Perishability – Why Long Shelf Life Equals Low Nutrition

Food items with a long shelf life are convenient. You can keep them tucked away in your pantry for weeks, months, or even years without them spoiling. This means you can buy them in bulk, which can be time-saving as well as cost-effective, and you can avoid throwing away foods that have gone rancid, moldy, or otherwise gross (a big bummer when you've paid good money for this food). Advances in developing non- or less-perishable foods over the last couple of hundred years has transformed the way that we feed ourselves, especially in the way it has allowed food to be transported over greater distances. The development of refined white flour from whole-grain flour, for example, helped to fuel the industrial revolution because grain could be grown in the countryside for a population living (and eating) in the city. More reliable long-term storage of food staples has also helped populations survive and thrive through harsh winters, droughts, etc. I would argue that many advances in civilization could not have happened if people were struggling just to survive. The pursuit of art, science, philosophy, literature, etc. requires free time and a full belly.

Dried grains: super convenient.  These have been in my cupboard for months.

So, refining and preserving food is a good thing, right? Unfortunately there's a dark side to this equation, and it makes sense if you think about what food spoilage is, and why it happens. If food goes moldy, rancid, stale, contaminated, or otherwise becomes inedible, it is generally because something else is eating it. That something may be a fungus, bacteria, insects, or rodents. The more nutritious something is, the more appealing it is to the microbes and critters that are ubiquitous in our environment. White flour goes rancid or stale more slowly than whole-grain flour because the process of refining flour removes its most nutritious elements, the germ and the bran, leaving behind the starchy parts that contain calories but few vitamins, minerals, or other chemicals that our bodies need to thrive. It also removes much of its flavor (I'll come back to this).

Apparently I buy all my non-perishables at Trader Joe's.

There are other methods of food preservation that make foods inhospitable to microbes without directly removing the nutritious parts. Pickling, canning, brewing, culturing, and jam-making fall into this category. These methods increase the acidity or the concentration of sugar or salt to the point that fungi and bacteria can't thrive. Some of these methods harness the powers of beneficial microbes. Think cheese, beer, or sauerkraut. And then there's dehydration, which removes the water that many microbes need, and, in the case of fruits, thereby concentrates the sugars naturally present in the food. Many of these foods still have beneficial nutritional qualities but must be eaten in small quantities because they are also concentrated sources of salt, sugar, and fat. And many of them do lose, through processing or over the passage of time, some of the nutritiousness present in their fresh state. Even freezing, which is probably the least chemically transformative method of preservation, does cause changes to the food over time (especially if the temperature fluctuates much within the freezer, resulting in that freezer-burnt taste), and requires an ongoing input of energy to maintain.

The bottom line is that if foods have been changed to make them less attractive to food-spoiling microbes, then they are almost certainly less nutritious for you. This means that it is in your best interest to eat foods that are more perishable, not less so. Does this mean eliminating all non-fresh foods from your diet? Of course not. But it does mean that you will be healthier, and will probably feel better, if you build your meals around fresh foods, filling in the gaps as needed with pantry items.

The drying process preserves many of the nutrients in sweet and savory fruits.

I mentioned that food refining removes flavor. Through human evolution, our bodies have become exquisitely adapted to detect whether something is good to eat. Our palates can identify when something tastes fresh and full of flavor, versus stale, bland, or a little bit off. Our eyes also identify bright colors as evidence of good nutrition, and with good reason. Fresh green leaves contain phytochemicals important for good health, and bright red, blue, and yellow berries have sugars that are rare in nature. Manufacturers of processed foods are well aware if this, which is why these foods have added colors and flavors to simulate fresh foods. There isn't necessarily anything deliberately insidious here; they are simply augmenting these products so that we will enjoy and buy them. Unfortunately they are taking advantage of our natural instincts to eat the things that will make us healthy, and are helping us to do exactly the opposite. Food science has become so advanced that it is possible to produce food products that are convincing facsimiles of fresh, healthy foods. Add this to the persuasive efforts of advertisers, and is there any wonder we are a nation full of malnourished people?

So keep some of those non-perishable items in your kitchen as a backup, but whenever you can, eat things that were recently alive, with vibrant and varied colors that came from nature. And the shorter the shelf life, the better.