It's that time of year. Daylight savings time has not come back yet, so we have no choice but to accept the onset of early dark in the afternoons. For many Americans, less sunlight and colder temperatures beginning midfall and lasting through winter can cause a form of depression known as seasonal affective disorder or the “wintertime blues.”
Scientists have theorized many ways to naturally reduce the symptoms of depression, and “good mood foods” have been researched ad nauseam. Studies have validated that food has a profound impact on mental health. Following a balanced diet rich in a variety of nutrients is believed to increase happiness and reduce stress and anxiety.
The health advantages of vegetables are widely acknowledged. Increasing vegetable consumption is recommended for preventing and managing a broad range of diseases. The perspective of thinking about vegetables as an investment in future well-being may be helpful to those not naturally inclined to them.
In 2021, a randomized controlled trial published in the Journal of the Academy of Nutrition and Dietetics examined individuals with consistently low vegetable intake. Over an eight-week period, participants who raised their consumption of both starchy and non-starchy vegetables to a minimum of two and a half cups daily reported improved mood compared to the beginning of the trial. Including starchy vegetables such as beans, potatoes, and sweet potatoes makes the study’s outcomes realistic and attainable for the average individual.
Over the past decade, scientific attention has been focused on the human gut, and the findings are captivating. Notably, our gastrointestinal tract is home to trillions of microorganisms, with the enteric nervous system integrated within its walls. This enteric nervous system oversees food digestion, nutrient absorption, and maintenance of the gut’s mucosal immune system. Additionally, similar to the brain, the enteric nervous system employs neurotransmitters, including serotonin. This leads to the concept of bidirectional communication between the gut and brain, known as the gut-brain axis. This connection enables the gut to influence mood. Consequently, optimizing gut health contributes to an improved outlook.
Incorporating fiber-rich foods into one’s diet, such as the starchy and non-starchy vegetables highlighted in the JAND study, whole grains, nuts, seeds, and fruits, is one way to promote gut health. During digestion, fiber breaks down into short-chain fatty acids like butyrate, which safeguards the gut lining’s integrity. In contrast, a low-fiber diet, high in saturated fats and added sugars, has been linked to cognitive decline, migraines, and chronic fatigue.
As previously mentioned, serotonin usage takes place in the gut. Serotonin, a “feel good hormone,” affects numerous bodily functions, including mood regulation, sleep quality, bowel regularity, and sexual desire. Low serotonin levels can lead to anxiety, depression, and digestive disturbances, among other disruptive symptoms.
Tryptophan, an essential amino acid or protein unit that must be obtained from the diet, is a precursor to serotonin. Tryptophan-rich foods include poultry, fish, shellfish, nuts, seeds, soy, beans, and legumes. Speculation indicates that regularly including a variety of lean protein sources in one’s diet may enhance serotonin levels; however, it’s important to note that tryptophan requires carbohydrates to cross the blood-brain barrier and elevate serotonin levels. This is one of several reasons to avoid unnecessarily eliminating specific foods or food groups.
Apart from the potential serotonin-related benefits, consuming protein with each meal and snack is advised for blood sugar regulation. Without protein pairing, rapidly digestible foods can lead to blood sugar spikes, resulting in intense cravings, irritability, brain fog, inflammation, and even hormonal imbalances.
Returning to the topic of the trillions of microorganisms inhabiting the GI tract, probiotics are beneficial gut bacteria. Multiple studies indicate that specific probiotic strains, notably from the Lactobacillus and Bifidobacterium families, have the potential to impact the central nervous system, the body’s control center, and alleviate stress and anxiety in adults.
One theory posits that robust probiotic colonies improve gut health and enhance effective communication within the gut-brain axis, consequently enhancing mood. Another theory suggests that Lactobacillus and Bifidobacterium can produce gamma-aminobutyric acid, a neurotransmitter associated with inducing a calming effect. Reduced GABA activity in the body might contribute to mood disorders, anxiety, and depression. Researchers investigating probiotics are optimistic that consuming fermented foods containing live probiotic cultures can elevate GABA activity. Fermented probiotic-containing foods include Greek yogurt, kefir, kimchi, kombucha, miso, sauerkraut, and tempeh.
Similar to tryptophan, omega-3 fatty acids are indispensable nutrients that must be sourced from the diet. Omega-3 sources encompass salmon, tuna, avocado, olives, and chia seeds. Research has extensively explored the protective role of omega-3 in promoting heart health, and recent scientific investigations are indicating a parallel benefit for gut health. Omega-3s have been shown to enhance the production of short-chain fatty acids, bolstering intestinal integrity and immunity. Furthermore, omega-3s may have the capacity to boost probiotic populations and reduce pathogenic gut bacteria in individuals with inflammatory conditions. In the realm of mental health, a study published this year in the Journal of Personalized Medicine concluded that combining omega-3 supplementation with antidepressants yielded more significant improvements in depressive symptoms compared to antidepressant use alone. This promising discovery warrants further exploration, ideally delving into the impact of dietary omega-3s on depression as opposed to supplementation.
If the seasonal transition has led to shifts in mood, incorporate vegetables, fiber, lean protein, probiotics, and omega-3s into your dietary regimen. Below are two recipes that hold the potential to boost mood.
Baked Dijon Salmon with Air Fried Sweet Potatoes and Brussels Sprouts
A delicious, omega 3-packed salmon dish served with fiber-rich, seasonal vegetables.
5 to 6 ounces salmon fillet
1 tablespoon of Dijon mustard
1 teaspoon of maple syrup
1 teaspoon garlic, minced
¼ teaspoon sea salt
Freshly ground black pepper, to taste
1 tablespoon extra-virgin olive oil
2 teaspoons apple cider vinegar
Dried dill for topping
Preheat oven to 400 F. While oven is warming, prepare marinade by mixing together Dijon, maple syrup, minced garlic, sea salt, olive oil, and apple cider vinegar. Place salmon in resealable bag and pour marinade over the fish. Marinate for 10 minutes. Line a baking sheet with tin foil and place the fish on top. Pour any leftover marinade on top. Bake fish for 14 minutes and check for an internal temp of at least 145 F. Top with dried dill if desired. Serves 1; easily double marinade for additional fish fillets.
1 medium-sized sweet potato, cubed
1 to 2 cups of Brussels sprouts, halved
Olive oil and desired seasoning
Add sweet potato to air fry pan. Drizzle with olive oil and season. I usually sprinkle with sea salt, black pepper, and garlic powder. Shake pan and air fry at 390 F for 10 minutes. While sweet potatoes are cooking, prep the Brussels. When 10 minutes have passed, remove air fry pan and add Brussels. Again, drizzle Brussels with olive oil and season. Shake pan and air fry with sweet potatoes at 390 F for another 10 minutes. Serves 1 with leftovers.