I remember when I was in CEGEP and couldn’t even handle the smell of coffee. Over the years, I guess you can say that I’ve become an avid coffee drinker. It started with the need to stay awake to study at University. Eventually, I started enjoying the taste of it with a bunch of milk/cream/sugar, and, currently, I’m drinking a cup of black coffee as I’m typing this post. Talk about character development!
Other than it has become a totally instagrammable food item, coffee has over time become one of the most internationally popular beverages and has become many people’s drink of choice when looking to increase productivity due to its awakening effects, but also because of its taste and aroma. It is mainly composed of water, but also many other compound molecules that give it its signature colour, flavour, aroma, and health benefits. These include but are not limited to caffeine, chlorogenic acids (antioxidants), phytochemicals, ethylphenol (aroma), but also certain vitamins like vitamin B3 (niacin).
Its relation to human health has also been extensively studied throughout the years. The general consensus is that drinking moderate amounts of coffee have proven health benefits, but excessive coffee drinkers will experience many other downsides in regards to health.
That being said, pretty much anything in excess can be harmful to the human body.
Here’s what current research about coffee indicates:
1. Caffeine and heart health
One extensive review suggests that moderate amounts of caffeine consumption (400-600mg/d) daily have no relation to total cardiovascular diseases, arrhythmia, heart failure and high blood pressure, and even reduces the risk of total cardiovascular disease in individuals who are in reasonable health.
Other studies show it may increase heart rate but this change of heart rate is not consistent among individuals and suggests that sensibility to caffeine might need to be evaluated on an individual approach.
However, people who have or are more prone to high blood pressure (it can sometimes be transmitted genetically) or already have hypertension may experience high blood pressure during coffee consumption and are therefore considered more sensitive to the effects of caffeine. However, changes in blood pressure remain acute and short-term, which normalizes later. But for these individuals, this change of blood pressure is observed from all sources of caffeine, not just coffee.
2. Coffee as an antioxidant
There are many components in coffee that have antioxidant and anti-inflammatory properties in the human body:
- A specific phenolic component found in coffee, chlorogenic acids, have proven to reduce oxidative stress by decreasing inflammatory markers in the body via a variety of cellular and molecular mechanisms;
- Caffeine itself may also induce these same benefits to your body;
- Cafestol & Kahewol that are naturally present in coffee beans contribute indirectly to antioxidative cellular pathways, but it is unsure whether they have direct antioxidant properties themselves when considered by themselves;
- Trigonelline, which also contributes to the bitterness of coffee decreases the concentration of oxidative components like malonaldehyde and nitric oxide in the body;
- Melanoidins may also be antioxidative and/or anti-inflammatory, but it seems that their efficiency decreases the longer the coffee brews.
” The preponderance of published literature demonstrates that for the general population of healthy adults, moderate caffeine consumption of 400 mg/d is not associated with toxicity, cardiovascular effects, effects on bone status and calcium balance (with consumption of adequate calcium), changes in adult behavior, incidence of cancer, or effects on male fertility (Nawrot et al., 2003). These conclusions are recognized by Health Canada, the U.S. Food and Drug Administration (FDA, 2012), the European Food Safety Authority (2015), and most recently the U.S. Dietary Guidelines for Americans (USDHHS & USDA, 2015). ”
3. People who consume moderate amounts of coffee have a decreased chance of mortality from all-sites cancer as compared to those who don’t consume coffee
This is (probably) mainly due to the mechanisms induced by the phytochemicals compounds mentioned above, such as the diterpenes, melanoidins and polyphenols. The observations weren’t exclusive to one type of cancer, but all-sites cancer. However, more research needs to be done to prove the effects of coffee on cancer, in a more holistic approach, which includes all the individuals’ lifestyles (for example smoking and exercising habits).
That’s the fascinating thing about science and nutrition, it’s ever-changing! It advances every single day.
4. Coffee has positive effects on your liver
Liver fibrosis, non-alcoholic fatty liver and cirrhosis are the leading liver diseases in those with liver failure or malfunction and is due mainly to an unhealthy lifestyle, constituted by the Western diet composed of foods that are very high in fat and sugar, and very low in essential nutrients. This type of diet causes an accumulation of fat in the liver leading to non-alcoholic fatty liver disease (or NAFLD), which can also lead to hepatocellular carcinoma, or more commonly, liver cancer.
Other than the antioxidant effects of certain compounds found in coffee, the protective effects against NAFLD are associated with caffeine, phenolic compounds and melanoidins.
The review article in question suggests that increased coffee consumption in the population has decreased mortality due to NAFLD, by reducing the blood levels of glutamyltransferase and other proteins that, during extensive stress on a cellular level, aggravate the risks of developing NAFLD.
5. The effect of coffee and on the immune system
Read this section carefully, the effect of coffee varies with the type of auto-immune disease in question:
- Coffee can be beneficial to those who have Multiple Sclerosis and Primary Sclerosing Cholangitis. It helps mitigate the progression of the disease;
- Coffee consumption may help reduce painful symptoms of Celiac’s Disease, for those who follow a gluten-free diet but still experience them;
- Coffee may increase the risk of occurrence of certains diseases such as Type 1 Diabetes Mellitus (T1DM) and Rheumatoid arthritis (RA). It may be beneficial to those who have RA and to avoid coffee when treated with methotrexate. The recommendation is the same for those with T1DM, since caffeine makes glycemic control difficult in many cases.
Do I think these studies mean we should drink nothing but coffee and caffeinated drinks? Absolutely not. If you’ve been following me for a minute, you know that my favourite motto when it comes to nutrition is ”everything in moderation”. It’s great that coffee has some health benefits, but other studies also show that an excess of coffee can really affect your body negatively… which calls for a part 2 about coffee!
I am always up for a discussion, so leave a comment if the topic interests you.
- Grosso, G. et al (2017). Coffee, Caffeine, and Health Outcomes: An Umbrella Review. Annual Review of Nutrition vol. 37: 131-156. https://www.annualreviews.org/doi/full/10.1146/annurev-nutr-071816-064941?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed (last consulted June 27 2019)
- Tumbull, D. et al (2017). Caffeine and cardiovascular health. Regul Toxicol Pharmacol 89: 165-185. https://www.ncbi.nlm.nih.gov/pubmed/28756014 (last consulted June 29 2019)
- Sharif, K. et al (2017). Coffee and autoimmunity: More than a mere hot beverage! Autoimmunity Reviews vol 16: 712-721. https://www.sciencedirect.com/science/article/pii/S1568997217301271?via%3Dihub (last consulted June 29 2019).
- Butt, MS. et al (2011). Coffee and its consumption: benefits and risks. Crit Rev Food Sci Nutr vol 51(4):363-73. https://www.ncbi.nlm.nih.gov/pubmed/21432699 (last consulted June 29 2019).