What Does Science Say About Caffeine?

There are different opinions regarding caffeine consumption. However, scientific studies have determined that, in most healthy adults, it has positive effects when taken in moderate amounts.

What does science say about caffeine? First, there is great public and scientific interest in the adverse health effects of regular consumption of caffeinated beverages.

However, the studies are not conclusive. To date, only one cause-effect association related to caffeine consumption and negative outcomes during pregnancy is known.

What science says about caffeine, especially through epidemiological studies, is that this substance has a beneficial effect on reducing the risk of numerous chronic diseases.

To understand its effect on health, it is first necessary to know where this active compound comes from.

Where does caffeine come from?

Caffeine is the most consumed stimulant in the world. Its main sources are:

Nuts glue ( glue acuminate ).
Cocoa beans ( Theobroma cacao ).
Yerba mate ( Ilex paraguariensis ), consumed in some South American countries.

Guarana berries ( Paullinia cupana ).
Roasted coffee beans ( Arabic and Robusto ) and tea leaves (Camellia sinensis) , their main food sources in the world.

In addition to the above sources, caffeine is found in some pain relievers, sodas and energy drinks, as well as dietary supplements.

Caffeine concentration varies widely among beverages that contain it; coffee is the beverage with the highest concentration, at 100 mg/cup. The second is mate, with an average of 78 mg, followed by black tea with 55 mg.

Coffee is the beverage with the highest concentration of caffeine. After him, we can mention mate and black tea.

Caffeine absorption and metabolism

Once ingested, caffeine is rapidly and completely absorbed from the gastrointestinal tract (bioavailability is 100%) to be metabolized in the liver to form 3 important metabolites:

3,7-dimethylxanthine
1,7-dimethylxanthine
1,3-dimethylxanthine

What does science say about caffeine about its absorption? This compound exerts physiological effects throughout the body. We will detail them below.

Physiological mechanisms of caffeine

First, caffeine works as an adenosine receptor antagonist in the brain since, having a similar molecular structure to adenosine, it has the ability to occupy its receptors (mainly A1 in the hippocampus and A2 in dopamine-rich brain areas ).

By blocking the binding of adenosine in neurons (which induces sleep), it stimulates the activity of the central nervous system (CNS). In general, the low consumption of this substance (between 20 and 200 mg per day) produces positive effects on the feeling of well-being, attention and energy.

However, higher doses can trigger nervousness and anxiety, especially in people who are not used to drinking beverages rich in this compound.

Caffeine Consumption and Parkinson’s Disease

Parkinson’s disease arises after the progressive reduction of dopaminergic neurons in the substantia nigra.

Caffeine, by improving the performance of the dopaminergic system thanks to its antagonistic effect on adenosine receptors, stimulates the release of dopamine, reducing the deterioration of fine and gross motor activities.

Caffeine consumption favors the production of dopamine, the neurotransmitter involved in Parkinson’s disease.

Caffeine Consumption in Obesity and Diabetes

What science says about caffeine and its effect on weight loss is extremely interesting. In this context, this substance has been shown to have an activity on metabolic rate, energy expenditure and thermogenic activities (mainly on lipids).

Consuming 300 mg/day of caffeine inhibits the AMP-phosphodiesterase cycle to increase cyclic AMP and, by antagonizing adenosine receptors, increases norepinephrine release; effects that induce weight loss by increasing lipolytic activity.

In addition , numerous studies suggest an inverse relationship between caffeine consumption from coffee and the risk of developing type 2 diabetes. In individuals who consume at least 6 cups of coffee a day, the risk of developing the disease was 35% lower. Meanwhile, for those who consume 4 to 6 cups, the risk reduction was 28%.

Effect of caffeine on mineral absorption

When consuming a beverage that contains caffeine with main meals, it is difficult to absorb important minerals such as iron and calcium.

Some cohort studies have reported that high doses of caffeine increase urinary calcium excretion, increasing the risk of bone problems. Therefore, the recommendation is to moderate the consumption of caffeine to, at most:

4 cups of black coffee.
3 cappuccinos.
6 cups of coffee.

Note: It is necessary to follow these recommendations with an adequate calcium intake.

Caffeine in pregnancy and breastfeeding

The reason caffeine is contraindicated during pregnancy and breastfeeding is because it has the ability to cross the placenta and stimulate the fetal metabolic rate.

High doses of caffeine ingested during pregnancy are associated with the development of congenital anomalies, miscarriages, low birth weight and changes in the behavior of the newborn.

Caffeine is also transferred directly through breast milk, causing irritability and sleep disturbances in the baby. Therefore, the maximum recommended intake of caffeine during pregnancy is less than 200 mg per day.

Excessive caffeine consumption during pregnancy and while breastfeeding is harmful to the baby.