Tellspec Top 5: The metals in your food

Today’s Top 5 from TellSpec is shedding light on the topic of metals in your food. What they are, where they come from, and what effects they may have on your health.

First, let’s clear up terms you may have heard:
Heavy metals refers to elements (the things that make up all of life as we know it) that have metallic properties. Heavy metals are not inherently bad; some, like zinc and copper are essential to life; but others, like mercury and lead are considered toxic metals, as significant levels can cause serious illness. However even essential metallic elements can be toxic at a high enough intake.

Alkaline metals refers simply to the group of alkaline earth metals of the periodic table, including calcium. These are distinct from the terms alkali and acidic, which are common in diet discussion.

Alkalinity in that context refers to the pH scale, where something is rated as more acidic or more alkaline (basic); think vinegar and baking soda. So “alkaline foods” or even “alkalized” foods, such as alkalized, Dutch process cocoa, do not necessarily contain significant levels of the alkaline metals.

Elements, minerals, and metals. These terms are overlapping and dependent on context or even quantity. For example copper: copper is a metal in the broad sense, it is also listed as a mineral on nutrition facts labels, and it is an element on the chemist’s periodic table.

The Top 5:

1.Al1. Aluminium has no known use within the body, and its main sources within the diet come from trace amounts in food, water, and transfer from aluminium foil and cooking tools. Acidic foods increase the amount of the metal that will leach from contact with aluminium pots, pans, foil, and utensils. Though no conclusive link has been proven, at the intake expected from a typical diet, studies have suggested a link between aluminium and disorders of the brain, including Alzheimer’s, dementia, and hyperactivity. Fortunately aluminium is not very readily absorbed by the body, however older individuals may be more susceptible to aluminium absorption and its effects.

References: Food Standards Agency 1 / Food Standards Agency 2 / Environmental Science Europe / NRC Research Press / Sage / Food Standards Agency 3

2.As_V22. Arsenic may or may not be essential to life, though it is certainly toxic at significant levels. Low level and chronic exposure to arsenic can cause nausea, vomiting, and cardiovascular issues, and is associated with increased cancer risk, lung damage, and possible problems in pregnancy and brain development. Sources of arsenic include pesticides, seafood, possibly fruit juices, and rice. Notably, brown rice will typically contain more arsenic relative to its polished white rice counterpart, as arsenic accumulates within the portion of the grain that is removed to form white rice.

References: NCBI / Journal of Nutrition / Food Standards Agency / European Commission / WebMD

3.Cd3. Cadmium has not been shown to be essential to human health, and its main sources are cigarettes, industrial pollution, and some foodstuffs. Seafood and organ meats have relatively high levels of cadmium, though grains and cereals as well as fruits and vegetables are a source, particularly as they are more common in the diet. Cadmium intake is generally quite low (though low iron increases its uptake), however it does not leave the body quickly and therefore can cause damage later in life. Cadmium is particularly toxic to kidney function, can cause reduced bone density, and is associated with increased cancer risk.

References: Wiley / Science Direct / Dart Mouth / Food Standards Agency / European Commission / EFSA

4.Cu4. Copper is essential to human life, and adequate levels are usually attainable with a healthy diet. Sources include seafood, organ meats, nuts, and legumes. Copper toxicity may be a risk if you make use of unlined, or worn-down, copper cooking implements, particularly if they maintain contact with acidic foods. Exercise caution with copper bowls and pots that have been used for awhile, or come from yard sales. Copper poisoning can cause vomiting, low blood pressure, and gastrointestinal issues; long-term exposure can damage liver and kidneys. High levels of copper within the body is associated with Alzheimer’s disease, though a causal link is not yet confirmed.

References: Food Standards Agency / Clinph Journal / Retinning / Food Science / SF Gate

5.Pb5. Lead is a well-known toxic metal, with significant negative health effects with acute and chronic exposure. Long-term effects are particularly concerning as lead takes between months and years to leave the body, during which time it can damage virtually every system in the body, particularly the brain. This is especially concerning for pregnant women, as lead stored in the bones during earlier exposure may be freed during pregnancy and breastfeeding, and can transfer to the baby in-utero or through breast milk, damaging the developing brain. Outside of environmental (air, dirt, dust), occupational, and incidental exposure (lead-containing paints, ceramics, and crystalware), food is a source of lead. Meat and organ meat have the highest levels, but trace amounts can be found in grains, dairy, and even fruits and vegetables. While lead is highly monitored, consumers should make informed decisions when incorporating certain items in their diet.

References: Health Canada / EFSA / Food Navigator / Food Standards / European Commission

Allura Acrylamide Atrazine

What do Allura Red, acrylamide, and atrazine have in common? (Aside from alliteration, of course). These three compounds are among the most prevalent within their class of chemicals and have gone under the consumer radar for years. Allura Red is the most popular red food dye; acrylamide can be found in the most popular carbohydrate-rich foods we consume; and atrazine is among the most popular pesticides used in corn crops—itself an incredibly widespread food. Today TellSpec is finally bringing these baddies into the light.

Allura Red AC, otherwise known as Red 40, is the most commonly used red food dye. Derived from petroleum, Allura Red is an azo dye that contains benzidene, a human and animal carcinogen. While studies of toxicity in animals have shown negative effects primarily at very high intake, case reports of human health effects differ somewhat. Indeed recent studies have suggested that consumption of artificial dyes, including Allura Red, in combination with benzoates, a type of preservative, can lead to hyperactive behaviour in children. Now this sounds like a fairly far-fetched concern, however given the prevalence of Allura Red in processed foods–processed foods which are likely to contain benzoate preservatives. Notably, sodium benzoate is used in acidic foods like salad dressings, soft drinks, fruit juice, and jam–all of which are prime targets for a dash of Allura to punch up the Red. Interestingly, Allura Red’s usage is discouraged in Europe and outright banned in certain countries, such as Denmark, Belgium, France, and Switzerland. It is also forbidden from use in animal feed due to concerns over its potential to interact with genetic material.

Whereas Allura’s status as an additive is fairly recent, acrylamide is something that has, as far as we know, been present in food for as long as we’ve been heating our carbohydrate sources–but it is only now coming under scrutiny. Acrylamide is a naturally occurring chemical that develops when high-starch foods meet high-heat (above 248oF or 120oC) cooking (though it is also present in less starchy foods like coffee and high fructose corn syrup.) Baking, frying, grilling, and roasting are associated with the greatest level of acrylamide production, whereas boiling and microwaving starches appears not to generate the compound. Generally speaking, the more browned the starch, the greater its acrylamide content. Something to consider when reaching for another slice of bread, with it’s golden crust, let alone tossing it into the toaster. So why are we focusing now on something that’s been around for ages? Because acrylamide has been classified as probably carcinogenic to humans; high intake has shown neurotoxic effects in humans, including cognitive impairment, muscle weakness, and loss of motor control; and the compound can cross the placenta to interact with the fetus–and maternal acrylamide intake has been associated with low birth weight and poor fetal growth, both of which are predictors for later health risks.

We can see Allura by its distinctive colour, and the golden hue and cooking method gives us a clue about acrylamide, but atrazine is undetectable to the ill-equipped consumer. Atrazine is an herbicide and pesticide, used in a great variety of crops to prevent weed growth. In fact it is reported to be one of the most widely used agricultural pesticides in the US (and Australia… the European Union has banned it entirely) and one of the most common pesticide contaminants of drinking water. What crops are the prime targets and of most relevance to consumers? Sugarcane, canola, and corn–and what processed foods don’t contain sugar, vegetable oils, and corn in some form, be that starch or syrup? Of course atrazine would be present in trace amounts, but awareness is important when we consider the health effects. Atrazine is an endocrine disruptor: it inhibits testosterone production in male rats; it disrupts communication between the brain and ovaries in female rats, likewise interfering with hormone production; and it leads to hermaphroditism in frogs. Atrazine alters thyroid function and levels of corticosteroid hormones–even at the low concentrations expected in ground water. Atrazine exposure has been linked in humans to increased risk of low birth weight and premature birth and impaired fetal development, including malformation of the genitals. Atrazine is also carcinogenic, having induced a variety of types of tumors (including a link to ovarian cancer) in rodent studies, and possibly obesogenic, having been associated with increased body mass and insulin resistance.

So what can the consumer do to avoid these chemicals? For Allura Red, read your labels and accept a duller colour to your food. For acrylamide, while it is important to recall that this compound has always been around, being moderate in one’s consumption of starchy foods (particularly ones best served baked, roasted, or toasted) is an option. For atrazine, invisible that it is, short of lobbying our governments to change their stance on their favourite helper in the corn field, consumers must unfailingly choose organic and settle for uncertainty regarding trace amounts throughout the food stream.


Food and Chemical Toxicology
Food and Chemical Toxicology 2
The New Yorker
Environmental Health Perspectives
The Lancet
Food Additives & Contaminants
The UK Food Guide
Food Standards Agency
Environmental Health Perspectives 2
Environmental Health Perspectives 3
Environmental Health Perspectives 4
European Commission Institute for Health and Consumer Protection
Reproductive Toxicology
Toxicology and Sciences
Toxicology and Industrial Health
Environmental Research
Public Health Reports
Toxicology in Vitro
American Journal of Medical Genetics
Annual Review of Public Health
Environmental Health Perspectives 5