A new study finds that drinking a small amount of caffeine in the morning may improve alertness, memory, and attention in healthy young men.
The caffeine dose was equivalent to about one cup of coffee.
Key Facts:
- 25 healthy young men drank either a placebo or 50 mg of caffeine (amount in a cup of coffee)
- Caffeine decreased a type of brain wave called alpha waves, which are linked to daydreaming/relaxation
- Caffeine improved performance on tests of processing speed, working memory, and attention
- The effects lasted for over an hour, even after exercise
- The findings suggest low caffeine doses may sharpen thinking and focus to start the day
Source: Physiology & Behavior (Vol 256, Nov 2022)
How Caffeine Affects the Brain
Many people consume caffeine in the morning for a burst of energy to tackle the day ahead.
Caffeine is found in various beverages like coffee, tea, soda and energy drinks.
It’s also added to some foods. Caffeine is considered a stimulant drug.
When consumed, it passes quickly into the bloodstream and travels to the brain.
There, it blocks receptors for a brain chemical called adenosine.
Adenosine normally builds up over the day and makes you feel tired.
By blocking its effects, caffeine provides a sense of alertness and increased energy.
Even small amounts around 50 mg, or half a cup of coffee, can produce these effects.
But caffeine doesn’t just make you feel more awake.
Evidence shows it can also sharpen thinking and focus, especially when you’re fatigued.
Researchers think this is because caffeine causes changes in brain wave patterns.
Our brains generate electrical activity in patterns called brain waves.
Certain types of brain waves are linked to being drowsy versus alert.
Alpha waves in particular are slower waves associated with quiet relaxation and daydreaming, whereas beta waves reflect active thinking and focus.
Previous studies found that caffeine decreases alpha waves in the brain, which is thought to support a more alert state.
This study aimed to confirm caffeine’s effects on brain waves using electroencephalography (EEG).
The Study on Caffeine, Brain Waves & Cognitive Function
The study was conducted by researchers at universities in Thailand. It included 25 healthy male college students. Their average age was 21 years.
On two occasions separated by a week, the young men consumed either 50 mg of caffeine or a placebo at breakfast.
Neither the researchers nor participants knew which was consumed until after the study.
After 30 minutes, the participants underwent EEG to measure brain waves.
EEG uses electrodes placed on the scalp to record the brain’s electrical activity.
The participants also completed tests measuring attention, working memory, and information processing speed.
These are cognitive skills needed for learning, reasoning and decision-making.
After exercising for 5 minutes on a stationary bike to simulate morning activity, they repeated the EEG and cognitive tests.
Caffeine Decreased Alpha Brain Waves
The EEG results showed caffeine caused a decrease in alpha waves compared to placebo.
Alpha waves were reduced across widespread areas of the brain including over the frontal lobe (linked to focus), parietal lobe (linked to processing information) and occipital lobe (linked to vision) regions.
This aligns with prior research indicating caffeine reduces alpha waves associated with a relaxed, idle state and increases alertness.
Alpha waves are considered a marker of reduced mental arousal.
Caffeine Improved Performance on Cognitive Tests
On the tests of thinking skills, caffeine improved working memory and processing speed compared to placebo.
- Working memory is vital for learning and problem-solving. It lets you temporarily hold information in mind and manipulate it. The researchers assessed working memory using a challenging test called the Trail Making Test Part B. Those who took caffeine completed the test faster and more accurately than those given placebo.
- Processing speed refers to how rapidly you can take in and react to information. It was measured using the Trail Making Test Part A in which participants quickly connected numbered dots on paper. Caffeine speeded up performance.
- Attention was evaluated using a test called Digit Span Forwards that involves repeating back increasingly long number sequences. Caffeine slightly improved attention span but the difference wasn’t statistically significant.
Overall, the findings add to existing research showing low to moderate doses of caffeine can enhance cognitive performance.
Caffeine’s stimulant effects likely sharpen attention processes and memory.
The Coffee Habit: Pros and Cons
Should you start drinking coffee for the brain boost?
Moderate caffeine intake of up to 400 mg per day is considered safe for most adults.
Beyond that, side effects like anxiety, insomnia, irritability and muscle tremors can occur.
For healthy people who enjoy its flavor and mild stimulant effects, coffee can be part of a healthy lifestyle.
In addition to increasing alertness, coffee provides antioxidants and may benefit heart health and liver function for some.
However, don’t rely on caffeine to function. Chronic use can lead to dependence.
If you try to cut back, withdrawal symptoms like headaches and fatigue can result.
Caffeine sensitivity can also vary widely between individuals due to genetics and other factors.
It tends to increase with age, so older adults may be more affected by a given dose.
The bottom line is caffeine can improve temporary alertness and focus when used judiciously.
But aim for moderation and avoid overdoing it. And be aware of your individual response.
How Long Do Caffeine’s Effects on Cognition Last?
An interesting finding from the study was that caffeine’s brain-boosting benefits persisted even after the participants exercised.
The 50 mg caffeine dose (equal to about 1 cup of coffee) continued to produce faster information processing speed and working memory 35 minutes post-drink.
This suggests low caffeine doses can prime the brain for cognitive work lasting over an hour.
Most prior research tested caffeine’s mental effects 20-60 minutes after consumption using resting brain wave measurements or cognitive tests.
This study incorporated light exercise to better mimic real world conditions after having morning coffee.
The 5 minutes of stationary biking was meant to simulate typical physical activity like showering, getting dressed or doing housework after drinking caffeine.
The fact that caffeine continued to enhance thinking after this activity implies its cognitive benefits can last through light morning routines before work or school.
Exactly How Does Caffeine Provide a Mental Lift?
Caffeine is known to improve mood, mental alertness and thinking abilities like focus, learning, and memory.
But scientists are still studying exactly how it exerts these effects in the brain.
Caffeine’s main mechanism is blocking adenosine, leading to increased firing of neurons and release of other natural brain chemicals that promote alertness like dopamine, acetylcholine, serotonin, adrenaline, and glutamate.
But researchers believe added mechanisms also play a role in caffeine’s cognitive enhancer effects.
Possibilities include increased blood flow to the brain, improved neuron connections and communication, and increased efficiency of key brain networks.
Interestingly, the researchers also observed that the decrease in alpha waves from caffeine was directly correlated with improved scores on the working memory test.
The decline in alpha waves likely reflects more active cognitive processing and less daydreaming.
This study provides stronger evidence of functional brain changes underlying caffeine’s benefits for thinking skills.
Using EEG was a key strength, as it provides direct insight into how caffeine alters brain waves to sharpen cognition.
Who Can Benefit from Caffeine’s Brain Boost the Most?
The participants were healthy young men in their early 20s with no sleep deprivation or disorders.
Yet a modest dose of caffeine still enhanced their brain activity and thinking skills.
Other research suggests caffeine’s cognitive benefits are even more pronounced for certain groups:
- Older adults: Cognition tends to decline with aging. Caffeine seems to provide greater stimulation for the aged brain. One study found 200 mg improved older adults’ speed and accuracy on cognitive tests.
- Tired individuals: Caffeine is particularly useful when you’re fatigued. Shift workers, for example, use it mitigate sleepiness and errors. One study found 600 mg reduced major mistakes among night shift nurses.
- Attention deficit hyperactivity disorder (ADHD): Those with ADHD may have abnormal arousal and attention brain networks. Caffeine helps normalize these networks to boost alertness, concentration, organization and impulse control.
- Memory impairments: By activating certain signaling pathways in the brain, caffeine may reverse memory deficits from conditions like Alzheimer’s disease in animal models. More research is underway.
Things to remember about caffeine
Consuming a small amount of caffeine equivalent to about one cup of coffee decreases alpha brain waves and increases alertness and focus.
Caffeine’s cognitive enhancing effects include improved working memory, information processing speed, and attention.
The mental boost lasts for at least an hour and persists even after light physical activity.
Caffeine provides greater cognitive benefits for the elderly, people who are tired, those with attention deficit disorders, and those with memory impairment.
While effective for temporary mental boosts, regular high intake of caffeine may cause dependency and other problems. Avoid excess consumption.
References
- Study: A low-dose of caffeine suppresses EEG alpha power and improves working memory in healthy university males
- Authors: Amornpan Ajjimaporn et al. (2022)
