases Acidity
Coffee contains various oils, acids and compounds like caffeine that can harm your stomach and intestines by irritating their linings. When you drink coffee in the morning, your stomach produces large amounts of hydrochloric acid (HCl). This overproduction of HCl is especially pronounced if you drink a cup of coffee on an empty stomach, making first thing in the morning probably the worst possible time.
4) Negatively Affects Our Brain
Coffee reduces (not increases as popularly believed) blood flow to the brain by about 25% in the morning when you need it most. Coffee and the caffeine play havoc with the metabolism of gamma-aminobutyric acid (GABA). GABA is found in both the brain and the gastrointestinal tract. In the brain, GABA plays an important role in regulating mood and stress management. In the gastrointestinal tract, GABA provides a calming effect on the whole system. Both of these functions are important for healthy digestion and indeed overall health and well being. Unfortunately, caffeine interferes with the way GABA binds to its receptors to provide that calming influence on both the brain and the GI tract. So by playing havoc with GABA in the morning, not only can it affect how you work throughout the day, but every meal you consume as well.