What is Phenylethylamine and Why is it in Food?
Phenylethylamine (PEA) is a biogenic amine that acts as a neurotransmitter and neuromodulator in the central nervous system. It is synthesized by plants, animals, bacteria, and fungi, and is often produced during processes like fermentation. While the human body can create its own PEA from the amino acid L-phenylalanine, the compound can also be acquired through diet.
However, it is crucial to understand that PEA from food sources is rapidly metabolized by the body's monoamine oxidase enzymes before it can reach the brain in significant quantities. This means that while some foods contain PEA, eating them does not guarantee a major mood-altering effect, contrary to popular myths. The psychological lift often associated with eating chocolate, for instance, is more likely tied to other compounds like theobromine or the simple pleasure of consuming sugar and fat.
Fermented and Microbial-Rich Foods
Fermentation is a key process for PEA production in food, as bacteria and fungi synthesize the compound. This explains why many fermented foods are listed as dietary sources of PEA.
- Natto: This traditional Japanese food, made from fermented soybeans, is a known source of phenylethylamine due to the bacterial fermentation process.
- Hard Cheeses: Aged and fermented dairy products often contain higher concentrations of biogenic amines, including PEA.
- Wine: The microbial activity involved in winemaking can result in the formation of PEA.
- Salami and Cured Meats: The fermentation and curing processes used for certain sausages and meats also contribute to their PEA content.
The Cacao Connection
Chocolate's reputation as a PEA source is well-established, but the levels are highly dependent on processing.
- Raw Cacao: Unroasted, fermented cacao beans contain significant levels of phenylethylamine.
- Dark Chocolate: Chocolate with a high percentage of unprocessed or minimally processed cocoa solids will retain more PEA. The high heat from roasting in standard chocolate production can degrade the delicate PEA molecule.
The Phenylalanine Pathway
A more reliable way to influence your body's PEA levels through diet is to consume foods rich in L-phenylalanine, the amino acid your body uses to produce PEA. This offers a more consistent supply for endogenous synthesis, rather than relying on the volatile PEA content in foods.
- Protein-Rich Animal Products: Eggs, beef, chicken, turkey, fish, and dairy products are all excellent sources of L-phenylalanine, as they contain all nine essential amino acids.
- Plant-Based Proteins: Legumes such as soybeans (including tofu and tempeh), lentils, and chickpeas are good sources of this essential amino acid.
- Nuts and Seeds: Almonds, walnuts, peanuts, flaxseeds, and pumpkin seeds also provide L-phenylalanine.
The Role of Processing
How food is prepared can significantly impact its PEA content. Heat and processing can destroy the compound, while fermentation can increase it. For example, the high heat used to roast cocoa beans reduces PEA, which is why raw cacao is a better source. Similarly, the fermentation of soybeans into natto creates PEA, while non-fermented soybeans contain only the precursor, phenylalanine.
Comparison of Phenylethylamine Food Sources
| Food Source | Primary Compound | Bioavailability | Relative Amount | Notes |
|---|---|---|---|---|
| Raw Cacao / Dark Chocolate | Direct PEA | Low (metabolized quickly) | Moderate to High | PEA levels decrease with roasting. |
| Fermented Foods (Natto, Cheese) | Direct PEA | Low (metabolized quickly) | Variable | Depends on microbial activity and aging process. |
| Protein-Rich Meats (Beef, Poultry) | Phenylalanine (Precursor) | High (for precursor) | High | Body uses the amino acid to synthesize PEA. |
| Legumes (Soybeans, Lentils) | Phenylalanine (Precursor) | High (for precursor) | High | Plant-based source of the essential amino acid. |
| Nuts and Seeds | Phenylalanine (Precursor) | High (for precursor) | High | Excellent source for endogenous PEA production. |
| Wine | Direct PEA | Low (metabolized quickly) | Low | Minor contribution from fermentation. |
Conclusion
While a range of foods, notably chocolate and certain fermented products, do contain phenylethylamine, consuming them directly does not reliably increase brain levels due to rapid metabolism. For a more consistent internal supply, focusing on foods rich in L-phenylalanine—the amino acid precursor—is a more effective dietary strategy. Ultimately, a balanced diet rich in various protein sources provides the building blocks for the body to regulate its own neurotransmitter levels. Understanding these pathways helps to separate nutritional science from the myths often surrounding so-called 'love chemicals' in food. For those with conditions like phenylketonuria (PKU), it is crucial to avoid dietary phenylalanine and consult a doctor.
Frequently Asked Questions
What foods have phenylethylamine in them directly? Foods like raw cacao, dark chocolate, certain hard cheeses, natto, and red wine contain phenylethylamine as a byproduct of fermentation.
Does eating chocolate increase my brain's phenylethylamine levels? No, studies suggest that the phenylethylamine in chocolate is rapidly broken down by enzymes in the digestive system before it can significantly impact the brain.
How can I increase my body's natural production of phenylethylamine? To support your body's synthesis of PEA, consume foods rich in the essential amino acid L-phenylalanine. This includes eggs, dairy, meat, nuts, seeds, and legumes.
Are there any risks to consuming foods high in phenylethylamine? For most people, consuming food sources of PEA is safe. However, individuals with phenylketonuria (PKU) must avoid phenylalanine-rich foods. Excessive intake of certain biogenic amines in fermented foods can also be problematic for some individuals.
What is the difference between phenylethylamine and phenylalanine? L-phenylalanine is an essential amino acid obtained from food. Phenylethylamine is a neurotransmitter that the body can synthesize from L-phenylalanine.
Why is raw cacao a better source of PEA than roasted chocolate? The delicate phenylethylamine molecule is sensitive to heat. The roasting process used in standard chocolate production degrades PEA, so raw cacao contains higher amounts.
Is phenylethylamine the only 'mood-boosting' compound in chocolate? No, the mood-lifting effect of chocolate is complex and likely involves other compounds like theobromine, caffeine, and the overall sensory experience, rather than just PEA.
Are all fermented foods high in phenylethylamine? No, the amount of PEA varies significantly depending on the specific fermentation process, the type of microbes involved, and the starting ingredients.
Can supplementation be used for phenylethylamine intake? Yes, PEA is available in supplement form, often marketed for mood and cognitive benefits. However, it's crucial to consult a healthcare provider before taking supplements due to potential side effects and interactions.
