The Connection Between Nutrition & Mental Health: What You Need to Know

By Lisa Jo Finstrom. MS, CNS, LDN, licensed board-certified clinical nutritionist

As a nutritionist who regularly collaborates with therapists, I’ve seen firsthand how combining therapy with targeted nutrition can improve overall physical and mental well-being. While therapy helps process emotions and rewire thought patterns, nutrition supports the biochemical foundation of mental health—your brain chemistry, hormones, and gut health.

Nutrition helps your brain function more effectively.

Balancing Blood Sugar to Prevent Mood Crashes

One of the first things I do with a new client is to evaluate them for sugar dysregulation, including reviewing blood work to check for prediabetes. One of the simplest yet most powerful ways to support your mood is by managing blood sugar levels. Many people don’t realize how much their emotions are affected by what—and when—they eat. When blood sugar spikes and then crashes (often after a high-sugar or high-carb meal), it can trigger irritability, anxiety, fatigue, and difficulty concentrating. Fortunately, there are many options available that can be pursued without resorting to drastic measures, such as very low-carb diets, which are usually unsustainable and stressful.

Simple ways to stabilize blood sugar:

• Start your day with protein and fiber, not just coffee and carbs. Try Greek yogurt with nuts, eggs with vegetables, or a smoothie with protein powder and chia seeds.
• Don’t skip meals. Long gaps between eating can trigger stress hormones that worsen anxiety.
• Pair carbs with protein or fat—like fruit with nut butter—to prevent rapid sugar spikes.

Stable blood sugar means more stable moods.

Looking at Blood Work for Clues

In addition to identifying prediabetes, lab work can reveal nutrient deficiencies or imbalances that affect mood and cognition. When I work with clients, I review blood tests to identify patterns that may contribute to depression, anxiety, or ADHD. I am trained in interpreting standard blood work, as well as ordering and interpreting specific biomarkers in adherence with Walsh protocols and his recommended brain chemistry panels (Nutrient Power, 2014), which specifically examine zinc, copper, ceruloplasmin, pylorria, and methylation status.

Some of the most common findings include:

• Low zinc: Zinc is essential for producing GABA, a neurotransmitter that promotes calmness. Low levels are linked to anxiety, depression, and ADHD.
• High copper: Excess “free copper” can overstimulate the brain and is commonly seen in postpartum depression, anxiety disorders, and ADHD.
• Iron, B12, or folate deficiencies: These nutrients support energy and neurotransmitter production.
• Inflammation markers: High C-reactive protein (CRP) levels can indicate systemic inflammation, which has been tied to depression and fatigue.

By identifying and correcting these biochemical imbalances, we can remove physiological barriers that make emotional healing more difficult. Certain imbalances, such as low zinc or high copper levels, can be improved within a matter of months.

Nutrition for Brain Health

Foods that support mental wellness:

• Omega-3-rich foods, such as wild salmon, sardines, walnuts, and ground flaxseeds, help reduce inflammation and support the health of brain cell membranes.
• Colorful fruits and vegetables: These are packed with antioxidants that protect the brain from oxidative stress. It helps to think of eating the rainbow, perhaps blueberries with breakfast, an assortment of greens with lunch, and sautéed carrots with fresh ginger with dinner.
• Fermented foods, such as yogurt, kefir, kimchi, and sauerkraut, support a healthy gut microbiome, which plays a crucial role in regulating mood and overall well-being.

Foods that can impair brain health:

• Highly processed foods, particularly those high in refined sugar or industrial oils, can disrupt gut health and promote inflammation. These are foods to eat in moderation.
• Excess caffeine can increase anxiety and disturb sleep when not balanced with food. Again, the keyword is moderation.
• Alcohol can disrupt neurotransmitters and interfere with nutrient absorption. Alcohol is also notorious for disrupting normal sleep patterns.

The Gut-Brain Connection

Most people with mental health challenges—especially anxiety—also experience digestive symptoms such as bloating, constipation, or diarrhea. The gut and brain communicate constantly through the gut-brain axis.

If the gut is inflamed or out of balance (a state known as dysbiosis), it can directly affect mood and cognition. Conversely, improving gut health through a balanced diet can enhance emotional resilience. That’s the remarkable thing about the gut-brain axis – it’s bidirectional. Calm the gut, and the brain gets the message!

Fiber plays a key role here. Most people get less than half of the recommended daily intake. Fiber feeds beneficial gut bacteria that produce short-chain fatty acids—compounds that calm inflammation and support mental clarity. Generally, women require at least 25 grams per day, while men require approximately 30 grams. I often ask my clients to use a free app for a day or two in order to get a baseline of their daily fiber intake. Most are shocked at how little they are actually consuming.

Increasing daily fiber intake is a great starting point for anyone seeking to optimize their mental and physical health!

The Role of Selective Supplementation

While I always prioritize food first, strategic supplementation can play a meaningful role in supporting mental health. I’m well-versed in using selective, evidence-based supplements while carefully avoiding any drug-herb or nutrient-drug interactions.

For example, if you’re taking an SSRI, supplements like tryptophan or 5-HTP should be avoided, as they can raise serotonin levels too high and increase the risk of a serotonin storm.

For most clients with mental health or sleep challenges, I often recommend starting with magnesium and gentle herbal support:

• Magnesium glycinate is the form least likely to cause gastrointestinal upset and helps promote relaxation.
• Magnesium threonate crosses the blood-brain barrier and supports cognitive health.
• A soothing cup of chamomile tea after dinner can aid both digestion and relaxation. Chamomile is a mild nervine, meaning it helps calm the nervous system. It’s also antispasmodic, making it especially helpful for those who experience symptoms of a “nervous stomach.”

Both magnesium glycinate and chamomile tea are inexpensive, well-tolerated, and safe for most people.

In some cases—such as mindless eating or sugar cravings—I may use targeted amino acid products to both support the gut and reduce cravings. Often, simply increasing daily protein intake has a similar effect, since amino acids are the building blocks of neurotransmitters and promote balanced appetite and mood.

Beyond Nutrition: Sleep, Elimination, and Exercise

Nutrition doesn’t work in isolation. Three other essential factors for mental health are sleep and proper elimination, and daily movement of some kind.

• Sleep: If you aren’t getting at least 7-8 hours of restorative sleep, your brain can’t regulate emotions effectively. Hint– stay off the phone before bed!
• Elimination: Constipation prevents the body from effectively removing toxins, which can lead to increased inflammation and, in turn, affect the brain. Hint – get enough fiber!
• Exercise: Physical activity of any kind, whether it’s taking a walk, hitting the gym, or going to a dance or yoga class, has tremendous benefits, including
  • A profound effect on neurotransmitter production
  • Reduction in stress hormones
  • Improved sleep
  • Increased connectivity to others and to the natural world

These three areas are foundational for good mental and emotional health. As a nutritionist trained in supporting integrative health, I help clients with more than just their diet.

A Gentle, Personalized Approach

I believe that nutrition should be realistic, compassionate, and sustainable. I’m mindful of cultural food traditions and budgetary constraints, and I do not promote restrictive diets or calorie counting. My approach is especially sensitive to those in trauma therapy, where safety and stability are key. No scales, no judgements.

That said, if your typical breakfast consists of a donut and coffee, I’ll gently guide you toward adding protein in order to better support your energy and mood. Small, consistent changes often yield the most lasting results.

Working Together

If you’re already working with a therapist, adding nutritional support, including lifestyle suggestions, can help you feel more stable, energetic, and clear-minded—allowing your therapy sessions to be more effective.

I’m licensed in Maryland and Illinois and can see clients virtually in approximately half of the U.S., including California. I also offer sessions in Spanish.

If you’d like to learn more about how nutrition can support your mental health journey, I invite you to reach out for a free 15-minute call or to email me at lisajo@lisajonutrition.com. For more information, visit my website www.lisajonutrition.com. Together—with your therapist and me as part of your care team—we can create a holistic plan to support your mind and body.