The Sugar Conspiracy
Things sweet to taste prove in digestion sour
William Shakespeare
Research into cardiovascular disease intensified after US President Dwight Eisenhower suffered a heart attack in 1955. There had been a surge in heart disease in developed countries after WWII, which had coincided with a significant increase in the consumption of both saturated fat and sugar. The research aimed to determine whether saturated fat or sugar were the cause of the spike, and it led to some robust debate on the subject.
The possibility that saturated fat was the cause of the increase in CVD was investigated by Ancel Keys, who had studied chemistry, economics, political science, zoology, oceanography, biology and physiology, mainly at the University of California, Berkley. Keys published numerous studies during his career, and authored or coauthored six books.
The possibility that sugar was behind the increase in CVD was explored by John Yudkin, who had studied biochemistry, physiology, medicine and nutrition at the University of Cambridge, and was a founding Professor of the Department of Nutrition at London’s Queen Elizabeth College. Yudkin also published many studies during his career, including one in 1957 that claimed sugar was the main cause of CVD, not saturated fat. He authored eight books, including Pure, White and Deadly, a critique of the health effects of sugar in 1972, and coauthored or edited eight more.
The rivalry between the two camps was intense, with Keys’ criticism of Yudkin at times vitriolic. Supported by sugar industry propaganda, Keys won the debate. Saturated fat was blamed for the increase in CVD, and sugar was exonerated.1
This led to a low-fat diet fad in the 1980s, but if you remove fat from food it loses flavour, so sugar was added to improve the taste. This was a mistake, because, while the research showed fat and sugar were both driving the increase in CVD, sugar was doing more harm than fat. The magnitude of the error may best be seen in the change in obesity rates in the US. In 1960 around 13% of American adults were obese, and by 1980 this had risen to 15%, an increase of just 2% in 20 years. By the year 2000 obesity among US adults was 33%, an increase of 18% in 20 years. In 2020 around 42% of American adults were obese.2
For more on this see the April 2016 Guardian feature article The Sugar Conspiracy (link in the references) or the SBS documentary of the same name. And for an insight into just how bad sugar can be for you, check out That Sugar Film by Damon Gameau, and Sugar: The Bitter Truth, by Robert Lustig.1
The World Health Organization recommends free sugar consumption be no more than 50g per day, although ideally it should be no more than 25g per day. The American Heart Association’s recommendations are similar at a maximum of 37.5 g/day for men and 25 g/day for women.3
Average sugar consumption in many countries around the world is far higher than this, with the US toping the charts at 126.4 g/day (Australia is 5th at 95.6 g/day, and the UK 7th at 93.2 g/day).4
Sucrose and high fructose corn syrup are of particular concern because they are both about half fructose. Fructose directly promotes obesity by inducing leptin resistance, and thus inhibiting satiety, and by blocking the oxidation of fats.5
Fructose can also be a direct driver of metabolic syndrome, even with people whose weight is normal. Fructose reduces insulin sensitivity, increases visceral fat stores and blood triglyceride levels, and has been linked with the development of diabetes, fatty liver, and heart disease.5
Diabetes was a rare disorder in the early 1800s, but it is now very common. Globally, diabetes effects around 9% of the population, and 14% of adults. The number of people who are diagnosed with diabetes is rapidly increasing, going from 200 million in 1990 to 830 million in 2022. The mortality rate of diabetes is also rapidly increasing, and in 2021 it was the cause of 3 million deaths, half of which were directly attributable to the disease, and half were indirect deaths associated with cardiovascular and kidney disease.6
High sugar soft drinks alone are the cause of around 180,000 deaths a year. With a can of soft drink containing up to 50gm of sugar, more than the American Heart Association’s recommended maximum daily intake for men and double that for women, we can see why it is a problem. One made worse by fact that sugar can be as addictive as nicotine and cocaine.7
It is important to note here that this is the effect of fructose when in the form of a free or processed sugar, such as sucrose or high fructose corn syrup. Fructose in its natural form does not have the same effect at all. Studies have shown that most fruits have an anti-obesity effect, despite the fact they have a significant sugar content, and that there is no association with moderate intakes of natural fructose and metabolic syndrome or cardiovascular disease.8
In a study by Madero et al, 131 obese and overweight persons were randomly selected to undergo a low-fructose reduction diet or a moderate fructose reduction diet with 50g of a natural fructose supplement per day. After 6 weeks on the diet the natural fructose group had lost nearly 50% more weight than the low-fructose group. What is truly remarkable about this study is that 50gm of fructose is the amount of fructose in 100g of table sugar, double the maximum intake of free sugars recommended by the WHO, and 3-4 times that of the American Heart Association.9
Why the fructose in fruit does not lead to metabolic disease, and how it reduces obesity, is baffling the scientific community, but there are several possible mechanisms thought to be involved.10
One explanation is that the relatively low energy density of fruit, and its essential nutrient and fibre content, leads to a reduction in caloric intake. This does not explain the effect of the natural fruit supplements used in the study by Madero et al, however, because the participants were all on a calorie-controlled diet. Wholegrain cereals have a similar nutrient and fibre content, but they do not have the same anti-obesity effect.11
Another proposed mechanism is that non-essential nutrients, such as antioxidants and bioflavonoids, increase fat use and reduce fat storage by influencing the expression of the various genes involved in maintaining body fat composition. However, supplements containing the same antioxidants and bioflavonoids do not have the same effect.10
A third posited explanation is that fruit may affect fat storage by modifying our gut flora. Early studies indicate that probiotics may have a similar effect, but they are not as effective.10
The general consensus among researchers is that several mechanisms are acting synergistically to achieve this effect.11
It is important to note here that not all fruits display anti-obesity effects; that anti-obesity effects are seen with moderate intakes of fruit and not excessive consumption; and that the effects are not seen in all population groups. Pro-obesity effects of fruit have been seen in studies involving children and pre-adolescents, and in studies that have investigated fruit juices and processed fruit in an energy dense form.10
Another issue with high intakes of sugar is that it can disrupt the balance of our gut flora, since the microbes that consume sugar will proliferate. Candida, a family of yeasts that feeds off sugars and foods made with white flour, is of particular concern because it has been linked to a number of chronic disorders.12
Candida can be found in the gut of all adults and most babies by the time they are six months old. Although the species found in the human gut are considered to be harmless, some varieties, such as candida albicans, can be problematic if they are allowed to proliferate. Due to an excessive consumption of sugar and white wheat flour in the western diet, candida overgrowth is endemic.12
Candida feeds in the opposite way to that of plants, absorbing nutrients through its foliage and excreting waste via its roots. The main waste product of candida is acetaldehyde, a toxic metabolite of alcohol, which has similar cognitive effects. Phillip Alexander, in his book ‘It Could be Allergy and it Can be Cured’, describes the effects of acetaldehyde as a ‘fuzzy, foggy, spaced out, off-the-planet feeling, with a periodic loss of memory and concentration, and an inability to clearly articulate ones thoughts and feelings.’ So, if you have a problem with brain fog you might be getting drunk from eating too much sugar.’13
References
- www.theguardian.com/society/2016/apr/07/the-sugar-conspiracy-robert-lustig-john-yudkin
- https://usafacts.org/articles/obesity-rate-nearly-triples-united-states-over-last-50-years/ www.niddk.nih.gov/health-information/health-statistics/overweight-obesity – Obesity rates.
- www.who.int/news/item/04-03-2015-who-calls-on-countries-to-reduce-sugars-intake-among-adults-and-children – WHO sugar recommendations. https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.109.192627 – AHA sugar recommendations.
- www.worldatlas.com/industries/countries-that-consume-the-most-sugar.html – National sugar consumption figures.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5421126/ – Sugar history and leptin.
- www.ncbi.nlm.nih.gov/books/NBK551501/ – Diabetes. www.who.int/news-room/fact-sheets/detail/diabetes – WHO diabetes fact sheet.
- https://www.hsph.harvard.edu/news/hsph-in-the-news/roughly-180000-deaths-worldwide-linked-to-sugary-drink-consumption/ – high sugar drinks linked to 180,000 deaths per year. https://pubmed.ncbi.nlm.nih.gov/23719144/ – sugar as addictive as cocaine.
- https://pubmed.ncbi.nlm.nih.gov/35139893/ – Added fructose vs natural and met dis. https://pmc.ncbi.nlm.nih.gov/articles/PMC5084020/#sec5-nutrients-08-00633 – Fruit and obesity.
- https://pubmed.ncbi.nlm.nih.gov/21621801/ – Madero
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5084020/#sec5-nutrients-08-00633 – Fruit and obesity.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11187407/ – Probiotics and obesity.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6363656/ – Candida and sugar.
- Collison, Dr. D. R. ‘Why do I feel so awful?’ Angus and Robertson, Sydney, 1989, p. 379. Alexander, P. ‘It Could be Allergy and it Can be Cured’ 3rd ed., Ethicare, Sydney, 1994, p. 53-4.