Reason: Vitamin B12 supports brain health in critical ways. The water-soluble B vitamin helps the body convert carbohydrates and fats into energy the brain needs to function properly. It also helps reduce the brain shrinkage often associated with cognitive disorders, supports healthy sleep-wake cycles (incredibly important, given what we now know about sleep and Alzheimer’s risk), and aids the proper “firing” of communications between neurons.
It is at the top of the supplement snake oil list thanks to tons of correlations; for a review, see Luchtman & Song 2013 but some specifics include Teenage Boys Who Eat Fish At Least Once A Week Achieve Higher Intelligence Scores, anti-inflammatory properties (see Fish Oil: What the Prescriber Needs to Know on arthritis), and others - Fish oil can head off first psychotic episodes (study; Seth Roberts commentary), Fish Oil May Fight Breast Cancer, Fatty Fish May Cut Prostate Cancer Risk & Walnuts slow prostate cancer, Benefits of omega-3 fatty acids tally up, Serum Phospholipid Docosahexaenonic Acid Is Associated with Cognitive Functioning during Middle Adulthood endless anecdotes.
1. Stough, C., Lloyd, J., Clarke, J., Downey, L. A., Hutchison, C. W., Rodgers, T., & Nathan, P. J. (2001). The chronic effects of an extract of Bacopa monniera (Brahmi) on cognitive function in healthy human subjects. Psychopharmacology (Berl), 156(4), 481-484. 2. Ishaque, S., Shamseer, L., Bukutu, C., & Vohra, S. (2012). Rhodiola rosea for physical and mental fatigue: a systematic review. BMC Complementary and Alternative Medicine, 12(1), 70. doi:10.1186/1472-6882-12-703. Pase, M. P., Kean, J., Sarris, J., Neale, C., Scholey, A. B., & Stough, C. (2012). The cognitive-enhancing effects of Bacopa monnieri: a systematic review of randomized, controlled human clinical trials. J Altern Complement Med, 18(7), 647-652. doi:10.1089/acm.2011.03674. Raghav, S., Singh, H., Dalal, P. K., Srivastava, J. S., & Asthana, O. P. (2006). Randomized controlled trial of standardized Bacopa monniera extract in age-associated memory impairment. Indian J Psychiatry, 48(4), 238-242. doi:10.4103/0019-5545.315555. Neale, C., Camfield, D., Reay, J., Stough, C., & Scholey, A. (2013). Cognitive effects of two nutraceuticals Ginseng and Bacopa [...]: a review and comparison of effect sizes. British Journal of Clinical Pharmacology, 75(3), 728-737. doi:10.1111/bcp.120026. Prynne, C. J., Thane, C. W., Prentice, A., & Wadsworth, M. E. (2005). Intake and sources of phylloquinone (vitamin K(1)) in 4-year-old British children: comparison between 1950 and the 1990s. Public Health Nutr, 8(2), 171-180.7. Ferland, G. (2012). Vitamin K and the nervous system: an overview of its actions. Adv Nutr, 3(2), 204-212. doi:10.3945/an.111.0017848. Zeidan, Y. H., & Hannun, Y. A. (2007). Translational aspects of sphingolipid metabolism. Trends in molecular medicine, 13(8), 327-336.9. Beulens, J. W., Bots, M. L., Atsma, F., Bartelink, M. L., Prokop, M., Geleijnse, J. M., . . . van der Schouw, Y. T. (2009). High dietary menaquinone intake is associated with reduced coronary calcification. Atherosclerosis, 203(2), 489-493. doi:10.1016/j.atherosclerosis.2008.07.01010. Geleijnse, J. M., Vermeer, C., Grobbee, D. E., Schurgers, L. J., Knapen, M. H., van der Meer, I. M., . . . Witteman, J. C. (2004). Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr, 134(11), 3100-3105.11. Theuwissen, E., Magdeleyns, E. J., Braam, L. A., Teunissen, K. J., Knapen, M. H., Binnekamp, I. A., . . . Vermeer, C. (2014). Vitamin K status in healthy volunteers. Food Funct, 5(2), 229-234. doi:10.1039/c3fo60464k12. Barros, M. P., Poppe, S. C., & Bondan, E. F. (2014). Neuroprotective properties of the marine carotenoid astaxanthin and omega-3 fatty acids, and perspectives for the natural combination of both in krill oil. Nutrients, 6(3), 1293-1317.13. Pashkow, F. J., Watumull, D. G., & Campbell, C. L. (2008). Astaxanthin: a novel potential treatment for oxidative stress and inflammation in cardiovascular disease. Am J Cardiol, 101(10a), 58d-68d. doi:10.1016/j.amjcard.2008.02.01014. Annweiler, C., Schott, A. M., Berrut, G., Chauvire, V., Le Gall, D., Inzitari, M., & Beauchet, O. (2010). Vitamin D and ageing: neurological issues. Neuropsychobiology, 62(3), 139-150. doi:10.1159/00031857015. Brown, J., Bianco, J. I., McGrath, J. J., & Eyles, D. W. (2003). 1,25-dihydroxyvitamin D3 induces nerve growth factor, promotes neurite outgrowth and inhibits mitosis in embryonic rat hippocampal neurons. Neurosci Lett, 343(2), 139-143.16. Naveilhan, P., Neveu, I., Wion, D., & Brachet, P. (1996). 1,25-Dihydroxyvitamin D3, an inducer of glial cell line-derived neurotrophic factor. Neuroreport, 7(13), 2171-2175.17. Tangpricha, V., Pearce, E. N., Chen, T. C., & Holick, M. F. (2002). Vitamin D insufficiency among free-living healthy young adults. Am J Med, 112(8), 659-662.18. Annweiler, C., Allali, G., Allain, P., Bridenbaugh, S., Schott, A. M., Kressig, R. W., & Beauchet, O. (2009). Vitamin D and cognitive performance in adults: a systematic review. European Journal of Neurology, 16(10), 1083-1089. doi:10.1111/j.1468-1331.2009.02755.x19. Annweiler, C., Montero-Odasso, M., Llewellyn, D. J., Richard-Devantoy, S., Duque, G., & Beauchet, O. (2013). Meta-analysis of memory and executive dysfunctions in relation to vitamin D. J Alzheimers Dis, 37(1), 147-171. doi:10.3233/jad-13045220. Balion, C., Griffith, L. E., Strifler, L., Henderson, M., Patterson, C., Heckman, G., . . . Raina, P. (2012). Vitamin D, cognition, and dementia A systematic review and meta-analysis. Neurology, 79(13), 1397-1405.21. Dean, A. J., Bellgrove, M. A., Hall, T., Phan, W. M. J., Eyles, D. W., Kvaskoff, D., & McGrath, J. J. (2011). Effects of Vitamin D Supplementation on Cognitive and Emotional Functioning in Young Adults – A Randomised Controlled Trial. PLoS One, 6(11), e25966. doi:10.1371/journal.pone.002596622. Etgen, T., Sander, D., Bickel, H., Sander, K., & Forstl, H. (2012). Vitamin D deficiency, cognitive impairment and dementia: a systematic review and meta-analysis. Dement Geriatr Cogn Disord, 33(5), 297-305. doi:10.1159/00033970223. Fontani, G., Corradeschi, F., Felici, A., Alfatti, F., Migliorini, S., & Lodi, L. (2005). Cognitive and physiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects. Eur J Clin Invest, 35(11), 691-699. doi:10.1111/j.1365-2362.2005.01570.x24. Huhn, S., Masouleh, S. K., Stumvoll, M., Villringer, A., & Witte, A. V. (2015). Components of a Mediterranean diet and their impact on cognitive functions in aging. Frontiers in aging neuroscience, 7.25. Bradbury, J. (2011). Docosahexaenoic Acid (DHA): An Ancient Nutrient for the Modern Human Brain. Nutrients, 3(5), 529-554. doi:10.3390/nu305052926. Einother, S. J., & Giesbrecht, T. (2013). Caffeine as an attention enhancer: reviewing existing assumptions. Psychopharmacology (Berl), 225(2), 251-274. doi:10.1007/s00213-012-2917-427. Johnson, L. C., Spinweber, C. L., & Gomez, S. A. (1990). Benzodiazepines and caffeine: effect on daytime sleepiness, performance, and mood. Psychopharmacology (Berl), 101(2), 160-167. 28. Smith, A., Kendrick, A., Maben, A., & Salmon, J. (1994). Effects of breakfast and caffeine on cognitive performance, mood and cardiovascular functioning. Appetite, 22(1), 39-55. doi:10.1006/appe.1994.100429. Smith, A. P., Kendrick, A. M., & Maben, A. L. (1992). Effects of breakfast and caffeine on performance and mood in the late morning and after lunch. Neuropsychobiology, 26(4), 198-204. doi:11892030. Smith, B. D., Davidson, R. A., & Green, R. L. (1993). Effects of caffeine and gender on physiology and performance: further tests of a biobehavioral model. Physiol Behav, 54(3), 415-422. 31. Warburton, D. M. (1995). Effects of caffeine on cognition and mood without caffeine abstinence. Psychopharmacology (Berl), 119(1), 66-70. 32. Wilhelmus, M. M., Hay, J. L., Zuiker, R. G., Okkerse, P., Perdrieu, C., Sauser, J., . . . Silber, B. Y. (2017). Effects of a single, oral 60 mg caffeine dose on attention in healthy adult subjects. J Psychopharmacol, 31(2), 222-232. doi:10.1177/026988111666859333. Fredholm, B. B., Battig, K., Holmen, J., Nehlig, A., & Zvartau, E. E. (1999). Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacol Rev, 51(1), 83-133. 34. Borzelleca, J. F., Peters, D., & Hall, W. (2006). A 13-week dietary toxicity and toxicokinetic study with l-theanine in rats. Food Chem Toxicol, 44(7), 1158-1166. doi:10.1016/j.fct.2006.03.01435. Kimura, K., Ozeki, M., Juneja, L. R., & Ohira, H. (2007). L-Theanine reduces psychological and physiological stress responses. Biol Psychol, 74(1), 39-45. doi:10.1016/j.biopsycho.2006.06.00636. Tian, X., Sun, L., Gou, L., Ling, X., Feng, Y., Wang, L., . . . Liu, Y. (2013). Protective effect of l-theanine on chronic restraint stress-induced cognitive impairments in mice. Brain Res, 1503, 24-32. doi:10.1016/j.brainres.2013.01.04837. Unno, K., Fujitani, K., Takamori, N., Takabayashi, F., Maeda, K., Miyazaki, H., . . . Hoshino, M. (2011). Theanine intake improves the shortened lifespan, cognitive dysfunction and behavioural depression that are induced by chronic psychosocial stress in mice. Free Radic Res, 45(8), 966-974. doi:10.3109/10715762.2011.56686938. Unno, K., Tanida, N., Ishii, N., Yamamoto, H., Iguchi, K., Hoshino, M., . . . Yamada, H. (2013). Anti-stress effect of theanine on students during pharmacy practice: positive correlation among salivary alpha-amylase activity, trait anxiety and subjective stress. Pharmacol Biochem Behav, 111, 128-135. doi:10.1016/j.pbb.2013.09.00439. Dodd, F. L., Kennedy, D. O., Riby, L. M., & Haskell-Ramsay, C. F. (2015a). A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology (Berl), 232(14), 2563-2576. doi:10.1007/s00213-015-3895-040. Rogers, P. J., Smith, J. E., Heatherley, S. V., & Pleydell-Pearce, C. W. (2008). Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. Psychopharmacology (Berl), 195(4), 569-577. doi:10.1007/s00213-007-0938-141. Foxe, J. J., Morie, K. P., Laud, P. J., Rowson, M. J., de Bruin, E. A., & Kelly, S. P. (2012). Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task. Neuropharmacology, 62(7), 2320-2327. doi:10.1016/j.neuropharm.2012.01.02042. Giesbrecht, T., Rycroft, J. A., Rowson, M. J., & De Bruin, E. A. (2010). The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutr Neurosci, 13(6), 283-290. doi:10.1179/147683010x1261146076484043. Haskell, C. F., Kennedy, D. O., Milne, A. L., Wesnes, K. A., & Scholey, A. B. (2008). The effects of L-theanine, caffeine and their combination on cognition and mood. Biol Psychol, 77(2), 113-122. doi:10.1016/j.biopsycho.2007.09.00844. Kahathuduwa, C. N., Dassanayake, T. L., Amarakoon, A. M., & Weerasinghe, V. S. (2016). Acute effects of theanine, caffeine and theanine-caffeine combination on attention. Nutr Neurosci. doi:10.1080/1028415x.2016.114484545. Owen, G. N., Parnell, H., De Bruin, E. A., & Rycroft, J. A. (2008). The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci, 11(4), 193-198. doi:10.1179/147683008x30151346. Einother, S. J., Martens, V. E., Rycroft, J. A., & De Bruin, E. A. (2010). L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness. Appetite, 54(2), 406-409. doi:10.1016/j.appet.2010.01.00347. Deijen, J. B., van der Beek, E. J., Orlebeke, J. F., & van den Berg, H. (1992). Vitamin B-6 supplementation in elderly men: effects on mood, memory, performance and mental effort. Psychopharmacology (Berl), 109(4), 489-496.48. Lewerin, C., Matousek, M., Steen, G., Johansson, B., Steen, B., & Nilsson-Ehle, H. (2005). Significant correlations of plasma homocysteine and serum methylmalonic acid with movement and cognitive performance in elderly subjects but no improvement from short-term vitamin therapy: a placebo-controlled randomized study. Am J Clin Nutr, 81(5), 1155-1162. 49. Bryan, J., Calvaresi, E., & Hughes, D. (2002). Short-term folate, vitamin B-12 or vitamin B-6 supplementation slightly affects memory performance but not mood in women of various ages. J Nutr, 132(6), 1345-1356. 50. Schneider, Z., & Stroinski, A. (1987). Comprehensive B12: chemistry, biochemistry, nutrition, ecology, medicine: Walter de Gruyter.51. Polich, J., & Gloria, R. (2001). Cognitive effects of a Ginkgo biloba/vinpocetine compound in normal adults: systematic assessment of perception, attention and memory. Hum Psychopharmacol, 16(5), 409-416. doi:10.1002/hup.30852. Subhan, Z., & Hindmarch, I. (1985). Psychopharmacological effects of vinpocetine in normal healthy volunteers. Eur J Clin Pharmacol, 28(5), 567-571. 53. Dollins, A. B., Krock, L. P., Storm, W. F., Wurtman, R. J., & Lieberman, H. R. (1995). L-tyrosine ameliorates some effects of lower body negative pressure stress. Physiol Behav, 57(2), 223-230. 54. Shurtleff, D., Thomas, J. R., Schrot, J., Kowalski, K., & Harford, R. (1994). Tyrosine reverses a cold-induced working memory deficit in humans. Pharmacol Biochem Behav, 47(4), 935-941. 55. Brzezinski, A., Vangel, M. G., Wurtman, R. J., Norrie, G., Zhdanova, I., Ben-Shushan, A., & Ford, I. (2005). Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Med Rev, 9(1), 41-50. 56. Ferracioli-Oda, E., Qawasmi, A., & Bloch, M. H. (2013). Meta-Analysis: Melatonin for the Treatment of Primary Sleep Disorders. PLoS One, 8(5), e63773. doi:10.1371/journal.pone.006377357. Inagawa, K., Hiraoka, T., Kohda, T., Yamadera, W., & Takahashi, M. (2006). Subjective effects of glycine ingestion before bedtime on sleep quality. Sleep and Biological Rhythms, 4(1), 75-77. doi:10.1111/j.1479-8425.2006.00193.x58. Bannai, M., Kawai, N., Ono, K., Nakahara, K., & Murakami, N. (2012). The Effects of Glycine on Subjective Daytime Performance in Partially Sleep-Restricted Healthy Volunteers. Front Neurol, 3, 61. doi:10.3389/fneur.2012.0006159. Yamadera, W., Inagawa, K., Chiba, S., Bannai, M., Takahashi, M., & Nakayama, K. (2007). Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep and Biological Rhythms, 5(2), 126-131. doi:10.1111/j.1479-8425.2007.00262.x60. Tuli, H. S., Kashyap, D., Sharma, A. K., & Sandhu, S. S. (2015). Molecular aspects of melatonin (MLT)-mediated therapeutic effects. Life Sci, 135, 147-157. doi:10.1016/j.lfs.2015.06.00461. Herxheimer, A., & Petrie, K. J. (2002). Melatonin for the prevention and treatment of jet lag. Cochrane Database Syst Rev(2), Cd001520. doi:10.1002/14651858.cd00152062. Deng, X., Song, Y., Manson, J. E., Signorello, L. B., Zhang, S. M., Shrubsole, M. J., . . . Dai, Q. (2013). Magnesium, vitamin D status and mortality: results from US National Health and Nutrition Examination Survey (NHANES) 2001 to 2006 and NHANES III. BMC Med, 11(1), 187. doi:10.1186/1741-7015-11-18763. Murck, H., & Steiger, A. (1998). Mg2+ reduces ACTH secretion and enhances spindle power without changing delta power during sleep in men -- possible therapeutic implications. Psychopharmacology (Berl), 137(3), 247-252. 64. Nielsen, F. H., Johnson, L. K., & Zeng, H. (2010). Magnesium supplementation improves indicators of low magnesium status and inflammatory stress in adults older than 51 years with poor quality sleep. Magnes Res, 23(4), 158-168. doi:10.1684/mrh.2010.0220

As a student Seltzer used both Adderall and piracetam. Now, after a hiatus of several years, he has recently resumed taking neuroenhancers. In addition to piracetam, he took a stack of supplements that he thought helped his brain to function: fish oils, five antioxidants, a product called ChocoMind and a number of others, all available at the health-food store. He was thinking about adding modafinil, but hadn't yet. For breakfast every morning he concocted a slurry of oatmeal, berries, soy milk, pomegranate juice, flaxseed, almond meal, raw eggs and protein powder. The goal behind the recipe was efficiency: to rely on "one goop you could eat or drink that would have everything you need nutritionally for your brain and body. I wanted to be able to keep it down - that was it." (He told me this in the kitchen of his apartment; he lives with a roommate, who walked in while we were talking, listened perplexedly for a moment, then put a frozen pizza in the oven.)

Fitzgerald 2012 and the general absence of successful experiments suggests not, as does the general historic failure of scores of IQ-related interventions in healthy young adults. Of the 10 studies listed in the original section dealing with iodine in children or adults, only 2 show any benefit; in lieu of a meta-analysis, a rule of thumb would be 20%, but both those studies used a package of dozens of nutrients - and not just iodine - so if the responsible substance were randomly picked, that suggests we ought to give it a chance of 20% \times \frac{1}{\text{dozens}} of being iodine! I may be unduly optimistic if I give this as much as 10%.

The demands of university studies, career, and family responsibilities leaves people feeling stretched to the limit. Extreme stress actually interferes with optimal memory, focus, and performance. The discovery of nootropics and vitamins that make you smarter has provided a solution to help college students perform better in their classes and professionals become more productive and efficient at work.
If you want to try a nootropic in supplement form, check the label to weed out products you may be allergic to and vet the company as best you can by scouring its website and research basis, and talking to other customers, Kerl recommends. "Find one that isn't just giving you some temporary mental boost or some quick fix – that’s not what a nootropic is intended to do," Cyr says.
Colorful vegetables and fruits—such as leafy greens, peppers, beets, and berries—are high in carotenoids and anthocyanins, antioxidant pigments that provide their bright hues. “Antioxidants protect brain cell linings from the damage caused by free radicals, which are harmful molecules that cause inflammation and result from factors like a poor diet or smoking,” explains Janis Jibrin, RD, adjunct professor of nutrition at American University in Washington, D.C.
The benefit of sequential analysis here is being able to stop early, conserving pills, and letting me test another dosage: if I see another pattern of initial benefits followed by decline, I can then try cutting the dose by taking one pill every 3 days; or, if there is a benefit and no decline, then I can try tweaking the dose up a bit (maybe 3 days out of 5?). Since I don’t have a good idea what dose I want and the optimal dose seems like it could be valuable (and the wrong dose harmful!), I can’t afford to spend a lot of time on a single definitive experiment.

Turns out, when compared with smokers who drank coffee regularly, non-coffee drinkers had twice as much of the cell damage associated with tobacco use. In addition, the smokers who didn’t consume coffee were up to seven times more likely to be affected by the same cancer as nonsmokers. Regular smokers who drank coffee fewer than two times each week had double the chances of developing cancer compared to those who drank coffee frequently. So ultimately, coffee-drinking cigarette-puffers have some kind of health advantage over their smoking counterparts who don’t drink coffee.
Nootropics (/noʊ.əˈtrɒpɪks/ noh-ə-TROP-iks) (colloquial: smart drugs and cognitive enhancers) are drugs, supplements, and other substances that may improve cognitive function, particularly executive functions, memory, creativity, or motivation, in healthy individuals.[1] While many substances are purported to improve cognition, research is at a preliminary stage as of 2018, and the effects of the majority of these agents are not fully determined.
×