Finding a usable product on Amazon caused me some difficulties. I wanted a 500mg magnesium-citrate-only product at <$20 for 120 doses, but I discovered most of the selection for magnesium citrate had sub-500mg doses, involved calcium citrate or other substances like zinc (not necessarily a bad thing, but would confound an experiment), were mostly magnesium oxide rather than citrate, or some still other problem. Ultimately I settled on Solgar’s $13 120x400mg magnesium citrate as acceptable. (To compare with the bulkiness of the LEF vitamin D+l-threonate powder, the Office of Dietary Supplements says magnesium citrate is 16% magnesium, so to get 400mg of magnesium as claimed, would take 2.5g of material, rather than 7g for 200mg; even if l-threonate is absorbed 100% and citrate 50%, the citrate is ahead. The pills turn out to be wider and longer than my 00 pills; if I want to get them into my gel capsules, I have to crush them into fine powder. The powder from one pill turns out to take up 2 00 pills.)

Googling, you sometimes see correlational studies like Intake of Flavonoid-Rich Wine, Tea, and Chocolate by Elderly Men and Women Is Associated with Better Cognitive Test Performance; in this one, the correlated performance increase from eating chocolate was generally fairly modest (say, <10%), and the maximum effects were at 10g/day of what was probably milk chocolate, which generally has 10-40% chocolate liquor in it, suggesting any experiment use 1-4g. More interesting is the blind RCT experiment Consumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort11, which found improvements at ~1g; the most dramatic improvement of the 4 tasks (on the Threes correct) saw a difference of 2 to 6 at the end of the hour of testing, while several of the other tests converged by the end or saw the controls winning (Sevens correct). Crews et al 2008 found no cognitive benefit, and an fMRI experiment found the change in brain oxygen levels it wanted but no improvement to reaction times.

[…] 2. Blueberries: Also called “brainberries” by Dr. Steven Platt, MD author of Superfoods Rx: Fourteen Foods Proven to Change Your Life, blueberries have one of the highest antioxidant capacities of all fruits and vegetables and are known to improve memory and cognitive function. They have memory-protecting properties and have even been associated with the prevention of Alzheimer’s disease. Add some blueberries to your breakfast and you may not need to check that to-do list several times throughout the day. Also Read The 7 Best Brain Boosting Supplements […]

Dr. Lisa Mosconi, PhD, INHC, is the associate director of the Alzheimer's Prevention Clinic at Weill Cornell Medical College (WCMC)/NewYork-Presbyterian Hospital, where she was recruited as an associate professor of Neuroscience in Neurology. She also is an adjunct faculty member in the Department of Psychiatry at NYU School of Medicine, in the Department of Nutrition at NYU Steinhardt School of Nutrition and Public Health, and in the Departments of Neurology and Nuclear Medicine at the University of Florence (Italy). Formerly, Dr. Mosconi founded and was the director of the Nutrition & Brain Fitness Lab at New York University School of Medicine (NYU), and an assistant professor in the NYU Department of Psychiatry, where she served as the director of the Family History of Alzheimer's disease research program. Dr. Mosconi holds a dual PhD degree in Neuroscience and Nuclear Medicine from the University of Florence, Italy, and is a board certified integrative nutritionist and holistic healthcare practitioner. She is well known for her research on the early detection of Alzheimer's disease and is passionately interested in the mitigation and prevention of memory loss through lifestyle modifications including diet, nutrition, and physical and intellectual fitness.

Next generation medical imaging and genomic sequencing studies, including my own work, have helped reveal that some foods are neuro-protective, literally shielding the brain from harm and supporting cognitive fitness over the course of a lifetime. Conversely, other foods are harmful for the brain, slowing us down in general, making us feel sluggish and tired, while at the same time increasing our risk of dementia.

The truth is that, almost 20 years ago when my brain was failing and I was fat and tired, I did not know to follow this advice. I bought $1000 worth of smart drugs from Europe, took them all at once out of desperation, and got enough cognitive function to save my career and tackle my metabolic problems. With the information we have now, you don’t need to do that. Please learn from my mistakes!
The main concern with pharmaceutical drugs is adverse effects, which also apply to nootropics with undefined effects. Long-term safety evidence is typically unavailable for nootropics.[13] Racetams — piracetam and other compounds that are structurally related to piracetam — have few serious adverse effects and low toxicity, but there is little evidence that they enhance cognition in people having no cognitive impairments.[19]