Over the past month, we’ve explored the various ways our diet can impact mental energy.

It’s clear that what we eat affects our cognition in both the short term and over the long run.

However, as we've seen previously here at OptiMindInsights, our perception often shapes our reality.

That led me to wonder:

Does our perception of what we eat also influence how our food affects our brain and body, in ways that matter for mental energy?

Today’s insights are mainly drawn from two different scientific articles:

“Placebo expectancy effects in the relationship between glucose and cognition” Green et al, 2001

“The influence of Caffeine Expectancies on Sport, Exercise and Cognitive Performance” Sharbir et al, 2018

Today's newsletter

• Takeaways:

• Glucose and cognition:

• Caffeine and belief:

• What can we learn from these studies?

Takeaways:

🧠 Perception powers performance

Believing you’ve consumed a “brain-boosting” nutrient (glucose, caffeine, etc.) can sharpen attention, memory, and even physical output.

🎯 Pair nutrients with mindset

Maximize the benefits of energizing foods and drinks by intentionally expecting them to help. A positive mindset can act as an amplifier for the effects you’re hoping for.

Glucose and cognition:

In today’s first study, the authors explored whether the cognitive benefits that can often be seen after glucose consumption are due to the glucose itself or to people’s expectations about its effects. 

They used a balanced placebo design, and had 26 participants complete cognitive tasks across four sessions where they received either a glucose or a placebo aspartame drink. 

Sometimes participants were being correctly informed about the contains of the drink, and sometimes they were informed the opposite.

The results showed that glucose did improve performance on a sustained attention task and reduced response times in a recognition memory task.

However, the improvement in attention was only observed when participants was informed, and therefore believed they had consumed glucose.

To put it simply, the results suggests that some of the cognitive benefits from glucose consumption may not stem purely from glucose’s physiological effects, but also at least to some degree from expectations about the effect of glucose.

This phenomenon - where our expectations change how something works - is also known as the placebo effect. If you’d like to learn more, check out this short video.

Caffeine and belief:

The second study of today is a systematic review that looks at how peoples expectations about caffeine, influence the effect caffeine has on sport, exercise, and cognitive performance.

The review analyzed 17 studies where participants were either given caffeine or a placebo and told various things about what they were consuming.

In 13 of those studies, the expectation of consuming caffeine improved performance in tasks ranging from endurance cycling to attention and memory.

The authors conclude that much like we saw in the glucose-study, caffeine’s performance-enhancing effects may come just as much from the mind as from the molecule itself.

One of the studies included in this review, was the Beedie et al. (2006)-study: 

In this study, well-trained male cyclists completed multiple cycling trials after being told they had consumed different doses of caffeine (low or high), although they were actually given a placebo every time.

Even though no real caffeine was ingested, performance improved in a dose-dependent manner based on what participants believed they had taken.

Cyclists who thought they had received a higher dose of caffeine produced more power than those who thought they had received a lower dose, and both outperformed the control trial.

Another study that looked at the effect of caffeine on cognitive performance is the Fillmore & Vogel-Sprott (1992)-study: 

This study explored how expectations about caffeine affect psychomotor performance. 

Participants all consumed decaffeinated coffee, and were decided into groups.

They were told the coffee would either enhance, impair, or have no effect on performance.

Despite ingesting no caffeine, those who expected a performance boost (the “told enhance” group) performed significantly better on a computerized motor tracking task than those told it would impair or do nothing.

👉 Want to try a computerized motor tracking task yourself? Try the Stroop Test on the resource site.

What can we learn from these studies?

These studies all clearly show that part of the diet’s effect on our cognition and physiology is affected by our perception of what we eat.

Although we have seen some interesting connections between nutrition and mental energy this month, the key takeaway is that our mindset toward what we ingest likely shapes those effects as well.

_{Disclaimer: The above is mainly based on the 4 articles mentioned in the beginning of this newsletter, and aims to provide key takeaways and a condensed overview of its content. While the essence is drawn from the original articles, some parts have been simplified or rephrased to enhance understanding. Please note that we at, OptiMindInsights or any other potential writers or contributors to our summaries, do not accept responsibility for any consequences arising from the use of these summaries and/or newsletters as a whole. The information provided should not be considered a substitute for personal research or professional advice. Readers are encouraged to consult the original articles for detailed insights and references. The summary does not include references, but they can typically be found within the original publication. Always exercise due diligence and consider your unique circumstances before applying any information in your personal or professional life. We refer to the creative commons for reproducibility rights.}