Tuesday, January 10, 2017

Manuka Tea, likely better mental booster than coffee

I think Manuka (Leptospermum scoparium) leaf tea may have the most pleasing flavor the native New Zealand flora has to offer.  Scientists have long known the plant contains the chemical 1 8 cineole (Ref 1), found in the leaves and bark. Recently scientists have found 1 8 cineole from Rosemary and other herbs boosts speed and accuracy at mental tasks (2). They also seem to report as a good thing that it is "negatively correlated with changes in contentment levels" I'm not sure what that means, perhaps it is some kind of mood stabilizer.

Many of the experiments involved inhalation of the chemical through essential oil of herbs but oral administration of essential oil and "extracts" was also effective (3, 4). I'm assuming just drinking the tea is a way of getting the benefits of 1 8 cineole but have not been able to find any experts committing on this. Essential oils can be extracted simply by pressing, crushing plants, I don't see how this would make any chemicals available not available through boiling, though they would be more concentrated. I expect essential oils are usually used in experiments because they can be bottled to prevent evaporation then stored for years and used when convenient. I find Manuka leaves loose most of their flavor in a matter of days once picked, presumably because the essential oils have broken down or escaped (presumably this would pose a serious problem for anyone trying to transport and sell the leaves for tea, significant seasonal fluctuations in quantities of 1 8 cineole in the leaves another issue(5)).

It is interesting that the BBC TV series 'Trust me I'm a Doctor' found in an experiment coffee makes you think you are performing better mentally but actually doesn't help, by contrast essential oil of Sage containing 1 8 cineole does improve mental performance (4*). So the humble, largely overlooked cup of Manuka tea may actually be a better workplace drink than coffee (I don't see anything wrong with coffee as recreational drug on the basis of their findings. At least coffee doesn't actually make you perform far worse while making you think you're doing wonderfully as alcohol and cannabis do, though glancing into certain "cool" and "classy" cafes I think this may need further research).

The similar, related native plant Kanuka (Kunzea ericoides) is also used as a tea (7) and also contains 1 8 cineole (1). I find the flavor facinatingly unique but overpowering, like essential oil straight. 

I also find it very interesting a popular tea in Ancient Egypt was made from the leaves of Artemisia arborescens which have been found to contain 0.4% 1 8 cineole (6) perhaps it was the secret of their astounding civilization. It is a very satisfying tea once you get used to it. I've often wondered why Mint (Mentha spicata) Tea is so popular in the Arab World since it doesn't appear to do anything like coffee, turns out it is rich in 1 8 Cineole (8) .

1 8 cineole is also found in the leaves of a number of other plants used to make very pleasant teas such as Broad Leaved Paperbark (Melaleuca quinquenervia)(9)*Myrtle (Myrtus communis) (10), once popular with French women, and Bay Laurel (Laurus nobilis) (11), perhaps this is why the Delphic Oracle of Ancient Greece used Bay as an aid in making prophecies.

Often confused with one another, I mainly tell Manuka and Kanuka apart by their leaf shape. Manuka (above) has broader more curved oval leaves, Kanuka (right) straighter, narrower leaves.


1. Brooker S G, Cain B F, Cambie R C. A New Zealand Phytochemical Register-Part 1. Transactions of the Royal Society of New Zealand Vol 1 No7 May 31 1963
2. http://www.scienceagogo.com/news/20120127011944data_trunc_sys.shtml
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3736918/
4. http://www.bbc.co.uk/programmes/articles/3KpL3khByCkMwS3jmcCQFMb/the-big-brain-boost-experiment

*This BBC experiment tested Coffee against Sage in a one off single experiment, most people probably use coffee to sustain effort over a long period throughout the day, the effectiveness of this strategy was not tested in this experiment.   

5. http://webcache.googleusercontent.com/search?q=cache:toKutzBZxIwJ:www.mdpi.com/1420-      3049/16/2/1181/pdf+&cd=8&hl=en&ct=clnk&gl=nz
6. Singh R J Editor. Genetic Resources, Chromosome Engineering, and Crop Improvement: Medicinal Plants, Volume 6. 2011
7. Crowe A. A Field Guide to the Native Edible Plants of New Zealand. 1981.
8. http://www.bio.auth.gr/v1/en/content/mentha-spicata-essential-oils-rich-18-cineole-and-12-epoxy-p-menthane-derivatives-zakynthos
9. Cribb AB JW. Wild Food in Australia. 
 *  The authors experimented with this tea and liked it, I don't know if it has become widely used (proven safe) as a result of their recommendations,  it appears no incidents have resulted from their publication, I like it a lot & use it a few time a month.
10. http://www.pharmaceutical-journal.com/opinion/blogs/aromatic-myrtle-and-its-medicinal-uses/11010104.blog
11. Facciola S Cornucopia II. 1998.

Tuesday, January 3, 2017

A possible reason the internet doesn't really seem to have made the world a better place overall.

One would expect the vast information, consumer and supposed social choices opened up by the internet would have made the world better than ever by now, it certainly usually feels to me like progress while I'm using it. But I'm not aware of any evidence the world has become a better place overall in recent decades. If anything I think it can be argued it's getting crazier; more random and impulsive, on the news, in traffic, on footpaths, workplaces, supermarkets and public transport. Simple tasks like walking in a straight line down the street now seem to be utterly impossible, even repugnant, for most people, even when they're not looking at their phones.

I think this may be because many aspects of the internet, such as largely random and arbitrary interpersonal exchanges, are contributing to what psychologists call "ego depletion" or the depletion of self-control. Psychologists believe we all have limited self-control, we are only capable of a certain amount each day, as we use it on resisting annoyances or temptations (for instance) it gets used up.

Despite its extraordinary potential for good the internet is also full of unprecedented temptations, annoyances, distractions and provocations which all deplete self-control. I think creating a whole new arena of ego-depletion may be too much for people, causing them to have less self-control in in the "real world" causing the world to become less civilized overall.

People concerned about this may need to either cut out certain aspects of internet use, if this is possible, or cut out some other depleting aspect of their lives such as living in cities if they are going to continue using the net.


Willpower. Rediscovering the Greatest Human Strength . Baumeister and Tierney. 2011.
Handbook of Personality and Self-Regulation. Ed. Hoyle. 2014.