How much benefit do we really get from Organic food?

Most people myself included tend to think of organic foods as healthier and safer. But that may not always be the case, points out Tamar Haspel in her recent article in The Washington Post's Health and food section. To make it simple she simply gives the evidence on the nutrition and contamination of both organic and conventional foods such as milk, meat, eggs, produce and fish. Here is a short excerpt of the article;

Is organic better for your health? A look at milk, meat, eggs, produce and fish.

Organic or conventional? It’s a choice many grocery shoppers are faced with, over and over. The price difference is easy to see; it’s right there on the product. The quality difference is much harder. Is the organic milk better for your kids? Is the conventional lettuce more likely to carry pathogens?

Leave aside for the moment whether organic agriculture is better for the planet and whether organic livestock have better lives, although there’s a strong case for both of those arguments. Leave aside flavor, too, because it’s subjective and variable. What motivates many organic buyers, particularly the parents of small children, is health benefits, and there are two questions: Do organics do us more good (in the form of better nutrition), and do they do us less harm (in the form of fewer contaminants and pathogens)? 

Milk 
 
Nutrition: Compared with conventional milk, organic milk has higher levels of omega-3 fats, which protect against heart disease and may decrease the risk of depression, stroke, cancer and other diseases, but the quantities are too small to be very meaningful. (It takes 11 quarts of organic milk to equal the omega-3s in four ounces of salmon.) Milk’s omega-3 content is a function of the cow’s diet, and higher levels reflect more grass. (A few other nutritional differences between organic and conventional milk have been studied, but there isn’t enough research to draw conclusions.)
Contamination: Neither organic nor conventional milk contains antibiotics. By law, every truckload of milk, organic and conventional, is tested for veterinary drugs, including antibiotics, by trained dairy workers. Any load that tests positive is pulled out of the food supply.
Hormones: The issue with milk is that many conventionally raised dairy cows, unlike organic ones, are injected with bovine growth hormone (BGH, the synthetic version of which is called either recombinant bovine growth hormone, rBGH, or recombinant bovine somatotropin, rBST) to increase their milk production.Both organic and conventional cows have IGF-I in their milk, but cows that get hormone treatment may have more of it.
The use of rBGH has fueled concerns among some parents about giving milk to children, but the FDA report concluded that “consumption by infants and children of milk and edible products from rBGH-treated cows is safe.”
Bottom line: Organic milk has higher omega-3 fat levels, but probably not enough to make a difference. Exposure to pesticides, contaminants or hormones is not a significant risk in either organic or conventional milk.
 
Produce

Nutrition: Many studies have compared the vitamins, minerals, macronutrients and other compounds in organic and conventional produce, and a 2012 review concluded that the results were all over the map. The one exception was that the phosphorus content of organic produce is higher, although the review, done by Stanford University scientists, calls that finding “not clinically significant.”
Contamination: There are two issues for foods that grow in the ground: pesticides and pathogens. There is widespread agreement that organic produce, while not pesticide-free, has lower residue levels and fewer pesticides.
Carl Winter, a toxicologist at the University of California at Davis, says that the Environmental Protection Agency, working from animal research and factoring in the special sensitivities of human subgroups such as babies and children, has found that lifetime risk of adverse health effects due to low-level exposure to pesticide residue through consumption of produce is “far below even minimal health concerns, even over a lifetime.” 
As for pathogens, the 2012 Stanford review found that E. coli contamination is slightly more likely in organic than conventional produce.
The best strategy to reduce risk from produce isn’t to buy either organic or conventional. Rather, it’s to cook your food.
Bottom line: While there may be no significant nutritional difference between organic and conventional produce, organic does have lower levels of pesticide residue. However, there isn’t universal agreement on the risk those residues pose.
 
Meat
 
Nutrition: As with milk, the main issue here is omega-3 fats. Some organic meat and poultry have more of them than conventional products do. The reason is diet: Animals that eat more grass have lower fat levels overall and higher omega-3 levels than animals fed more grain.
Although measurements of omega-3 fats in beef vary, the numbers are low and substantially below what can be found in a serving of salmon.
Contaminants: The USDA randomly tests carcasses for residues of pesticides, contaminants and veterinary drugs including antibiotics. In 2011, it screened for 128 chemicals, and 99 percent of the tested carcasses were free of all of them.
It found a few with residue violations and a similar small number with residue within legal limits (mostly of arsenic and antibiotics). Although the USDA doesn’t report organic and conventional separately, contaminant risk overall is extremely low.
The bigger concern is pathogens. Studies of bacterial contamination levels of organic and conventional meat show widely varying results. These findings suggest that organic meat may be slightly more likely to be contaminated, possibly because no antibiotics are used. But conventional meat is more likely to be contaminated with antibiotic-resistant bacteria. But the risk in meat overall was essentially the same. And whether meat is conventional or organic, the solution is adequate cooking.
Bottom line: Grass-fed beef has a slight edge over grain-fed because of higher omega-3 levels, but the amounts are probably too small to affect human health.

Eggs
 
Nutrition: As with milk and meat, the omega-3 levels of eggs are affected by the hens’ diet and can be increased by pasturing or diet supplementation for either organic or conventional hens. Eggs high in omega-3s are generally labeled.
Contaminants: There’s very little research on contaminants in eggs. The 2012 Stanford review concluded that there is “no difference” in contamination risk between conventional and organic eggs.
Bottom line: There are no significant differences affecting health between organic and conventional eggs.  

Fish
 
The USDA has not issued any organic standards for farmed fish or shellfish, but several overseas organizations have. (Because there’s no way to control the diet of wild fish, “organic” doesn’t apply.) Canadian standards prohibit antibiotics and hormones, restrict pesticides and set criteria for acceptable feed. There’s not enough research comparing organic and conventional fish to draw any conclusions about their health benefits.


Reference:
Is organic better for your health? A look at milk, meat, eggs, produce and fish.


(The Washington Post- Health, Science and Environment 07/04/14)