Albert Anker's 1891 painting "Still Life with Coffee, Bread and Potatoes" shows some of what may go into a positive diet for mental improvement: caffeine and wholesome foods. (Public Domain)
It seems caffeine may enhance memory and learning, but not if it is taken before the lesson is to be learned. Research says caffeine should be taken after that important business meeting, crucial college lecture or other knowledge-imparting event you need to recall.
Some studies show a benefit from caffeine on memory, some show none. Same with alcohol. But it seems scientists find with few exceptions that good diets promote healthy minds and bodies.
Caffeine and memory
Researchers led by Daniel Borota from the Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland, published a study in the journal NatureNeuroscience stated in their abstract,  "We conclude that caffeine enhanced consolidation of long-term memories in humans."
In this video, Dr. Oz explores the topic of memory boosters and whether they are safe and effective.
It was a complicated study in which 160 healthy women age 18 to 30 performed what a blog [https://blogs.scientificamerican.com/the-curious-wavefunction/should-you-drink-coffee-before-or-after-a-learning-task/] on Scientific American's website calls "a series of learning tasks."
Scientific American summarizes how the study was conducted:
The subjects were handed cards with pictures of various random indoor and outdoor objects (for instance leaves, ducks and handbags) on them and asked to classify the objects as indoor or outdoor. Immediately after the task the volunteers were handed pills, either containing 200 mg of caffeine or placebo. Saliva samples to test for caffeine and its metabolites were collected after 1, 3 and 24 hours.
After 24 hours the researchers tested the participants' recollection of the past day's test. Along with the items in the test ('old') they were presented with new items ('foils') and similar looking items ('lures'), neither of which were part of the task. They were then asked to again classify the items as old, new and similar.
There was a statistically significant percentage of volunteers in the caffeinated group that was more likely to mark the 'similar' items as 'similar' rather than 'old'. That is, caffeinated participants were clearly able to distinguish much better between the old and the other items, indicating that they were retaining the memory of the old items much better than the people in the placebo group.
The authors attempted to differentiate between memory retrieval and consolidation by doing another test. Participants were given caffeine one hour before a learning task on the second day.
There were no statistical differences between the placebo and caffeine subjects between a 200 mg dose and the 300 mg dose. There was a finding that 200 mg helped memory more than 100, however, suggesting a minimum dose is needed. The author said this warrants more study.
Caffeine, diet, alcohol
The Harvard Medical School blog had a posting  citing some research that said diet and alcohol and caffeine may play a role in memory. That blog states:
If a study published in this month's Journal of Nutrition is any indication, the caffeine in coffee might offer not just a momentary mental boost but also longer-term effects on thinking skills. Having an alcoholic drink a day might also benefit our mental performance, but the line between just right and too much is uncertain. An even better strategy for maintaining memory and thinking skills with age may be to eat a healthy diet.
In the study, researchers from the National Institute on Aging compared scores on various tests of thinking skills and memory with caffeine, alcohol, and nutrient intake in 727 men and women taking part in the Baltimore Longitudinal Study of Aging. Over all, participants who ranked high on the healthy diet scale did better on 10 tests of memory than those with lower diet scores. The same held true for those who took in more caffeine. The effects for moderate alcohol drinking were mixed.
But if you are older and were hoping you might retain your memory better with a daily dose of caffeine, it does not appear to help, according to one study.
"The Journal of Nutrition study isn't the last word on the subject of caffeine and memory," Harvard Health writes. "It showed that people, particularly those who were ages 70 and over, who took in more caffeine scored better on tests of mental function, but not on memory tests or other measures of mental ability."
'Quick wakeup call'
Harvard writes that the brain gets a "quick wakeup call after chugging a mug of coffee."
The author says caffeine is believed to trick the brain because it is a stimulant in itself and because it blocks adenosine receptors, which normally prevent the brain from releasing more stimulating chemicals. When adenosine is blocked, the brain exciters are produced in greater numbers, giving a burst of energy and perhaps improving cognition.
It's important to note what Harvard says about these studies: "Some previous studies have shown improved long-term memory performance and thinking ability in regular caffeine consumers; others haven't shown any connection."
You can get caffeine in Viter Energy Mints . The mints come in handy if you are in a place where you can't get a mug of coffee or tea and need a mental boost. The mints also contain B vitamins.
Viter Energy Mints  also freshen the breath in case you don't have a toothbrush with you. They are sugar-free and are made of wholesome ingredients.
Benefits from drinking alcohol came only when men had no more than two drinks per day and women one drink per day. More than that and people suffer brain damage and short-term memory loss. One or two drinks a day improved working memory and attention.
Diet and cognition
It makes sense that this study found a good diet improved mental performance. Harvard wrote:
People who ate foods with plenty of healthful nutrients had better attention and memory than participant with poorer diets. A healthy diet was also linked to good thinking skills in women and participants under age 70. In particular, foods that are part of the Mediterranean diet, fruits, vegetables, nuts, fish, olive oil, and whole grains, show promise for preserving memory and preventing Alzheimer's and other forms of dementia. This study is just one of many linking healthy eating habits with maintaining memory and thinking skills into old age. Continuing a healthy diet, or switching to one, makes sense on many levels. It probably is good for your brain, and it's definitely good for your heart, bones, muscles, and overall health.
Delicious news about diet and memory
Healthline.com has some great news  about which delicious foods to eat if you want to improve your memory. The foods include chocolate, blueberries, nuts, oranges, and, yes, coffee with that caffeine that boosts mental clarity and alertness.
Fatty fish, which contains omega 3 fatty acids. The thinking is that because the brain consists largely of fat, including omega 3, eating fish containing it helps improve thinking and memory.
Coffee, which has caffeine, which improves your mood, increases your alertness, and sharpens your concentration.
Blueberries, which contain anti-oxidants that may fight aging of the brain and neurodegenerative diseases. Some scientists have found that blueberries fight memory loss and improve short-term memory.
Turmeric may help fight memory loss, alleviate depression, and help new brain cell growth.
Broccoli may help the growth of another fatty tissue in the brain, sphingolipids. And it may help improve memory and have anti-inflammatory and anti-oxidant effects that reduce brain degeneration.
Pumpkin seeds have zinc, magnesium, copper, and iron, all of which are anti-oxidants that are necessary for good brain health and function.
Dark chocolate! "The flavonoids in chocolate may help protect the brain. Studies have suggested that eating chocolate could boost both memory and mood," Healthline says.
Nuts improve both brain health and heart health, and a healthy heart means a healthier brain. "Nuts contain a host of brain-boosting nutrients, including vitamin E, healthy fats and plant compounds," the article states.
Oranges contain the vitamin C that your brains needs to combat aging. Other foods high in C are bell peppers, guava, kiwi, strawberries, and tomatoes.
Eggs contain several important B vitamins and choline, which keep the brain developing and functioning well. They also regulate mood.
Green tea has caffeine, L-theanine that helps you relax, and other anti-oxidants that prevent brain damage.
In terms of memory loss or enhancement, caffeine, diet and drinking, it seems like age-old common sense is a good guide: a lot of good things, but everything in moderation.
Erectile dysfunction. In combination, those are two of the ugliest words known to man. But can caffeine help you get it up?
Science hasn't found the definitive answer to this question, but one study concluded that fewer men who consume caffeine have problems performing. The study said:
Caffeine intake reduced the odds of prevalent ED, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive, but not among diabetic men. Yet, these associations are warranted to be investigated in prospective studies