Health Conditions

Food Additives & Preservatives

Understanding what's in your food — and what it may be doing to your body over time.

Have you ever looked at the ingredient list on a packaged food and found yourself reading a list of words you can't quite pronounce — and wondered what they actually are? You're not alone. The modern food supply contains thousands of approved additives and preservatives, and most of us consume them daily without much thought. It's worth knowing what they are and why they matter.

What Are Food Additives?

Food additives are substances added to food during processing for reasons that have nothing to do with nutrition. They extend shelf life, improve texture, enhance colour, prevent separation, and make food taste more appealing — all of which serve the manufacturer's needs. Some are derived from natural sources; many are synthetic. Health Canada permits thousands of them, which means a food can carry an "approved" label while still containing a long list of substances worth paying attention to.

The most commonly encountered categories include preservatives (sodium benzoate, BHA, BHT, nitrates/nitrites), artificial colours (tartrazine, Red 40, Yellow 5 and 6), flavor enhancers (monosodium glutamate, or MSG, and its many disguised names), artificial sweeteners (aspartame, sucralose, acesulfame-K), and emulsifiers and stabilizers (carrageenan, polysorbate 80, carboxymethylcellulose). Each category has its own mechanism and its own body of research.

Did you know? The European Food Safety Authority has banned or restricted several artificial food dyes — including tartrazine (Yellow 5) and Red 40 — that are still permitted in Canada and the United States. Foods containing these dyes in Europe are required to carry a warning label stating they "may have an adverse effect on activity and attention in children." No equivalent labelling is required here.

What They're Doing in Your Body

The concern with food additives isn't usually one exposure — it's the cumulative, daily load across dozens of foods over years. Your body processes these substances through the liver, and while it handles the occasional unfamiliar compound reasonably well, a constant stream of synthetic chemicals is a different matter. The liver has real work to do.

Emulsifiers — specifically polysorbate 80 and carboxymethylcellulose (CMC), two of the most widely used — have attracted significant research attention in recent years. A 2015 study published in Nature found that these compounds disturbed the gut microbiome in mice, thinning the protective mucus layer that lines the intestinal wall and increasing intestinal permeability — what's commonly called "leaky gut." Subsequent research has pointed toward similar effects in humans. A compromised gut lining allows partially digested food proteins and bacterial fragments to enter the bloodstream, triggering a low-grade systemic inflammatory response that can manifest as digestive issues, skin conditions, fatigue, or mood disturbances.

Artificial colours are derived primarily from petroleum and have been linked in multiple studies to hyperactivity and attention difficulties in children, as well as allergic reactions in sensitive individuals. Tartrazine (Yellow 5) in particular is a known trigger for hives and asthma in people with aspirin sensitivity. Sodium nitrate and nitrite, used to preserve processed meats, convert in the body to nitrosamines — compounds classified as probable human carcinogens by the World Health Organization.

Did you know? MSG — and the dozens of ingredient names used to disguise it, including "hydrolyzed protein," "autolyzed yeast extract," and "natural flavors" — is an excitotoxin. It overstimulates glutamate receptors in the brain and nervous system. While individual sensitivity varies considerably, some people experience headaches, flushing, chest pressure, and mood changes after consuming it. Reading ingredient labels carefully is the most reliable way to identify it, since "MSG-free" products can still contain glutamate under other names.

What You Can Do

Eliminating all additives is neither realistic nor necessary. The goal is reducing your overall daily load — particularly the compounds with the strongest evidence of harm — and giving your gut and liver the support they need to handle what you do consume.

Practical steps to reduce your additive load

It's also worth noting that organic certification limits — though does not entirely eliminate — synthetic additives. Choosing organic versions of the foods you eat most frequently is one of the more practical ways to reduce exposure without overhauling your entire diet.

If you've been eating a heavily processed diet for years and are dealing with symptoms that haven't responded to other approaches — digestive issues, fatigue, skin conditions, brain fog — what you're eating daily is worth looking at closely. We can help you identify what your body may be reacting to, support your gut and liver, and build a realistic eating pattern that works for your life.

This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before making significant dietary changes or beginning any new supplement or treatment plan. Dr. Irene Chan is a licensed Naturopathic Doctor regulated by the College of Naturopaths of Ontario.