Caffeine is one of the most used psychoactive drug in the world, it can be found in coffee, tea, chocolate and other foods. Studies show that coffee could be beneficial for lowering the risk of developing certain age related diseases, improve mood and boost cognitive abilities. But its caffeine content could also impact sleep and stress in a negative way.

In the first article in the series we discussed the effects of cocoa on our health and longevity. In the following article we’ll examine the effect of coffee and caffeine on our health span on our health span and well-being.

Let me just say that I love coffee, It helps me wake up less groggy for work, gives me a little pick me up at noon, and of course, helps my ability to write articles. Even now as I’m writing these words I drink a cup of coffee with a bit of dark chocolate on the side.

Michael Pollan also loves coffee and in his new book “caffeine” he describes he’s experience of giving up coffee. He did so to help him understand more deeply the effect has on him and our society as a whole. Pollan says that modern society uses caffeine in order to control our biological clock and that this type of usage is of great importance to our ability to work in the evenings and nights. That is one reason why he believes that coffee has a large impact on our society. Pollan said to NPR:

“Caffeine really helps capitalism conquer the frontier of night. And that’s why it was so important to the Industrial Revolution, where you had these expensive machines you wanted to keep running all night and you moved to two and three shifts. Did people work at night before that? Not very much. “ (1)

Michael Pollan

The needs of society also impact our individual selves, if the society needs coffee in order to work, so are we. A lot of people drink coffee in order to adjust themselves to their work hours and of course also for the pleasure and taste of it. But could our use of coffee help us to live healthier and longer?

Could be. Caffeine is one of the most studied psychoactive substance in the world. hundreds of studies examined its effects on different health components and found that coffee could help decrease the risk of age related illness like Alzheimer’s disease, type 2 diabetes and cardiovascular diseases. Coffee is also found to have the ability to improve our mood and cognitive performance.

Decreased Alzheimer’s risk

A number of studies show that caffeine consumption is associated with lower risk of Alzheimer’s disease. a quantitative review shows that coffee consumers has a 30% less risk of getting Alzheimer in comparison to those who didn’t consumed caffeine (2). Another review showed that consumption of 3-5 cups of coffee per day is associated with around 65% lower risk of Alzheimer in comparison to lower amounts of consumption (3,4). One possible explanation for the results can be found in rat studies. Rats who consumed water with added caffeine showed lower amounts of the Aβ peptide in the hippocampus compared to rats who drank normal water.  High amounts of the Aβ peptide is one of the characteristics of Alzheimer’s disease (5).

Lower risk of type 2 diabetes

 a statistical analysis on 457,922 participants from 8 different countries has shown an significant association between coffee consumption and lower risk of type 2 diabetes (6).  Another review from 2018 on more than a million participants shows that higher amounts of consumption relates to lower risk of diabetes. Those who consumed 5 cups of coffee per day had 29% lower risk of developing type 2 diabetes then those who did not consumed coffee (7). Interestingly, those who consumed decaffeinated coffee also showed similar results (but not in every study). One possible explanation for these results may be the effect of a unique type of polyphenols found in coffee called chlorogenic acids (CGA’s) that has a positive effect on glucose regulation (8).

Lower risk of cardiovascular diseases 

 A systemic review and meta-analysis that examined the relation between coffee consumption and cardiovascular diseases shows a positive association between coffee consumption and lower risk of heart failure. The results show that this relation is at its highest when participants consumed 4 cups per day, and that consumption of more then that had an opposite effect of higher risk instead of lower (9). Another 2014 study showed similar results, that consumption of 3-5 cups of coffee per day had lower association of cardiovascular diseases, and that more than that had an opposite effect (10).

Improved mood and cognitive performance

Lowering the risk of age related diseases is extremely important but as the title of the article show, we went also to have a good mood and to perform at our best. Consumption of one cup of coffee every 4 hours is positively related to a stable increased in mood with a larger effect for those who suffer from fatigue. On the other hand the study also found that consuming too much caffeine is related to higher stress and anxiety levels (11). Coffee also has a positive effect on cognitive abilities, with a greater effect seen in times of arousal. Coffee consumption is positively related to enhanced concentration, safety while driving at night and in monotonous roads, reaction time and maybe even short term memory (12).

So how much coffee is a good amount?

When observing the studies shown you could see that different amount of coffee could have different results. It is important to note that most studies of coffee are observational, it could mean that maybe there are more components that effect the results. With that said, it seems like coffee could help us in times of tiredness, for improving our mood and lowering our risk of certain age related diseases. 

But as we all know coffee also has its downsides. Caffeine could negatively impact our sleep and stress levels. Psychologist Matthew Walker addresses coffee in his book ‘Why We Sleep’, he explains that our amount of deep sleep decreases with age and that coffee could also lower our deep sleep (13). Caffeine has a half life of around 6 hours, what means that quarter of the amount of the caffeine you had in noon, will stay in your body at midnight (14).

For these reasons we’ll recommend you stop your coffee consumption around 14 pm. This way you can have the benefits to your mood and health span and also lower the negative effects on sleep. It is also recommended that the coffee will be without sugars and milk which can also effect health in an unwanted way.

And what about addiction, it does exist, but with all of the benefits of coffee, maybe addiction is not the right word. Michael Pollan eventually got back to his coffee habit. He addresses addiction In his NPR interview:

“I think the word ‘addiction’ has a lot of moral baggage attached to it, as Roland Griffiths told me, if you have a steady supply of something, you can afford it and it’s not interfering with your life, there’s nothing wrong with being addicted.” 

Michael Pollan


  1. https://www.npr.org/sections/health-shots/2020/02/10/803394030/michael-pollan-explains-caffeine-cravings-and-why-you-dont-have-to-quit
  1.  Barranco Quintana J.L. et al. (2007) Alzheimer’s disease and coffee: a quantitative review. Neurol Res, 29:91-5.
  2.  Eskelinen M.H, Kivipelto M. (2010) Caffeine as a protective factor in dementia and Alzheimer’s disease. J Alz Dis, 20 Suppl 1:S167-74
  1. Eskelinen M.H. et al. (2009) Midlife coffee and tea drinking and the risk of late-life dementia: a population-based CAIDE study. J Alzheimers Dis, 16:85-91.
  1. https://pubmed.ncbi.nlm.nih.gov/28533411/
  1. Huxley R. et al. (2009) Coffee, Decaffeinated Coffee, and Tea Consumption in Relation to Incident Type 2 Diabetes Mellitus. Arch Int Med, 169:2053-2063. 
  1. Carlstrom M. and Larsson S.C. (2018) Coffee consumption and reduced risk of developing type 2 diabetes: a systematic review with meta-analysis. Nutr Revs,76(6):395-417
  1. Mattila P. et al. (2006) Phenolic acids in berries, fruits, and beverages. J Agric Fd Chem,54:7193-7199.
  1. Malerba S. et al. (2013) A meta-analysis of prospective studies of coffee consumption and mortality for all causes, cancers and cardiovascular diseases. Eur J Epidemiol, 28(7):527-39
  1.  Ding M. et al (2014) Long-term coffee consumption and risk of cardiovascular disease: a systematic review and a dose-response meta-analysis of prospective cohort studies. Circ, 129(6):643-59.
  1.  Nehlig A. (2010) Is Caffeine a Cognitive Enhancer?J Alzheimers Dis, 20(S1):85-94.
  1.  https://www.coffeeandhealth.org/ 
  1.  Walker, Matthew (2017). Why We Sleep: The New Science of Sleep and Dreams. Description & arrow/scrollable preview. Retrieved 15 October 2020.
  1.  https://www.ncbi.nlm.nih.gov/books/NBK223808/