Increasingly, more research is emerging that supports the mental health benefits of eating a healthy diet, specifically low glycaemic index (GI) diets that are rich in vegetables, fibre, protein, and healthy fats. (1) Conversely, high GI diets are linked to increased risk of mental health disorders, depression, and psychological distress. (2) General mood has been shown to be improved on a high protein, low GI diet when compared to a high GI diet, (3) attributed to the superior diet quality of the low GI diet pattern.
For example, in a 2019 study, adults following a low GI diet ate more veggies (around 24 grams of fibre per day), nearly 100 grams of protein per day, and 40% of their calories from fats, and had lower scores for depressive symptoms, mood disturbance, and fatigue. (3)
What are the common characteristics of these foods? First, they are low glycaemic index, meaning they have a minimal impact on raising glucose after a meal. Additionally, foods in the diets studied were rich in magnesium, B vitamins, and omega-3 fats, which are key nutrients for the nervous system that affects mood. (2) Further, high fibre foods like vegetables support a healthy gut microbiome, which has implications on mood via a connection called the gut-brain axis. (4)
10 mood-boosting foods:
1. Salmon
Fatty fish like salmon not only contain high levels of protein (20 grams of protein per 100-gram portion), salmon is also rich in omega-3 fats, which play a role in brain processes related to the origin of anxiety and depression (5)
Lingo tip: Did you know you can cook salmon directly from frozen? Try pan-frying, baking, air frying, or grilling filets directly from the freezer. Just rinse under water, then cook. Finish with seasoning.
2. Blueberries
Berries are bursting with anthocyanins, a compound that helps the body overcome stress. (6) Blueberries in particular have been shown to help adults make decisions more quickly and accurately, supporting sharp brain function. (7) The same study also found the single serving of wild blueberries improved glucose and insulin responses to a meal. Plus, blueberries have been shown to increase positive mood in young adults. (8)
Lingo tip: Keep frozen berries on hand for smoothies. Or add fresh blueberries to a green salad for a sweet flavour burst.
3. Raspberries
These brightly pigmented berries contain several essential micronutrients, dietary fibres, and polyphenolic components, specifically ellagitannins and anthocyanins. They are among the highest whole food sources of dietary fibre, providing 6.5 grams of fibre per 100 gram weight. (9)
Lingo tip: Add raspberries to Greek yoghurt for a high-protein snack.
4. Walnuts
Walnuts have the ability to improve mood. (10) They contain a number of potentially neuroprotective compounds like vitamin E, folate, melatonin, several antioxidative polyphenols and significant amounts of omega-3 fatty acids.
Lingo tip: Keep walnuts on hand for an easy snack – in your desk drawer, purse or book bag, or in your car.
5. Coffee
Cognitive benefits from coffee are typically attributed to caffeine, but there are many compounds in coffee that likely have a synergistic effect on mood, including the amino acid L-theanine and chlorogenic acids. Benefits are seen around 100 mg caffeine per day, which is the amount of caffeine in 240 mL (about one cup) of brewed coffee (moderation is up to 400 mg per day). (11)
Lingo tip: Glucose responses to caffeine vary by individual, and black coffee generally is the most glucose friendly. If you don't take your coffee black coffee, stick to adding in unsweetened milk and limit added sugars.
6-8. Spinach, broccoli, brussels sprouts
Folate, the B vitamin in these greens, supports the body making the neurotransmitters serotonin, norepinephrine, and dopamine, which are all strongly linked to mental health. (1) What’s more, around 90% of your body's serotonin is made in the gut, (12) which is affected by dietary factors like fibre. In fact, high vegetable intakes (>8 portions per day) is associated with higher positive affect, lower negative affect, and greater eudaemonic well-being. (1)
Lingo tip: See how many meals you can add greens to: toss a handful of spinach into scrambled eggs at breakfast, dip broccoli in hummus for a filling snack, have a side of roasted brussels sprouts with your dinner.
9. Fermented foods
Microbes found in fermented foods, such as Lactobacillus and Bifidobacteria species, may influence brain health via direct and indirect pathways. (13)
Lingo tip: While Greek yoghurt is an excellent source of protein and calcium, the beneficial bacteria amounts vary by brand. Look for kefir, a drinkable style high-protein yoghurt, sauerkraut, or kimchi as other ways to add fermented foods into your day.
10. *Dark* chocolate
The mood and cognition-enhancing effects of cocoa and chocolate are linked to its flavanols, methylxanthines, salsolinol, and orosensory properties. (14) Dark chocolate (85% or greater cacao) acts as a prebiotic, feeding the healthy bacteria of the gut, which may improve negative emotional states via the gut-brain axis. (15)
Lingo tip: Combine mixed nuts with mini dark chocolate chips for a sweet treat.
A final note from Lingo
Mood and well-being are influenced by a variety of factors; diet is just one of them. And eating a low-glycaemic diet and staying steady can contribute to your overall health and well-being. Using a CGM like Lingo is a tool to understand the relationship between your health and glucose. Tracking your food, exercise, and stress in the app can help you visualise the impact these have on your glucose. Mood is another metric to observe as it relates to the big picture of your health.