Monday, November 15, 2010

Selenium and Depression

The good news about selenium and the brain is that one can become familiar with the literature with full institutional access to pubmed and an hour or so of reading time. The bad news is that the mechanisms of selenium and the brain are rather Mysterious, so all we have are a few papers, some micronutrient supplementation, and some speculation.

All right. Let's talk pregnancy and depression for a minute. Little known fact that slightly more women are depressed during pregnancy than after it (1). And if you combine ante and post-natal depression statistics, this is what you get for the moms and kiddos: poor maternal self-care, increase in alcohol and drug use during pregnancy, decrease in seeking medical care during pregnancy, more pre-eclampsia, birth difficulties, preterm delivery, reduced breastfeeding, lower APGAR scores, poor sleep, failure to thrive, developmental delays, greater risk of illness in the baby, more behavioral problems, and at 16 years, offspring of depressed mothers are almost five times more likely to suffer depression themselves.

There are any number of social and medical factors that are linked to perinatal depression, but let's focus a bit on the nutritional ones - links have been found with folate status, vitamin B12, calcium, iron, selenium, zinc, and omega 3s. Kaplan and colleagues, in a must-see literature review, found potential beneficial effects from B vitamins, vitamin C, D, and E, calcium, chromium, iron, magnesium, zinc, selenium, and choline on mood symptoms. (Real Food = Best Fetal Dinner). A very recent study (to which I, sadly, do not have full access) showed a significantly decreased Edinburgh Postnatal Depression Scale score (that's good) in pregnant women randomized to receive 100 mcg selenium daily from the first trimester until delivery.

Back to selenium - as you recall, it is a vital component of the selenoprotein glutathione peroxidase and is required for the synthesis and metabolism of thyroid hormones. And way back in 1991, Benton and Cook did a randomized controlled crossover trial of 100 mcg of selenium vs placebo in 50 people for 5 weeks, followed by a 6 month washout, then the crossover arm of the trial. Selenium supplementation was associated with increases in self-reported mood. This same paper tells us that when push comes to shove and selenium is deficient, the brain is the last place that selenium levels drop, suggesting that in the brain, selenium is Important. More recently, Gosney et al reviewed the effects of micronutrient supplementation on mood in nursing home residents, finding that no residents started out with insufficient serum levels of selenium, yet 8 weeks of 60 mcg selenium supplementation (included in a multivitamin/multimineral with 150 mcg iodine) was directly correlated with decreases in depression scores and increases in serum levels. The supplementation of these elderly people with selenium resulted in reduced serum T4 and increased serum T3, suggesting that the additional selenium helped the rather boring T4 become the metabolically active T3 and kick some serious sluggish metabolic and depression expletive deleted here. (Any of you with hypothyroidism on synthroid (T4) get a recommendation from your doctor to supplement iodine or selenium? Hmmm.)

In other studies, selenium serum level was associated with cognition in the elderly. In a 9 year follow-up of Alzheimer's patients, cognitive decline associated with dropping selenium levels.

There's hardly enough data even to speculate, but I'll give it a whirl. Selenium is more like magnesium than zinc. I think most non-alcoholic non-anorexic meat-eaters not on thiazide diuretics probably have enough zinc on board, though stress and yellow number five might make you waste it a bit faster than normal. But magnesium is low in pretty much everyone, as is selenium (if you aren't a coal miner or a fish in selenium rich fertilizer run-off lakes). Selenium deficiency will mask itself as a somewhat subclinical (or clinical) hypothyroidism, with depression, fatigue, and grumpiness along for the ride. Replete the selenium and jazz up the T3. Happiness to follow. Not sure what that has to do with the brain holding onto selenium, but maybe that's where the glutathione comes in.

But I have a lot more reading to do before I jump into the thyroid. In the mean time - that multimineral ain't such a bad idea. Or seaweed and brazil nuts (though Barkeater was right! According to the Internet, brazil nuts have 1000 times more radium than other foods - not that much is supposedly retained in the body??) Or organ meats. Good fuel for everyone (6 months and older).


  1. Eeek! To those of us non-breeding evo-psyc followers, that is one helluva scary photo! :)

  2. an interesting and powerful mineral indeed! any idea if a selenium deficiency can (reliably) be diagnosed by a simple blood test?

    apropos nutritional status and pregnancy, heh:

  3. That's an adorable baby. Looks determined, too.

  4. Qualia - I can't find where I read it, but there was some thought that brain levels weren't well reflected by serum levels, however in most of the studies serum selenium levels linearly and inversely correlated with depression.

    Retreiver - one day old and not particularly pleased about it!

  5. 1000 times the radium. How about a followup on that? I was eating Brazil nuts the last few days because of the suggestion in the Jaminets' book. Sheesh. How about the omega 6 content of Brazil nuts?

  6. I'm certainly interested in your thyroid info when you get to it. I have Hashimotos. I tried the high iodine route with horrible consequences (thyroid enlargement, increasing TSH and weight gain). Selenium, magnesium and zinc are good for me though. I use Dr Kharrazian's guidelines

  7. Does seaweed have a lot of selenium? I know it's got a decent dose of iodine and other trace minerals. I try to use kombu or dulse a couple of times a week. I throw it in the pot whenever I make a soup or stew. Btw, I was able to download a pdf of the article to which you did not have access. Email me and I can send it to you.

    @Jamie, just remember the wise words of Rodney Dangerfield: "The best part about kids is makin' them!"

  8. Jeremy - I'm no nuclear physicist, but I seem to recall that ingesting radium or lead or whatever isn't nearly as dangerous as inhaling it - lead levels go up in kids in old homes during remodeling because of the sanding, for example. It may also be that 1000 times the radium is still not very much radium. I'll have to look into it more, though. Too bad as brazil nuts are a great source of selenium.

    Julianne - I want to get and read Dr Ks book before my thyroid post and review my Harrisons, so it may be a little while. But it seems to be one of the poorly understood metabolic missing links in all of this mess.

    Aaron - yes, Ill email you. Seaweed is not a good source of selenium. I put that up there as an iodine containing complement to the radioactive brazil nuts. Seaweed can also be problematic due to toxins, but what can you do? I get my dulls from whole foods, and the package claims it is from clean waters in Maine.

  9. Emily,

    I don't think that the content of radium in brazil nuts are something of much concern. In north of Brazil people have been eating a lot of brazil nuts without any know problem that I aware of (tought I live in south of Brazil).

    Second, before your thyroid post, please also read the works of Dr. Abraham (, for a totally opposite view from Dr. K. I also have Hashimoto and took a high dose of iodine (50mg/day) plus selenium (200ug) and my thyroid and health is better day after day.

    A high intake of iodine plus some selenium and sea salt is needed nowadays to counterbalance the high bromide, among other contaminants, in our environment. Below is a recent study done in a China city:

  10. @mario read the last paragraph (VII. Epilogue) in this document ( of Abraham and you will never believe a single word again of the stuff he wrote. why should anyone follow his recommendations when he clearly is a case for the nut house? higher doses might be safe for most healthy people, but certainly not based on the "research" of a mentally handicapped "doctor".

  11. @qualia,

    Really weird!!

    But, fortunatly, I do not base my iodine intake just by his research! And, most important, I base my iodine effectiveness thru blood tests and my well being.

    Anyway, just because he has some really strange ideas, this does not disqualify his iodine work. Been married to a psyquiatrist myself, I can assure you!

  12. @mario i know - many otherwise intelligent and competent people can be completely backwards and weird in a different, unrelated area. but still - i can certainly not respect him as a scientist/researcher with such a view - even tho his findings about iodine might be factually correct. btw, i also did several months of high dose iodine therapy with IOSOL, and the only thing it did was give me a long lasting skin rush on my forehead lol (looks like a bromide acne or so). no benefit at all (only some short-term energy and thermal bursts right after taking 50mg). 50mg didn't even manage to mitigate a slight throat infection. in fact, it made it worse *g* so, even tho i was optimistic before, i now am cautious for dosages above, say, 6mg a day (level to saturate the thyroid), and would not recommend to go higher without a good and specific reason. and ALWAYS check for hashimoto markers *before* starting iodine of course.

  13. fyi all: nice presentation by mark hyman about brain health and the "depression" label from the perspective of functional medicine:

  14. Just about two years ago I started looking for information on the question of whether American diets generally and my diet in particular might be short on any key nutrients. I became convinced that it is pretty hard to get adequate dietary magnesium and selenium without really loading up on some things. I believe 4700 mg a day of potassium can be a challenge, too.
    My interest was first nutritional approaches to reducing heart disease risk (primary prevention), having given up statins and given stubbornly high LDL levels, and second nutritional approaches to depression.

    I am so pleased to have Dr. Deans weigh in on these issues. In pointing out magnesium and selenium as likely chronically deficient and potentially with huge health benefits when replete, she is countering a lot of main stream conventional wisdom that eating a "good diet" (whatever is meant by that) will get you everything you need.

    As an N=1 experiment, examine your normal diet for magnesium, selenium, potassium, and anything else you can think of. You probably will find you are 100 to 200mg a day shy of the recommended 420mg per day of magnesium, 50% shy of 150mcg of selenium a day, and a third or more shy of 4700mg of potassium.

    For magnesium, I highly recommend magnesium water (4 Tablespoons of milk of magnesia (containing the otherwise nearly useless magnesium hydroxide) dissolved in two liters of seltzer water, yielding highly absorbable magnesium bicarbonate. Very low cost, very easy, very absorbable, no problems with diarrhea. My 65 lb dog had frequent seizures (at least monthly), for years, which have been cured with only one thing -- I share my mag water with him. I doubt that this is a placebo effect.

  15. Thank you so much for your blog, I have have had major issue with Panic and Depression.....I have been reading much about magnesium and find that it helps tremendously. The only issue with magnesium is that I find that it give more fatigue...this varies from the different types of magnesium that I have tried.