For years, scientists have been telling us that a balanced diet can improve our overall health and well-being.  In addition, there are several foods that are consistently touted as “brain food,” in that they can improve cognitive function and brain health.  Just in case you’re not familiar with them, though, let’s go over a few of the most well-researched and helpful ones.

1.  Salmon: studies show that Omega-3 fatty acids are crucial to cognitive function, and the body cannot produce these kinds of fat itself, so you have to get your Omega-3s from food or supplement sources.  There are all kinds of health considerations for various populations, and if you’d like to know more, you can read up on it here.  But the main idea is that there is a lot of scientific evidence showing that foods rich in Omega-3 fatty acids truly do feed your brain.

2.  Nuts and seeds: foods like flaxseed and walnuts pack the same kind of Omega-3 punch that salmon does, and have the added benefit of providing fiber, which helps to maintain physical health in many ways.

3.  Blueberries: there is evidence showing that people who eat a cup of blueberries per day perform 5 to 6% better than a control group does on a test of motor skills.  In addition, many studies show that the antioxidants in blueberries can help to reverse age-related reductions in cognitive function, such as memory loss.  Plus they make a pretty tasty pie!

Now, here’s the big news: for a few days before taking your GMAT, you might want to move away from your usual healthy diet and indulge a little.  We’re not advocating a total fast food pig-out; you still need to make sure that you get the usual required amounts of nutrients, and don’t overdo it on the calories, as that can make you sluggish.  But a study revealed in September 2009 indicates that eating a high-fat diet for four to seven days before an intellectually strenuous task can have a beneficial impact on performance.  The study, titled “Nutritional Effects on Cognitive Performance”, was reported by researchers at the John D. Odegard School of Aerospace Sciences, part of the University of North Dakota at Grand Forks, and produced results that were surprising to many.

The study tested pilots on a full-motion flight simulator, and also measured their short-term memory.  Four different diets were tested: high fat, high carbohydrate, high protein, and balanced.  The researchers found that pilots on the high fat diet consistently out-performed those on other diets: 27% better than the high protein group, and 10% better than the balanced group, with less significant margins over the high carb group.  The high carb group also outperformed the high protein group by 22%, and pilots on the high protein diet reported feeling irritable and having difficulty sleeping.

What does this mean for you?  Well, if you’re planning to go to business school, it’s not likely that you’ll be piloting an airplane in the near future.  But many of the cognitive functions used by pilots—short term memory, quick decision-making, and multi-tasking—will be crucial to you on test day.  The message here ISN’T to forgo healthy eating for months of carbohydrate and fat-loading.  But for a few days before the test, it might not be a bad idea to have a little extra butter on your bread, and some gravy on your potatoes.  After all, every little bit helps, and as GMAT preparation goes, you’ll probably enjoy those mashed potatoes and gravy a lot more than you would an extra round of Grockit Quant practice!