Harriet Hall, MD also known as The SkepDoc, is a retired family physician who writes about pseudoscience and questionable medical practices. She received her BA and MD from the University of Washington, did her internship in the Air Force (the second female ever to do so),  and was the first female graduate of the Air Force family practice residency at Eglin Air Force Base. During a long career as an Air Force physician, she held various positions from flight surgeon to DBMS (Director of Base Medical Services) and did everything from delivering babies to taking the controls of a B-52. She retired with the rank of Colonel.  In 2008 she published her memoirs, Women Aren't Supposed to Fly.
Some people warn of the dangers of modafinil. There are anecdotal personal accounts online of people becoming dependent on this drug. Modafinil is the generic of the brand Provigil, a nootropic. Provigil is FDA-approved to stimulate wakefulness in people suffering from sleep disorders, such as narcolepsy and sleep apnea. Initially, Provigil was thought to have a benign, non-addiction-forming profile. As such, the Drug Enforcement Administration classifies Provigil as a Schedule IV drug, a category reserved for drugs with low abuse potential; however, recent research conducted by the National Institute on Drug Abuse (NIDA) has found that Provigil may in fact be addictive.[10]
With just 16 predictions, I can’t simply bin the predictions and say yep, that looks good. Instead, we can treat each prediction as equivalent to a bet and see what my winnings (or losses) were; the standard such proper scoring rule is the logarithmic rule which pretty simple: you earn the logarithm of the probability if you were right, and the logarithm of the negation if you were wrong; he who racks up the fewest negative points wins. We feed in a list and get back a number:
You have probably heard and you already love the term “soul food.” You should know that there’s “brain food” too. Natural supplements are the best way to express your gratitude for all the hard work your brain does for you around the clock. These products aren’t reserved only for the elderly users. On the contrary, if you start using them while you’re still young and sharp, you can ensure the proper protection against all those age-related mental deterioration processes.
Finally, it’s not clear that caffeine results in performance gains after long-term use; homeostasis/tolerance is a concern for all stimulants, but especially for caffeine. It is plausible that all caffeine consumption does for the long-term chronic user is restore performance to baseline. (Imagine someone waking up and drinking coffee, and their performance improves - well, so would the performance of a non-addict who is also slowly waking up!) See for example, James & Rogers 2005, Sigmon et al 2009, and Rogers et al 2010. A cross-section of thousands of participants in the Cambridge brain-training study found caffeine intake showed negligible effect sizes for mean and component scores (participants were not told to use caffeine, but the training was recreational & difficult, so one expects some difference).

The evidence? Found helpful in reducing bodily twitching in myoclonus epilepsy, a rare disorder, but otherwise little studied. Mixed evidence from a study published in 1991 suggests it may improve memory in subjects with cognitive impairment. A meta-analysis published in 2010 that reviewed studies of piracetam and other racetam drugs found that piracetam was somewhat helpful in improving cognition in people who had suffered a stroke or brain injury; the drugs’ effectiveness in treating depression and reducing anxiety was more significant.
Broccoli is great source of vitamin K, which is known to enhance cognitive function and improve brainpower. Researchers have reported that because broccoli is high in compounds called glucosinolates, it can slow the breakdown of the neurotransmitter, acetylcholine, which we need for the central nervous system to perform properly and to keep our brains and our memories sharp. Low levels of acetylcholine are associated with Alzheimer's.
(As I was doing this, I reflected how modafinil is such a pure example of the money-time tradeoff. It’s not that you pay someone else to do something for you, which necessarily they will do in a way different from you; nor is it that you have exchanged money to free yourself of a burden of some future time-investment; nor have you paid money for a speculative return of time later in life like with many medical expenses or supplements. Rather, you have paid for 8 hours today of your own time.)

These brain enhancers allow users to go without sleep for extended periods of time. But in the long-term, insomnia is a hazardous side effect, not a so-called benefit. Lack of sleep is extremely detrimental to your brain health and function. It’s during sleep that your brain consolidates memories, cleans away toxins, repairs itself, and creates new brain cells. (52, 53, 54, 55)
It’s that time of the year again. It’s Blue Monday. We’re halfway into January, trudging through the deepest and darkest of the winter months, as we try to keep our heads high after the Christmas festivities with the motivation of our New Year’s resolutions. Some of you may have never heard of Blue Monday and let’s just say you’re not exactly missing out.
Following up on the promising but unrandomized pilot, I began randomizing my LLLT usage since I worried that more productive days were causing use rather than vice-versa. I began on 2 August 2014, and the last day was 3 March 2015 (n=167); this was twice the sample size I thought I needed, and I stopped, as before, as part of cleaning up (I wanted to know whether to get rid of it or not). The procedure was simple: by noon, I flipped a bit and either did or did not use my LED device; if I was distracted or didn’t get around to randomization by noon, I skipped the day. This was an unblinded experiment because finding a randomized on/off switch is tricky/expensive and it was easier to just start the experiment already. The question is simple too: controlling for the simultaneous blind magnesium experiment & my rare nicotine use (I did not use modafinil during this period or anything else I expect to have major influence), is the pilot correlation of d=0.455 on my daily self-ratings borne out by the experiment?
In my last post, I talked about the idea that there is a resource that is necessary for self-control…I want to talk a little bit about the candidate for this resource, glucose. Could willpower fail because the brain is low on sugar? Let’s look at the numbers. A well-known statistic is that the brain, while only 2% of body weight, consumes 20% of the body’s energy. That sounds like the brain consumes a lot of calories, but if we assume a 2,400 calorie/day diet - only to make the division really easy - that’s 100 calories per hour on average, 20 of which, then, are being used by the brain. Every three minutes, then, the brain - which includes memory systems, the visual system, working memory, then emotion systems, and so on - consumes one (1) calorie. One. Yes, the brain is a greedy organ, but it’s important to keep its greediness in perspective… Suppose, for instance, that a brain in a person exerting their willpower - resisting eating brownies or what have you - used twice as many calories as a person not exerting willpower. That person would need an extra one third of a calorie per minute to make up the difference compared to someone not exerting willpower. Does exerting self control burn more calories?

Some people consider stimulants to be a form of nootropic, while others distinguish them from the likes of caffeine, and Adderall -- of which there's currently a nationwide shortage. Most legal users of this attention-deficit hyperactivity disorder (ADHD) drug are children; it's prescribed sparingly in adults for fear of abuse. The FDA caused the shortage by halting delivery to drug manufacturers of the drug's active ingredient, an amphetamine, for months, arguing that enough Adderall had already been produced to satisfy all legal demand. The agency argued that abusers of Adderall are responsible for the shortage. That's a group that includes students and professionals using Adderall to help boost productivity during stressful times.
Drugs such as Adderall can cause nervousness, headaches, sleeplessness and decreased appetite, among other side-effects. An FDA warning on Adderall's label notes that "amphetamines have a high potential for abuse" and can lead to dependence. (The label also mentions that adults using Adderall have reported serious cardiac problems, though the role of the drug in those cases is unknown.) Yet college students tend to consider Adderall and Ritalin as benign, in part because they are likely to know peers who have taken the drugs since childhood for ADHD. Indeed, McCabe reports, most students who use stimulants for cognitive enhancement obtain them from an acquaintance with a prescription. Usually the pills are given away, but some students sell them.
I do recommend a few things, like modafinil or melatonin, to many adults, albeit with misgivings about any attempt to generalize like that. (It’s also often a good idea to get powders, see the appendix.) Some of those people are helped; some have told me that they tried and the suggestion did little or nothing. I view nootropics as akin to a biological lottery; one good discovery pays for all. I forge on in the hopes of further striking gold in my particular biology. Your mileage will vary. All you have to do, all you can do is to just try it. Most of my experiences were in my 20s as a right-handed 5’11 white male weighing 190-220lbs, fitness varying over time from not-so-fit to fairly fit. In rough order of personal effectiveness weighted by costs+side-effects, I rank them as follows:

In addition to diet, there are many other things you can also do related to lifestyle, such as stress management through mindfulness (8) or gentle movement such as pre or post natal yoga (9), which have both shown to be incredibly helpful in encouraging mental wellbeing. If you feel you need extra support, personalised nutritional therapy can be very helpful as there can often be other drivers such as nutrient deficiencies and digestive complaints that can play a significant role in mental health and will need to be addressed in a way that is tailored to the individual. 
Another promising "smart pill" is phosphatidylserine, or PS, a natural substance that helps cell walls stay pliable and is thought to boost the effectiveness of neurotransmitters, which relay brain signals. In a May 1991 study published in Neurology, neuroscientist Thomas Crook found that patients with age-associated memory impairment improved their scores on key performance tests after 12 weeks on PS. Yet more research is needed before doctors can know that the supplement is safe and effective.
Including comprehensive lists of what to eat and what to avoid, a detailed quiz that will tell you where you are on the brain health spectrum, and 24 mouth-watering brain-boosting recipes that grow out of Dr. Mosconi’s own childhood in Italy, Brain Food gives us the ultimate plan for a healthy brain. Brain Food will appeal to anyone looking to improve memory, prevent cognitive decline, eliminate brain fog, lift depression, or just sharpen their edge.

He used to get his edge from Adderall, but after moving from New Jersey to San Francisco, he says, he couldn’t find a doctor who would write him a prescription. Driven to the Internet, he discovered a world of cognition-enhancing drugs known as nootropics — some prescription, some over-the-counter, others available on a worldwide gray market of private sellers — said to improve memory, attention, creativity and motivation.
DAY B-1 1.5 mg B-2 1.7 mg Niacin 30 mg B-6 40 mg Folic Acid 400 mcg B-12 500 mcg Biotin 100 mcg Pantothenic Acid 10 mg Magnesium 100 mg Spirulina Algae Powder 5 mg Tongkat Ali Root 5 mg Panax ginseng 5 mg American Ginseng 5 mg Rhodiola rosea 5 mg Maca Root 5 mg L-Taurine 100 mg Acai Fruit 100 mg Caffeine Anhydrous 100 mg NIGHT Ginkgo biloba 50 mg Phosphatidylserine 125 mg N-Acetyl L-Carnitine HCl 50 mg St. John's Wort 250 mg L-Glutamine 50 mg Bacopa 100 mg Vinpocetine 2 mg Huperzine-A 10 mcg
Artichoke + Forskolin: There is plenty of evidence that suggests artichoke extract supplements (made from the leaves of artichokes) offer strong neural antioxidant properties. Additionally, Forskolin (Coleus forskohlii) is one of the few studied compounds known to naturally boost cAMP (Cyclic Adenosine Monophosphate) in your brain and is also important for neural signaling within brain cells (291m 292). I’ve experienced noticeably enhanced memory and word recall when consuming this combo. Tim Ferriss talked about this one a bit in my podcast with him, particularly referencing its presence in the somewhat popular cognition supplement “CILTEP”. Made primarily from artichoke extracts and forskolin, CILTEP is a stack that also contains vitamin B6, L-phenylalanine and acetyl-L-carnitine.  It is recommended to take two to three capsules at the beginning of each day and to skip dosage one or two days per week to achieve optimal results.
I usually use Alpha Brain but have found the delivery times and cost per bottle to be too much .Its great to find a UK based nootropic supplement company giving Alpha Brain a run for their Yankee Dollar . Ultra is a very smooth nootropic - i find my thinking clear and my brain feels more alert and alive - hard to explain but Ultra makes me feel more 'present' and alive . Highly recommended. 5 STARS! MC (Wales)
I am sort of a health nut. I only use natural medicines- never prescriptions. Lately I have been experiencing some brain fog in spite of my detoxing, so I tried this product. I LOVE IT! I really can tell a difference. I have tried many memory and brain support supplements before, but this one seems quite different. I love the daytime and separate night time formulas. I have never slept so soundly in my life. In fact, I've always had a lot of trouble sleeping, but I sleep like a baby and wake feeling refreshed and full of energy.
The bitter reality of life is that there’s no organ of our body, which can defy the effects of aging with success. At least not entirely on its own. That’s why we need supplements in the first place. Remember? That’s only the beginning of the bad news for your brain. Certain sections of our brain, especially prefrontal cortex and hippocampus, can be seriously reduced in size as you are getting older. In addition, the number of capillaries in your head reduces, as well. Let’s not forget the arteries that become narrower and therefore limit the blood flow.
These days, young, ambitious professionals prefer prescription stimulants—including methylphenidate (usually sold as Ritalin) and Adderall—that are designed to treat people with attention deficit hyperactivity disorder (ADHD) and are more common and more acceptable than cocaine or nicotine (although there is a black market for these pills). ADHD makes people more likely to lose their focus on tasks and to feel restless and impulsive. Diagnoses of the disorder have been rising dramatically over the past few decades—and not just in kids: In 2012, about 16 million Adderall prescriptions were written for adults between the ages of 20 and 39, according to a report in the New York Times. Both methylphenidate and Adderall can improve sustained attention and concentration, says Barbara Sahakian, professor of clinical neuropsychology at the University of Cambridge and author of the 2013 book Bad Moves: How Decision Making Goes Wrong, and the Ethics of Smart Drugs. But the drugs do have side effects, including insomnia, lack of appetite, mood swings, and—in extreme cases—hallucinations, especially when taken in amounts the exceed standard doses. Take a look at these 10 foods that help you focus.
✅ YOUR COMPLETE ALL-IN-ONE BRAIN SOLUTION - rather than drink coffee and energy drinks to help you stay productive and struggle to get thru the day - AND instead of having to buy several different products to help with stress, memory, concentration, energy and Brain Support, Neuro Brain Clarity offers you the benefits of several different brain pills and supplements in one package, which is cheaper and more convenient for you.
All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact  your local health care provider. See our website terms and conditions for more information.
If I assume that the coefficient of +1.22 for as.logical(Magnesium.citrate)TRUE’s effect on MP in the previous analysis represents the true causal effect of 0.156g elemental magnesium without any overdose involved and that magnesium would have a linear increase (up until overdose), then one might argue that optimistically 0.078 would cause an increase of ~0.61. Or one could eyeball the graph and note that the LOESS lines look like at the magnesium peak improved by <+0.5 over the long-run baseline of ~3 Then one could do a power estimate with those 2 estimates.
One SCFA in particular, called propionic acid, has been identified as a driver for abnormal behaviour that is related to both ADHD and the autism spectrum. This SCFA can alter metabolic and immune pathways, as well as gene expression, which can affect the functionality of the brain cells and their receptivity to neurotransmitters, as well as their ability to regenerate and regulate inflammatory responses. Certain strains of pathogenic bacteria, such as clostridia, have been implicated in producing large amounts of propionic acid. This strain of bacteria is naturally present in the gut, however, an overgrowth can occur when good bacteria levels are compromised and/or there is an acute infection. In addition, processed wheat and dairy products often contain propionic acid as a food preservative in the form of calcium propionate.
*Results for individuals will vary, depending on existing health factors, lifestyle and level of fitness. The information contained on this site is intended to educate only and is in no way, a substitute for medical advice that your doctor or healthcare provider can offer, with whom you should always consult with before making any dietary changes. Information within should not be used for diagnosis, treatment or prevention of any disease. Testimonials and results contained within may not be an implication of future results. Testimonials on this site are based on the experiences of a few people and you may not have similar results. These statements have not been evaluated by the Food and Drug Administration.
To our partners, community supporters, and funders: The Brainfood journey has taken us many places, and at each fork in the road we discovered an amazing network of youth advocates ready to help lift our work to the next level. Whether you donated pro-bono consulting hours, connected us to allies in the city, or came in to meet our students and see a class, you helped us build something really special. Thanks for believing in us.
Coconut oil was recommended by Pontus Granström on the Dual N-Back mailing list for boosting energy & mental clarity. It is fairly cheap (~$13 for 30 ounces) and tastes surprisingly good; it has a very bad reputation in some parts, but seems to be in the middle of a rehabilitation. Seth Robert’s Buttermind experiment found no mental benefits to coconut oil (and benefits to eating butter), but I wonder.

Modafinil, also known as Provigil, Modalert, and Alertec, was originally made and marketed for sleep disorders, and has been prescribed in the US for this reason since 1998. It was found only by chance to help with focus and concentration, and it is only approved for the treatment of narcolepsy, shift work sleep disorder, and obstructive sleep apnea.
To thwart the rise of non-prescription nootropics, opponents may rally for increased regulation; however, at present, there is insufficient research available to support that non-prescription nootropics pose a danger to public health. Prescription nootropics, such as Ritalin, are already regulated. Further, these drugs have a proven beneficial treatment purpose for intended users.

Manually mixing powders is too annoying, and pre-mixed pills are expensive in bulk. So if I’m not actively experimenting with something, and not yet rich, the best thing is to make my own pills, and if I’m making my own pills, I might as well make a custom formulation using the ones I’ve found personally effective. And since making pills is tedious, I want to not have to do it again for years. 3 years seems like a good interval - 1095 days. Since one is often busy and mayn’t take that day’s pills (there are enough ingredients it has to be multiple pills), it’s safe to round it down to a nice even 1000 days. What sort of hypothetical stack could I make? What do the prices come out to be, and what might we omit in the interests of protecting our pocketbook?
He recommends a 10mg dose, but sublingually. He mentions COLURACETAM’s taste is more akin to that of PRAMIRACETAM than OXIRACETAM, in that it tastes absolutely vile (not a surprise), so it is impossible to double-blind a sublingual administration - even if I knew of an inactive equally-vile-tasting substitute, I’m not sure I would subject myself to it. To compensate for ingesting the coluracetam, it would make sense to double the dose to 20mg (turning the 2g into <100 doses). Whether the effects persist over multiple days is not clear; I’ll assume it does not until someone says it does, since this makes things much easier.
A constituent of the turmeric spice, curcumin was first discovered for its brain health benefits when epidemiological studies revealed those in regions with a high consumption of the curry spice turmeric had fewer reported cases of cognitive diseases. It is theorized that the unmatched anti-inflammatory power of curcumin, in combination with its unique antioxidant make-up, inhibits the formation of amyloid build up in the brain.
If I assume that the coefficient of +1.22 for as.logical(Magnesium.citrate)TRUE’s effect on MP in the previous analysis represents the true causal effect of 0.156g elemental magnesium without any overdose involved and that magnesium would have a linear increase (up until overdose), then one might argue that optimistically 0.078 would cause an increase of ~0.61. Or one could eyeball the graph and note that the LOESS lines look like at the magnesium peak improved by <+0.5 over the long-run baseline of ~3 Then one could do a power estimate with those 2 estimates.
As a general class, nootropics are not usually addiction-forming.[6] Two of the strongest hallmarks of addiction-forming drugs is that they cause users to develop dependency and experience withdrawal when the drug use is eliminated or reduced. While there are some reports of nootropic users experiencing brain fog after use is discontinued, these side effects are not considered to be akin to withdrawal effects of addiction-forming drugs.[7]
For this batch, I tried out NOW Foods Magnesium Citrate Powder ($7 for 227g); the powder was still a bit sticky but much easier to work with than the Solgar pills, and the 227g made 249 gel capsule pills. The package estimates 119 serving of 315mg elemental magnesium, so a ratio of 0.315g magnesium for 1.9g magnesium citrate, implying that each gel cap pill then contains 0.152g magnesium (\frac{(119\times315)}{249}=150) and since I want a total dose of 0.8g, I need 5 of the gel cap pills a day or 35 per block.

When you drink tea, you’re getting some caffeine (less than the amount in coffee), plus an amino acid called L-theanine that has been shown in studies to increase activity in the brain’s alpha frequency band, which can lead to relaxation without drowsiness. These calming-but-stimulating effects might contribute to tea’s status as the most popular beverage aside from water. People have been drinking it for more than 4,000 years, after all, but modern brain hackers try to distill and enhance the benefits by taking just L-theanine as a nootropic supplement. Unfortunately, that means they’re missing out on the other health effects that tea offers. It’s packed with flavonoids, which are associated with longevity, reduced inflammation, weight loss, cardiovascular health, and cancer prevention.

Smart drugs offer significant memory enhancing benefits. Clinical studies of the best memory pills have shown gains to focus and memory. Individuals seek the best quality supplements to perform better for higher grades in college courses or become more efficient, productive, and focused at work for career advancement. It is important to choose a high quality supplement to get the results you want.
There are a variety of substances to get magnesium from. Considerable enthusiasm for the new compound magnesium l-threonate was stirred by 2 small animal rat studies finding that magnesium l-threonate was able to increase magnesium levels in the brain and improve learning/memory tasks. (There are no published human trials as of October 2015, and evidence of publication bias, which I take as evidence against there being large effects in humans.) Animal studies mean very little, of course (see the appendix), but I thought it’d be interesting to try using l-threonate, so I bought the $30 Life Extension Neuro-Mag Magnesium L-Threonate with Calcium and Vitamin D3 (205g), which according to the LEF product page works out to ~60g of Magtein™ magnesium L-threonate and ~4.31g elemental magnesium inasmuch as LEF claims 2000mg of threonate powder provides 144mg elemental magnesium or a 14:1 ratio. (I don’t need the calcium or vitamin D3, but this was the only magnesium l-threonate on Amazon.) Experiment-wise, I’ll probably look at sleep metrics and Mnemosyne performance; I put off designing a blind self-experiment until after trying some.
Bacopa is a supplement herb often used for memory or stress adaptation. Its chronic effects reportedly take many weeks to manifest, with no important acute effects. Out of curiosity, I bought 2 bottles of Bacognize Bacopa pills and ran a non-randomized non-blinded ABABA quasi-self-experiment from June 2014 to September 2015, measuring effects on my memory performance, sleep, and daily self-ratings of mood/productivity. Because of the very slow onset, small effective sample size, definite temporal trends probably unrelated to Bacopa, and noise in the variables, the results were as expected, ambiguous, and do not strongly support any correlation between Bacopa and memory/sleep/self-rating (+/-/- respectively).

One thing I notice looking at the data is that the red magnesium-free days seem to dominate the upper ranks towards the end, and blues appear mostly at the bottom, although this is a little hard to see because good days in general start to become sparse towards the end. Now, why would days start to be worse towards the end, and magnesium-dose days in particular? The grim surmise is: an accumulating overdose - no immediate acute effect, but the magnesium builds up, dragging down all days, but especially magnesium-dose days. The generally recognized symptoms of hypermagnesemia don’t include effect on mood or cognition, aside from muscle weakness, confusion, and decreased reflexes…poor appetite that does not improve, but it seems plausible that below medically-recognizable levels of distress like hypermagnesemia might still cause mental changes, and I wouldn’t expect any psychological research to have been done on this topic.

After we had ordered beers he said: "One of the most impressive features of being a student is how aware you are of a 24-hour work cycle. When you conceive of what you have to do for school, it's not in terms of nine to five but in terms of what you can physically do in a week while still achieving a variety of goals - social, romantic, extracurricular, CV-building, academic."
The nootropics community is surprisingly large and involved. When I wade into forums and the nootropics subreddit, I find members trading stack recipes and notifying each other of newly synthesized compounds. Some of these “psychonauts” seem like they’ve studied neuroscience; others appear to be novices dipping their toes into the world of cognitive enhancement. But all of them have the same goal: amplifying the brain’s existing capabilities without screwing anything up too badly. It’s the same impulse that grips bodybuilders—the feeling that with small chemical tweaks and some training, we can squeeze more utility out of the body parts we have. As Taylor Hatmaker of the Daily Dot recently wrote, “Together, these faceless armchair scientists seek a common truth—a clean, unharmful way to make their brains better—enforcing their own self-imposed safety parameters and painstakingly precise methods, all while publishing their knowledge for free, in plain text, to relatively crude, shared databases."
As discussed in my iodine essay (FDA adverse events), iodine is a powerful health intervention as it eliminates cretinism and improves average IQ by a shocking magnitude. If this effect were possible for non-fetuses in general, it would be the best nootropic ever discovered, and so I looked at it very closely. Unfortunately, after going through ~20 experiments looking for ones which intervened with iodine post-birth and took measures of cognitive function, my meta-analysis concludes that: the effect is small and driven mostly by one outlier study. Once you are born, it’s too late. But the results could be wrong, and iodine might be cheap enough to take anyway, or take for non-IQ reasons. (This possibility was further weakened for me by an August 2013 blood test of TSH which put me at 3.71 uIU/ml, comfortably within the reference range of 0.27-4.20.)
These pills don’t work. The reality is that MOST of these products don’t work effectively. Maybe we’re cynical, but if you simply review the published studies on memory pills, you can quickly eliminate many of the products that don’t have “the right stuff.” The active ingredients in brain and memory health pills are expensive and most companies sell a watered down version that is not effective for memory and focus. The more brands we reviewed, the more we realized that many of these marketers are slapping slick labels on low-grade ingredients.
Notice that poor diet is not on the list. They recommend active treatment of hypertension, more childhood education, exercise, maintaining social engagement, reducing smoking, and management of hearing loss, depression, diabetes, and obesity. They do not recommend specific dietary interventions or supplements. They estimate that lifestyle interventions “might have the potential to delay or prevent a third of dementia cases.”
However, normally when you hear the term nootropic kicked around, people really mean a “cognitive enhancer” — something that does benefit thinking in some way (improved memory, faster speed-of-processing, increased concentration, or a combination of these, etc.), but might not meet the more rigorous definition above.  “Smart drugs” is another largely-interchangeable term.