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The Impact of Caffeine on the Body: Exploring Its Benefits and Drawbacks

For many years there has been an ongoing debate on caffeine and its impact on our health & wellbeing. For many of us this means knowing how many coffees to limit ourselves to each day, however, caffeine is prominent in many different food and drink sources, meaning before we know how much caffeine we should be consuming, we should first probably know everything  contained within! Lucky for you, we’ll let you know in this article.

Caffeine: Where Is It & What Is It?

Caffeine is a drug, a stimulant often used to increase our energy, this occurs as the stimulant increases the activity of our brain and nervous system. Caffeine has numerous pharmacological and physiological effects, including renal, cardiovascular, respiratory, and muscle effects. On top of this, caffeine impacts our mood, memory, alertness, and physical and cognitive performance.

Commonly people associate caffeine with coffee, however, caffeine is also found in many other drinks and foods. Some of those include:

Any foods or drinks made containing these ingredients will then also have traces of caffeine! If our caffeine intake is already possibly too high from coffee alone it’s crucial to remember what other foods you may be consuming which also contain caffeine.

Weighing The Caffeine Pro’s and Con’s

The effect of caffeine on the body varies from person to person and is influenced by genetics, body weight, medications, health conditions, and an individual's regular caffeine intake.

People with high blood pressure or heart conditions should be cautious when consuming caffeine as it can increase blood pressure and heart rate. Those with anxiety disorders may find that caffeine exacerbates their symptoms, causing increased nervousness and jitteriness. Additionally, caffeine can interfere with sleep quality, causing insomnia and restlessness, which can have a negative impact on overall health and wellbeing.

Moderate caffeine intake can have positive effects on the body:

  • Energy Boost: Caffeine acts as a stimulant, blocking a neurotransmitter called adenosine, which triggers the release of norepinephrine and dopamine. These chemicals make us feel more alert, energised, and awake.
  • Increased Exercise Performance: Caffeine ingestion has been shown to enhance physical performance, particularly in terms of maximal muscle strength and muscle power.
  • Increased Metabolism: Caffeine can slightly increase metabolic rate by 3-11%, mainly due to its fat-burning properties.
  • There is ample evidence to show that drinking some caffeine supports cardiovascular health and reduces heart disease risk.

Caffeine Can Exacerbate Stress and Anxiety

While it's advised that no one consumes more than 400mg of caffeine a day (which is about 4 or 5 shots of espresso), you might be one of the people who find their anxiety spikes after 240mg.

Caffeine acts as a stimulant that elevates the activity levels within the brain and nervous system. Its primary mode of action involves the stimulation of the adrenal glands, which are small glands positioned just above the kidneys, leading to the release of stress hormones such as adrenaline and cortisol.

This surge of adrenaline and cortisol is responsible for the mildly euphoric and awakened state experienced after consuming caffeine. However, it is important to acknowledge that these hormones can also induce negative effects. Excessive caffeine consumption in the short term can potentially result in dizziness, irritability, anxiety, sleep disturbances, dehydration, restlessness, and a more pronounced energy slump once the effects of caffeine wear off. Excessive consumption over the long term can lead to symptoms such as confusion, lethargy, increased weight gain in the abdominal region, as well as heightened cravings for sugars and processed carbohydrates.

Caffeine Affects Cortisol Levels: Drink After 8 am And Before 2 pm

Cortisol is a hormone that can enhance alertness and focus. It also regulates your metabolism, immune system response, and blood pressure. Caffeine disrupts the regular rhythm of cortisol.

Drinking coffee too soon after rising decreases its energising effects, as your stress hormone cortisol is at its peak level between around 7:00–08:00 a.m, it is suggested that by delaying your consumption of caffeine until after this period would mean you would likely benefit from more sustained energy.  

It is also recommended to not consumer any caffeine after around 2-3pm to keep a healthy sleep & wake cycle intact. It is important to note that whilst there's plenty of research proving that caffeine disrupts sleep, there's only one study focusing on how caffeine consumption timing affects sleep. This study's results confirmed that having caffeine as early as six hours before bedtime can impact sleep, even if you don't actually notice the disruption.

Quitting Caffeine Without a Plan Is Not Recommended

If a reduction to your consumption of caffeine is necessary, due to planning pregnancy or in order to manage a health condition, it is recommended to prepare and seek advice from your GP for some potential side-effects from withdrawal;

“Withdrawal from caffeine causes mild to clinically significant distress and impairment of normal functioning. The severity of symptoms vary from individual to individual, and most commonly include a headache, fatigue, decreased energy/activeness, decreased alertness, drowsiness, decreased contentedness, depressed mood, difficulty concentrating, irritability, and feeling foggy/not clearheaded.” (Karima R, et al 2022)

The severity of the above symptoms intensifies with increases in the daily dose of caffeine. Still, abstinence from low doses, such as about one small cup of coffee per day, also produces symptoms of withdrawal.

The Bottom Line

While caffeine has several benefits, excessive intake can have negative effects on the body. Moderation is crucial to enjoy the benefits of caffeine without negatively impacting health.

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