Why You Should Keep Drinking Coffee

The popular author Michael Pollan recently recommended giving up coffee. His main concern is its effects on sleep.

Mr. Pollan is a gifted storyteller; however, he might not have fully considered the entire story about coffee. Everyone is familiar with the fact that caffeine in coffee, tea, or sodas delays the onset of sleep and disrupts normal sleep patterns. However, this negative does not outweigh the many benefits of coffee. My own suggestion is that you should continue to consume coffee daily; however, coffee should not be consumed within six to eight hours of going to bed.

Most drugs, including coffee, have unintended consequences on health—both positive and negative. Here are a series of recently published studies that will make you want to keep drinking coffee.

The Benefits of Drinking Coffee

Similar to all naturally occurring drugs, coffee is a complex blend of biologically active compounds. Many of them have already been discovered to have health-promoting properties, particularly for the cardiovascular and central nervous systems. Coffee also produces many positive effects on the digestive tract, such as its popular pro-motility effects on the external muscle layers of the intestines. Coffee also contains chemicals that are antioxidant, anti-inflammatory, and antiproliferative in terms of its ability to prevent certain brain cancers. Let’s take a look at the recent literature on coffee.

A study of the Japanese population evaluated a cohort of 106,324 subjects (50,438 men and 55,886 women) from 1990 until 2013. The authors reported a significant association between increased coffee consumption and reduced brain tumor risk. In particular, the risk of gliomas tended to decrease with higher coffee consumption (greater than 3 cups/day).

Numerous studies during the past forty years have reported a similar dose-dependent protection from coffee. For example, the incidence of Parkinson’s disease also decreases a coffee consumption is increased up to 5 cups/day.

Another recent study investigated the effect of coffee on brain MRI changes that are associated with dementia and impaired cognitive performance. A group of 2,914 participants (average age: 59.3 years, 55 percent female), were assessed for coffee consumption and general cognitive function and then had a brain MRI. After five years of coffee consumption, the cognitive assessment was repeated.

This study discovered that higher coffee consumption was associated with a lower prevalence of small brain infarcts related to ischemic strokes. In addition, those subjects who drank the most coffee per day showed the best performance on the Letter Digit Substitution Task, Word Fluency test, and Stroop interference tasks. Interestingly, recent memory performance did not improve.

A related study investigated the effect of chronic coffee ingestion on cognitive behavior and changes in the various antioxidant systems in the brain. Coffee, or just caffeine alone, improved long-term memory, reduced the lipid peroxidation of brain membranes, and increased the concentration of the antioxidant glutathione in its reduced form. Thus, in addition to improving cognitive function, chronic coffee consumption enhances the endogenous antioxidant systems in the brain. The authors speculated that chronic coffee ingestion may help prevent age-associated decline in cognitive function.

Coffee also produces immediate benefits on cognitive performance. One recent study reported that caffeine—either from coffee or from another drink containing caffeine—improved performance on a large variety of cognitive tasks. The authors obtained coffee and caffeine intake through two 24-hour dietary recalls. The study examined 2,513 people who were 60 years or older. Their results were compared with people who consumed no coffee or caffeine in any form. Coffee improved performance on tests of verbal fluency, the 15-item Boston Naming Test, a standard Mini-Mental State Examination typically given to patients with Alzheimer’s disease, the 10-item Word List Learning test, and a standard Recall and Recognition Test.

There is accumulating evidence that coffee may reduce the risk for type 2 diabetes, a known risk factor for Alzheimer's and other neurological diseases. It follows, then, that coffee may reduce the risk for Alzheimer's disease and non-Alzheimer's dementias. The problem, however, is that the caffeine in coffee produces cardiovascular side effects that limit its usefulness for elderly people.

A recent study reported that decaffeinated coffee drinks significantly attenuated the development of high-fat diet-induced deficits in glucose-tolerance response, improved brain mitochondrial energy metabolism, and actually positively influenced a number of genes in the brain that play a role in cellular energy metabolism.

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Overall, there are numerous health benefits of coffee consumption that far outweigh any negatives. If coffee is interfering with your sleep, stop drinking it later in the day. The half-life of caffeine is only five hours. Therefore, within two half-lives, or about ten hours later, there is no longer enough caffeine left in the blood to impact brain function.

Science writers often spin a good story, but too often get the science wrong. There is simply no good reason to give up your coffee consumption.