What if the foods we eat influence more than our waistline? What if they also influence the raw materials and metabolic signals involved in brain chemistry?
That was one of the fascinating themes in my conversation with Cristine Hull, author of 10 Ways to Balance Brain Chemistry, on Energize & Revitalize with Dr. Amy.
During our discussion, Cristine referenced the well-known book Potatoes Not Prozac by Kathleen DesMaisons and its intriguing theory about the relationship between carbohydrates, tryptophan, serotonin, cravings and mood.
The idea sounds almost too simple: Could eating a potato affect serotonin?
The answer requires a little more explanation.
Your Brain Chemistry Starts With What You Eat
Neurotransmitters are chemical messengers that help regulate many functions throughout the nervous system, including mood, motivation, appetite and sleep.
And your body needs raw materials to make them.
One important example is tryptophan, an amino acid that serves as a precursor for serotonin. Another is tyrosine, which is involved in the production of dopamine and norepinephrine.
That gives us an important reason to pay attention to the quality and variety of the foods we eat. Nutrition isn’t simply about calories. It’s also about providing the nutrients your body needs to carry out complex biochemical processes.
The Fascinating Connection Between Carbohydrates and Serotonin
Here’s where the potato comes into the conversation.
Research has demonstrated that carbohydrate consumption can affect the availability of tryptophan to the brain. One proposed mechanism involves insulin: after carbohydrate consumption, insulin changes the levels of several amino acids circulating in the blood. Because those amino acids compete with tryptophan for transport into the brain, changes in their relative concentrations can make tryptophan more available.
In controlled research, carbohydrate-rich meals have been associated with increases in brain tryptophan and serotonin synthesis, particularly in animal studies.
And that brings us to Potatoes Not Prozac.
What Does a Potato Have to Do With Potatoes Not Prozac?
Kathleen DesMaisons’ book takes this biochemical concept and incorporates it into a broader seven-step nutritional approach.
The idea isn’t simply “eat potatoes and cure depression.”
Rather, the book proposes that dietary patterns, blood sugar regulation, cravings and brain chemistry are interconnected. One of the distinctive elements of the program is the use of a potato as a carbohydrate source in a particular context.
This is where it gets especially interesting.
The underlying biochemical theory is that a carbohydrate-rich, relatively protein-free meal can increase the ratio of tryptophan to competing amino acids, potentially allowing more tryptophan to enter the brain. Research has demonstrated this mechanism in controlled experimental settings.
So the interesting question isn’t really: “Does a potato contain a magic serotonin ingredient?”
It doesn’t.
The more accurate question is: “Can the carbohydrate content of a food influence the biochemical environment that affects tryptophan availability and serotonin synthesis?”
There is research supporting that biological mechanism, although that doesn’t establish that eating potatoes treats depression or other mood disorders.
Why Protein Still Matters
This discussion shouldn’t be interpreted as an argument against protein. Quite the opposite.
High-quality protein is incredibly important. Protein provides amino acids that the body uses for muscle, enzymes, hormones and neurotransmitter production. Tryptophan and tyrosine are examples of amino acids involved in pathways related to neurotransmitters.
And this is another place where nutrition gets more complicated than social media often makes it seem.
A high-protein meal contains many amino acids that compete with tryptophan for transport into the brain. In controlled studies, carbohydrate-rich meals and protein-rich meals can therefore have different short-term effects on brain tryptophan and serotonin synthesis.
That doesn’t mean “protein lowers serotonin” or that you should avoid protein. It means that different nutrients can influence different biochemical pathways in different ways.
And that’s exactly why I think it’s worth understanding the science rather than labeling foods as simply “good” or “bad.”
Another Reason to Prioritize Quality Protein
For people interested in healthy aging, there is another compelling reason to pay attention to protein: maintaining muscle.
As we age, preserving muscle mass and strength becomes increasingly important for maintaining mobility, metabolic health and independence.
So while we’re thinking about brain chemistry, we shouldn’t lose sight of the bigger picture.
A healthy diet needs to support the entire body—including the brain and the muscles. The goal isn’t to find one magical food. It’s to create a dietary pattern that provides adequate protein, nutrient-dense carbohydrates, healthy fats, vitamins and minerals while supporting the metabolic and lifestyle factors that influence health.
Could Food Influence Cravings?
This is one of the most intriguing parts of the conversation.
We’ve all experienced food cravings. Sometimes they seem almost impossible to ignore. Could there be a biological component?
Research has explored the relationship between carbohydrate consumption, brain serotonin and carbohydrate cravings, including the possibility that changes in brain serotonin may influence food selection.
That doesn’t mean every craving is caused by a neurotransmitter imbalance. Cravings can be influenced by many things, including:
- Hunger
- Habit
- Sleep
- Stress
- Food availability
- Emotional associations
- Blood glucose regulation
- Reward pathways
- Individual biology
But it does suggest that our relationship with food is more complicated than willpower.
What Can We Take Away?
My biggest takeaway from this conversation is that nutrition deserves a more sophisticated discussion.
Instead of asking “Are carbohydrates good or bad?” or “Is protein good or bad?” we should be asking:
- What does this nutrient do?
- How does it interact with other nutrients?
- What does the research actually show?
- And how might individual differences change the response?
Listen to the full episode of Energize & Revitalize with Dr. Amy and decide what you think.
This article is for educational purposes only and is not medical advice. Nutrition can influence many aspects of health, but it should not be used as a substitute for appropriate medical evaluation or treatment of mental health conditions.