The food meant to nourish us can also harm us. You may have allergies, come into contact with food-borne bacteria, or simply be eating an ingredient that can be detrimental to your health. Here, we consider GMO versus organic produce, grass-fed versus grain-fed beef, and what the deal really is with eggs and cholesterol…

01 THE GUILTY THREE

The common culprits associated with poor health are salt, sugar and ‘bad’ fats. “Cooked vegetable fats are extremely problematic for human health and when people regularly eat fast food, this is probably the most damaging factor,” says Keith Littlewood, an expert in health, fitness, and functional medicine (balancedbodymind.com).

If you vigorously shake salt over your food, stop. We’re only meant to have one teaspoon per day, but it’s often hidden in things like processed or convenience foods. Here’s why too much of this seasoning is bad: Your body tries to dilute excess sodium, so fluid accumulates around your cells, increasing your blood volume, and straining your blood vessels and heart. This can cause high blood pressure, heart attack/failure, and stroke. Salt can also cause kidney disease, reduce bone density, and may even cause stomach cancer. Find other ways to flavour your food, and train your palate by gradually cutting back on salt.

Our bodies also aren’t meant to process lots of sugar, specifically fructose (fruit sugar). Too much overloads the liver, interferes with insulin production, and increases uric acid levels. It can lead to non-alcoholic fatty liver disease, Type 2 diabetes and metabolic syndrome, and has been linked to Alzheimer’s. Worse, fructose ‘feeds’ cancer cells, causing them to multiply.

Practise moderation. Keith says, “People often blame sugar but, like any food, it’s the amount that’s the problem. Sugar doesn’t cause diabetes but reliance on processed sugars without other nutrients can be problematic.”

02 DOES ‘GMO’ = ‘GOOD’?

The jury’s still out on this contentious one. Because research has mostly been done on animals, it’s hard to say what the effects on human health are. The animal studies showed GMO food impacted metabolism, liver and kidney function, and fertility, but the WHO and the American Medical Association have stated that they’re safe to eat.

But mistrust remains, even among wellness experts. GM crops are heavily treated with herbicides that may pose cancer risks, says Sinead Scott Kelly, head nutritionist at Talise, Jumeirah Group. “Personally, I feel there’s not enough public information about GMOs and their effects. We need clear package labelling of GMOs for tracking the emergence of new food allergies and assessing the effects of chemical herbicides. Splicing plant genes can also threaten allergy sufferers if an allergen is mixed with a staple, like corn or soybeans. I recommend avoiding GMOs.”

03 THE CASE FOR ORGANIC

Organic food hasn’t been scientifically proven to be more nutritious, but it does contain less heavy metals and pesticides. Certain synthetic hormones and herbicides are carcinogenic, some insecticides cause development delays in babies, and pesticide residues can contribute to reduced sperm count in men and ADHD in kids.

So organic IS less dangerous, but it’s also more costly. You may want to go organic for items you eat daily, or for those fruit and veg that retain pesticide residues the most. According to the US Environmental Working Group and the Department of Agriculture, the ‘Dirty Dozen’ are (in order): strawberries, spinach, nectarines, apples, grapes, peaches, cherries, pears, tomatoes, celery, potatoes and sweet bell peppers.

The ‘Clean 15’, containing less pesticide residues, can probably be non-organic: Avocados, sweet corn, pineapples, cabbage, onions, frozen sweet peas, papayas, asparagus, mangoes, eggplants, honeydews, kiwis, cantaloupes, cauliflower and broccoli.

04 MEATY MATTERS

Meat farming harms the environment, but our health? Meat may increase the risk of diabetes and cardiovascular disease, but this is likely for processed meat, or unprocessed meat that’s overcooked.

Should your rare steak be grass- or grain-fed? Grass-fed beef seems to be slightly better for your heart (thanks to more Omega-3s, antioxidants and conjugated linoleic acid), but grain-fed isn’t necessarily bad. You may want to go with your gut on this. “Grains contain polyunsaturated fats, increase inflammation and are generally used for the marbling for better meat grading. Grass is what cows eat and is therefore an optimal food source for them,” Keith believes.

With meat, the fat count and preparation are the key. Go for ten per cent (or less) fat, and go easy on the charcoal grill. Potentially cancer-causing compounds are formed when meat’s cooked at high temperatures, so avoid charred meat.

05 SOMETHING FISHY

The ocean holds edible riches − full of long-chain omega-3 fats, low in saturated fat, good for the heart and blood vessels. According to Harvard TH Chan School of Public Health, eating fish once or twice a week may reduce the risk of depression, stroke and Alzheimer’s.

The, er, catch? Sea pollutants. Keith says, “The accumulation of pollutants, like heavy metals and plastic, is a considerable burden to marine and human physiology. Eating a couple of pieces of fish/seafood per week may be useful for nutrients like zinc and selenium, but a diet high in seafood may pose problems due to pollution”.

High levels of mercury can cause nerve damage in adults and disrupt the brain development of a foetus or young child. But experts say you shouldn’t avoid fish – even if pregnant or nursing.

While high mercury may hamper a baby’s brain development, a low intake of omega-3 fats is also risky. One study published in the Lancet found that children born to women who ate less than two servings of fish per week performed less well on intelligence, behaviour and development tests than those born to moms who had fish at least twice a week.

Know your fish. Avoid those higher in mercury (shark, swordfish, king mackerel, tilefish and albacore tuna), and stick with low-mercury options, like shrimp, canned light tuna and salmon.

06 THE ISSUE OF GLUTEN

It’s almost fashionable to be intolerant to this protein set, but some are claiming to be so without being properly diagnosed. While those with coeliac disease, a wheat allergy, or non-coeliac gluten-sensitivity do benefit from going gluten-free, it’s often too readily dismissed as ‘bad’.

“Most people don’t have an issue with gluten, they have a stressed digestive system that often affects the individual’s capacity to digest gluten,” says Keith, who names ‘cell danger response’ as one such stress response impacting gluten processing.

Ditching gluten could unnecessarily restrict your diet. Gluten-free foods can be refined or processed, with little nutritional value. And going gluten-free without a diagnosis may make getting such a diagnosis tricky. If you haven’t had gluten in a while, tests may not pick up coeliac disease or gluten sensitivity.

07 EASY ON THE EGGS?

They were once deemed too high in cholesterol. But although that’s true, it’s not the type that raises the ‘bad’ (LDL) cholesterol (LDL). Eating them often isn’t harmful – unless you’re pregnant or diabetic, smoke, are at high risk for heart disease or have elevated blood cholesterol levels. Eggs contain antioxidants, selenium, choline (good for the brain) and protein (60% is in the white). And while the yolk does have more fat, it’s also where you’ll get vitamin A and D from.

So, how many? If you don’t fall into the categories above, seven a week is fine. But it depends on what else you’re eating − and how you cook your eggs. If you don’t eat meat, you can have more per week. Poached, scrambled and boiled (not fried) is best. For extra health benefits, go for omega-3-enriched eggs. Keep in mind that free-range hens may eat non-organic feed and be given antibiotics. To avoid these, go organic.

Plant-based isn’t perfect

If you think you’re safer from food-borne illnesses because you don’t eat animal products, think again.

“A diet high in fruits and vegetables, combined with adequate fats and proteins, is advantageous for many,” says Keith. “But just because a food is in its greenest or brownest state doesn’t necessarily mean it’s the best from a health perspective. Large amounts of nuts, seeds, and undercooked vegetables can be a recipe for disaster for many people. For example, many brassica vegetables like broccoli and cauliflower contain potent hormone reducing compounds. I’m not saying don’t eat these but don’t let foods like this form a daily, considerable part of your diet.”

Remember that plants can also carry bacteria like Listeriosis. While meat, poultry and raw oysters are the better-known causes of food poisoning, less known sources include fresh sprouts (an outbreak of sprout-based E. Coli caused 50 deaths in Europe in 2011). In a 2013 study of which foods make people sick the most often, the US Centers for Disease Control and Prevention (CDC) found that nearly half were from produce, including fruit, leafy greens, nuts and roots. In fact, 22 per cent of illnesses came from lettuce and spinach.

The main takeaway seems to be: practise good kitchen hygiene, and exercise caution.