With an estimated 44 million Americans experience a mental disorder annually, according to the National Mental Health Center, consumers want their natural product retailers to help them battle mood disorders, such as depression. Major depressive disorder is the leading cause of disability in the United States for ages 15 to 44; it affects approximately 14.8 million American adults annually, according to the National Institute of Mental Health (NIMH). Natural product retailers can help with supplements and an educated staff.
Ingredients with Potential
There are a host of nutritional ingredients with substantiated research for their impact in affecting mood. Long-term consumption of fish appears to help support mental health, reducing the risk of mental disorders by up to 30 percent.(1)(2) And while additional lifestyle factors may also play a role in the link between dietary fish intake and depressed mood,(3) studies do support that consuming a diet high in fish can help reduce incidence of depression.(4)
The good news about fish is getting out to consumers, noted Baldur Hjaltason, sales manager, North America, Japan and China, EPAX AS. “In the United States, we have seen that within 2006 and 2007 there was an increase of 5 percent in awareness of the importance of omega-3 fatty acids in brain health,” he said. “This is very positive since a dietary survey of nine countries clearly demonstrated higher prevalence of mental depression in populations not eating fish, linking onset of depression to changes in our diet.”
Intervention trials with fish oil and isolated omega-3 essential fatty acids (EFAs), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have shown generally positive results. A recent meta-analysis looked at 10 double blind, placebo-controlled studies in patients with mood disorders, and concluded long-chain polyunsaturated fatty acids (LC-PUFAs) have significant anti-depressant activity, although more work on dosages was suggested.(5) Additionally, studies have shown that providing omega-3s to patients with Alzheimer’s disease or with Parkinson’s disease may reduce incidence of depression, often without the use of pharmaceutical antidepressants.(6)(7)
A recent study out of the University of California, Berkeley, suggests EPA and DHA may work even more effectively in addressing mood conditions when combined with phospholipids, such as phosphatidylserine (PS).(8) This phospholipid nutrient is found in all cells and is most concentrated in the human brain. PS serves as a universal building block for cell membranes, managing the cellular life processes. “PS is a well-known, natural and effective mental performance enhancing ingredient,” said Scott Hagerman, president and CEO, Chemi Nutra, supplier of SerinAid® PS. “A tremendous body of science and clinical research exists, which also supports its role in suppressing stress, improving mood and helping to fight depressive symptoms.”
For example, British researchers reported providing 300 mg/d of PS for one month reduced stress and improved mood in young healthy adults when subjected to a stressful mental task.(9) Similarly, a study out of Germany found providing 400 mg/d of PS to healthy adults prior to administering the Trier Social Stress Test (TSST) significantly blunted serum markers of adrenal stress and had a positive effect on emotional responses as well.(10) Another trial out of the University of Milan, Italy, reported PS (300 mg/d) treatment for 30 days in elderly women with depressive disorders improved depressive symptoms and behavior.(11)
Augmenting the options for companies looking to offer nutritional products for mood support are a number of specialty compounds. For example, the orthomolecule acetyl-L-carnitine (ALC) supports mitochondrial energy production and enhances the production neurotransmitter acetylcholine (ACh). Research shows ALC has the ability to enhance cognition and exert an antidepressant effect.(12)(13) Clinical work even suggests it works as well as pharma treatments in dysthymic patients, and should possibly be a first-line treatment in such cases given the greater tolerability and chronic nature of dysthymia, which can require extended treatment.(14)
SAM-e (S-adenosylmethionine) has been extensively studied for its antidepressant activity.(15) It works as a methyl donor involved in the synthesis of several neurotransmitters, and studies have shown doses of 200 mg/d to 1,600 mg/d are superior to placebo and as effective as tricyclic antidepressants in alleviating depression.(16) While its mechanism of action is unclear, it is suggested that SAM-e may normalize levels of specific neurons in the brain(17) and support brain bioenergetics.(18)
Other nutrients that impact neurotransmitters have been closely studied for their possible applications in treating depression. L-tryptophan, for example, is suitable for treating mild forms of depression and also benefits sleep; it also has a low level of side effects in comparison to pharma antidepressants.(19) L-tryptophan’s efficacy has been established in clinical trials, including a recent trial in healthy women, which found L-tryptophan induces a positive bias in emotional interactions, similar to that of serotonergic antidepressants.(20)
5-HTP (5-Hydroxy-L-tryptophan) is the immediate precursor to L-tryptophan and has been a popular choice in mood enhancing dietary supplements. Studies show it is well-absorbed from oral dosing, easily crosses the blood-brain barrier and effectively increases central nervous system synthesis of serotonin, working to address conditions such as depression and anxiety.(21)
A proprietary extract of Griffonia simplicifolia seed (as Serotain™, from Triarco) has been studied as a natural 5-HTP source. Mark Anderson, Ph.D., director of research and development, Triarco, noted the proprietary formula is safe and efficacious. “Research shows Serotain elevates mood by making serotonin more available to the body,” he said. “Serotain helps to balance mood and suppress appetite, making it ideal for consumers looking to control cravings when dieting and for those experiencing depression or anxiety.”
Another interesting amino acid with a role to play in the natural antidepressant market is L-theanine, a free amino acid found almost exclusively in tea plants. Studies suggest L-theanine increases brain levels of serotonin, dopamine and GABA (gamma aminobutyric acid), a key inhibitory neurotransmitter, and can exert neuroprotective effects and cognitive enhancement.(22) Clinical studies suggest L-theanine may increase alpha wave activity, relaxing and focusing the brain without inducing drowsiness, and also decrease anxiety by inhibiting cortical neuron excitatation. (23)(24)
The idea of relaxing via a glass of warm milk before bed gave rise to research into milk protein hydrolysate; the ingredient, now available as Lactium®, from Pharmachem, contains a bioactive deca-peptide with relaxing properties. “Lactium helps control stress and regulate its effects on the body, as well as enhance emotional well-being,” Skop said. “It has been the subject of several clinical studies that have shown it to be safe, without side effects and effective at regulating the major symptoms of stress on the digestive and cardiovascular systems, as well as enhancing social, emotional and intellectual capabilities.”
Clinical work out of France has found Lactium can reduce the mental stress response,(25) and improve stress symptoms such as anxiety, sleep problems and general fatigue.(26) While the mechanism of action is not fully elucidated, it has been shown to decrease plasma cortisol concentrations and blood pressure during stress tests.(27)