Nutritional knowledge and the way we eat have changed hugely over the years. Humans had been hunter-gatherers for thousands of generations, and then made use of agriculture for the last 300 or so generations. Processed and refined foods have been around for only about 80 years and yet comprise much of the diet of many if not most people, especially in this country. On an even shorter timeline, nutritional fads come and go on a decade or even an annual basis. Some cynical nutritionists joke about the nutrient-of-the-month club.
A blast from the past
Consider the typical American non-farm family from the 1950-60s era. Let’s say that the family is affluent enough so their food choices aren’t constrained by finances, and that the homemaker is caring and knowledgeable about food. A typical meal back then was meat, vegetables that were canned or cooked to a gray-green mush, almost-white iceberg lettuce salad since that was the only kind of lettuce available, white “enriched” bread with margarine, and heavily sweetened canned fruit. Before graduating to these kinds of meals, a baby was fed formula consisting of diluted cows’ milk sweetened with corn syrup. This kind of diet wasn’t only typical of the time, it was about the best one could expect back then. How far we’ve come! However…read on.
The basic food groups
Every so often the government comes out with new nutritional recommendations. In the 1940s there were seven basic food groups. In the 1950s and 1960s, there were considered to be four basic food groups: meat, dairy, vegetables and fruits, and starch (now carbs). There’s the curious fact that fully half of these foods, two of the four groups, come from cows – political influence comes to mind, showing that the government may not be the unbiased source of nutritional knowledge that one might believe it is. Then there were various incarnations of food pyramids, each one an improvement, more or less, on the previous one, although the oils that we now know are essential didn’t make the list until quite recently. Replacing the food pyramids, now there’s My Plate, although they may have come out with something new by the time you read this. These food charts still say nothing about the difference between whole grains and processed white flour, or between enzyme-rich raw and enzyme-dead cooked vegetables and canned fruits, or between healthful oils and fried foods. The recommended diet is high in wheat and dairy and thus allergenic potential.
Nutritional Fad-of-the-Month
Fads come and go, having more to do with marketing and profit than science. For example, noni juice, $30 per bottle a decade or more ago, has disappeared from the radar. Moringa and hoodia, previously unknown but very expensive at the height of their popularity… where are they now? It’s quite possible that acai berries, goji berries, pomegranate juice, and the grain farro will follow these others into nutritional marketing oblivion a few years from now, if they haven’t already by the time you read this.
It’s interesting that all these tend to be previously unknown and exotic, and thus expensive enough to be quite profitable for manufacturers and marketers. When was the last time you heard about the benefits of cheap, common rice or apples?
Giving it up
Along with the well-hyped food of the month, there is typically also a food villain of the month or year, such as high fructose corn syrup, trans fats, gluten, soy, saturated plant oils, or egg yolks. Most of these restrictions are actually good advice, but the emphasis waxes and wanes depending on food fashion, and in some cases are even overturned (egg yolks and coconut oil are now known to be beneficial) based on later knowledge.
On a related note, most fad diets are described in the negative, and are about what one must give up. Some diets want you to give up carbs, while others focus on limiting fats. So many people who see themselves as eating healthfully also define their diets in the negative, in terms of what they don’t eat: they’re vegan (no animal products), gluten free, sugar free, raw (no cooked food), and so forth.
Food manufacturers are aware of these fads and adjust their labels and food formulations accordingly, listing on the front of the label what their product does or does not contain. These adjustments are for their profit more than your benefit, although they can be useful.
Several lessons
There are several lessons to be learned here. One is that new miracle foods are more the creation of food marketing departments than rigorous scientific studies, and so can’t necessarily be believed. Another is that government recommendations are not always the latest knowledge, nor are they always free of market and political influence.
Another thing to know and accept is that the progress of nutritional knowledge will likely never be complete, and nobody has the bottom line on the single best diet that will withstand the changes of time. There might well be as much difference in nutritional advice between now and 60 years from now as there has been between 60 years ago and now.
Consider the source
Consider the source of the information and avoid or discount information that comes from special interest groups that have a financial stake in your food buying decisions. Dairy interests promote the benefits of milk. The sugar industry has been so successful in (correctly) demonizing high fructose corn syrup that some products now have labels that boast “contains real sugar.” News about the latest high-priced and previously unknown berry juice usually comes from the sellers of the product.
The bottom line
All of this sounds discouraging, but it comes down to this: All anyone can give in the way of nutritional advice is the best of what is currently known. At least any current advice is usually, but not always, an improvement on what came before, so there’s progress and will continue to be progress.
Even knowing that things will change over time, it is important to keep up with nutrition news and work with practitioners and nutritionists who do so.
