Coconut water is a "total con" and everything else we learned from Dr Karl.

You might remember him from listening to Triple J as a teenager or perhaps you just caught him on The Project last night, but Dr Karl Kruszelkicki has spent his life engaged in a daily battle with misinformation.

Back in December, he delivered a Secular Sermon at Melbourne’s School of Life on the importance of scientific rigour in public discourse.

He also answered some of those niggling questions that crop up in your mind whenever a person utters a phrase like “clean eating”.

Are anti-oxidant supplements really good for you? Does coconut water really make you more hydrated? What happens when you “break the seal”? Does [insert inanimate object encountered daily] give you cancer?

We chatted to the good doctor and he dispels more than a few common misconceptions for us.

Here’s a few of the things we learned:

Coconut water. It’s a sham.

“People claim that coconut water is an essential party of our healthy daily life,” says Karl, “of course it’s a total con.”

Despite being spruiked as the ultimate rehydration agent there is simply no evidence that coconut water is any better for simple hydration than the regular kind.

In his new book, Karl also examines some of the more outrageous claims about the “flavour of the month in Food Fad Land”, such as whether or not it can safely be injected.

Spoiler alert: It can under exceptional circumstances, but there’s no proof that it will help.

Short Back and Science (my new book) coming straight to you! #booknumber38 #ShortBackandScience

A photo posted by Dr Karl Kruszelnicki (@doctor_karl) on Oct 16, 2015 at 12:06am PDT

What about antioxidants, surely they’re good for me?

Despite what the rows of supplements in your local health food store may suggest, antioxidants aren’t all they’re cracked up to be.

According to Karl, they’re the 21st century version of Snake Oil (funny, I thought that was the Paleo diet).

While in some circumstances they can be good for you, in others they  might actually be harmful.

Sigh.

Now that antioxidants won’t save me from cancer, should I stop eating bacon/burnt toast/potatoes/using my mobile phone?

It’s about weighing up the risks, apparently. If you smoke everyday your risk of cancer in your lifetime is increased 2o00%, if you eat processed meat on a regular basis it’s more like 18%.

Dr Karl sorts fact from fiction on the project last night.

Let’s talk diets. Do fad diets ever work?

“Overwhelmingly the people who recommend these various diets are not dieticians,” Karl says.

While studying medicine, Dr Karl did eight hours of dietetics, a qualified dietician does four year. You can get a certificate online in two hours.

His main piece of advice is, when in doubt, ask an actual expert otherwise:

“Watch what you eat, understand your food, know you food.”

He sums it up in seven words; “Eat food, mostly plants, not too much.”

By which he means “something that you grandparents would recognise, not processed, something you know the history of.”

“There’s nothing wrong with ‘processing’, but the processed foods that comes from the big food companies are overloaded with fat and sugar.”

So why do we fall for it? The snake oil merchants, the supplements, the “superfoods”?

According to Dr Karl it’s because of the “power of the anecdote”.

“We need anecdoes to keep the group together,” he explains. “Part of the evolution of the human race is the dependence in our brains that we can communicate with one another to help make us stronger.

“As a result, accidentally along the way we’ve also got it wired into us that anything we’re told can be believed.”

“If someone tells me a TV is the best and aother says the same thing, I’ll buy it.”

He sites the example of a celebrity with breast cancer.

“Every time a celebrity gets breast cancer suddenly people become aware of it… or if you have a family member that gets breast cancer, one week later you are at the doctor trying to get a mammogram.”

“The power of the anecdote can overpower the power of irrationality.”

How on earth, in age of the Internet when our smartphones and web browsers are saturated with information, do we sort the science from the snake oil?

“Most people would rather be lazy than right, whatever they find in a Google search the first entry they’ll believe it,” Karl explains.

The answer, he says, is to take time, find out the facts and “think critically”.

Dr Karl’s latest book ‘Short Back & Science’ is out now. Read more about the Secular Sermon (including how to get your tickets here)