The European Food Safety Authority published new dietary reference values (DRVs) for carbohydrates, sugar, fibre, fats and water confirming proposals made last year. The final levels have drawn criticism from some scientists.
The EU risk assessor was asked by the European Commission to update DRVs for a slate of nutrients on the basis of the most recent scientific evidence, as the last time these were set was in 1993. The values released today are the first of three batches: advice on protein and energy is in the works, and EFSA will start working on vitamins and minerals later this year.
EFSA held public consultations on the new DRVs prior to confirming them. The values will now be used as an evidence base underpinning nutritional policies, public health targets, and consumer info and education programmes.
Carbs, sugar and fibre
EFSA’s advice on total carbohydrates is that intake should comprise between 45 and 60 per cent of total energy intake for both adults and children. A daily intake of 25g of fibre is recommended for normal bowel function in adults; EFSA has also recognised evidence linking fibre to reduced risk of cardiovascular disease and type 2 diabetes, and its role in weight management.
However it could not find sufficient evidence to support the role of the glycaemic index and glycaemic load in maintaining weight and preventing diet-related diseases.
No upper limit for sugars has been set, either, because of insufficient evidence and health effects are a matter of what foods are consumed and how often, rather than the amount of sugar per se. The panel does recognise that there is “good evidence that frequent consumption of foods high in sugars increases the risk of tooth decay”. But says policy makers should consider evidence for consumption patterns of sugar-containing foods when making national nutrition recommendations.
Overall, EFSA says fat intakes should range between 20 and 35 per cent of total energy for adults (the values for children are adjusted to take account of their developmental needs).
But evidence for impact of different kinds of fat is recognised, such as the link between saturated and trans fats and blood cholesterol levels. Here too, though, EFSA leaves it to national policy makers to decide how to couch the message that mono- and poly-unsaturated fatty acids are better than trans and saturated.
In the case of long-chain omega-3 fatty acids, however, it is more prescriptive. It says a daily intake of 250mg for adults “may reduce the risk of heart disease”. However academics and industry have been lobbying for far higher values than this – ideally over 500mg a day.
Following the publication of the proposed values, a 22-strong of scientists wrote to EFSA to ask it to “reconsider its conclusions and advice on omega-3 fatty acids afresh, right from the beginning.”
The scientists also objected to the proposal that ALA (alpha-linolenic) acid is a “viable precursor” to longer-chain DHA and EPA fatty acids. EFSA’s final opinion states that “ALA cannot be synthesised by the body, is required to maintain metabolic integrity, and is therefore considered to be an essential fatty acid”.
It proposes an adequate intake level of 0.5 per cent of energy, but says there is not enough evidence to set an average requirement, a lower threshold intake or a population reference intake. It also sees no need for a tolerable upper intake level, as it says there is no convincing evidence of any detrimental health effects.
The final DRV included in the current batch is for water. EFSA says 2 litres a day is considered adequate for women, and 2.5 litres for men.