Caffeine: what effects does it have on health and vision?

Lenstore analyzed the possible symptoms in the short and long term, and also revealed the ranking of the most “caffeinated” cities based on coffee consumption and the cost of a cup at the bar.

For many of us, the morning does not start without a cup of coffee. Giving us the fee is caffeine, a substance that we also find in many other foods, such as tea, chocolate, energy drinks and Coca Cola. His benefits are many: it reduces the risk of type 2 diabetes, protects against Alzheimer’s and dementia, even helps burn fat.

Although it is a valuable ally for health, caffeine can cause various problems if we consume too much of it. Lenstore has analyzed the possible symptoms short and long term, such as blurred vision, muscle aches and insomnia. It also reveals the ranking of cities more “caffeine dependent” based on the consumption of coffee and the cost of a cup at the bar.

What happens if we drink too much coffee? – A healthy adult should not consume more than 400 mg of caffeine per day, which is almost four cups of coffee. In Italy, the average per capita coffee consumption is 3.7 kg. What risks do we run if we do not change our habits?

  • Anxiety – Caffeine stimulates the production of adrenaline, the hormone behind the fight or flight reaction (in English fight or flight). Excessive consumption amplifies these effects, causing nervousness, anxiety and tension. It has also been shown to increase stress levels regardless of the dose taken.
  • Insomnia – If you love coffee, remember not to drink it before you go to bed. Caffeine actually alters sleep cycles and prevents you from resting well (according to various studies, it can remain in the circulation for up to nine hours). Insomnia can cause many vision problems, such as dry eyes. To alleviate it, use moisturizing eye drops and avoid using contact lenses as much as possible.
  • Migraine – Did you know that caffeine can both cause and cure migraines? This is supported by a survey conducted in the UK. In fact, 22% of respondents said they had a headache after taking caffeine, while 43% said the opposite. How is that possible? This substance narrows the blood vessels around the brain, which reduces inflammation and thus provides relief. Not surprisingly, many over-the-counter painkillers are available. However, it is the same mechanism that can cause migraines. In fact, when you do not take caffeine for a while, your blood vessels expand again and the pain returns.
  • Dizziness and dizziness – Like other stimulants (such as tobacco), caffeine also reduces the blood supply to the brain and abusing it can make you dizzy and dizzy.
  • Muscle tremors – Too much caffeine can also cause various types of spasms, such as tremors in the eyelids or hands. Often these are just transient sensations, but sometimes they can mean that it is appropriate to reduce the consumption of coffee.
  • Blood hypertension – Caffeine does not seem to affect the risk of heart disease, but according to several studies, it increases blood pressure. This is why you need to be careful about how much you take if you already have high blood pressure – if you abuse it, you may have a higher risk of heart attack or stroke.
  • Hypertension and vision – High blood pressure can damage the small blood vessels that carry blood to the eyes. Retinopathy is a possible complication that affects the retina and can lead to blurred vision, eye bleeding and even blindness. Hypertension is also responsible for various problems with the nervous system, which plays an important role in eye health. An example is choroidopathy, a disease that causes fluid to accumulate in the retina, which impairs vision. Various studies also show a link between excessive daily caffeine consumption and the risk of glaucoma for those with a genetic predisposition to high eye pressure. Symptoms of glaucoma include pain and redness in the eyes, seeing rings around a light source and blurred vision. If left untreated, it can lead to blindness.
  • Confusion and hallucinations – Irritability, anger, confusion: Caffeine can trigger a range of strong emotions, even if not consumed for a certain period of time. The reactions range from difficulty concentrating to depression. If you notice that your mental health is affected, talk to your doctor. In addition, excessive consumption of coffee can raise stress levels (and thus those of adrenaline) and cause confusion or even hallucinations. On the other hand, caffeine withdrawal can often cause mental fog. If you have ever had these problems, it means that you need to start reducing your consumption of this substance.
  • Blurred vision – Excessive consumption of caffeine can cause a sudden increase in blood sugar levels. Possible consequences are blurred vision, eye twitching and potentially a burning or stinging sensation in the area around the eyes.

The ranking of the capitals where most coffee is drunk – To find out which are the 20 most “caffeinated” capitals, Lenstore examined various parameters: coffee consumption, the number of bars per square kilometer (2.59 km)2) and the average cost of a cup of coffee. Let’s see the result.

Top 20 of the most caffeinated capitals

Village City Number of bars Bars per square kilometer (2.59 km2) Bars for 10 square miles (25.9 km)2) Coffee consumption per capita (kg) per year Cost of a coffee (€)
Greece Athens 261 17.4 174.0 2.4 2.96
Slovenia Ljubljana 45 0.7 7.1 6.1 1.86
Italy Gypsy 677 1.4 13.6 3.4 1.30
Finland Helsinki 113 0.4 4.1 9.6 3.97
Portugal Lisbon 169 4.3 43.3 2.6 1.78
Hungary Budapest 340 1.7 16.7 3.1 1.51
Sweden Stockholm 144 2.0 19.7 8.2 4.01
Netherlands Amsterdam 186 2.2 21.9 6.7 3.53
Iceland Reykjavík 41 0.4 3.9 9 4.15
Costa Rica San Jose 40 2.4 23.5 3.7 2.20
Spain Madrid 484 2.1 20.8 3 2.02
South Korea Seoul 2192 9.4 93.7 2.6 3.65
Germany Berlin 689 2.0 20.0 5.2 3.05
Colombia Bogotá 156 0.3 2.5 1.4 1.11
Austria Vienna 287 1.8 17.9 5.5 3.46
Estonia Tallinn 71 1.1 11.5 4.2 2.81
Belgium Brussels 68 1.1 10.8 4.9 3.15
France Paris 287 7.0 70.0 3.2 3.83
Czech Republic Prague 438 2.3 22.8 2.3 2.30
Ireland Dublin 234 5.1 50.9 3.5 3.54

With 677 bars, Rome ranks third among the capitals where most coffee is consumed, immediately after Berlin (689) and London (1570). The Eternal City is also one of the cheapest places in the world to have a coffee (€ 1.30), only beaten by Bogota (€ 1.11) and Istanbul (€ 1.13). Athens, on the other hand, is ranked first as the most coffee-obsessed city in general. It has more than 174 bars per 10 square kilometers, followed by South Korea (94) and France (70).

But who drinks the most coffee? The Nordic countries dominate the top 10 where we find Finland, Iceland and Sweden. Finland even has an annual per capita consumption of 9.6 kg of coffee, more than three times as large as in countries such as the United Kingdom (1.7 kg), New Zealand (1.3 kg), the United States (3, 1 kg ) and France (3.2 kg). kg). At the bottom of the ranking we find Turkey, with a per capita consumption of only 0.4 kg per year. Strangely enough, the United States consumes less coffee than most other countries (3.1 kg) and the United Kingdom is among the bottom seven.

The 10 cities where a coffee is cheaper

City Village Cost of a coffee (€)
Bogotá Colombia 1.11
Istanbul Turkey 1.13
Gypsy Italy 1.30
Budapest Hungary 1.51
Lisbon Portugal 1.78
Ljubljana Slovenia 1.86
Mexico City Mexico 2.00
Madrid Spain 2.02
San Jose Costa Rica 2.20
Bratislava Slovakia 2.21

Bogotà wins the title of the cheapest city to have a coffee: it costs only € 1.11, almost a fifth of the price we find in Copenhagen (€ 5.35). In general, Europe and South America dominate the ranking: Rome, for example, is in third place with € 1.30.

The 10 cities with the highest number of bars per square kilometer (2.59 km)2)

City Village Bars per square kilometer (2.59 km2)
Athens Greece 17.4
Seoul South Korea 9.4
Paris France 7.0
Tokyo Japanese 6.0
Dublin Ireland 5.1
Lisbon Portugal 4.3
London UK 2.6
Copenhagen Denmark 2.5
San Jose Costa Rica 2.4
Prague Czech Republic 2.3

Methodology – For the purposes of this study, Lenstore analyzed the long- and short-term effects of high caffeine consumption, both physically and mentally. To find out in which capitals the most coffee is consumed, he then examined: the consumption of coffee per capita, the average cost of a coffee and the number of bars per square kilometer. Finally, he used Google Keyword Planner to get a seed list of the most popular coffees in 38 countries.

Nurse Times editorial staff

Leave a Comment