Sugar is Poison
“Sugar is bad for you”
A mother told me, and that was the reason she removed the fruit from her five year olds school lunch box.
“These look delicious”
I said to my client who brought me a tray of home made muffins.
“And they are very healthy” She said, “I didn’t use any sugar at all. Only coconut oil, chia seeds and honey.”
“It’s not the fat that makes you fat”
A doctor friend of mine smugly proclaimed to me.
“It’s the sugar”.
With books containing provocative titles such as Sweet Poison, Pure, White and Deadly and I Quit Sugar, along with major news reports claiming that sugar is similar to excessive alcohol consumption in it’s ill health effects on humans, it is little wonder why the public has been concerned about sugar and fructose in food choices.
But is sugar and fructose really as evil as some are loudly saying? Is it not a little too much to ask a chef at a restaurant to design a special menu for her and her friends that contains absolutely no sugar because her and her friends have ‘quit sugar’? Yes, true story.
I don’t know of many other professional or scientific fields where the voices of a viewpoint have gained so much ‘airtime’, informed the public about the evils of a nutrient and published best-seller books with minimal to no formal scientific training in the area.
Should that not concern us? I, for one, wouldn’t volunteer my car to be serviced by someone who merely owns a car and has an opinion on how a car should be serviced!
It is important to remember that that the ‘sugar is poison’ notion is not new. As early as 1912, a French physician warned of the evils of consuming meat, alcohol and sugar. The 1960s saw John Yudkin point the finger at sugar on its causative role in cardiovascular disease.
And from that time, more research has been conducted in humans and animals on understanding the effects of sugar and fructose on numerous aspects of human health, disease and obesity than we could ever hope to read in our lifetime.
I say this to highlight the point that our knowledge on this topic is voluminous. It never ceases to amaze me that there are some that make such fantastic claims about sugar that are in direct opposition to the published research. Do authors ever fact check anymore?
Or is this one of those cases where facts should not get in the way of a good book sale?
Of course, we should be extremely interested in foods and nutrients that may have an impact on our health. Is a confectionary bar better than an apple? Doesn’t need an answer, does it.
But is an apple a better choice than a zucchini? Some would say one has fructose and it should not be eaten.
Should we feel guilty for eating an apple? Or should I feel bad for adding a teaspoon of sugar to my Thai minced chicken salad to balance the flavours? Well, lets see what the proposed ill effects of sugar and fructose consumption are.
Sugar and fructose are implicated in causing hypertension, heart disease, dyslipidaemia, pancreatitis, obesity, insulin resistance, liver dysfunction and addiction.
A superficial glance at the science reveals an enormous amount of research supporting the negative health consequences of sugar. But when you dig deeper, a few issues arise that make that interpretation of the science seem less clear-cut.
(1) Many studies have been performed on animals and fed such high amounts of fructose that would be typically impossible (or unlikely) to consume as a human.
(2) Sugar is often fed in both animal and human studies in excess of energy requirements, making it difficult to disentangle the effects of sugar vs the effects of excess energy intakes.
When well-controlled studies have accounted for the effects of excess energy intake or have fed sugar as part of an energy balanced diet, the negative effects of sugar are no longer remarkable.
It is claimed that sugar is turned straight to fat. Haven’t we all heard this?! This effect is seen in animal studies fed huge amounts of fructose, but the amount that fructose is converted to fat in humans is less than 5% and may increase to 10% when fed a long-term energy excess diet comprised of fructose.
Possible? Maybe. But, highly unlikely.
Studies show that fructose consumed at around 10% of energy intake (around 50g/day) do not change blood lipids (ie, it is not turned to fat).
There is also data to show that small amounts of fructose (7.5g) consumed with each meal actually improves long-term glycaemic control (by reducing post-meal glucose response). This suggests that fruit with or after a meal is beneficial for glucose handling.
A claim we hear most often is that sugar makes you fat. Studies do not show under normal conditions that fructose increases body weight.
Controlled studies that feed excess energy demonstrate that indeed excess fructose increases weight but no more than excess energy from other food stuffs, strongly suggesting that excess energy is the driver of increased body weight and not fructose.
Again, this is hardly remarkable.
A dose threshold of harm for fructose is above 100g a day (or >60g/day in the diabetic population), where we see an increase in serum triglycerides. The issue interpreting these findings is disentangling the effect of fructose from the effect of excess energy intake.
The primary point here is that excessive energy intake, either from fructose, other carbohydrates or from fat is not advised long term. But that is hardly surprising or going to make a book a best seller.
A recent expert review of the topic of sugar concluded:
Based on the currently available data, however, any statement that ordinary fructose intake is toxic and that consumption of fructose-containing drinks are the leading cause of the global obesity epidemic is not supported by scientific consensus.
The common sense interpretation of the scientific understanding of sugar/fructose is that foods containing high amounts of added sugar are generally foods that are low in nutritional quality and, as such, should be minimized. High palatability, rich in energy and little filling effect leads these foods to be over eaten, and the result is clear: increased body fat.
Eating foods with small amounts of added sugar or adding sugar to balance flavours in your cooking will cause no harm to health (and might improve the taste of your cooking in some instances).
Regular overeating, whether from all food, in general, or from sugar, in particular, is not recommended. And if you have been frightened into avoiding fruit because of the fruit sugars and have been choosing a kale smoothie instead, I hope you feel liberated to add back the fruit!
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