The supermarket is a minefield of economic, health, environmental and ethical decisions, each consideration potentially at odds with another. Take the egg display. Thoughtful people could spend a long time there, wondering if it's morally defensible to save money by buying eggs laid by chickens that spend their lives crammed into a cage smaller than a sheet of 8.5-by-12 paper. We might want to imagine the eggs laid by happy chickens, freely roaming and pecking the ground. Yet shoppers may recall articles explaining that even "cage-free" may mean only that huge flocks of chickens take a few steps around an enormous coop but never make it out of doors. Then there is the question of what those chickens ate: Was it a diet that included flax and other nutrients to enhance the healthy Omega-3s in the yolks, thereby possibly reducing heart disease risk in humans? Were they fed antibiotics that may make their way into our human bodies? And what about the carton? Is it biodegradable or a permanent addition to the landfill?
If our conscientious consumers haven't already gotten a furrowed brow and a bit of an anxiety headache, what then happens when they proceed to the meat, fish, poultry, dairy, and, perhaps most difficult of all, the produce sections?
It's little wonder, then, that a recent Stanford University study on organic foods set off a firestorm, with some people actually starting a protest petition to have the paper withdrawn. Researchers had relatively modest goals when compared to the myriad of problems the public sees with food. The Stanford research, as often occurs in systematic reviews and meta-analyses, looked at results from 237 earlier studies to try to get at whether foods grown organically -- that is, following certain agricultural rules and not using chemical pesticides, antibiotics or hormones -- is more nutritious than conventionally grown food. The researchers did not perform actual analysis on food; rather, they analyzed published studies that did do such analyses and combined the results where possible to draw conclusions.
What the Study Found
There is good news for those who cannot afford organics and feel guilty that they are feeding their loved ones second-rate food full of dangerous chemicals. These consumers can say "Phew!" as they toss more affordable lettuce, peaches or broccoli into their carts. The study showed that, while organic foods have lower levels of pesticides, conventionally grown foods contain levels of pesticides that fall at or below federal standards of safety.
When it comes to nutrients, an avocado is an avocado, an orange is an orange and whether the fruit is organically or conventionally grown, there are no significant differences in vitamin content. Researchers found no significant differences in fat or protein content in dairy foods, though they did find that organic milk contained higher levels of healthful Omega-3 fatty acids.
What We Don't Know
In some cases, findings might seem to lean in favor of organic foods, but we lack the scientific evidence to know for sure. The Stanford researchers, for example, cited two earlier studies that found and analyzed that children who ate organic diets had lower levels of pesticides in their urine than children who ate conventionally grown foods. But science doesn't yet know what, if any, clinical significance that will have on child health.
It makes sense that having less exposure to pesticides is better than having more exposure. But even that basic level of logic isn't quite clear. A diverse group of chemicals, including many pesticides, are known to affect human hormones and potentially can result in reproductive and fertility problems in humans and they are suspected in some cancers. They're called endocrine disrupters; they don't always act in a more-is-worse way.
The Endocrine Society released a scientific statement showing just how much we have yet to understand about this group of chemicals. When it comes to endocrine disrupters, they said, we cannot assume that low doses are safe and that the greater the dose, the worse the effect. Many of these chemicals act in a U-shaped curve fashion, meaning they may, in some case, have more potent effects in lower doses than in the mid-dose range and then again have disruptive effects at higher doses.
Antibiotics and Hormones
The Stanford study found that pork and chicken raised conventionally had higher levels of antibiotic-resistant microbes. And we do know that the antibiotics given to chickens, cows and pigs have led to a nightmare of germs in our environment that have become resistant to many of the antibiotics we have at our disposal, making what once were routine infections potentially lethal. (It should be noted, however, that most of the antibiotic-resistant microbes that we deal with are due to the indiscriminate use of antibiotics to treat colds and flus and other nonbacterial infections.)
And organics have lower levels of hormones, including estrogen, fed to animals to quickly fatten them up. (I'm not concerned about growth hormone, since humans don't absorb the growth hormone given to animals.) There are questions that the estrogens used in meat and dairy production might be in part responsible for a host of problems, including breast cancer and early onset of puberty in girls. However, there is at present no conclusive scientific data for or against this hypothesis.
Shopping Decisions
Maybe the first decision when grocery shopping could be to get yourself to a farmer's market if you can. Much of the produce sold at such markets is organic, but even if it is not, it is freshly picked, giving you the best shot at a boatload of nutrients.
The nutrient content of food -- that is, the amount of vitamins and minerals that remain intact when we actually eat it -- has more to do with how long it's been off the vine, out of the ground or dead, rather than whether it was grown using organic or conventional means. The nutrient content is highest when it is picked fresh and eaten soon. So the longer the fruit or vegetable spends on a truck, a store shelf or your own refrigerator, the more nutrients will be lost, regardless of how it was grown.
When it comes to what we Americans eat, it's not hard to find areas to attack -- from how animals are fed to what is sprayed on growing plants to when it is picked to how it is shipped to the dearth of food choices in poor neighborhoods to the glut of fast food options open to all of us. We have a lot that needs fixing in our food growing and food distribution systems, and as individuals, we have a lot to fix in the meal and snack choices we make.
If you can afford to buy organic, and want to do your part to help clear the earth of pesticides, or to help ensure humane treatment of the animals we eat, then do it. If you understand that science has a lot to learn about nutrition and meanwhile you want to avoid antibiotics, hormones and pesticides in your diet, that's all to the good. And who knows: Organic food might taste better to you.
Except for the added cost, there isn't much of a downside to buying organic. But if you can't afford the added cost of organics, fill up your cart or your recyclable shopping bag with the freshest produce you can find and you'll be serving yourself and your family well.