Australian dietary guidelines don’t have a specific recommendation for how much added sugar we can safely consume each day.

Instead, there’s a vague message to take it easy. How?

“By limiting intake of foods and drinks containing added sugars.”

These include confectionery, sugar-sweetened soft drinks and cordials, fruit drinks, etc.

For people prone to bargaining (and who isn’t?) it’s easy to talk oneself into believing that you’re doing a good job limiting those sweet treats.

By the way, added or free sugar refers to sugar added to packaged foods, as well as what you’re spooning into your coffee and corn flakes, and so forth.

So how much is OK? A new study suggests not much, if any.

Six teaspoons a day max

Specifically, the authors recommend reducing consumption of added (‘free’) sugar to less than 25 grams a day (about six teaspoons). They also advise limiting sugar-sweetened drinks to less than one serving a week.

Why? They found “significant harmful associations between sugar consumption and 45 outcomes, including asthma, diabetes, obesity, heart disease, depression, some cancers and death”.

Their findings came from an umbrella study of existing evidence. The findings have been published by the British Medical Journal.

Isn’t this old hat?

Cancer? Heart disease? Obesity? Haven’t we heard this before from the sugar police?

Yes and no. There’s a lot of research about sugar and health.

But the quality of that research is varied, and recommended daily doses of sugar have been more a rough guide, difficult to adopt, probably too generous, and confusing.

For example, the World Health Organisation makes a “strong recommendation” that both adults and children reduce the intake of free sugars to less than 10 per cent of total energy intake.

Get your slide rule out, Poindexter! 

However, additionally WHO makes a “conditional recommendation” that a further reduction to below 5 per cent of total energy intake is a good idea.

Like we said, vague, difficult to apply and confusing.

Step 1: Make sure the evidence is reliable

The researchers, based in China and the US, started with a simple premise. To accurately calculate safe sugar intake, the quality of existing evidence needed to be comprehensively evaluated first.

To that end, they reviewed 73 meta-analyses (67 observational studies and six randomised, controlled trials) from 8601 articles covering 83 health outcomes in adults and children.

They graded the evidence for each outcome as high, moderate, low or very low quality.

The findings

They found significant harmful associations between sugar consumption and 45 outcomes.

Significant harmful associations were found between dietary sugar consumption and:

• 18 endocrine or metabolic outcomes. These included diabetes, changes in body mass index in children, gout, obesity, latent autoimmune diabetes in adults, and liver fat accumulation
• 10 cardiovascular outcomes. These included coronary heart disease, cardiovascular disease, hypertension in children and adolescents, myocardial infarction, change in systolic blood pressure in children and adolescents, and stroke
• Seven cancer outcomes. A higher risk of cancer was observed for breast cancer, hepatocellular carcinoma, prostate cancer, pancreatic cancer, overall cancer risk, and overall cancer mortality.

Finally, harmful associations were found between dietary sugar consumption and asthma in children, attention deficit/hyperactivity disorder, bone mineral density, depression, and non-alcoholic fatty liver disease.

A safety issue

Moderate quality evidence suggested that sugar-sweetened beverage consumption was significantly associated with increased body weight.

Any versus no added sugar consumption was associated with increased liver and muscle fat accumulation.

However, the researchers acknowledge that the existing evidence is mostly observational. They stress that evidence for an association between dietary sugar consumption and cancer remains limited but warrants further research.

On the other hand, the evidence does keep pointing in one direction – added sugar isn’t good for you.

That means the researchers found it doesn’t enhance your health in any way. And it appears to do a lot of harm. Sugar has become a safety issue.

And we need to find an easy, practical way for consumers to measure and control their intake. User-friendly food labelling might be a good place to start.