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.

Difficulty remembering.  As discussed previously, challenges with episodic memory may start as early as middle age, even if your brain is healthy.  As you get older, problems with memory tend to become more and more frequent.  Once you reach your mid 30s, you will most likely begin to notice an increased frequency of forgetfulness.  At this point, it may become common for you to lose your belongings and misplace your possessions, like your car keys or smartphones.  This can truly be frustrating at best.  At worst, it can be downright scary.  You might also start misplacing names and having more “tip of the tongue” moments.
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.

And many people swear by them. Neal Thakkar, for example, is an entrepreneur from Marlboro, New Jersey, who claims nootropics improved his life so profoundly that he can’t imagine living without them. His first breakthrough came about five years ago, when he tried a piracetam/choline combination, or “stack,” and was amazed by his increased verbal fluency. (Piracetam is a cognitive-enhancement drug permitted for sale in the U. S. as a dietary supplement; choline is a natural substance.)
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]