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What is the truth about ‘toxic’ food?

These days, we are often bombarded in traditional and social media with messages about our food. Often, we hear the word “toxic” referring to a food or ingredients in our food. Are these strident messages from fear mongers correct, or are they just a way to convince us to buy other products?

Right now, it seems like sugar is the toxic ingredient du jour. But is it really? Let’s look at some definitions. Toxic (an adjective) means poisonous.

A toxin (a noun) refers to toxic chemicals created by plants and animals, usually for their own defense. In truth, sugar is one of the least-toxic of the chemicals we consume. Toxicity of substances is classified by measuring what happens when a single dose of the compound is fed to rats. The lethal dose per kilogram of body weight can then be established, i.e. what dose it takes to kill half (50 percent) of the rats. This “lethal dose” is known as LD50 and is expressed in terms of the dose per kilogram. The lower the LD50, the greater the toxicity (meaning it took less of the substance to kill a rat) and conversely, a higher the LD50 means the lower the toxicity (more of the compound could be consumed without killing a rat). Based on studies on rats:

  • Cyanide and vitamin D (calciferol) LD50: 10 (highly toxic)
  • Caffeine — LD50: 200 (very toxic)
  • Table salt — LD50: 3,000 (slightly toxic)
  • Sugar — LD50: Greater than 15,000 (practically nontoxic)

So, when you hear people proclaiming an ingredient is “toxic,” think about these key points:

  • The dose makes the poison. How much is being consumed?
  • Is the person proclaiming the food/ingredient “toxic” trying to sell you something? Buyer beware!
  • Natural isn’t necessarily safer. Our food and water all naturally consist of chemical compounds.
  • Any chemical, if consumed in inappropriate quantities, can be toxic.
  • Some food or ingredients can lead to health problems if consumed in large quantities or over long periods of time, but this does not mean they are toxic.

Talk to Leah

Leah McGrath is the corporate dietitian for Ingles Markets. Follow her @InglesDietitian. Contact her at, 800-334-4936 or at

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