Products that contain more than 1,100 micrograms (mcg) of the herbicide glyphosate per daily serving will, starting July 2018, be required to have a label warning if sold in California, which has applied a fairly strict limit based on current science. However it seems unlikely that any food products exceed this limit, as explained below. The label will warn the product contains a chemical known to cause cancer and birth defects or other reproductive harm. This level of exposure is estimated to pose a 1 in 100,000 lifetime risk of cancer
, as determined by the International Agency for Research on Cancer part of the World Health Organization. However, as discussed below, it seems unlikely that any food product will exceed this limit.
In contrast, the European Food Safety Authority concluded that glyphosate is unlikely to pose a carcinogenic hazard
(and that it does not have endocrine disrupting properties
) but set a maximum acceptable daily intake limit based on reproductive toxicity shown in animal studies. The limit in Europe is currently set at 0.5 milligrams (or 500 mcg) of glyphosate daily per kilogram of body weight, which works out to about 34 milligrams, or 34,000 mcg, for a 150 lb person. The U.S. daily limit, set by the Environmental Protection Agency, is 3.5 times as high Europe's, although some have called for lower limit.
Glyphosate is the synthetic chemical in RoundUp
herbicide, designed to kill weeds around plants that have been genetically altered to withstand it, such as genetically modified (GMO) soybeans and corn. It is also sprayed on many types of conventional crops such as wheat, oats, and barley prior to harvest as a drying agent and to even-out maturity. A USDA study in 2012 found that it was also commonly used on cherries, avocados, apples, lemons, grapefruit, peanuts, pecans, and walnuts (https://drive.google.com/file/d/0B-pJR4cGo9ckdHpFUmFGUWQzZDQ/view
). Glyphosate is also found in processed foods containing these ingredients cannot be removed by washing, cooking, or baking. It can remain stable in food for a year or more.
Independent testing commissioned by the advocacy organization Food Democracy Now! and reported in November 2016 showed the concentrations of glyphosate
in popular foods. The highest level was 1,125.3 ppb (or 1.1253 mcg per gram) in Original Cheerios
. Based on this, a suggested serving of 28 grams of Original Cheerios
would contain 32 mcg of glyphosate. This is much lower than California's 1,100 mcg warning level limit and far from the European daily intake limit of about 34,000 mcg for a 150 lb adult. Other breakfast cereals, such as Corn Flakes
, Raisin Bran
, Special K, and Wheaties
contained less than one-tenth the amount in Original Cheerios
. Although one might expect organic foods to be devoid of glyphosate, Food Democracy Now! actually found a higher concentration (119 ppb) of glyphosate in 365 Organic Golden Round Crackers
than in most cereals, and even Kashi Organic Promise
cereal contained glyphosate at 25 ppb, possibly due to cross-contamination of ingredients. The report notes that "...even organic farmers are having their crops/ our food contaminated."
The relatively high concentration of glyphosate in Original Cheerios
is due to its main ingredient: whole grain oats. Independent testing shown in a 2016 presentation by and FDA scientist (see slide 30)
found a similar level of glyphosate in other oat cereals, such as instant oatmeal packets, steel-cut oats, and infant oat cereal, although there was no detectable glyphosate in the organic
oats it tested from Bob's Red Mill
, 365 Whole Foods
, or Nature's Path
It's possible that dietary supplements containing grains, soy, fruits, and whole food supplements could contain glyphosate, as could supplements with other ingredients that are cross- contaminated with glyphosate from other sources. Again, however, it would be highly unlikely that the amount of glyphosate would exceed established safe limits, particularly as serving sizes for supplements are typically smaller than that of foods.
The bottom line: Glyphosate safe or unsafe?
Glyphosate is known to cause reproductive toxicity bases on animal models, and it may possibly be a carcinogen -- although there is dispute about this. Due to its widespread use as an herbicide, it is found in many foods. However, at standard serving sizes (and even several times those sizes) even foods with the highest known concentrations of glyphosate, such as conventionally grown oats, appear to contain amounts of glyphosate far below those that pose a safety risk or require any type of warning. However, if you are concerned,
glyphosate can be largely avoided by choosing organically-grown foods
. However, be aware that some "organic" processed foods, such as cereals, will contain glyphosate, likely due to cross-contamination of ingredients.
When evaluating reports on glyphosate, it is important to distinguish between the concentration in a product, typically in ppb (1,000 ppb = 1 mcg per gram), and how much you would consume, i.e., the concentration times the grams in a serving.
Also see ConsumerLab.com's Oat Cereals Review
, which compares amounts of ochratoxin A (a potential carcinogen and kidney toxin) and gluten in popular products. Glyphosate was not tested in the Review, which was conducted prior to the classification of glyphosate as a probable carcinogen in the U.S., but levels would likely be similar to those reported above.
This CL Answer initially posted on 11/11/2017.