How can motivation be increased by improving brain chemistry with nutrition and activities?

Question

I'm reading some material about motivation and brain chemistry. One of the interesting articles is "7 Ways to Increase Motivation by Improving your Brain Chemistry". I'm interested in a more scientific treatment of the topic. Thus,

• How can motivation be increased by improving brain chemistry with nutrition or various activities (sport, exercise, relationships etc.)?
• What scientific articles exist on this topic?

It would be great if there was some article targeting this exact topic with references.

Answer 1

The best thing you can do is avoid nutritional deficiencies and exercise. In general, it's the same as for the rest of the body. Many people have subtle nutritional deficiencies that they may never know about their whole life just based on eating habits. As Chuck Sherrington said, neurotransmitter-based treatments are subject to homeostatic compensation, but if you have a deficiency, it may be more complicated.

Nutrition

Particularly, the same things that increase pulmonary/circulatory health are going to increase brain health[1,2]. A large contribution to health in the developing fetal brain comes from the mother's diet. There are lots of diseases associated with maternal nutrtional defecits[3,4].

Exercise

Running and other physical activities increases neurogenesis [5,6]. But does it do it "intelligently"? I don't know. More neurons isn't automatically more motivation or intelligence. But it is a stress-relief technique, and too much stress can certainly kill motivation.

Behavior

You didn't ask, but behavioral practice is probably another strong factor. For example, breaking jobs into smaller tasks: getting the first small task done can give a motivational boost towards getting the second done (and so on). They've actually found a correlation between paying smaller loans off first (even though not mathematically more efficient in terms of costs) is more likely to lead to loans being paid off all the way because of the human element[9]

Answer 2

Low / loss of motivation is associated with several Disorders of Diminished Motivation (DDM) (eg, akinetic mutism, abulia, apathy) that occur frequently in individuals with traumatic brain injury or other underlying neurological disorder, as well as avolition, and is a prominent symptom of dysthymia, motivational anhedonia, schizophrenia, and others.

There is not much research on treatment of motivation in these disorders with nutrition, possibly because of the underlying neurological causes, the complexity of studying nutrition, and low incidence rates. For a reasonably useful answer, I will instead review the effect of nutrition on motivation in depression, where much more research is available, and this would hopefully extend to low motivation in general.

Personalized Nutrition:

There are several reasons why it may be impossible to find clear answers on nutritional treatments for motivation. For one, known nutrient deficiencies rarely manifest in isolated cognitive symptoms such as low motivation - but rather with acute physical disease symptoms.

Another important factor is that nutrient deficiencies may have as much to do with individual characteristics as general dietary ones - that is, a dietary prescription may not work the same for everyone. Unfortunately, nutritional genomics as a field is currently in its infancy - see Ordovas et al (2018) for a recent review.

There are also many unknowns remaining regarding the role of the gut microbiome in depression, and the placebo effect of treatment - ie, seeing a nutritionist may well be as important as the prescription they provide. And ironically, some research suggests that fasting may be effective with depression - implying the opposite of a nutrient deficiency!

Healthy Diet:

Rigidly set dietary prescriptions can have advantages even when not personalized. For example, they take the onus off patients to make healthy diet choices, and may be more likely to be followed.

However, research on a variety of diets demonstrate that healthy diets have positive effects on depression (Molendijk et al, 2018; Opie et al, 2015; Firth et al, 2019). The general recommendation therefore is well known: Reduce sugar and processed foods, increase fruits and vegetables. This has the added bonus of not just improving motivation, but also improving overall physical and mental health!

So, the below recommendations are fine to follow, but just note that any healthy diet is fine too.

Dietary Prescriptions:

Several recent reviews of current findings containing specific dietary prescriptions are listed below, with relevant extracts. I encourage reading the papers for specific tests of nutritional interventions and their results, as recommendations may or may not be applicable.

Sathyanarayana et al (2008): Understanding nutrition, depression and mental illnesses

The dietary intake ... are often deficient in many nutrients, especially essential vitamins, minerals, and omega-3 fatty acids.

Khanna, Chattu, & Aeri (2019): Nutritional Aspects of Depression in Adolescents - A Systemic Review

... several healthy foods such as olive oil, fish, nuts, legumes, dairy products, fruits, and vegetables have been inversely associated with the risk of depression and might also improve symptoms.

WebMD: Depression and Diet

... while certain eating plans or foods may not ease your symptoms or put you instantly in a better mood, a healthy diet may help as part of your overall treatment.

Brown (2012): Nutritional Brain Energy Enhancement for Reducing Mental Fatigue and Improving Mood and Cognition

The enhancement of brain energy metabolism with nutritional factors such as creatine, acetyl-l-carnitine, multivitamins and polyphenol rich diets may be a novel strategy for reducing mental fatigue and improving mood and cognition ...