Most nutritional studies are observational meaning that researchers observe what happens in a given population as a result of consuming a food or beverage without any sort of intervention on their part. Such studies usually depend on participants filling out questionnaires about the amounts of specific foods consumed as well as the frequency of consumption. This is problematic because of faulty recall, inability to estimate amounts, and a tendency to report what the subject thinks should have been eaten as opposed to what was actually consumed. These reporting problems are less likely to apply to coffee consumption since this is a habitual practice and people have a good idea about the number of cups they consume per day. As far as studies go, less than one cup a day is judged to be low consumption, one to four cups are moderate, and more than four cups a day are deemed to be high consumption.
Numerous studies have linked health benefits to moderate coffee consumption. These include reduced risk of stroke, diabetes, heart failure, Parkinson’s disease and some cancers. Better weight management, improvement in liver function, and enhanced athletic performance have also been associated with moderate coffee consumption. Regular coffee consumers rarely report any adverse effects, but in some caffeine sensitive individuals coffee can cause restlessness, a spike in blood pressure and abnormal heart rhythm. Then there is a simple answer. Avoid coffee.
Since coffee flavour is composed of more than 1000 compounds, attribution of benefits to any specific component is not possible, although polyphenols with their antioxidant activity are likely candidates. These may also be responsible for the benefits of coffee consumption on cognition that has been documented in a number of studies. One such study extracted data from the UK Biobank database that has been compiling information since 2006 about dietary patterns, lifestyle and health status of some half million participants who routinely fill out dietary and health questionnaires. They also provide blood, urine and saliva samples and take various tests that assess abstract reasoning, memory and logical thinking.
To study the effects of coffee on cognition, researchers examined data obtained over a nine-year period from a subset of 8451 cognitively unimpaired people over the age of 60. As one would expect, there was a decline in test scores as the years passed, but the decline was steepest in the high coffee consumption group. It seems that moderate consumption slows the decline. What we have here is another example of the time-tested cornerstone of toxicology, namely that dose matters. Moderate coffee consumption is fine, more than four cups a day likely is not. This result is corroborated by Harvard researchers who followed 6000 subjects over the age of fifty for seven years and found moderate coffee consumption to be associated with a 28% lower risk of dementia.
An Australian study further documents the benefits of coffee on cognition including possible protection against Alzheimer’s disease. In the “Australian Imaging, Biomarkers and Lifestyle Study,” 227 cognitively normal adults were followed for ten years. They periodically filled out questionnaires about diet and health and underwent a battery of cognitive tests. A subset of the subjects was investigated via brain imaging for the buildup of beta-amyloid, a protein that is the hallmark of Alzheimer’s disease. The conclusion was that “increasing intake from one to two cups per day could potentially provide up to 8% decrease in executive function decline over an 18-month period and up to 5% decrease in cerebral beta-amyloid accumulation.”
Can coffee’s effect on cognition be further improved by the addition of butter made from the milk of grass-fed cows and oil composed of medium-chain triglycerides? This concoction, known as “Bulletproof” coffee, is the brainchild of Dave Asprey, an entrepreneur with no background in nutrition. He champions a high-fat, low-carbohydrate diet that is claimed to cause weight loss and reduce inflammation without any supporting evidence. Asprey is a “biohacker” who experiments with different substances to enhance his biology with hopes of improved health and longevity. He takes over a hundred dietary supplements, bathes in infrared light, and uses a hyperbaric oxygen chamber in an attempt to live to the age of hundred and eighty. It is a safe bet that he will fail.
The idea for Bulletproof coffee came to Asprey after drinking yak-butter tea in Tibet. Apparently, it made him feel better and helped boost his IQ by some twenty points although he has not provided any documentation for this alleged increase in brain power. Nevertheless, he claims Bulletproof coffee has a massive impact on cognitive function. This intrigued a group of students from the Faculty of Psychology and Neuroscience at Maastricht University in the Netherlands who decided to put the claim to a test. Twenty-two undergraduates were recruited to alternately drink either regular coffee, decaffeinated coffee or Bulletproof coffee in repeated blinded trials before undergoing computerized spatial and working memory tests. There was no difference in performance.
Although Bulletproof coffee failed in this particular trial to live up to its claims, the consumption of medium chain triglycerides for improved cognition is not a scientifically bankrupt idea. The brain uses glucose as its main source of energy and in Alzheimer’s disease there is impairment of its ability to metabolize glucose. However, the brain can use ketones, specifically acetoacetate and beta hydroxybutyrate, as an alternate source of fuel, and these can be produced in the liver from medium-chain triglycerides.
Fats are composed of triglycerides, molecules in which three fatty acids are attached to a backbone of glycerol. During digestion, the triglycerides are broken down into glycerol and fatty acids that are then absorbed into the circulation. Medium chain fatty acids are composed of 6-10 carbon atoms in a chain and are metabolized in the liver differently than shorter or longer chain fatty acids. They yield ketones that can then be transported to the brain as a source of energy.
In a University of Alberta double-blind, randomized, placebo-controlled trial, twenty subjects in the early stages of Alzheimer’s disease consumed 2 tablespoons (28 grams) of medium-chain triglycerides from coconut or palm oil. After nine months, eighty percent of the subjects had either stabilized or showed improvement in cognition. No adverse effects were noted on blood cholesterol despite the consumption of these saturated fats. Given the lack of effective treatments for Alzheimer’s disease, further study of medium-chain triglycerides is warranted.
Joining Bulletproof coffee in being void of evidence of benefits is “Cognition Coffee,” produced by “The Mushroom Pharm,” a company that sells a variety of supplements made from foraged wild mushrooms. Cognition coffee, said to be more flavourful because the beans come from trees grown at high altitude, is fortified with air-dried, ground Lion’s Mane and Chaga mushrooms. This coffee is claimed to be a “nootropic,” a substance that improves memory and concentration. There is some evidence, mostly anecdotal, that these mushrooms may be useful in treating neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease, but of course randomized trials would be required to prove that Cognition Coffee really enhances cognition.
Now I’ll go and brew up another cup o’Joe, the second one I’ll have today. There will be no more. And I am not tempted to muddy it with any butter or coconut oil.
