In a commentary published in the July issue of The Lancet, nutrition scientist Professor Dariush Mozaffarian expressed concern about a blanket approach to sugar reduction in food and beverages. He argued that while there is strong scientific evidence linking sugar-sweetened beverages to adverse health outcomes, there is not sufficient evidence to support a similar focus on reducing added sugar in foods.
With this in mind, he called for a shift in policy to prioritise action on sugar-sweetened beverage intakes.
“It is time to recalibrate clinical and policy focus to reduce sugar-sweetened beverages and at the same time, moderate hyperbolic claims of all added sugar in foods being toxic or the greatest dietary threat to human health, especially when added sparingly to otherwise healthy ingredients,” wrote Prof. Mozaffarian in The Lancet.
He also said actions are “urgently needed” to address the “even larger disease burdens” attributable to highly processed refined grains - a challenge that he said remains largely ignored or unrecognised by clinical, policy, and private sector actors.
His views garnered support from consultant nutritionist Dr Carrie Ruxton, of Nutrition Communications, who told this publication: “At last, a highly respected scientist in the nutrition community has come out and said what many people have been thinking – that the current war on sugar has become too broad and risks banning or taxing foods that can actually do us some good.
“As Professor Mozaffarian recommends, diet policy needs a laser focus on the obvious health harms posed by high consumption of sugar-sweetened beverages. It’s not fibre-rich breakfast cereals, yoghurts, fruit juices or fruit/nut bars that are causing our current health woes, even if they do contain small amounts of sugar, which enhance palatability. However, the catch-all approach taken by diet policy could end up making these foods less affordable or available to consumers.”
Mozaffarian penned the commentary in response to a paper published in the British Medical Journal. In the paper, Yin Huang and colleagues reviewed published meta-analyses of randomised trials and observational studies investigating sugar consumption and health outcomes. They concluded that high dietary sugar consumption, especially intake of sugars that contain fructose, is associated with a number of harmful health outcomes.
They therefore recommended reducing the consumption of free sugars or added sugars to below 25 grams a day (approximately six teaspoons a day) and limiting the consumption of sugar-sweetened beverages to less than one serving a week.
However, Mozaffarian pointed out that none of the meta-analyses they reviewed evaluated added sugar from foods, naturally occurring free sugars (such as those in fruit juice) or total sugars (such as those in fruit).
He argued that such data was important for making inferences about the health effects of these sources of sugar, and referenced findings from other meta-analyses to fill these gaps.
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No evidence of link
These meta-analyses, he said, showed no significant association between 100% fruit juice and diabetes. Nor did they reveal any significant associations between added sugar in foods and obesity, hypertension, fatty liver, gout, or diabetes.
On the other hand, he said each of these reports consistently identified harmful associations of sugar sweetened beverages with these health outcomes.
Ruxton agreed that much of the evidence showing negative effects of sugars are dominated by studies on sugar-sweetened beverages.
“This is especially the case for 100% fruit juice which is often categorised in studies with added sugar drinks such as nectars, juice drinks and even cider, which skews the evidence towards harm. However, when fruit juices are examined separately, as Professor Mozaffarian comments, there are no health harms and even some health benefits such as blood pressure reduction and antioxidant effects. This is because fruit juices are a rich source of plant polyphenol compounds and vitamin C,” she said.
At the same time, Mozaffarian said the evidence does not support a similar, simplistic focus on reducing added sugars in foods.
“At low amounts and added to otherwise healthful foods, sugars will have little adverse metabolic effects. Excessive focus on added sugars in foods will also divert clinical, policy, investor and food sector attention from the much larger problem of poor-quality carbohydrates,” he noted.
In support of this last point, Prof Mozaffarian cited a recent global analysis which estimated that the top dietary drivers of type 2 diabetes worldwide are insufficient whole grains and excess refined rice and wheat.
He said the bottom line is this: “avoid sugar sweetened beverages and refined grains. If there's a bit of added sugar in an otherwise healthy food, don't worry so much about it.”