Interestingly I just came back from a health talk today and the focus was on research translation and it brings back the memories of me attending the 2014 - 3rd annual NHMRC Research Translation Faculty Symposium – "Achieving better health outcomes for Australians living with chronic conditions through more effective research translation". It is very true that although a lot of money has been spent on research and there are abundance of quality and interesting research work being done, the public and the health professionals doesn't necessarily know about it. Just think even if you only learn about 1 research per day, wouldn't that add more value to your life?
I was browsing through one of the hottest topic in research now which is Vitamin D because if you know me personally, the latest project I worked on was on Vitamin D and Type 2 Diabetes. Matter of fact, Vitamin D is also linked to depression!
Depression affects 350 million people worldwide and it is the leading cause of disability. At its worst, depression can lead to suicide and over 800 000 people die due to suicide every year with suicide being the second leading cause of death in 15-29year olds according to WHO. On the other hand Vitamin D deficiency is now a global public health problem affecting a billion people worldwide and studies have found that one third of Australians are Vitamin D deficient. Knowledge on Vitamin D has grown exponentially in recent years with 95% of our current knowledge published in the last 15 years. Interestingly, vitamin D has also been known to be associated with breast cancer fatality rate as shown in my other post.
A longitudinal study found that low vitamin D levels are associated with depressive symptoms, especially in persons with a history of depression (1). Researchers suggested that it might be important to check Vitamin D levels in diagnosed depression cases.
In a randomised double blind controlled trial of 20,000 or 40,000 IU vitamin D per week versus placebo for 1 year on 441 subjects (159 men and 282 women, aged 21-70 years), subjects with serum 25(OH)D levels < 40 nmol L(-1) scored significantly higher (more depressive traits) than those with serum 25(OH)D levels > or = 40 nmol L(-1) on the Beck's Depression Inventory (BDI). In the two groups given vitamin D, but not in the placebo group, there was a significant improvement in BDI scores after 1 year.
Some studies might argue about Vitamin D's controversial theory in aiding depression but overall, being deficient in a vital vitamin for the body is never a good thing so it is very important to make sure your Vitamin D levels are in the normal range to start with.
1: Hoang MT, Defina LF, Willis BL, Leonard DS, Weiner MF, Brown ES. Association between low serum 25-hydroxyvitamin D and depression in a large sample of healthy adults: the Cooper Center longitudinal study. Mayo Clin Proc. 2011 Nov;86(11):1050-5. doi: 10.4065/mcp.2011.0208. PubMed PMID: 22033249; PubMed Central PMCID: PMC3202994.
2. Jorde R, Sneve M, Figenschau Y, Svartberg J, Waterloo K. Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial. J Intern Med. 2008 Dec;264(6):599-609. doi:10.1111/j.1365-2796.2008.02008.x. Epub 2008 Sep 10. PubMed PMID: 18793245.
There is increasingly more evidence that omega-3 supplements (aka. fish oil) plays an important role in depression.
In 2010, a group of researchers did a meta-analytic review comparing the levels of polyunsaturated fatty acids between depressive patients and control subjects (1). The result ---Compared with control subjects, the levels of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total omega-3 (n-3) polyunsaturated fatty acids were significantly lower in depressive patients. There was no significant change in arachidonic acid (AA) or total omega-6 (n-6) polyunsaturated fatty acids. Thus this implies that omega-3 plays a vital role in pathogenesis of depression. This result is in line with research done back in 1998 and published in Journal of Affective Disorders where researchers noted significantly lower levels of omega-3s in the red blood cell membranes of patients with depression (2).
More recently, a study published in Jan 2016 in Journal of Psychiatric Research shows white matter deficits in depression improved after 6 weeks of fish oil supplementation (3). These therapeutic effects of omega-3 PUFAs may be related to improvements in white matter integrity.
Fish oil is not a definitive treatment of depression, but it may be helpful as an addition to prescribed medications or other treatment. Although more studies are needed to determine exactly what role omega-3s play in depression, it's possible that fish oil supplements high in omega-3s may help lower the risk of depression — and omega-3 has many other health benefits.
1: Lin PY, Huang SY, Su KP. A meta-analytic review of polyunsaturated fatty acid compositions in patients with depression.
Biol Psychiatry. 2010 Jul 15;68(2):140-7. doi: 10.1016/j.biopsych.2010.03.018. Epub 2010 May 10. PubMed
2: Edwards R, Peet M, Shay J, Horrobin D. Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients. J Affect Disord. 1998 Mar;48(2-3):149-55. PubMed PMID: 9543204.
3: Chhetry BT, Hezghia A, Miller JM, Lee S, Rubin-Falcone H, Cooper TB, Oquendo MA, Mann JJ, Sublette ME. Omega-3 polyunsaturated fatty acid supplementation and white matter changes in major depression. J Psychiatr Res. 2016 Jan 11;75:65-74.
doi: 10.1016/j.jpsychires.2015.12.007. [Epub ahead of print] PubMed PMID: 26802812.
Dr Nicole Ng (MBBS) is a medical doctor with a passion in women's health and medical research