Coffee May Reduce Your Suicide Risk, Study Finds

Story at-a-glance

  • A meta-analysis of more than 208,000 people found that drinking two to four cups of caffeinated coffee daily was associated with a 50 percent reduced suicide risk among adults
  • Caffeine promotes production of the neurotransmitters serotonin, dopamine and noradrenaline. It also triggers the release of Brain-Derived Neurotrophic Factor (BDNF), which activates brain stem cells to convert into new neurons
  • Recent research also suggests that low BDNF levels may play a significant role in depression, and that increasing neurogenesis has an antidepressant effect, which may help account for the reduction in suicide risk
  • To get the therapeutic health benefits from drinking coffee, make sure to use organic, pesticide-free coffee, and drink it black, without milk or sugar


This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

By Dr. Mercola

For years, coffee has suffered a bad rap, suspected of causing high blood pressure and contributing to heart disease, ulcers, and diabetes.

Most recently, Senator Durbin used caffeinated energy drinks as an example of the dangerous and 'unregulated' supplement industry, which he proposes should be regulated like the drug industry. But mounting research is casting doubt on the "common wisdom" that coffee is nothing but bad for you.

Certainly, coffee should not be used in excess. However, study after study has failed to prove that moderate coffee consumption increases your risk for cardiovascular disease or any other serious illness.

In fact, it's beginning to look like coffee—at least in moderation—may have a number of unrecognized health-promoting properties.

Part of the confusion is that while caffeine in and of itself is a potent and addictive drug, coffee made from whole roasted coffee beans is also a whole food, containing a wide range of micronutrients in addition to caffeine.

As a result of evaluating the growing list of therapeutic benefits, I've changed my recommendations on coffee consumption, placing the emphasis on making sure it’s fresh, organic, and consumed black, should you decide to drink it.

Can Coffee Reduce Suicide Risk?

Most recently, a meta-analysis of three large studies on coffee consumption, published in the World Journal of Biological Psychiatry,1, 2 found that drinking two to four cups of caffeinated coffee daily was associated with a 50 percent reduced suicide risk among adults, compared to drinking one cup or less of caffeinated coffee, or decaf.

Drinking more than four cups a day did not lead to any further decrease in suicide risk. In all, the studies included more than 208,000 Americans, whose caffeine consumption was analyzed from a variety of sources, including coffee, tea, soda and chocolate. Coffee accounted for 71 percent of the total caffeine consumed. According to the authors:

“These results from three large cohorts support an association between caffeine consumption and lower risk of suicide.”

How Caffeine Affects Your Brain Chemistry

It’s worth noting that these studies were cohort3 studies, from which you cannot elicit or determine causation. A cohort study simply looks at occurrence rates of disease among individuals with differing exposure levels to a suspected factor, such as a food, over a longer period of time, typically years.

Cohort studies can either be performed prospectively or retrospectively from historical records. That said, other research lends support to this finding by proposing the mechanisms of action of coffee on your brain. For example, one decade-old study4 found that caffeine reduced certain types of stress responses.

Another 2011 study5, 6 found that women who drink coffee cut their risk of depression by 15 percent compared to those who don’t. Caffeine7 has also been found to promote production of the neurotransmitters serotonin, dopamine and noradrenaline. As explained by World of Caffeine:8

“Many of caffeine’s powers depend on its power to pass into the central nervous system (CNS). To enter the CNS, caffeine must cross the blood-brain barrier... Even when injected into the bloodstream, many drugs fail to penetrate this barrier... However, caffeine passes through the blood-brain barrier as if it did not exist. All psychoactive drugs, including caffeine, achieve their effects by imitating or altering the release or uptake of neurotransmitters, the chemical messengers that direct how the neurons of the CNS interact with each other.

Caffeine achieves many of its effects by blocking the activity of adenosine... Because one of the primary actions of adenosine is to make us tired or sleepy, caffeine, by blocking the uptake of adenosine, keeps us from feeling the effects of fatigue. But scientists have learned that, largely as a consequence of its blockade of adenosine receptors, caffeine also has profound effects on most of the other major neurotransmitters, including dopamine, acetylcholine, serotonin, and, in high doses, on norepinephrine.”

Increasing your dopamine levels may have a beneficial impact on mood, while increasing acetylcholine may help improve long-term memory. Meanwhile, it is commonly thought that adjusting your serotonin levels upward may play a role in relieving depression. This is primarily how antidepressants work.

That said, it’s worth noting that the low serotonin theory, which antidepressant drugs attempt to address, has been thoroughly debunked. Investigations have been done to see whether or not depressed people actually have lower serotonin levels in their brains, and in 1983 the National Institute of Mental Health (NIMH) concluded that:

"There is no evidence that there is anything wrong in the serotonergic system of depressed patients."

Still, coffee appears to affect a number of neurotransmitters related to mood control, so it’s certainly plausible that this could have an effect on your general sense of wellbeing.

Research has also shown that coffee triggers a mechanism in your brain that releases a growth factor called Brain-Derived Neurotrophic Factor (BDNF), which activates your brain stem cells to convert into new neurons, thereby improving your brain health. Interestingly enough, recent research9 also suggests that low BDNF levels may play a significant role in depression, and that increasing neurogenesis has an antidepressant effect! This may be yet another piece of the puzzle explaining why exercise tends to have a higher success rate in treating depression than antidepressant drugs do, as exercise naturally increases BDNF levels10 in your body.

High-Quality Coffee Can Have Other Therapeutic Benefits

My understanding of coffee's virtues was greatly enhanced by my interview with Ori Hofmekler, author of The Warrior Diet and Unlocking the Muscle Gene, who has researched coffee extensively. Although I personally do not like the taste of coffee and have only consumed a few cups in my entire life, there seems to be a compelling case to justify the use of healthy coffee.

Ori explained how coffee, when consumed in the right way, can be effectively used as part of your overall health and fitness plan. For example, coffee increases your metabolism by up to 20 percent, and can be quite beneficial if consumed before exercise. According to a study published in the March 2007 issue of The Journal of Pain,11 consuming the equivalent of two cups of coffee an hour before training can also help reduce post-workout muscle soreness by up to 48 percent.

Ori still believes many of the warnings about caffeine are well-warranted however, as caffeine in and of itself it can be quite toxic, especially for pregnant women. But like so many other natural topics, when it comes to the whole food, in this case the coffee bean as opposed to the isolated caffeine, the converse is oftentimes true. The natural blend of polyphenol antioxidants (including chlorogenic acids), bioflavonoids, vitamins and minerals in coffee beans all work together to help neutralize the harsher effects of the caffeine.12 There are literally thousands of different natural chemical compounds in coffee, and science now suggests the synergy between them can pack a nice nutritional punch. According to Ori:

"Every time you get naturally occurring caffeine, such as in cocoa beans, coffee or tea, you get it from a nutritionally dense healthy whole food. And note that when you use the same food in a decaffeinated form such as decaffeinated coffee, or decaffeinated tea, you ingest 'nutritionally deficient inferior' foods. A tea without caffeine is useless. It loses all the antioxidant bioflavonoids in the processing. Same with decaffeinated coffee… it has zero nutritional value."

Splurging on Organic Coffee Is Likely Worth the Extra Cost

One area of particular concern is that most coffee produced today is heavily contaminated with pesticides. It's actually one of the most heavily sprayed crops grown. So, it’s important to remember that when we’re talking about getting therapeutic health benefits from drinking coffee, we’re talking about organic, pesticide-free coffee.

Coffee that is labeled and sold as an organic food in the United States must abide by US standards for organic coffee production. To qualify, the crop must have been grown using at least 95 percent organic fertilizers and without the use of chemical pesticides for at least three consecutive years. The regulations also specify crop rotation methods must be used to protect the soil from erosion, and the beans may not be irradiated. To ensure compliance with organic industry standards, look for the USDA 100% Organic seal. If you have trouble finding organic coffee in your local grocery store, check online, as there are many organic coffees available.

Which Is Better: Dark or Light Roast?

Other issues that can come to bear on the end health effects of the coffee include the way it's dried and roasted, as this will not only affect the beneficial antioxidant content of the coffee, but also the formation of toxic acrylamides. Here, making any definitive recommendations becomes quite tricky...

In general, it has been shown that when it comes to the health benefits of organic whole-bean black coffee, the darker the roast, the better.13 It's often the case that foods with the darkest pigments offer the most robust benefits to health, and dark roast coffee, such as French or Italian Roast, or roasts used to make espresso or Turkish coffee, appear to be no exception.

Roasted coffees are higher in neuroprotective agents than green (unroasted) coffees. For example, a study in Molecular Nutrition & Food Research14 found that dark roast coffee restored blood levels of the antioxidants vitamin E and glutathione more effectively than light roast coffee. The dark roast also led to a significant body weight reduction in pre-obese volunteers, whereas the lighter roast did not. Other studies have shown that dark roast coffee produces more of a chemical called N-methylpyridinium, which helps prevent your stomach from producing excess acid, so darker roast coffee may be easier on your stomach than lighter roast coffee.15

That said, the process of roasting will also produce acrylamide—a toxic byproduct created when you expose a food to high heat. Acrylamide has been associated with an increased cancer risk. From the perspective of limiting your exposure to this toxin, a light roast might be preferable. I don’t claim to have the answer here, but the evidence supporting dark roast for higher antioxidant content is quite compelling. It could be that a higher antioxidant content of a dark roasted organic coffee might outweigh the acrylamide formed during the roasting process... Unfortunately, I have no evidence to support such a proposition.

In the end, the best recommendation I can come up with is to simply use coffee in moderation, limiting your consumption to a maximum of two or three cups per day, since most studies find no added health benefits above this amount. Another general rule to determine the quality of coffee is by its taste and smell. Rancidity can be detected immediately. A coffee that doesn't have a good aroma or taste—whether it’s a dark or light roast—is most likely stale and useless.

Avoid All Forms of Caffeine During Pregnancy

I do NOT recommend drinking coffee during pregnancy however, even if it’s organic. As discussed earlier, caffeine easily passes through both the blood brain barrier and the placenta. It is also transferred through breast milk. Research has shown that ingesting caffeine during pregnancy can result in a wide range of problems for your baby, including:

  • Increased risk of miscarriage
  • Low birth weight
  • Birth defects such as cleft palate
  • Increased risk of Sudden Infant Death Syndrome (SIDS)
  • Decreased cardiac function (Please note that the equivalent of just two cups of coffee during the entire pregnancy – not two cups of coffee per day—has been shown to affect your child’s heart function!)

Five Tips to Remember for Healthier Java

While coffee has long suffered a poor reputation, studies have not only failed to prove that moderate coffee consumption increases your risk for cardiovascular disease or any other serious illness, a number of health promoting properties have also been ascertained in recent years. Benefits of moderate coffee consumption include increasing metabolism, reducing post-workout muscle soreness, increasing BDNF and improving brain health, and potentially even reducing your suicide risk by as much as 50 percent...

When it comes to achieving any therapeutic benefits from coffee, only quality coffee will do however. You can find a great deal of information at Coffee & Conservation.16 Here are five primary considerations if you choose to drink coffee:

  • Choose Organic: Coffee beans are one of the most heavily sprayed crops with pesticides. So, you should select only coffee beans that are certified organic. Remember, you will obliterate any positive effects if you consume coffee that's been doused in pesticides or other chemicals. Whenever possible, purchase sustainable "shade-grown" coffee to help prevent the continued destruction of our tropical rain forests and the birds that inhabit them. There are many who say shade grown coffee tastes better as well.
  • Whole Bean: You'll want to purchase whole bean coffee that smells and tastes fresh, not stale; if your coffee does not have a pleasant aroma, it is likely rancid. Grind it yourself to prevent rancidity as pre-ground coffee may be rancid by the time you get it home.
  • Drink It Black: If you're interested in the health benefits, drink your coffee black, without sugar or cream or flavorings. Add sugar and you'll certainly ruin any of the benefits discussed above by spiking your insulin levels, which contributes to insulin resistance. Make sure the water you're using is pure.
  • Coffee Filters: If you use a "drip" coffee maker, be sure to use non-bleached filters. The bright white ones are chlorine-bleached, and some of this chlorine will leach from the filter during the brewing process. Bleached filters are also notoriously full of dangerous disinfection byproducts, such as dioxin.
  • Coffee Mugs: Please be careful about the container you use. Avoid plastic cups as the BPA will leach into your drink, and also avoid Styrofoam cups that can leach polystyrene molecules. Your best bets include glass and ceramic travel mugs.

Many have now started using Keurig coffee makers, which brew a single cup at a time, using small plastic coffee inserts. While the inserts claim to be BPA and phthalate-free,17, 18 they still contribute to the ever-growing problem of non-biodegradable waste. Fortunately, the machine comes with reusable pieces that allow loose coffee grounds to be used instead of the pre-made disposable plastic cups, which would be a better option.


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