The definitive guide to how coffee affects your happiness and health
Coffee is easily one of the most widely-consumed beverages in the world. Who doesn’t love a steamy cup with the Sunday morning paper, or an espresso shot after dinner on an Italian piazza, or even a gas station brew on a long road trip? But for being so popular, many people are confused about the pros and cons of consuming a little—or a lot of—java. Hot, cold, blended, shot, infused, flavored, organic, fair-trade, brewed, dripped, pressed … however you prepare it, coffee has a few benefits and a few risks.
Coffee is a beverage prepared from the roasted seeds (beans) of the coffee plant, which are found in the cherries. Coffee contains caffeine, which gives it its stimulating effect. It is one of the most traded agricultural commodities in the world.
The Case for Coffee
- Routine: It’s unconventional, but let’s take a moment to consider the happiness-boosting power of routine. You have a cup of coffee every morning while you read the paper/check your email/drive to work. You know the Starbucks barista. You take coffee breaks during the day and walk down the street—you’re exercising! There’s something steady and calming about routines. There are worse habits to have.
- Coffee boosts metabolism: Caffeine is a central nervous system stimulant and some studies have found that a daily dose can kickstart your metabolism by up to 8%, burning an extra 100 calories or so per day.
- Coffee boosts cognitive performance: Coffee “wakes you up.” In tests of short-term recall, simple reaction time, choice reaction time, incidental verbal memory, and visuospatial reasoning, there’s a positive relationship between test scores and the amount of coffee regularly drunk.
- Coffee looks good on you: Caffeine is a vasoconstrictor, temporarily constricting blood vessels. Redness-reducing face lotions and eye creams often contain caffeine; topical caffeine can also reduce the look of cellulite.
- Coffee is a pain-killer: Caffeine is an analgesic that increases the effectiveness of other pain killers, especially for headaches.
- Coffee may lower the risk of:
- Alzheimer’s disease, Parkinson’s disease, and dementia: moderate coffee drinkers (3-5 cups/day) are significantly less likely to develop Alzheimer’s disease and dementia than light coffee drinkers (0-2 cups/day). One recent study found an an inverse relationship between the amount of coffee regularly drunk and the likelihood of developing Parkinson’s disease.
- Type 2 diabetes: Studies show that men and women coffee drinkers who drink 4-5 cups per day cut their risk of developing type 2 diabetes by 29 to 50 percent.
- Skin cancer: Women who drank more than three cups of coffee per day had a 20% reduction in risk for basal cell carcinoma in comparison to women who drank less than 1 cup of coffee per month. Men who drank more than three cups of coffee per day had a 9% reduction in risk of basal cell carcinoma. The antioxidants in coffee may be protective against hydrogen peroxide-induced cell death in primary neuronal cells. There is also exciting new research in animal studies showing that a topical dose of caffeine to skin that’s been exposed to UV can block skin cells from undergoing genetic changes that can lead to skin cancer.
- Cardiovascular disease: Some studies have shown that coffee moderately reduces the incidence of dying from cardiovascular disease.
- Stroke: A new study reveals that women who drink more than a cup of coffee a day decreased their stroke risk by 22-25%.
- Depression in women: As reported in this preliminary study.
- Too much of a good thing: Heavy coffee drinkers—more than 6 cups or 600mg/day—can have insomnia, anxiety, restlessness, irritability, nausea, and headaches.
- Addiction: Withdrawal symptoms like headaches, nausea, and fatigue can occur in some people with just a one-cup-a-day habit.
- Gastrointestinal problems: coffee can damage the lining of the gastrointestinal organs, causing gastritis and ulcers.
- Effects on pregnancy: coffee, even decaf, is a potential health risk for babies, because they cannot metabolize caffeine. One study showed that heavy coffee consumption during pregnancy significantly increases the risk of stillbirth—drinking 8 or more cups a day may increase risk by 220% compared with nondrinkers.
- Inflammation: Consumption of coffee is associated with significant elevations in biochemical markers of inflammation.
- Coffee as Diuretic: Contrary to popular belief, caffeine does not act as a diuretic when consumed in moderation (less than five cups a day or 500 to 600 milligrams)
- Blood pressure: Caffeine has previously been implicated in increasing the risk of high blood pressure but recent studies have not confirmed any association.
Perhaps the most interesting news in coffee is the newer understanding that, like food, coffee is metabolized by different people in different ways—so you can be an effective caffeine metabolizer, or you can be a slow caffeine metabolizer. If you’re an effective caffeine metabolizer, you may reap the benefits of coffee, but if you’re not, you might not.
- Placebo Effect: A small new study reports that frequent coffee drinkers develop a tolerance to the effects of caffeine. So frequent coffee drinkers may feel alerted by coffee, but they don’t actually gain an advantage from consuming caffeine: although they feel alert, this is caffeine bringing them back to normal.
- Are You Stressed?: Robb Wolf, New York Times Best-Selling author of The Paleo Solution, has a post on RobbWolf.com that points out that your status as someone with adrenal fatigue, stress, or cortisol issues can also greatly affect what caffeine does to your body. Kevin Cann writes:
- “Methylxanthine is used in COPD treatment for its effects as a bronchodilator. On top of stimulating our airways methylxanthine also increases heart rate and is an antagonist to adenosine receptors (Nehlig, 1992). Adenosine is a neurotransmitter that causes us to become drowsy when it binds with its receptors due to the slowing of nerve cells. Caffeine actually looks like adenosine to the receptors and will bind with them. This disallows the adenosine to bind with those same receptors and make us drowsy (Ribiero, 2010). Caffeine then increases neuron firing and this sends a signal to the brain that something is not right. The pituitary gland is thus stimulated and releases the hormones responsible for our fight or flight response such as cortisol.”
There’s no easy answer: you have to understand your body and your health before you can make an informed decision about your coffee consumption. Oh, fine, want the easy answer? You can probably drink 2-4 cups of coffee per day without any negative effects and possibly with positive ones—but you may not NEED your cup of coffee either.