1. (of a drug) used to enhance memory or other cognitive functions.
Nootropics are all the rage today, with supplement manufacturers touting products that can dramatically improve cognitive domains such as attention, focus, and working memory.
As someone with a personal and professional interest in optimizing cognitive health and function via whichever means necessary, I am often asked my opinion on nootropics, and which ones I like to use, if any. My response is often disappointing to those looking for a pill-based solution, because... wait for it... food is my favorite nootropic! (This isn't to say that I'm disinterested in nootropic supplements, however, I find many people usually look for an easy solution while ignoring the "low hanging fruits" in their diet.)
So, without further adieu, are my 10 favorite cognition-boosting foods.
Eggs are the top known source of choline, which is critical for proper signaling at your neuronal membranes. It is also the precursor to the neurotransmitter acetylcholine. (R)
Acetylcholine is important for learning and memory, as well as deep sleep. Some of the drugs approved to treat the symptoms of Alzheimer's disease, a fatal memory disorder, work by boosting levels of acetylcholine in the brain.
While the body is able to produce small amounts of choline, we don't produce enough for good health and therefore must get it from our food (choline was actually once considered a vitamin!). Sadly, 90% of people consume inadequate amounts of choline. (R)
The current Institute of Medicine adequate intake for choline is:
425 mg/day for women (450 mg/day for pregnant women, 550 mg/day for lactating women)
550 mg/day for men
One egg contains 125 mg of choline in its yolk. Other great sources include liver, seafood, and shellfish.
In one study of 2500 men across 22 years, frequent egg consumption was associated with better results in certain tests measuring cognitive performance. (R)
2. Dark leafy greens
Dark leafy greens like kale and spinach are a top source of lutein and zeaxanthin, two carotenoids which have been the focus of numerous recent studies.
In volunteers, supplementing with lutein and zeaxanthin led to faster processing speed. (R) This effect was significant "even when testing young, healthy individuals who tend to be at peak efficiency," wrote study authors.
In another study, human subjects with higher levels of lutein and zeaxanthin did better on a test of working memory, while their brains seemed to be working more efficiently when observed under fMRI. (R)
Finally, lutein (found in egg yolks, spinach and kale) was associated with greater crystalized intelligence—the ability to use learned knowledge and experience—in older adults. (R)
3. Dark chocolate
A robust link has been observed between dark chocolate consumption and cognitive function, owed in part to the flavanols (a type of polyphenol) found in the cocoa bean. This benefit to memory may be partly explained by cocoa's ability to increase blood flow to the brain, (R) as well as by enhancing functioning of the dentate gyrus, a region of the brain's memory center where neurogenesis (the growth of new brain cells) is known to occur.
In a study of nearly 1000 people of all ages, habitual chocolate consumption was significantly associated with stronger cognitive function “irrespective of other dietary habits”. More frequent chocolate consumption was “significantly associated with better performance on [cognitive tests including] visual-spatial memory and organisation, working memory, scanning and tracking, abstract reasoning, and the mini-mental state examination”. (R)
I try to consume at least one 85% chocolate bar every week (click here to see my article on how to ensure that the chocolate you are purchasing is of high quality).
Evidence suggests that coffee consumption plays a protective role in risk for multiple sclerosis (MS), Alzheimer's disease, and Parkinson's disease, and may even prevent early mortality (R).
Coffee is the most common source of caffeine in the diet, which has been shown to enhance cognitive performance in part by blocking the activity of adenosine, an inhibitory neurotransmitter in the brain. This neurotransmitter can reduce mental stamina and make one feel drowsy.
Recent research has found that caffeine might also block gene pathways involved in systemic inflammation. (R) Higher levels of this type of inflammation has been associated with reduced cognitive performance.
Excessive caffeine consumption on the other hand can create the sensation of being "wired and tired"—this is known informally as "adrenal burnout." Therefore, a "sweet spot" for cognitive enhancing may be 1 to 2 cups per day.
One method to optimize caffeine consumption is to cycle off by drinking only decaf for a week, which could theoretically help sensitize you to caffeine's biochemical effects. The smell and flavor of decaf coffee may still provide a boost, thanks in part to the power of classical conditioning.
Finally, always drink your coffee before 2pm (some may be able to consume it later) so as not to interfere with sleep.
5. Green tea
Green tea is a favorite of many "biohacks." While it contains small amounts of caffeine, it is more notably known for its catechin and L-theanine content. Theanine is a powerful cognitive booster shown to promote relaxation without sedation, while catechins are flavanols (similar to those in chocolate) which seem to favorably promote brain function.
In one small study, green tea consumption appeared to increase connectivity between frontal and parietal brain regions during working memory processing. (R) This is compelling because activity in the frontal region of the brain is correlated to executive function, while the parietal region handles sensory input. The researchers found that green tea consumption enhanced performance on a test of working memory.
6. Extra-virgin olive oil
In a large, randomized control trial, people who added an additional liter of extra-virgin olive oil per week to diets that resembled a healthy "Mediterranean-style" diet (typically defined as being high in vegetables, fish, and legumes, and low in sugar, refined carbs, and processed oils) showed improved cognitive function over 6 years compared to placebo. (R)
In a mouse model of accelerating aging and neurodegeneration, extra-virgin olive oil corrected learning deficits (compared to butter) and enhanced memory, and reduced oxidative stress in the brain in part by boosting levels of glutathione, the body's most potent endogenous antioxidant. (R)
7. Broccoli sprouts
Many plant compounds (including coffee) activate the body's NRF2 pathway, a powerful master-modulator of inflammation. When activated, this pathway increases production of powerful endogenous antioxidants. Think of it as a genetic "app" whose job it is to mop up free radicals and quench oxidative stress.
While many NRF2 activators have limited bioavailability—meaning they are generally difficult for the body to absorb or use—one compound has emerged as a top NRF2 activator in part because of its high bioavailability: Sulforaphane. (R)
While many cruciferous vegetables release sulforaphane when chewed raw (broccoli and kale, to name a few), broccoli sprouts release the most. In fact, when chewed, broccoli sprouts release 10-100x more sulforaphane than adult broccoli. (R)
Research has shown that sulforaphane has been effective in alleviating symptoms of depression and autism (R). Insofar as neuroinflammation can negatively affect working memory and executive function, it's likely that sulforaphane is a powerful nootropic as well.
Blueberries are rich in a class of compounds called anthocyanins which have been shown to protect the brain against aging (equating to up to 2.5 years for the highest level of berry consumption) in human observational studies. (R)
Animal studies are just as compelling. Aging rats that consumed diets supplemented with blueberries improved both their learning capacity and motor skills, making them mentally equivalent to much younger rats. (R)
Turmeric is another powerful activator of the NRF2 pathway. In research on humans with prediabetes, turmeric was shown to enhance working memory (R). Other studies have shown a positive effect of turmeric on symptoms of depression.
I like to include whole turmeric in my cooking, and ensure that whenever I'm using it, I am cooking with fat and black pepper—two ingredients which enhance the absorption of turmeric and its constituent compounds.
10. Fatty fish
Many studies have shown a link between fish consumption, brain health, and better memory function. Fatty fish (such as wild salmon or sardines) are rich in omega-3 fats, which can assist in optimal brain function. There are two types of omega-3 fats found in the fat of fish: DHA, which is essential for healthy neuronal membranes, and EPA, which is a powerful anti-inflammatory.
EPA in particular is useful for fighting inflammation, which is increasingly implicated as an underlying mechanism of depression. When people were injected with inflammation-promoting chemicals, they experienced a reduction in cognitive function and mood. They also felt the sensation of anhedonia—a reduced ability to experience pleasure. However, in another study, when people were given a supplement containing EPA at the same time as such inflammation-instigating chemicals, these effects were significantly reduced. (R)
Another fishy compound found in crustaceans as well as wild salmon is astaxanthin. Astaxanthin is a powerful carotenoid (pigment) antioxidant that has been shown to enhance cognitive function while protecting neuronal cell membranes from oxidative stress. It can also promote neurogenesis.
Even mild dehydration (at levels common during daily living) can negatively affect cognitive function, altering a person's mood, energy levels and processing speed. (R) Drink up, pee clear!
Do you have a favorite memory-boosting food? Let me know in the comments below!