In North America, there has been a focus in the last decade or so on the unhealthy production and consumption of food. The dependence of North Americans on processed, convenient food has led to a widely discussed and studied problem with obesity, in adults as well as in children.
In an effort to move North Americans away from processed and fast food, the nutritional experts have been pushing people to eat more fresh fruit, vegetables and lean meats (especially fish) in order to promote a healthier, leaner lifestyle. While fresh food is without a doubt the preference over processed and fast food, there are questions as to what chemicals in fresh foods can contribute are contributing to the ill-health of our population.
In studying the literature, there are three major concerns in the general population when it comes to pollutants in our food: dioxins, mercury, and pesticides (which encompass a number of chemicals). A quick survey of the effects of these pollutants and how you can avoid them will give you a better understanding of how to optimize your healthy diet until further studies can determine the effects of these chemicals on the body.
The term “dioxin” refers to a family of organic chemical compounds that contain carbon, hydrogen, oxygen and chlorine. Dioxins are a byproduct of both natural and industrial pollution. In the natural world, dioxins are released into the environment from volcanoes and forest fires. Human production practices such as incineration, manufacturing plants, vehicle exhaust, and pulp and paper bleaching also contribute to the levels of dioxins in the environment. Dioxins enter the human body primarily through our diet, in fact 95% of dioxins enter our bodies through the food we eat.
Dioxins enter fish through the water, settle on plants through particles in the air, and enter animals through what has settled on their food. Dioxins on plants can be removed simply by washing the plants (as they are not absorbed, but rather sit on the surface). Like most pollutants, however, dioxins are fat soluble, and accumulate in the fatty tissue in animals and fish. When humans consume an animal, their accumulated dioxins are transferred into their fatty tissue.
Since the 1980s, governmental regulations put in place led to the reduction in the amount of dioxins in the North American environment by 80%, and the amount in our food chain has also subsequently decreased. The levels of dioxins in imported foods will depend on the levels of dioxins in their native countries. Dioxins levels in fish, who live in the very environmentally sensitive ocean, will vary.
Mercury is a metallic element that was once used quite liberally in everything from dental fillings to hat manufacturing. Its detrimental effect were hinted at in the old saying, “Mad as a hatter,” which originated with the stereotype of hat makers being an eccentric brood. The truth to this stereotype was in the fact that the mercury used in the manufacture of hats, to which the hatters were directly exposed, caused dementia. They were, in fact, mad after years of exposure to the soft metal.
These days, the most significant source of mercury in our bodies is through the consumption of seafood. Fish absorb mercury through water that is filtered through their gills. Mercury from the water is absorbed and accumulates in the fatty tissue throughout the fish. It accumulates over their lifetimes, so the longer a fish lives, the more mercury it will have absorbed. Likewise, mercury accumulates in our systems and is stored in our fatty tissues.
The dilemma here is that nutritional experts have really been pushing fish as a part of a healthy diet. Fish are an excellent source of protein, and an essential source of omega-3 fatty acids, which are thought to be beneficial for everything from lowering bad cholesterol to preventing cancer. On the other side of the debate are the purists who say that no amount of mercury is safe and that we should be seeking our omega-3 elsewhere.
Until this issue is studied further, the best recourse is to limit your fish intake to once a week and supplement your diet with a fish oil supplement if you can. There are also some fish that are safer than others. If you can, avoid shark, swordfish, king mackerel, tilefish, bluefish, wold striped bass, American eel, marlin, and spotted trout. Tuna steaks are also thought to be high in mercury and not recommended for children and women who are pregnant or in their childbearing years. Even canned tuna should be limited for mothers and children.
Although no fish is completely free of mercury and other pollutants, safer fish include: wild salmon, sardines, anchovies, Atlantic herring, Dungeness crab, Alaskan Black and Pacific cod, farmed striped bass, tilapia, farmed catfish, clams, mussels and Pacific oysters.
The term “pesticide” refers to a diverse group of chemicals used to protect food from insects, rodents, weeds, molds, and bacteria in order to increase the yield of crops and lower the cost of food. According to the EPA (Environmental Protection Agency in the United States), pesticides can affect the nervous system, the endrocrine system (hormones), and irritate eyes and skin, depending on the category of chemicals. In North America, both domestic and imported foods are tested to make sure that the pesticide residue found on food is within the legal limit or tolerance.
As it stands, not enough research has been done on each type of pesticide used to determine how the residuals of various chemicals used in pesticides, and the compounds that they break down into in our systems, effect human health after long-term exposure.
Alternatives such as organically grown food, which is grown without the use of chemical pesticides, and food grown using Integrated Pest Management (in which pest-resistant varieties of plants and natural pest enemies are used to increase yield and decrease dependence on chemical pesticides) can reduce your exposure to pesticides.
Some fruits and vegetables show higher levels of pesticide residue, so look for organically grown versions if you can. These include: peaches, strawberries, apples, spinach, nectarines, celery, pears, cherries, potatoes, bell peppers, raspberries, and imported grapes. Safer fruits and veggies (with lower levels of pesticide residues) include: onion, avocado, frozen sweet corn, pineapple, oranges, asparagus, frozen sweet peas, kiwi, banana, cabbage, broccoli, and papaya.
The only way to lower your exposure to mercury in fish is to decrease your intake and avoid those fish on the high-mercury list. Dioxins and pesticides are a little easier to reduce, however. Obviously, there is the organic route, which can be more expensive, but is deemed worth the extra cost for some. If your access to organically grown food is limited, then the best tips are the following:
- Wash your fruits and veggies under running water. If they have a tough skin, like potatoes, scrub them with a brush. You can peel them if you like (although there are many important nutrients found in the skin in many cases). Also, cooking fruits and veggies can help further eliminate pesticide residue (although, again, nutritive value suffers slightly).
- Eat lean cuts of meat, and trim any fat form the cut that you can. Toxins of all kinds accumulate and are stored mainly in fat tissue. Consume low- or no-fat dairy products and reduce your total intake of saturated fats.
- Eat a variety of foods. Especially in the case of pesticides, certain chemicals are used on certain crops. By eating a variety of foods, you are limiting the intake and accumulation of one type or category of chemical.
There are so many varying opinions about what we should and should not eat out there, it seems as though nothing we put in our systems is universally good for us anymore. This article is not suggesting that the chemicals in our environment is causing any specific disease or that the healthy foods discussed here should be eliminated from your diet.
All of the foods discussed are essential for a healthy diet. A well-informed consumer, however, can make the best choices for him- or herself, and knowing that there are always healthier choices in our world of landmine nutrition makes you an empowered consumer.