Miriam E Tucker
January 07, 2016
Establishment of a policy whereby manufacturers slowly and imperceptibly reduce the amount of sugar in sweetened beverages over a 5-year period — without the addition of artificial sweeteners — could dramatically cut the prevalence of overweight, obesity, and type 2 diabetes in the population, a new modeling study from the United Kingdom suggests.
The findings were published online January 6 in Lancet Diabetes & Endocrinology by Yuan Ma, a PhD student at Peking University, Beijing, China, and colleagues, with whom she is currently working at the Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom.
According to their estimates, small annual reductions in the sugar content of sugar-sweetened beverages of just under 10% — totaling 40% by 5 years — would result in about a 2-percentage-point reduction in obesity overall in the United Kingdom, leading to a drop of more than a quarter of a million new cases of type 2 diabetes over the subsequent 2 decades.
The sugar reduction, they say, combined with other measures such as soda taxes and advertising bans, could have a powerful public-health impact in the United Kingdom and could be scalable worldwide.
Another report, published in the BMJ this week, shows that, 1 year after a 10% sugar tax was introduced on sugar-sweetened beverages in Mexico, there has been a moderate reduction in sales, by as much as 12% per month in some cases, and a 4% increase in purchases of untaxed beverages (BMJ 2016;352:h6704).
Modeling Sugar Cuts on Salt Reduction — UK Leading the Way
The study’s principal investigator is Graham A MacGregor, MBBChir, FRCP, a professor of cardiovascular medicine and chair of Action on Sugar, a consortium that is working to reach a consensus with the food industry and the UK government to improve public health by reducing the amount of sugar in processed foods.
Dr MacGregor told Medscape Medical News that the current study was aimed at quantifying the benefits of such a policy, which is modeled after a salt-reduction program instituted in the UK in 2003–2004, also led by him, and which is credited with a 42% decrease in stroke mortality within 8 years, among other health benefits (BMJ Open. 2014;4:e004549).
“We’ve had a very successful salt-reduction program in the UK, setting salt-reduction targets for industry,” he said, explaining that nearly all food products in the United Kingdom now contain 30% to 40% less salt than they did previously. And because it was done incrementally, people didn’t notice the difference.
“It’s brilliant public-health policy. People are buying the same foods, yet their salt intake has fallen, and the companies don’t lose any profits because they’ve got the same sales, yet they’ve made the food more healthful. All we’re asking them for is to do the same for sugar as exemplified in sugar-sweetened drinks,” he said, noting that future plans also include eventually attempting similar reformulation to reduce saturated-fat content.
Other countries have adopted their own salt-reduction policies based on the United Kingdom’s model, he noted. “So now we’re planning to do the same for obesity and type 2 diabetes. We want to set it up in the UK, and then once we’ve demonstrated that it’s possible to get the food industry to work with it, spread it out to the rest of the world.”
In an accompanying editorial, World Obesity Federation policy director Tim Lobstein, PhD, of Curtin University, Perth, Western Australia, raises a few caveats about the current modeling study, including the fact that it assumes people wouldn’t compensate for the sugar reduction by changing their diet in other ways and that the survey-derived estimates of beverage consumption are subject to underreporting.
Nonetheless, Dr Lobstein essentially agrees with the authors’ conclusions, writing, “Any public-health measures that can reduce the prevalence of obesity, and especially reduce the likelihood of transitioning from healthy weight to obesity, must be worth exploring, especially if the measure is likely to have the greatest effect on population groups most at risk. And better still if the measure can be introduced without a substantial effect on commercial activity.”
The modeling used in the study, he said, “is probably the best we can expect for the available data, and it brings a very positive message to policy makers.”
Incremental Sugar Reduction Can Make a Big Difference
In their work, Ms Ma and colleagues modeled a gradual reduction of 9.7% per year in the amount of free sugars added to sugar-sweetened beverages, aiming for a 40% reduction over 5 years.
They used nationally representative data from the National Diet and Nutrition Survey rolling program from 2008 to 2012 and British Soft Drinks Association annual reports to calculate sugar-sweetened beverage consumption (both with and without fruit juices) and its contribution to free sugar and energy intake in the UK population.
With additional modeling, they estimated the predicted reduction in calorie consumption, the resulting weight loss per individual and per population, and subsequent drops in prevalence of overweight/obesity and type 2 diabetes.
Overall, a 40% reduction in free sugars added to sugar-sweetened beverages over 5 years would lead to an average reduction in intake of 38.4 kcal per day, resulting in an average 1.2-kg reduction in bodyweight in adults by year 5. This would cut the adult prevalence of overweight by 1.0 percentage point (from 35.5% to 34.5%) and obesity by 2.1 percentage points (from 27.8% to 25.7%)
This would amount to approximately 0.5 million fewer cases of overweight and 1.0 million fewer cases of obesity in the United Kingdom.
The resulting 1.5% reduction in body mass index (BMI) would in turn prevent between 274,000 and 309,000 new cases of type 2 diabetes over the next 2 decades, or roughly 15,000 cases per year.
Since reformulation of fruit juices might present a greater challenge, Ms. Ma and colleagues performed the same calculations with fruit juices excluded from the category of sugar-sweetened beverages. Here, there would be a 31.0-kcal intake reduction per day, leading to a 0.96-kg body-weight reduction and reductions in overweight and obesity of 0.7 and 1.7 percentage points, respectively.
And, even with fruit juices remaining unchanged, the 40% drop in sugars in other beverages would prevent between 221,000 and 250,000 new diabetes cases after the predicted body-weight reduction is achieved, the investigators estimate.
But How Feasible Is It?
Based on the salt-reduction experience, the authors point to several reasons to believe incremental sugar reduction would work on a large scale. First, as has been seen with salt, human taste preference adapts to small, gradual reductions and is unlikely to lead to increased consumption of sugar from other sources.
“After 5 years, people have gotten used to the reduction because the taste receptors’ appreciation of salt or sugar is reduced. That’s been demonstrated time and time again. Once you get used to it, you prefer foods with less salt and sugar,” Dr MacGregor said.
In addition, because the reduction of added sugar to sugar-sweetened beverages will have little effect on the cost and price of the product, it is unlikely to affect sales and profits for the soft-drink industry, which could help politically.
However, unlike the salt initiative, which has been voluntary, Action on Sugar is calling for the UK government to impose industry mandates. Even the British retail consortium, which represents UK supermarkets, is backing the idea. “If they know they’ll have to do it, they want a regulated system because they’ll know that all the other companies have to do it….They want a level playing field,” Dr MacGregor explained.
In his editorial, Dr Lobstein points out that a successful obesity-prevention policy will need to include several elements beyond sugar reduction, “not least to restrict the inducements to consume unhealthy food — which are beamed at children through much of the media they use — as well as the implementation of a soft-drinks tax.…In combination, such measures could have a substantially greater effect on sugar consumption than in isolation, bringing even greater relief to the overstretched budgets of the UK’s health services.”
Dr MacGregor said that British Prime Minister David Cameron is due to announce an obesity-prevention plan toward the end of February. “If Cameron did produce a successful obesity plan, he would leave a great legacy….It would be of great benefit to the UK and the rest of the world.”
Neither the investigators nor the editorialist have relevant financial relationships.
Lancet Diabetes Endocrinol. Published online January 6, 2016. Article