So what's in fresh produce that we should be concerned about? To start with, that would be pesticides, hormones, antibiotics and genetically modified food.

(1) Pesticides are primarily used to control pests and thereby maximize yield. The downside to is that many pesticides are persistent and stay in fresh produce long after it has left the farm. In fact, pesticides make their way onto our dining table and into our body. The most common source of pesticides is fresh fruit and vegetables. According to the Daily Green, “if consumers get their USDA-recommended 5 daily servings of fruits and veggies from the 15 most contaminated, they could consume an average of 10 pesticides a day.”

The Environmental Working Group (EWG) regularly issues a list of food products with the highest (The Dirty Dozen) and lowest levels (The Clean Fifteen) of pesticides. The EWG Shopper’s Guide to Pesticides was developed based on data from nearly 87,000 tests for pesticide residues in produce conducted between 2000 and 2007 and collected by the USDA and the US FDA.

(2) Hormones are common in animal-based food such as meat and dairy, whereas pesticides are common in plant-based food.  Farmers use growth hormones such as rBGH or rBST (short for recombinant bovine somotrophin growth hormone) to make cows produce more milk and thereby can easily increase its yield by 10 to 15%. Cattle farmers also use hormones to speed up growth of cows meant for meat.

Unfortunately, the hormones stay in the milk. In addition, cows treated with rBGH produce abnormally high amounts of the growth factor IGF-1 which also goes into the milk. Some studies have even linked hormones in food to early onset of puberty in girls though the current state of evidence is not compelling enough to cause alarm.

rBGH is produced by the chemical giant Montsanto under the trade name Posilac. An excerpt from the Montsanto website says: “Monsanto’s rBST product, Posilac, is a supplement of the naturally occurring cow hormone BST, that when administered to cows allows them to produce more milk. Many dairy farmers use Posilac because they can produce more milk with fewer cows. The milk from treated cows is identical to milk produced by cows that are not treated. There is no laboratory anywhere in the world that can tell the difference between milk from a cow that has been treated with Posilac and milk from one that hasn’t been treated. Milk from treated cows is just as safe as milk from untreated cows. This has been affirmed by the U.S. Food and Drug Administration, World Health Organization, American Medical Association, American Dietetic Association and regulatory agencies in 30 countries."

What is interesting is the fact that rBGH is banned in Europe and other countries such as Canada and New Zealand mainly due to animal welfare issues. But it is still widely used in the US.

(3) Antibiotics are also commonly to protect animals from diseases. It is estimated that 70% of all antibiotics in the US are used as prophylaxis for healthy animals. About 80 to 90% of these antibiotics are excreted into the environment to contaminate ground and water. It is not clear how much antibiotics get into the meat, eggs, and milk produced by these farms. According to Sustainable Table “Industrial farms have been mixing antibiotics into livestock feed since 1946, when studies showed that the drugs cause animals to grow faster and put on weight more efficiently, increasing meat producers' profits. Today antibiotics are routinely fed to livestock, poultry, and fish on industrial farms to promote faster growth and to compensate for the unsanitary conditions in which they are raised.”

(4) Genetically modified (GM) food ranges from plant-based food products to meat, dairy, and poultry. GM food comes from plants and animals genetically-engineered to grow bigger and faster (thus getting rid of growth hormones), look better, and be more resistant to diseases (thus getting rid of pesticides and antibiotics). However, many people are wary of the health consequences of GM food. After all, you can wash away pesticides but you cannot remove something that is inside the food itself. Plants were the first to be genetically modified and nowadays, almost every kind of fruit and vegetable in the supermarket from apples to soy exist in the GM version. Equally infamous are food products from cloned animals. In January 2008, the US FDA declared that milk and meat from cloned animals are safe for human consumption. Though strictly speaking not genetically modified, consumers are still wary about the health impact of this food source. Currently, there is no data available on the health effects of GM food.

Manufactured food, on the other hand, which comes in tins, jars or other packages has its own special additives each with its own set of concerns.

(1) Artificial sweeteners have been in our food supply since the middle of the 19th century when saccharin was accidentally discovered. Currently six sugar substitutes have been approved in the United States including saccharin, aspartame, sucralose, neotame, acesulfame potassium, and stevia. Controversy still exists as to whether artificial sweetener usage is hazardous to your health. However, the health authorities in the US and Europe have declared all the artifical sweeteners to be safe at current levels of consumption. Aspartame appears to have engendered the most publicity which may have partly been due to the fact that Montsanto used to own the NutraSweet company. NutraSweet was eventually sold to another company.  To get both sides of the story about the facts and myths about aspartame, check out the Aspartame Information Center and Sweetpoison.com.

(2) Other Additives may be food-grade preservatives to extend shelf life of products, food coloring and flavoring, as well as thickeners and emulsifiers. Food manufacturers are required to reveal what are the additives in their food products and are identified by a number. In Europe, those E’s on the food packaging are codes for food additives.  Similar numbers may also be found in food labels in Canada, Australia and other countries (without the E prefix which stands for Europe) but is still not widely used in the US. A complete list of food additives can be found in the Codex Alimentarius (Latin for food code) set up by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO), and recognized by the World Trade Organization (WTO).

There are some additives that may be allowed in one country but prohibited in another. In the EU, for example, the yellow coloring tartrazine (E102) is not a permissible additive. Many other coloring additives are slowly being phased out in many countries due to potential carcinogenicity and toxicity. European consumers are wary of food products that contain a lot of “E” substances. However, not all food additives are artificial or harmful. Alginates (E400-409), for example, which are seaweed extracts are popularly used as thickeners. Curcumin (E100) is from the turmeric plant and gives curry its yellow-red coloring. Vitamins and minerals are also sometimes added to fortify certain food stuffs. In the US, milk is fortified with vitamin D and flour with folic acid.

(3) BPA (Bisphenol A) has become a hot issue during the last couple of years and has been covered extensively in the past two years including the article " BPA is Everywhere - Are We Safe?"  Plastic bottles, cans, soup packets, and even baby formula containers contain BPA, which leaches from the packaging into the food and drinks we ingest. And if that isn't enough, in December 2007, the EWG checked for BPA in baby formula and found that most formulas are sold in cans lined with BPA-containing plastics. It was also found in the packaging of powdered formula manufactured by 4 out of the 5 top manufacturing companies in the US. This issue will continue to evolve.

So what can we do? We cannot simply resign ourselves to the fact that our food is tainted with potentially harmful chemicals. But we also cannot do without nutrition especially the food and vegetables we need every day. There are several ways to minimize the risk of ingesting these chemicals and some of them are listed here.

(1) Buy organic. The best way to go is to grow your own fresh produce but this is not always feasible. Fortunately, many fruit and vegetables are produced in an organic way, e.g. without the use of pesticides or artificial fertilizers. The downside of organic products is that they tend to be more expensive and they are not easily available. In their Shopper’s Guide to Pesticides, the EWG recommends to buy organic those products listed under “The Dirty Dozen”, e.g. those products with the highest pesticide levels.  The “Clean Fifteen”, however, are those products with the lowest levels of pesticides and can therefore be bought at conventional supermarkets. Organic meat is another produce that is recommended if you want to avoid hormones and antibiotics. If you know of a local organic producer, try to buy your food products there. That way, you’d know where your food is coming from. Caveat: Beware of “greenwashing” or “organic fraud” where producers and retailers may try to pass on nonorganic products as organic. A well-publicized case involved the company Aurora Dairy  which was accused of selling phony organic milk. In June this year, a judge in federal district court in St. Louis, rejected 19 class-action lawsuits filed by consumers against the dairy company. For a more detailed review of organic food, check out If You Think 'Organic' Food is 'Organic', Think Again.

(2) Check the labels. Make a habit of checking the labels of the products you buy including the additive food codes. Organic food labeling is based on certain criteria depending on the country. In the US, the official organic seal is given only to products that meet the criteria of 95 to 100% organic ingredients. Caveat: Beware of mislabeling. “Organic” is not synonymous to “All-natural.” Several cases of mislabeling have been reported. One of them involved the well-known retailer Wal-Mart which added the word “organic” to its price labels. In addition, the USDA organic labeling has lately come under fire for being too lax.

Some countries require labeling that differentiates between GM and conventional produce. This can also be checked through the price look up (PLU) code. The PLU system is governed by “voluntary cooperation” of counties participation in the International Federation for Produce Standards. It is also not clear how reliable is the PLU system since there is no regulatory body that governs it. PLUs consist of 4 to 5 digit numbered code and the first “prefix” digit of the code can tell consumers whether a produce is transgenic or not. So far 3 digits have been allocated for international recognition:

It is also not clear how reliable is the PLU system since there is no regulatory body that governs it

(3) Get information. There are several non-profit organizations which act as “watchdogs” for consumers. These groups are an invaluable source of information about consumer safety in general and food safety in particular and include the following groups.

• Environmental Working Group
• Cornucopia Institute
• The Daily Green
• Sustainable Table
• Union of Concerned Scientists

• Aspartame Information Center. 
• Codex Alimentarius. 
• Cornucopia Institute. Mislabeling Organic Food at Wal-Mart. January 2007.
• EWG. Shopper’s guide to pesticides. Environmental Working Group 
• IFPS. Produce PLU: A Users’ Guide 2006. International Federation for Produce Standards. 
• Jacobson M. The genetically modified food fight. West J Med. 2000 April; 172(4): 220–221 
• Lunder S, Houlihan J. EWG's Guide to Infant Formula and Baby Bottles. Environmental Working Group.  December 2007. 
• Monstanto . Milk Labeling – Is Monsanto Opposed to Truth in Labeling? Accessed Oct 20, 2009 
• Sustainable Table. Antibiotics 
• Sustainable Table. Dairy 
• The Daily Green. How to Avoid Pesticide Residue. 
• US FDA. FDA Issues Documents on the Safety of Food from Animal Clones. January 15, 2008. 
• WebWire. Judge’s Ruling Fuels Meltdown in Organic Dairy Industry. June 9 2009.