What we’ve learnt about fruit juice in 2024

The Fruit Juice Science Centre is proud to commission scientific projects from leading scientists in European universities. This is what we’ve learnt about fruit juice so far this year.

Does offering fruit juice to preschool children lead to a higher risk of obesity in adulthood?

This question was posed by Professor David Benton of the University of Swansea in the UK, in a study published in the European Journal of Clinical Nutrition [1]

The study, which tracked nearly 14,000 British children from birth to their mid-twenties, found that offering fruit juice does not lead to excess weight gain or obesity.

In fact, children given 100% fruit juice in their early years tended to have diets containing more fruit and fewer fatty foods.

Additionally, girls who drank fruit juice in their preschool years were more likely to have lower body fat at 24 years old.

In contrast, young children who were given sugar-sweetened beverages, such as fizzy drinks, ate more fatty foods and developed higher body fat by their mid-twenties.

Following the guidance of the Healthy Beverage Consensus Statement [2], the Fruit Juice Science Centre recommends that children can start drinking a small daily glass of fruit juice from school-age onwards.

Does fruit juice still contain vitamin C when you buy it from a supermarket?

The answer can be found in a new study by Dr Salar and collegues published in the International Journal of Food Sciences and Nutrition [3].

The research team from CSIC/CEBAS in Murcia, Spain, sampled popular orange juices from stores in Spain, France, Germany and the UK and analysed their nutritional composition. They also made freshly squeezed orange juice in the laboratory.

The findings showed that just one glass of supermarket orange juice provides 90% of our vitamin C recommendation on average. Freshly squeezed orange juice had a higher vitamin C content but started to deteriorate within hours. This is because the enemy of vitamin C is oxygen.

All types of orange juice provided polyphenols, specifically hesperidin – a beneficial polyphenol found in citrus fruits and their juices.

So, if you don’t have the time to squeeze juice every day at home, you still get a lot of benefit from a supermarket orange juice.

Are all sugars in the diet equal?

This was the topic of a new review paper published in the European Journal of Nutrition by Professor Javier Gonzalez [4]. In it, he discussed the role of the food matrix in the body’s physiological responses to sugars.

The U.S. Department of Agriculture defines a food matrix as “The nutrient and non-nutrient components of foods and their molecular relationships, i.e. chemical bonds, to each other” [5]. In plain English, this means natural compounds like nutrients, fibre and plant bioactives that are present in foods such as fruit or fruit juice but absent from certain processed foods.

In reviewing the data on direct comparisons between whole fruit and 100% fruit juice, Gonzalez found no evidence for meaningful differences in blood sugar control, inflammation, or blood pressure. However, there were clear differences in health markers when fruit juice and sugar-sweetened beverages were compared in human studies. This suggests that fruit juice is more similar to fruit than to sugar-sweetened beverages.

Additionally, Gonzalez did not find expected differences in body weight or body fat in short-to-medium term intervention studies, despite acute appetite responses suggesting that whole fruit increases satiety (feelings of fullness) more than fruit juice.

Acknowledging a need for more long-term data, Gonzalez said initial evidence suggests that the physical structure of foods and drinks, including fibre, potassium content, polyphenol content and energy density play a key role in some of the observed physiological responses to different sources of dietary sugars.

How much fruit juice do we drink in Europe?

We’re often led to believe that Europeans are drinking many litres of fruit juice a week, but this is untrue. A new international analysis [6] by Dr Walton and Dr Kehoe from Munster University in Cork, Ireland, has found that the average fruit juice consumer drinks less than 150ml daily. But when the overall population, including non-consumers, is taken into account, the average European adult drinks less than 70ml a day.

Despite the modest amount of fruit juice drunk, it contributes up to a quarter of our daily vitamin C intakes as well as providing significant amounts of potassium (for normal blood pressure) and folate (for immune function support). The study, published in Nutrition Research Reviews, also found that fruit juice only contributes 1-2% of daily energy (calorie) intakes.

Given that 29-90% of European adults drink fruit juice regularly, depending on the country, there is scope for non-consumers to complement their daily fruit and vegetable intakes by enjoying a regular glass.

References

1 Benton D & Young HA (2024) https://www.nature.com/articles/s41430-024-01430-y

2 Healthy Beverage Consensus Statement https://healthyeatingresearch.org/wp-content/uploads/2019/09/

3 Salar FJ et al. (2024) https://pubmed.ncbi.nlm.nih.gov/38230429/

4 Gonzalez JT (2024). https://pubmed.ncbi.nlm.nih.gov/38492022/

5 USDA. https://agclass.nal.usda.gov/vocabularies/nalt/concept?uri=https://lod.nal.usda.gov/nalt/17238

6 Walton J & Kehoe L (2024) https://pubmed.ncbi.nlm.nih.gov/38356367/