Diet science presents many questions

24 February 2015 - 14:36 By Comment by Katharine Child
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FINE DINING: Guests can create their own steak tartare combinations
FINE DINING: Guests can create their own steak tartare combinations

Over-simplification of science and an evangelical approach undermines good research-backed arguments on healthy eating

The low carbohydrate, high fat conference in Cape Town at the weekend, organised by Real Meal Revolution's Professor Tim Noakes and Karen Thomson of the Sugar Free Revolution online programme, was billed as a health summit to broaden knowledge about nutrition and obesity. Attended by about 400 doctors and dieticians from SA, the UK, US and Canada, Katharine Child reports the conference actually exposed how much we still need to learn.

Attending the conference was a privilege except for the Cape Town International Convention Centre catering staff acting as the sugar police. I had to sneak in my own sugar each day to add to my coffee and I felt like a drug addict.

I learnt a lot about what not to eat - and also how to spot bad science.

Useful health information shared included:

  • It is best to avoid sugar, especially if you are overweight and diabetic.
  • Processed food as in junk food (not frozen veggies or tinned fish) is bad for your body.
  • Refined carbohydrates such as white bread, pasta, anything with added sugar and white rice should be avoided most of the time.
  • There is little evidence that animal fat in milk and meat is bad for you, so feel free to stop eating margarine and enjoy butter
  • The cholesterol in eggs won't lead to the bad (specifically sized LDL cholesterol particles) cholesterol in blood.
  • Snacking between meals means our pancreas secretes too much insulin, so eat less or nothing between meals.

Unfortunately, many of us won't follow this wise advice. I ate chocolate while listening to the speakers.

Here are my other observations:

Life is not simple. Medicine is not simple. The low carb high fat theory is simple.

Our bodies are highly complex. There are 21 000 genes in the human genome.

There are more than 200 types of pancreatic cancer, alone.

There are many rare diseases that doctors will never see in their lifetime.

Just ask Kelly Du Plessis, founder of local rare diseases NGO, and any of the parents, she knows, who have taken their sick child from doctor to doctor, who puzzle over what could be wrong.  Diseases and the body are so complex.

But if you are a low fat high carbohydrate fan, medicine is simple. Too simple.

This was one of the first observations I made at the world's first Low Carb High Fat conference, now travelling to the UK in 2016 and to Washington the year after that.

The "#lchf experts" take observations to new extremes and come to strange conclusions.

Eskimos ate fat, so we must too. Many speakers mentioned the Inuit and I think they gave away the sheer lack of data by all focusing on this people group. Eskimos featured in far too many presentations.

Their conclusions were also too simple. Eskimos didn't eat carbs and were healthy.  I think this shows that humans adjust to the food available so we can survive on high carb (as the ancient Kittavans and the Chinese did) or high fat diet depending on what food can be accessed.

It doesn't mean we should all eat high fat.

Other silly comments included:

  • Fruit was not available all year round to ancient people, (neither was meat or iphones or soap) so we should avoid it.
  • Do you see a pasta tree? No, eat real food.

My answer is: do cows udders' secrete parmesan or mature cheddar? By that logic we shouldn't eat cheese.

Oversimplification of science undermines the good research-backed argument that sugar and refined carbohydrates really should be avoided by the overweight and diabetic.

Experts are not experts on everything

This is supremely obvious and if a dentist suddenly wanted to pilot the plane you were on, 'because pilots and dentists, they both use machines', you would be worried.

Yet at the conference, an expert in bariatric surgery tried to explain food addiction, psychiatry, how to raise children and what happens to the brain when overloaded with carbs (It gets concussed). Please can surgeon Dr Robert Cwyes stick to operating on the grossly obese and never submit another audience to his strange conclusions.

The Australian orthopaedic surgeon Gary Fettke, who I would trust with a broken leg, tried to explain cancer. He pointed out that all cancers all metabolise glucose (eat) the same way, which is why they can all by detected by a PET scan.

By the way, avoiding sugar won't help you stay cancer-free. The body converts most food, including protein, into glucose.

The common way of digesting glucose shared by all cancers was published in 1973. It is not new and until you can show me why it matters, it doesn't matter to lay people.

Fettke almost wrote off chemo because of its appalling side-effects.

Oversimplification, sweeping statements and experts revealing expected ignorance in their areas of non- expertise were too prevalent at a conference that was advertised as scientific and not faith-based.

Cherry-picking data to support your theory

I won't write too much on this because the very-nice-in-real-life Jacques Rousseau has pointed it out in blog post after blog post, when taking on low carb high fat logical fallacies.

At the conference, the researcher Zoe Harcombe pointed out the largest European study into cancer risk (EPIC) that has tracked over half a million people and their diets and disease outcomes over 20 years did not show that fruit and vegetables had a protective effect in reducing cancer incidence and death.   

Epic data showed a link between a diet high in processed red meat and colon cancer, by the way.

No one ever mentions that.

Research speaks volumes.

The best speakers at the conference used research. They were Duke University's Dr Eric Westman, Dr Aseem Malhotra and Dr Stephen Phinney, who has for years studied athletes eating high fat diets.

We now know endurance athletes can do well on high fat diets or high carbohydrate diets thanks to Phinney.

Wetsman's work with diabetic patients and his research has shown that diabetics thrive without carbohydrates in the diet.

Cardiologist, Marholtra told the audience the best data showing which diet is good for your heart is the Mediterranean diet. This, he explained, is a diet high in uncooked olive oil and nuts includes vegetables as carbohydrates

Anecdotes, no matter how cute, are not science

Dr Jay Wortman showed us a video of his five-year-old daughter skiing and another of how well she skiied at nineteen months, when she couldn't talk yet. She is adorable but her stamina on the slopes and alleged brilliance at school reveal two things:

- If you learn to ski from 19-months-old as she did, you will develop good muscle memory and will be a star on the slopes at five.

- Wortman really loves his daughter.

But that's not science and it's not proof that raising a child on a high fat diet is healthy, as he suggested to the audience.

Trying to present a cute kid as evidence, just undermines your cause.

Too little focus on the poor

In a country where one in four children go to bed hungry (according to a huge statistically significant national health survey conducted by the HSRC in 2012) the conference really was for people with first world problems.

If we could put the same effort into getting children eating well and preventing malnourishment in million of kids whose brain development is compromised by malnutrition, our country would be better for it.  

And most diabetics (there are at least 2 million of them in SA) are poor and live on refined maize meal and white bread. That’s the real problem, not how much Greek yoghurt the white-middle class should eat. The really sick in South Africa can't afford vegetables, meat and cheese.

I don’t know

I spoke to a few dieticians and PhD academics who opened their mind and hearts to the opposition and attended the conference. One whispered to her colleague:  "It feels like we are at a Weigh Less conference".

Another was a little disappointed at the lack of science.

Which brings me to a final  point: It is okay to say 'I don't know'.

There is a lot in medicine that brilliant scientists don't know. For example Alzheimer'sdisease: detecting it early enough and what causes it remains a mystery although the low carb people will call it Diabetes Three, as if the understanding of its cause (why would there only be one?) is all settled.

Science knows the dietary advice that avoiding saturated fat in eggs and animals is not based on good studies. We can probably eat lots of three-egg omelettes. But we don’t know how much animal fat, cream or eggs we should eat.

Author of Big Fat Surprise, Nina Teicholz, wrote in the New York Times editorial a few days ago that lack of evidence for cholesterol means no one should have given population-based dietary guidelines to avoid animal fat. Without evidence, don’t tell people what to eat, she correctly states (and then she finishes her editorial telling readers what to eat).

We don't know what to eat partly because putting thousands of people on a specific diet and ensuring they stay on it for 20 years and observing their health is close to impossible.

So perhaps we can say:

  • Sugar, especially the quantities we eat it, is bad for health and weight.
  • Animal fat isn't linked to bad cholesterol (quantities to eat unknown).
  • Carbs don't damage all people. Even Noakes admitted at his low carb conference that Kenyan athletes do very well after carbo-loading.
  • Incessant eating all day is not great for the pancreas and occasional fasting is.  

But Science doesn't have all the answers about exactly what to eat and in what quantities.

"I don't know."  Say it.

It would be better than romanticising the eskimos.

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