Mental health relates to your emotional, psychological, and social well-being. It affects how you think, feel, and act – a Mind/Body Connection. It also helps determine how you handle stress, relate to others, and make choices. Mental health is important at every stage of life, from childhood and adolescence through adulthood. In 2017, an estimated 11.2 million (4.5%) adults in the U.S., had a severe psychological condition, according to the National Institute of Mental Health (NIMH). Mental illnesses, such as depression, are the third most common cause of hospitalization in the U.S., and adults living with serious mental illness die on average 25 years earlier than others [Kessler et al 2007].

Everyone has some risk of developing a mental health disorder, irrespective of their age, sex, income, or ethnicity. Several factors can affect mental health such as your genes or brain chemistry; life experiences (i.e. trauma or abuse); family history of mental disorders; as well as your lifestyle including diet, physical activity, and substance use. Poor mental condition can also affect your physical state and increase the risk for stroke, type 2 diabetes, and heart disease. Therefore, a basic knowledge on brain chemistry and its related functions may help design proper lifestyle measures to improve your mental health and optimize your overall well-being.

The brain is an organ with a large mass of nerve tissue located in the skull. It is made up of two types of tissue, the grey matter, and the white matter. Grey matter is involved in analyzing information, whereas the white matter transmits information between the grey matter areas. The ratio of grey to white matter changes over the lifespan. In general, the brain can be divided into three major functional regions:

• Frontal region (Cerebrum), the largest part of the brain with two halves or hemispheres – right and left. The right hemisphere controls the left side of the body, and the left hemisphere controls the right side. Their functions include motor skills, temperature, touch, vision, hearing, reasoning, problem solving, emotions, and learning.
• Mid region (Brain Stem) includes the pons, and the medulla that connects to the spinal cord. It contains nerve fibers that carry signals to all parts of the body. The brain stem also regulates bodily functions such as consciousness, fatigue, heart rate, and blood pressure. Damage to the brain stem can cause loss of consciousness.
• Basal region (Cerebellum) is located at the base of the skull with a curved mass of nerve tissue. It regulates voluntary muscle movements and to maintain posture, balance, and homeostasis.

Your body is controlled by your brain with billions of neurons that communicate through chemical signals collectively known as neurotransmission or synapse.

Neurotransmitters play an important role in neural communication. They are chemical messengers that carry messages between nerve cells (neurons) and other cells in your body. This uninterrupted signaling process sustains brain activity and influences every function from breathing to heartbeat to mood to involuntary movements. This process is generally referred to as neuro- or synaptic transmission. A neurotransmitter influences a neuron in one of three ways: excitatory, inhibitory or modulatory. An excitatory transmitter promotes the generation of an electrical signal called an action potential in the receiving neuron, while an inhibitory transmitter prevents it. Whether a neurotransmitter is excitatory or inhibitory depends on the receptor it binds to. Neuromodulators are not restricted between two neurons, and so can affect large numbers of neurons at once. The brain uses specific neurotransmitters to instruct specific physiological functions at designated target sites in your body (TABLE).

Most neurotransmitters are either small molecules, amino acids, or neuropeptides. There are about a dozen known neurotransmitters and more than 100 different neuropeptides. Maintaining optimum levels of neurotransmitters requires a healthy balanced diet to provide the brain with vital neuro-chemical building blocks to support their synthesis, transportation, and activity. Although various diets may contain neurotransmitters and their precursors, their ability to reach the brain depends on how easily they can cross the Blood-Brain Barrier (BBB). Neurotransmitters like dopamine and serotonin cannot cross the BBB due to lack of necessary ‘transport’ mechanisms.

The BBB is a unique dynamic regulatory interface located at the border between the blood stream and the brain. The BBB protects the brain against circulating toxins or harmful microbial pathogens. As the ‘gatekeeper’ to the central nervous system (CNS), the BBB facilitates uptake of vital nutrients, vitamins, and hormones to sustain cerebral growth and metabolism, as well as in maintaining the cerebral ionic and volume balance [Sharif et al 2018].

Therefore, the delivery of nutrients to the central nervous system (CNS) pose several challenges, among which the BBB is the critical limitation [Moradi et al 2020]. To cross the BBB, various approaches have been evaluated including the carrier-mediated delivery systems and use of specific ligands for transport/target delivery. Most proteins in the plasma can not cross the BBB due to their size and hydrophilicity. Only few specific proteins such as lactoferrin (LF), insulin, insulin-like growth factors and vasopressin cross the BBB by a receptor-mediated transcytosis [Laterra et al 1999].

Lactoferrin has been widely used as a functional component in the medical, food, veterinary, and cosmetic industries. Lactoferrin-based materials, such as complexes, nanoparticles, hydrogels, and emulsions, to encapsulate, protect and deliver bioactive compounds is gaining increasing attention [Liu et al 2018]. Lactoferrin-conjugated polyethylene-glycol (PEG) liposomes or solid lipid nanoparticles (SLN) are shown to facilitate the diffusion of molecules across the BBB and are effective target delivery systems for loading diagnostics or therapeutics for various brain conditions [Huang et al 2013, Singh et al 2016]. A novel lactoferrin-based PORTIN® technology is currently used in the dietary supplement industry for target delivery of bioactive nutrients to specific tissue sites in the body, i.e. synovial joint [Naidu 2011].

Lactoferrin acts as an adaptogen and helps reduce stress-induced surges of corticosterone levels within 30 min [Aleshina et al 2016]. In vivo, the mood-boosting effect of lactoferrin was demonstrated in a repeated forced-swim test (FST) stress in animal models. Oral administration of lactoferrin is shown to play a role in down-regulating dopamine and serotonin release in the brains and support healthy locomotor function [Izumo et al 2020]. A clinically tested lactoferrin-based nutritional technology to improve human sleep patterns has been developed [Naidu et al 2013]. Severe, repeated or chronic stress leads to negative health outcomes including disruptions of the sleep/wake cycle. Lactoferrin is shown to reduce the negative physiological impacts of stress and facilitate non-rapid eye movement (NREM) sleep consolidation as well as enhanced rapid eye movement (REM) sleep rebound [Thompson et al 2017].

Mental well-being is a major public health concern worldwide. The current pandemic with quarantine measures, social distancing and life-style restrictions are implicated in psychological distress and compromised physical performance of individuals of both genders and all age groups. Generalized recommendations such as a balanced diet, regular exercise, yoga and meditation should be practiced; however, overall mental health is contingent upon the bioavailability of functional neurochemical blocks to the brain and its CNS. It should be noted that the BBB is the body’s designated ‘gatekeeper’ that strictly regulates the movement of vital nutrients in-and-out of the brain and its CNS. Therefore, a mere presence of a nutrient or a vitamin in a dietary plan or a supplement regimen will not ensure its crossing the BBB and bioavailability to its target site – the brain, unless there is a specific delivery mechanism. Only a few molecules in your body possess such unique ability to cross the BBB. Lactoferrin, an iron-binding glycoprotein in your body fluids, is one such extraordinary transport module! Recently in pharmacology and nutritional science, lactoferrin has emerged as a promising target-delivery system for effective delivery of bioactive compounds across the BBB. Combined with its multifunctional spectrum, lactoferrin is a promising all-natural nutraceutical that can help promote regular brain function and optimum mental health.