MARIKA SBOROS: Cancer risks should not be sugar-coated
A new study points to a possible link between higher consumption of sugary drinks and an increased risk of cancer
Could just one small glass of freshly squeezed orange juice really increase your cancer risk? A French research team believes that it could.
Their study, just published in the British Medical Journal, reports a strong, possible association between higher consumption of sugary drinks and an increased risk of cancer.
The researchers — from the Sorbonne, French Public Health Agency and Avicenne Hospital — readily admit that cautious interpretation is needed. Their study is associational and therefore does not prove causation. However, it is large and well-designed.
They have adjusted for a wide range of potentially influential factors, such as age, sex, educational level, family history of cancer, smoking status and physical activity levels. And they report that further testing left their results largely unchanged. Thus, their findings appear able to withstand scrutiny.
They say that their findings add to a growing body of evidence indicating that limiting sugary drink consumption, with taxation and marketing restrictions, might contribute to a reduction in cancer cases.
Their study leaves some experts wondering why most governments, including the SA government, and dietitians’ organisations such as the Association For Dietetics in SA (ADSA) and their members still promote fresh fruit juice as healthy.
Growing evidence shows the opposite.
The researchers say that consumption of sugary drinks has increased worldwide during the last few decades and is convincingly associated with the risk of obesity, which is well-recognised as a strong risk factor for many cancers.
Many people mistakenly believe that a juice that is 100% fruit, even freshly squeezed, is healthy. It isn't.Dr Frank Lipman
But research on sugary drinks and the risk of cancer is still limited, the researchers say. Thus, they set out to assess the associations between the consumption of sugary drinks (sugar-sweetened beverages and 100% fruit juices), artificially sweetened (diet) beverages, risk of overall cancer as well as breast, prostate and bowel (colorectal) cancers.
They looked at 101,257 healthy French adults (21% men; 79% women) with an average age of 42 years at inclusion time from the NutriNet-Santé cohort study.
Data showed that an increase in consumption of sugary drinks of just 100 ml per day was associated with an 18% increased risk of overall cancer and a 22% increased risk of breast cancer. (That’s relative, not absolute risk — the one you really need to worry about. A relative risk of 18% is small, relatively speaking, and in this case therefore, the absolute risk turns out to be negligible.)
And when the group of sugary drinks was split into fruit juices and other sugary drinks, the consumption of both beverage types was associated with a higher risk of overall cancer.
The researchers found no association for prostate and colorectal cancers, but say that the numbers of cases were more limited for these cancer locations.
In contrast, they found that consumption of artificially sweetened (diet, “soft”) beverages was not associated with a risk of cancer. However, the authors warn that caution is needed in interpreting this finding due to a relatively low consumption level in this sample.
They speculate on possible explanations for the results: the effect of the sugar in sugary drinks on visceral fat (the type that is stored around and “migrates” into vital organs, such as the liver and pancreas), blood sugar levels and inflammatory markers.
All these are linked to increased cancer risk, the researchers say. Other chemical compounds, such as additives in some sodas, might also play a role, they add.
They say that they cannot rule out some misclassification of beverages or guarantee detection of every new cancer case. However, they conclude that their data supports the “relevance of existing nutritional recommendations to limit sugary drink consumption, including 100% fruit juice, as well as policy actions, such as taxation and marketing restrictions targeting sugary drinks”.
SA-born, US-based Dr Frank Lipman agrees that cautious interpretation is needed as the study is associational. However, he endorses existing nutritional recommendations to limit and preferably stop sugary drinks, including 100% fruit juice.
Lipman runs the Eleven Eleven Wellness Centre in the Flatiron district of Manhattan, the first-of-its-kind clinic that he founded in 1992. There, he practises an integrative, functional approach that he calls “good medicine”. He defines it as “an appropriate blend of cutting-edge, modern medicine with optimum nutrition and age-old healing techniques from the East” to provide personalised health care.
The method he advocates to patients is not just to reduce cancer risk but to boost health generally is simple: remove what is harmful and add what is beneficial.
Sugar and sugary drinks are among foods he thinks we should all avoid like the plague if we are serious about reducing the risk of developing cancer.
“Many people mistakenly believe that a juice that is 100% fruit, even freshly squeezed, is healthy. It isn’t,” Lipman says. “It’s just one big, hefty dose of sugar.
“And if you already have cancer, sugar is not one of the best foods to fight it.”
Lipman’s advice to patients includes optimum diet to reduce the inflammation that he and others say lies at the heart of all life-threatening disease. One of the best weapons to fight or prevent cancer or any other dread disease is an anti-inflammatory diet, he says.
It’s an understatement to say that Lipman is no fan of sugar when it comes to what’s on his menu for an effective anti-inflammatory diet.
He calls sugar “public health enemy number one”. He says that sugar is “the worst toxin we expose ourselves to daily on the conventional American (and SA) diet”.
Ingesting it consistently sets us up for inflammation, he says.
“It lays the groundwork for every flavour of modern distress — from cancer, diabetes and heart disease, dementia and depression, to infertility, acne and more.”
The fight against cancer
Diet and nutrition are at the forefront as adjuncts to treat and prevent cancer as limitations of orthodox medical treatment methods become more apparent. Evidence for two areas currently exciting interest among oncologists globally includes:
The metabolic model of cancer
Based on the pioneering work of German physician Dr Otto Warburg in the 1920s, the model theorises that all cancer is a disease of energy metabolism and mitochondrial dysfunction. Rebooting mitochondrial function and depriving cancer of the fuel (glucose) it needs to survive lie at the heart of Warburg’s work.
Experts say that depriving cancer cells of glucose is not as easy as simply cutting sugar and other carbohydrate foods from the diet. Protein foods also produce glucose by a process known as gluconeogenesis.
Drugs and foods that deprive cancer of the new blood-vessel growth (angiogenesis) it needs to thrive and survive in a host body. So far, anti-angiogenesis drugs have not met early expectations. That has put the focus back on an “anti-cancer diet” of foods and drinks, particularly fruits and vegetables — broccoli among them — that have proven anti-angiogenic effects.