It has been suggested that people who consume diets that are high in sugar tend to have a lower intake of beneficial micronutrients such as vitamins and minerals, as a result of the food choices they make.
But a review of 15 studies conducted since 1980 concludes that no firm conclusions can be reached. The results have been publicised by The Sugar Bureau, which said that further review is important from a public health point of view, as recommendations for food choices that are easier to understand can then be made.
"In addition, other macronutrient components of the diet might also be investigated to see if these are negatively associated with micronutrient intake," said the association.
Sugar, salt and saturated fat content in packaged foods has come under the spotlight as food labelling initiatives have set out to avoid foods that are high in unhealthy ingredients being marketed on a health angle because they are also high in beneficial nutrients.
For instance, the UK's Food Standards Agency's controversial traffic light labelling scheme aims to provides easy-to-understand advice on foods that have high, medium and low amounts of saturated fats, sugars and salt by use of red, amber and green colour coding on packaging.
At the European level, nutrient profiling was a major topic of debate in the drawing up of the new European nutrition and health claims regulation.
It was finally decided that foods that do not respect the nutrient profiling would still be able to make health claims as long as only one nutrient exceeds the limit and this is indicated on the label.
The objective of the review, conducted by Dr Kirsten Rennie and colleagues at the University of Ulster, Northern Ireland, was to determine whether dietary added sugar intake was associated with micronutrient intakes, and if so, whether there was evidence of micronutrient dilution as a result of higher dietary added sugar intake.
If micronutrient dilution was present, they wanted to determine whether there was enough evidence to support a threshold effect above which micronutrient intake started to decline.
To these ends they conducted a search of literature written in English since 1980, and identified 15 that assessed associations between added sugar or non-milk extrinsic sugar intake and micronutrients.
Overall, the researchers found there were insufficient data and too much inconsistency between studies to establish a clear relationships between added sugars and micronutrient intakes.
Moreover, there no clear evidence of micronutrient dilution or a threshold for a quantitative amount of added sugar intake was seen for any of the micronutrients investigated.
The current evidence base is considerably constrained by methodological issues.
"Further research is required to determine which food products high in added sugars might adversely affect micronutrient intakes by displacing other food items from the diet," concluded Dr Rennie.
"Analyses should take into account the magnitude of any observed associations to determine their true biological significance."
Publication: British Journal of Nutrition
Title: "Associations between dietary added sugar intake and micronutrient intake: a systematic review"
Authors: Kirsten Rennie and M Barbara E Livingstone