Dangers associated with food dyes

Synthetic food dyes are used in many processed foods, such as colored breakfast cereals, candy, and “fruit-flavored” beverages and snacks. A total of 15 million pounds of dyes are added to the U.S. food supply each year. Our consumption of food dyes has increased 5-fold since 1955 as our nation has consumed more and more packaged foods.1

Colored cereal

These synthetic dyes have been linked to a wide variety of health concerns including behavioral problems, hyperactivity, allergic reactions, and even cancers. The Center for Science in the Public Interest (CSPI), an organization that advocates for nutrition and food safety, is calling for a ban on these synthetic dyes. Food-based dyes such as beet juice and turmeric are readily available, but are more expensive and often less bright, making synthetic dyes more attractive to food manufacturers.

Food dyes and allergic reactions:

Blue 1, Red 40, Yellow 5, and Yellow 6 have been reported to cause allergic reactions in some people.

Food dyes and hyperactivity:

Food dyes are of particular concern for children, since many colored foods are marketed to children, and their smaller body size makes them more susceptible to potential toxins. Hyperactivity in children following ingestion of food dyes is well-documented in placebo-controlled studies. Furthermore, a 2004 meta-analysis of 16 studies in children who were already hyperactive showed that their hyperactive behavior increased in response to food colorings.2 In a study published in Lancet in 2007, researchers tested two different mixtures of food dyes vs. placebo in children of two age groups – one mixture increased hyperactivity in 3 year old children, and both mixtures increased hyperactivity in the 8-9 year-olds.3 This study sparked a reaction by the British government. They instructed food manufacturers to eliminate all of these synthetic dyes by the end of 2009. In fact, starting later this month, a warning notice will be required on dyed foods in Europe stating that these foods “may have an adverse effect on activity and attention in children.”4  As a result, several international food companies now produce products with food-based dyes or no dyes in the U.K., but continue to include synthetic dyes in their U.S. products.

Food dyes and cancer:

There are eight commonly used synthetic dyes in the U.S., and all have undergone toxicity and tumorigenicity testing in animals. CSPI summarized the results of cancer-related studies in a recent report1:

  • Red 3 was acknowledged by the FDA to be a carcinogen in 1985 and was banned in cosmetics and externally applied drugs. However Red 3 is still used in ingested drugs and foods.
  • The three most widely used dyes (Red 40, Yellow 5, Yellow 6) which account for 90% of dyes in the U.S. are contaminated with low levels of chemical carcinogens, as byproducts of the manufacturing process. Although the FDA places limits on the concentrations of these contaminants in the final dye products, they still may pose risks.
  • Citrus Red 2 added to the diet resulted in bladder tumors.
  • Red 3 resulted in thyroid tumors and caused DNA damage.

In their report, CSPI noted flaws in many of the animal cancer studies on Yellow 6, Yellow 5, Red 40, Green 3, and Blue 2, including bias – most studies were either commissioned or conducted by dye manufacturers, short duration, and lack of exposure to dyes during fetal development. Additional studies are likely needed to determine whether these dyes are safe.

The simplest and most effective way to avoid the potential harmful effects of synthetic dyes is to avoid processed foods.   Unrefined plant foods contain health promoting phytochemicals, not empty calories and synthetic additives of questionable safety. When buying the occasional packaged food, check the ingredient list to avoid synthetic dyes.


1. Center for Science in the Public Interest. Food Dyes: A Rainbow of Risks. http://cspinet.org/new/pdf/food-dyes-rainbow-of-risks.pdf

2. Artificial food colouring and hyperactivity symptoms in children. Prescrire Int. 2009 Oct;18(103):215.

Schab DW, Trinh NH. Do artificial food colors promote hyperactivity in children with hyperactive syndromes? A meta-analysis of double-blind placebo-controlled trials. J Dev Behav Pediatr. 2004 Dec;25(6):423-34.

3. McCann D, Barrett A, Cooper A, et al. Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial. Lancet. 2007 Nov 3;370(9598):1560-7.

4. CSPI Says Food Dyes Pose Rainbow of Risks. http://cspinet.org/new/201006291.html

Pesticides commonly found on berries and other fruits may contribute to ADHD

A new study in Pediatrics has made a connection between exposure to organophosphates – pesticides used on berries and other fruit and vegetable crops – and Attention Deficit/Hyperactivity Disorder (ADHD) in children.1

Organophosphates kill agricultural pests by acting as neurotoxins in insects.  Excessive exposure to organophosphates in humans are now  known to have toxic effects. Children are thought to be most vulnerable because the developing brain is especially susceptible to neurotoxic substances. Organophosphate exposure during fetal development and the first 2-3 years of life has previously been linked to detrimental effects on neurodevelopment in young children, including behavioral problems and deficits in memory and motor skills.1,2 High levels of organophosphate metabolites have also been found in children with leukemia.3

Since dysfunctional acetylcholine signaling is thought to be involved in ADHD, and organophosphates act by disrupting acetylcholine signaling, scientists decided to investigate a possible link between organophosphate exposure and ADHD. The researchers pulled data from the National Health and Nutrition Examination Survey (2000-2004) on urinary metabolites of organophosphates in children 8-15 years of age. 

Their findings showed that children with higher than median excretion of dimethyl thiophosphate, the most common of the organophosphate metabolites, had double the risk of ADHD compared to children with limits below detection. This result is alarming, because it suggests that levels of organophosphate exposure common among U.S. children are capable of promoting ADHD – not just the highest levels of exposure.1

How are children exposed to organophosphates?


Since organophosphates are commonly sprayed on many agricultural products (including corn, apples, pears, grapes, berries, and peaches), diet is the major source of organophosphate exposure in children.  Insecticides used in and around the home are also potential sources, but diet is believed to be predominant. Forty different organophosphate pesticides are currently in use in the U.S., and based on 2001 estimates 73 million pounds of organophosphates are used per year.1

In 2008, the USDA conducted tests that found malathion (one of the 40 organophosphate pesticides) residues in 28% of frozen blueberries, 25% of strawberries, and 19% of celery.1 The Environmental Working group has found that commercial baby food is the predominant source of organophosphate exposure in infants 6-12 months of age. For young children, the most common culprits are apples, peaches, applesauce, popcorn, grapes, corn chips, and apple juice.4

What can you do to limit exposure?

A study that switched children from conventional to organic foods found a dramatic decrease in urinary metabolites of organophosphates.5  You can reduce your (and your children’s) exposure to organophosphates and other potentially harmful pesticides by buying organic produce whenever possible, especially when buying foods that are most heavily laden with pesticides – celery, strawberries, blueberries, peaches, apples, and grapes  rank among these high-pesticide crops. 

Read more about choosing produce wisely to minimize your family’s exposure to pesticides.



1. Bouchard MF, Bellinger DC, Wright RO, et al. Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides. Pediatrics 2010;125:e1270–e1277

2. Harari R, Julvez J, Murata K, et al. Neurobehavioral Deficits and Increased Blood Pressure in School-Age Children Prenatally Exposed to Pesticides. Environ Health Perspect. 2010 Feb 25. [Epub ahead of print]

Jurewicz J, Hanke W. Prenatal and childhood exposure to pesticides and neurobehavioral development: review of epidemiological studies. Int J Occup Med Environ Health. 2008;21(2):121-32.

3. Fallon Nevada: FAQs: Organophosphates. http://www.cdc.gov/nceh/clusters/Fallon/organophosfaq.htm

4. Environmental Working Group. Overexposed: Organophosphate Insecticides in Children’s Food. http://www.ewg.org/book/export/html/7877

5. Lu C, Toepel K, Irish R, et al. Organic diets significantly lower children's dietary exposure to organophosphorus pesticides. Environ Health Perspect. 2006 Feb;114(2):260-3.



Which foods should we buy organic?



The Environmental Protection Agency reports that the majority of pesticides now in use are probable or possible cancer causes. Studies of farm workers who work with pesticides suggest a link between pesticide use and brain cancer, Parkinson’s disease, multiple myeloma, leukemia, lymphoma and cancers of the stomach and prostate.1 

The question remains, however, does the low level of pesticides remaining on our food present much of a risk? Some scientists argue that the extremely low level of pesticide residue remaining on produce is insignificant and that there are naturally occurring toxins in all natural foods that are more significant. The large amount of studies performed on the typical pesticide treated produce have demonstrated that consumption of produce, whether organic or not, is related to lower rates of cancer and increased disease protection. The health benefits of eating phytochemical rich produce greatly outweigh any risk pesticide residues might pose. Certainly, it is better to eat fruits and vegetables grown and harvested using pesticides than to not eat them at all, but it is also wise to minimize our pesticide exposure. 

Environmental concerns

When we buy organic, we minimize our pesticide exposure, and we are also minimizing the amount of these pesticides that our environment is exposed to. Organic farming is clearly the more environmentally-friendly choice. According to the USDA, organic farming “integrat[es] cultural, biological, and mechanical practices that foster cycling of resources, promote ecological balance, and conserve biodiversity.” Although organic cropland acreage in the U.S. has increased five-fold since 1995, organic cropland still accounts for only 0.57% of total cropland. Supporting organic agriculture will increase the demand for organic produce and decrease the percentage of farmland (and farm workers) exposed to potentially harmful agricultural chemicals.

Nutritional benefits

Organic produce usually has more nutrients – especially minerals and antioxidant nutrients – than conventional produce.  Organic apples, plums, blueberries, grapes, strawberries, and corn have all been shown to have higher antioxidant capacities than their conventional counterparts. Organic strawberries were even found to have more anti-cancer activity than conventional strawberries! Scientists have theorized that when the plants are grown without pesticides, they are forced to deal with the stress of insects, which causes them to produce more antioxidant compounds, which are beneficial to humans.4,5 

The Environmental Working Group provides lists of produce called the ‘Dirty Dozen’ (highest in pesticides) and the ‘Clean 15’ (lowest in pesticides). These are their most recent lists.3   


Highest in pesticides – buy organic if possible:

 1. Celery

 2. Peaches

 3. Strawberries

 4. Apples

 5. Blueberries

 6. Nectarines

 7. Bell Peppers

 8. Spinach

 9. Kale

10. Cherries

11. Potatoes

12. Grapes (imported)

Peaches have the most pesticide residue of all fruits – 97% of conventional peaches test positive for pesticides, and as many as 53 different pesticides can be found on peaches. The most pesticide-laden vegetables are celery and bell peppers. Sixty-four different pesticides were found on bell peppers. Imported produce is also more likely to contain higher levels of pesticides.2,3 Choosing to buy these fruits and vegetables organically grown will help to protect us against the possible risks of pesticide exposure. If you do buy the conventional versions of these foods, it is best to wash them with soap and remove the skin before eating them.


Lowest in pesticides – buy either organic or conventional:

 1. Onion

 2. Avocado

 3. Sweet corn

 4. Pineapple

 5. Mango

 6. Sweet peas

 7. Asparagus

 8. Kiwi

 9. Cabbage

10. Eggplant

11. Cantaloupe

12. Watermelon

13. Grapefruit

14. Sweet potato

15. Honeydew melon


Buying organic is a wise choice – organic foods taste better, and organic agriculture protects farmers and our environment.



1. Sanderson WT et al Environ Res. 1997;74 (2): 133-144. 

Zahm SH, Blair A. Am J Ind Med 1993;24(6): 753-766.

Brown TP et al. Environ Health Perspect 114:156–164 (2006).

2. Reynolds JD. J Land Use Environ Law, 1997;13(1). 

Whitford F et al. Purdue Univ Coop Ext Serv p22, 1/17/05

3. http://www.foodnews.org/fulllist.php , http://www.foodnews.org/methodology.php, http://www.foodnews.org/sneak/EWG-shoppers-guide.pdf

4. .Grinder-Pederson L et al. J Agric Food Chem 2003; 51(19): 5671-5676.

Lairon D. Agron. Sustain. Dev.30 (2010) 33-41

5. Olsson ME et al. J Agric Food Chem. 2006 Feb 22;54(4):1248-55.

CDC reports risk of urinary tract infection from chicken products

Raw chicken

There is growing concern about the safety of agricultural products, especially meat. Recalls are becoming more frequent - it’s early February, and according to the USDA, there have already been three meat recalls so far this year. Even more troubling is that approximately 70% of antibiotics produced in the U.S. are regularly given to farm animals for non-therapeutic reasons - not to treat existing infections – non-therapeutic use of anibiotics has been used for decades to promote weight gain in animals, which increases meat production and therefore profits.1  These practices are potentially fueling the emergence of dangerous drug-resistant strains of bacteria, which could make their way into our food supply.

Six to eight million cases of urinary tract infections (UTIs) occur each year in the U.S., 80% of which are caused by E. coli that is ingested in food, lives in the intestinal tract, and then travels from the intestinal tract to the urinary tract. Infections of the urinary tract are also the most common source of bacteria causing sepsis, or infection of the bloodstream. Drug-resistant bacterial UTIs are of course more difficult to treat.

Since intestinal E. coli is the most common source of UTIs, a group of Canadian researchers decided to test whether there was a link between contaminated food products and UTIs. These researchers had previously found that women who frequently ate chicken and pork were more likely to have drug-resistant UTIs.2

They collected urine samples from women diagnosed with urinary tract infections between 2005 and 2007. During this same time period they also collected samples of supermarket purchased chicken products, restaurant meals, and ready-to-eat foods.

Two isolated groups of E. coli were genetically indistinguishable between the chicken samples and human UTI samples. This means that these bacteria likely originated from the same source, and furthermore establishes that chicken products are a food-based source for bacteria that cause human UTIs.3

If you do not consume animal products, you can still reduce your risk of exposure by washing produce thoroughly – produce can become contaminated by animals or humans infected with E.coli.4

If you do eat animal products, you can take these steps to reduce the risk of ingesting harmful bacteria: cook meat and eggs thoroughly, be careful not to contaminate surfaces or other foods with raw meat, refrigerate leftovers promptly, and wash produce thoroughly. 

Purchasing meat from a source that does not practice non-therapeutic antibiotic use is a further step you can take to not promote the practices that drive the emergence of drug-resistant bacterial strains. Animals raised for meat and poultry products that carry the USDA organic label are not permitted to be given antibiotics.5



1. http://www.scientificamerican.com/article.cfm?id=most-us-antibiotics-fed-t


2. Manges AR, Smith SP, Lau BJ, Nuval CJ, Eisenberg JN, Dietrich PS, et al. Retail meat consumption and the acquisition of antimicrobial resistant Escherichia coli causing urinary tract infections: a case-control study. Foodborne Pathog Dis. 2007;4:419–31. DOI:10.1089/fpd.2007.0026

3. Vincent C, Boerlin P, Daignault D, et al. Food reservoir for Escherichia coli causing urinary tract infections. Emerg Infect Dis. 2010;16:88-95.



4. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2007/ucm108873.htm

5. http://www.nal.usda.gov/afsic/pubs/ofp/ofp.shtml