Stalking the Wily Food Craving (April 11, 2017)
Everyone has had food cravings. Everyone. And everyone has used the mildly shameful excuse “my body wanted it” as a reason for giving in to them. They are a bit weird and a bit mysterious, and as such are worthy of a little attention.
They are weird and mysterious because craving a particular food doesn’t, in this day and age, make a lot of sense. Why would a perfectly well-nourished (more often than not, sadly, rather over-nourished) individual suddenly absolutely HAVE to eat some very specific food item? Especially when said food item is not particularly nourishing. It’s odd.
Food cravings are called by the people who are supposed to know about these things “selective hunger” and are defined just as you would think – as an intense desire for a particular food. Most people who experience them, or charitably observe them in others, assume that there is some legitimate physiological reason for that particular craving. Makes sense, right?
Now it IS true that, as well-fed as we generally are these days, the majority of us have at least one nutrient deficiency. (Vitamin D is the most common one. Magnesium, omega-3 fatty acids, iron are a few others.) Could the lack of a particular nutrient be the driving reason behind most food cravings? Annoyingly enough, the present scientific consensus is “not in people".
Some of the lower animals (and I used that term “lower animals” advisedly, particularly in light of many recent human political behaviors) are driven to eat particular foods when they are deficient in certain nutrients. This is called “specific hunger” and has been found to exist in such critters for specific vitamins and minerals as well as for protein, water and calories generally.
There is no good evidence, however, that (except for salt) this is the case in people. Now, just because there’s no evidence supporting something doesn’t mean that it’s not true. It could be just that nobody has ever really looked into the thing, so there's no evidence of any kind. In this case, I suspect that because food cravings have never been associated with any kind of meaningful health issue, no one has ever been persuaded to throw any real money at it. No money, no evidence.
They wouldn't be easy to study anyway. Anything health-wise in people is murder to study because our big brains are always chiming in and distorting what would otherwise be normal biological behavior. The memory areas of the brain seem to be important in food cravings -- the history you've had with a particular food (maybe your brain jumps right to "bacon" when you're wanting salt) could be playing a big part here. So even if there was a nutritional deficiency driving a particular food craving, by the time the individual had sorted out what should be eaten to satisfy that craving, s/he might have gone most of the way around Robin Hood’s barn and arrived at McDonald's.
So the answer to "do nutritional deficiencies drive food cravings?", as it is to pretty much every other health-related question out there, is Maybe But We Really Aren’t Sure, with just a bit of extra emphasis on the Probably Not part. And that "Maybe" answer, as it always does, seems to spawn a million stupid articles.
Ice chewing is a sign of anemia -- except when it isn’t. Chocolate eating could be self-medicating depression – if so, it’s amazing that there’s any market left for Prozac at all. People with cognitive deficits crave cheese twice as often as people who don't have such deficits -- oh, for Pete's sake. Don't waste your time on that stuff.
Still, it seems that if a food cravings was a legitimate attempt by the body to get hold of some nutrient it’s lacking, we’d be craving fatty fish and beef liver (vitamin D), spinach and beans (magnesium), and carrots (vitamin A). Not Krystals or Tater Tots.
If someone were perfectly nourished, would they still have food cravings? Said experts mentioned above say "yes", again because they are supposedly unrelated to nutrient deficiencies. What about overeating generally, though? The jury's out on that one still. I suspect -- and this is just my thing -- that the tendency to overeat may very well be driven by nutrient deficiencies. It's not a huge jump from that to craving a particular food.
So this is what I take away from this admittedly not-exhaustive research on the subject. Food cravings are unlikely to be very meaningful on the health front. Someone eating a good diet and drinking enough water (dehydration is often confused with hunger) probably won’t have many. And if they have one, they might as well go ahead and eat the thing unless there’s a good reason not to do so. And live well.
--dr. diane holmes
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