Food + Mood Quiz: Sadly, it’s true – too much caffeine can affect your mood – and worsen the symptoms of anxiety and depression.

Its important to know how food can impact mood, so we can regulate our eating and drinking habits… This is especially important if you’re prone to low mood – or if you’re particularly sensitive to caffeine. In fact, caffeine affects mood in a surprising number of ways …

1. Central Nervous System Stimulation

Caffeine acts as a stimulant that affects our central nervous system, (CNS). When caffeine is consumed, it leads to an increase in the release of neurotransmitters (chemical messengers) such as dopamine and noradrenaline, resulting in heightened alertness and improved mood when consumed in moderation. All great – however, excessive caffeine can lead to feelings of nervousness, restlessness, and irritability – potentially contributing to anxiety.

2. Disturbed Sleep Patterns

Caffeine can remain in the system for an extended period, so if caffeine is consumed later in the day, it can disrupt the ability to fall asleep or get restful sleep.  As you might expect, poor sleep quality and insufficient sleep are associated with mood disturbances – and an increased susceptibility to anxiety and depression. This is especially so if you are older, as we metabolise caffeine more slowly as we age. This means the caffeine stays in our system for longer.  So if you could tolerate 8 cups of coffee a day in your 20s, you may no longer be able to do so in your 40s. In terms of heart health, its thought that more than 4 cups a day is linked to heart ‘events,’ like stroke.

3. Cortisol Production

Caffeine consumption can stimulate the release of cortisol, a stress hormone. Elevated cortisol levels are linked to heightened stress and anxiety. Prolonged consumption of caffeine can establish an uncomfortable cycle of increased cortisol production and an intensified stress response.

4. Imbalance of Mood Chemicals 

Excessive caffeine intake may, over time, disrupt the regulation of mood-related neurotransmitters such as serotonin. Reduced serotonin levels may be associated with symptoms of depression, and some research suggests that excessive caffeine consumption may contribute to this imbalance.

5. Withdrawal Symptoms

Of course, regular caffeine intake can lead to dependence. When caffeine consumption is abruptly reduced, withdrawal symptoms may be experienced, including irritability, low mood and fatigue. So if you would like to reduce your consumption, do so very slowly – to avoid withdrawal symptoms similar to the ones you’re trying to reduce in the first place. For example, if you typically drink 6 cups of coffee a day, switch to 5 cups for a week, then drop to 4 the following week. You could swap the coffee for decaf coffee or tea or even dandelion coffee, which is caffeine free. If you’re concerned about decaffeination and solvents, be sure to use decaf products that have used water to remove (99% or so) of caffeine rather than solvents. Nespresso, for example use water based decaffeination methods in their pods. Twinings are believed to use the water and carbon dioxide to decaffeinate their teas. Call your favourite brand and ask them.

6. Interactions with Medications

Caffeine may interact with certain medications, including SSRI’s such as Sertraline and Seroxat. These interactions may either intensify the effects of these medications – or potentially even lengthen the time the caffeine is in the body. Individual sensitivity to caffeine varies widely, and some people may be more susceptible to its negative effects, for example, a feeling of ‘jitteriness.’ Some people may only tolerate much less caffeine.

It’s worth knowing that green tea contains about 20% of the caffeine found in coffee. This allows for a smoother caffeine lift than that from a cup of coffee. According to the literature, green tea may even offer antidepressant* effects.

Now we know how caffeine affects mood, body and brain, we can make adjustments –

To promote improved mood and mental well-being, consume caffeine in moderation and to be mindful of its impact on mood and sleep especially if you have a history of anxiety or depression. Secondly, avoid caffeine later on in the day, especially after lunch. Bear in mind that caffeine is found in some energy drinks, as well as tea, including green and jasmine tea and in chocolate – more so in dark chocolate. Choose naturally decaffeinated drinks such as ginger or peppermint tea.

For more detail on how caffeine or other foods in your diet are affecting your mood or sleep, book a nutrition consultation with Sarah.

*Akbarialiabad H, Dahroud MD, Khazaei MM, Razmeh S, Zarshenas MM. Green Tea, A Medicinal Food with Promising Neurological Benefits. Curr Neuropharmacol. 2021;19(3):349-359. doi: 10.2174/1570159X18666200529152625. PMID: 32469701; PMCID: PMC8033961.