In 2015, the World Health Organization's cancer agency put processed meat in Group 1, the same group as tobacco smoking. It was easy to read that as bacon being as deadly as cigarettes. That is not what the classification said.
Group 1 measures how sure the evidence is that something causes cancer. It says nothing about how much cancer it causes. The evidence on a ham sandwich and on a pack of cigarettes is equally sure. The danger is nowhere near equal. One of them comes with mustard.
That gap, between how sure and how much, runs through most food scares. Some of them hold up. Some were overblown from the start, and one of the loudest, the fear of MSG, was never true at all. And some were real, and have since been dealt with.
So here are seven everyday suspects, the hidden ways food is said to be sabotaging your health, and a verdict on each.
1. Hidden sugar and starch: guilty
Sugar turns up where you would not look for it: in pasta sauce, bread, salad dressing, "savoury" crackers, and above all in anything sold as low-fat, because the taste has to come back from somewhere. Read the ingredients and ignore the front of the pack. Names ending in "-ose", and syrups of every kind, near the top of the list mean the product is built on them.
Refined starch belongs on the same charge sheet. White bread, pastries and most cereals end up as glucose in your blood, fast. How to Fix Blood Sugar Spikes Naturally has where cutting them leads: when 23 tests in people with type 2 diabetes were pooled, those on low-carb diets were far more likely to bring their long-term blood sugar back below the diabetes line after six months, 57% against 31% on other diets.
The fix is not brown rice. It is meat, fish and eggs on the plate, and the packets left on the shelf.
2. Sweeteners: guilty, and honey is no way out
Diet drinks were meant to be the free pass. 10 Eye-Opening Benefits of Cutting Out Sugar and Choosing Healthier Sweeteners has why they are not: when 120 healthy adults took sachets of saccharin, sucralose, aspartame or stevia for two weeks, saccharin and sucralose worsened their blood sugar response, and all four changed their gut bacteria. The same article has the World Health Organization's advice not to use them for weight control. Aspartame made its own headlines in 2023, when the WHO's cancer agency classed it as "possibly carcinogenic to humans" on limited evidence, while its food-additives committee left the safe daily limit where it was. How sure, and how much, again.
The old version of this list suggested honey and maple syrup instead. Those are sugar. The body treats them as what they are. A bee does not make sugar healthier.
3. Processed meat: guilty, but size the charge
This is the Group 1 suspect, and the case against it is real. Ham, bacon, salami and hot dogs are cured with nitrite or nitrate, and in the body and during curing these can form N-nitroso compounds that damage the cells lining the bowel. Hidden Toxins in Your Diet, linked below, calls processed meat the best-established food cause of bowel cancer.
Now the size. The agency's own estimate was an 18% higher risk of colorectal cancer for every 50 grams of processed meat eaten every day. That is a rise in your own risk. It does not mean 18 people in every hundred.
Fresh meat is a different case. Unprocessed red meat went into Group 2A, "probably", on weaker evidence, with a 17% higher risk for every 100 grams a day if it causes cancer at all. And the curing chemical is not unique to meat: about 80% of the nitrate a typical person eats comes from vegetables, spinach and beetroot among them.
So the swap is not beans or a plant-based sausage. It is fresh meat, fish and eggs, with the cured meat kept for occasions.
Watch the word "uncured" while you are at it. Meat sold as uncured, or with "no nitrates or nitrites added", may be cured with celery powder instead, a natural source of nitrite. When Consumer Reports looked into it in 2019, the celery brought nitrates and nitrites in all the same, and the US Department of Agriculture allows the label anyway.
Curing has already changed once for the better. In the 1920s, a change in American curing practice cut the average nitrite in cured meat by 69%, and a dramatic fall in deaths from stomach cancer began soon after. Around 1970, vitamin C was found to block the formation of nitrosamines, and cured meats made in the United States now have to contain at least 550 parts per million of it, or of erythorbic acid, a cheaper and equally effective cousin. Look for ascorbate or erythorbate on the label beside the nitrite.
4. Trans fats: guilty, and mostly dealt with
This one was real, and it has largely been fixed. Artificial trans fats came from partially hydrogenating vegetable oils, the process behind Crisco and decades of margarine and biscuits. By 1994 they were estimated to cause at least 20,000 deaths from heart disease a year in the United States alone.
The irony is in the frying pan. A campaign against animal fat ended McDonald's practice of cooking its fries in beef tallow. From Soap Factory to Frying Pan: How Seed Oils Got Here has the rest of that story. Denmark was the first country to limit industrial trans fats, in 2004. Crisco was reformulated in 2007. In 2015 the US Food and Drug Administration ruled that partially hydrogenated oils were not "generally recognised as safe", and from 18 June 2018 they were banned from American food.
Not every trans fat comes from a factory. Butter is about 3% trans fat by weight, made by bacteria in a cow's stomach that turn the polyunsaturated fats toxic to them into other forms. Only a few specific types form, among them vaccenic acid and CLA, and US labels do not count CLA as trans fat at all. Not every natural type is harmless, though, so the honest summary is small amounts of a different mix.
The live issue now is the oil that replaced the hydrogenated fats. Where Seed Oils Are Hiding in Your Food — and How to Read Labels Around Them has where the seed oils are and how to read around them. At home, cook in butter, ghee such as , lard or tallow.
5. MSG: not guilty
MSG has had worse press than almost any ingredient. The story was that it caused headaches and other discomfort, a cluster that came to be called "Chinese restaurant syndrome". When the idea was tested blind, with MSG eaten in food in normal amounts, those effects did not appear. Large amounts taken without food can upset a small number of people. A normal plate of food is not that. It is also lower in sodium than its reputation suggests: MSG is about 12% sodium by weight, roughly a third of the 39% in table salt.
MSG has an older and better story. In 1908, Kikunae Ikeda of Tokyo Imperial University set out to find what gave kombu, the seaweed in Japanese stock, its savoury taste. He isolated glutamate and named the taste umami, "delicious taste". The same glutamate occurs naturally in tomatoes, in stews and in meat soups. A pot of meat broth carries it without anyone adding a thing. Grandmother's soup was, chemically speaking, full of the stuff.
6. Additives: one acquitted, two not
Carrageenan is a thickener made from red seaweed, used in milk drinks, ice cream and processed meats. It was accused of causing inflammation. When the European Food Safety Authority re-examined it in 2018, it found it non-toxic below 75 milligrams per kilo of body weight a day, and asked for more work on what happens to it during digestion. Not proven guilty, and the file is still open. Seaweed on probation.
Another thickener has a human test against it. Foods That Upset Your Gut: What's Real and What's Personal has it: when healthy volunteers ate food containing cellulose gum, also called carboxymethylcellulose, the protective mucus layer in their gut thinned and bacteria crept closer to the lining than they should. That is the one worth looking for on a label.
One more additive really is dangerous for some people. Sulphites, used in wine and dried fruit, can bring on breathing difficulty within minutes, and people with asthma are at higher risk. The US banned them from raw fruit and vegetables in 1986, and wine with more than 10 parts per million must say "contains sulphites" on the label. If you have asthma, that line is worth reading.
7. Plastic: guilty, and the law has caught up
Bisphenol A, or BPA, was used for decades in hard plastics and in the coating inside food tins. It mimics oestrogen, weakly, and the exposure is lifelong. In 2023 the European Food Safety Authority re-examined it and cut the amount it considered safe to take in each day by a huge margin. In December 2024 the European Union banned BPA from everything that touches food, with up to three years for the ban to come into force.
The replacements need watching too. BPS, a close chemical cousin, is used in place of BPA and turns up in tin cans. In January 2023 the European Chemicals Agency listed it as a "substance of very high concern" while it investigates whether it harms fertility and disrupts hormones, and California lists it as a reproductive toxicant. Hidden Food Contamination: BPA, Microplastics, and Heavy Metals in Your Clean Diet has more on what goes into the tin. "BPA-free" on a label solves one chemical.
Plastic sheds into food and drink in other ways too. Tea Bags vs Loose Leaf: What's Really Steeping in Your Cup has the single plastic mesh tea bag that, steeped at brewing temperature, released about 11.6 billion microplastic particles and 3.1 billion even smaller nanoplastic particles into the cup. What to Drink Instead of Plain Water — and What the Popular Alternatives Do to Your Body has the bottled water: about 240,000 plastic particles in a litre, nine in ten of them nanoplastics.
Ban or no ban, the habit is simple. Store food in glass or stainless steel, such as , and never heat food in plastic. Heat it in a pan or in the oven. Make tea with loose leaves, and carry water in glass or steel.
How sure, and how much
Back to the ham sandwich in Group 1. The suspects that matter most are the ones that hold up and are eaten every day: sugar and refined starch, sweeteners, cured meat eaten daily, plastic that gets heated. The ones that made the loudest headlines, MSG among them, held up least. The scariest name on the label is not always the guilty one.
Next time you buy ham or bacon, turn the packet over and look for sodium nitrite, potassium nitrate or celery powder, and buy fresh meat instead whenever you can.
Wondering what else rides along with healthy food? Hidden Toxins in Your Diet: What's Really in Your Healthy Food — rice and arsenic, big fish and mercury, cured meat, and the ones you can ignore.
Want the label read for you? What Processed Food Is Really Made Of — the seed oils, emulsifiers, sweeteners and preservatives, and how to spot them.
Know someone who checks every label for MSG and eats ham every day? Send them this, and point them at section 3.
Disclaimer: This article is general information. For advice about your own health or diet, talk to a qualified health professional.
Affiliate Disclosure: This article contains affiliate links. As an Amazon Associate, All For Life earns from qualifying purchases, at no extra cost to you. We only link to products we would recommend without the commission.
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