In the constant see-sawing over what are good things to eat and what could be doing you untold damage, let’s take a confusing look at where we are with some of the more contentious things to put into our bodies.

“Evil” seed oils

For a new ingredient to demonise in the kitchen, go no further than seed oils like grapeseed and sunflower. Apparently we use too much of them and that means we now consume way too many Omega-6 polyunsaturated fatty acids. Like Omega-3, Omega-6 is a good thing, but too much of it can build up in our cell membranes and lead to the latest modern evil, inflammation.

That word has become health blogger shorthand for an underlying factor in anything from cardiovascular disease and cancer, to diabetes and arthritis.

But Omega-6 is essential to human health, and not all foods that contain it cause inflammation. Balance is best.

“Neurotoxic” heated oils

Weighing in on the oil debate and, cynics might say, possibly seeking to increase olive oil sales along the way, is a body of research that shows that other oils, including seed oils, deteriorate more problematically than extra virgin olive oil when heated to 180°C for cooking.

Several studies have found that the best, fresh peppery extra virgin olive oil resists oxidation better than many other cooking oils and doesn’t suffer the same rise in problematic polar compounds. Author of Toxic Oil, David Gillespie, puts it rather more dramatically: “When [vegetable oils] interact with heat and oxygen, they release neurotoxic, DNA-mutating chemicals that are known to cause cancer.” Better pass on having those fries in my souva then.

Arsenic and white rice

If white rice didn’t already have a bad enough rap as being high-GI, now worries over arsenic levels are setting alarm bells ringing all over the internet. It’s all apparently due to industrial toxins and pesticides that lie hidden in some soil.

Consuming too much arsenic can lead to developmental problems, heart disease, diabetes and cancer. At least here, Food Standards Australia New Zealand (FSANZ) set acceptable trace arsenic levels for rice sold.

Any arsenic that is present can be dealt with fairly simply, says Professor Andy Meharg of Queens University Belfast. He says levels can be halved if rice is cooked in lots of water rather than steamed or cooked using the absorption method. Also, soak the rice overnight and rinse before cooking to reduce levels even further – by up to 80 per cent.

“Killer” coconut oil

Cardiovascular disease (CVD) is the leading global cause of death, killing 17.3 million people per year. Saturated fat is the main enemy and in controlled trials coconut oil was found to increase LDL (aka “bad”) cholesterol.

The American Heart Association recently compared coconut oil unfavourably as a source of saturated fat with other previously demonised sources like butter, palm oil and beef fat. It pointed to coconut oil being 82 per cent saturated fat compared to butter (63 per cent) and beef fat (50 per cent). The AHA said: “Because coconut oil increases LDL cholesterol, a cause of CVD, and has no known offsetting favourable effects, we advise against the use of coconut oil.”

Some coconut oil boosters claim that an increase in “good” HDL cholesterol offsets the LDL spike but research appears inconclusive. While evidence has suggested consumption of coconut flesh or squeezed coconut in the context of traditional dietary patterns doesn’t lead to adverse cardiovascular outcomes, due to large differences in dietary and lifestyle patterns, these findings cannot be applied to a typical Western diet.

Activated charcoal cleanse?

This black powder made from burning wood (or those coconut shells left over after harvesting coconut oil) will cleanse your system, boost your heart health and make you live longer, or so say some corners of the internet. Apparently, it traps toxins and chemicals – but it will also grab onto nutrients.

The trend to add activated charcoal to juice and health foods was debunked in the Journal Of Food Quality which found that it reduced the levels of available vitamins C, B6, B1 and niacin. This has led some health professionals to suggest there is no proof that regular dietary intake of activated charcoal is beneficial or helpful in any way if your skin, lungs, kidneys, colon and liver are doing their usual job of detoxifying the body.

Diarrhoea, vomiting and constipation can all be side effects, which is a bonus of sorts. Just not a good one. So overall just remember, it’s all just food. You won’t go far wrong if you focus on a balanced diet with lots of veg, some good carbs and lean proteins.

Also it is not unknown for people to be selective in how they mine research to support their political, profitable or polemic positions, so always be suspicious of claims – especially if they are asking for your money!