Not all “New Zealand blackcurrant” supplements deliver the science they claim

For US runners, cyclists and endurance athletes, New Zealand blackcurrant is becoming a sought-after ingredient because of its growing body of sports performance research. 

But as interest grows, so does the risk of products borrowing from the science without delivering the ingredient, dose or quality used in that science.

CurraNZ is not just one brand among many. It is the ingredient behind the clear majority of peer-reviewed, published New Zealand blackcurrant sports-performance datasets, including studies in:
- cycling 
- repeated sprint running
- rugby-specific performance
- heat-stress exercise
- 5km running
- high-intensity intermittent running
- GI symptoms in the heat
- muscle recovery
- fuelling
- cardiovascular health and function

These studies use defined New Zealand blackcurrant extract - CurraNZ - and researched anthocyanin doses, commonly 300mg/day providing 105mg anthocyanins, 600mg/day providing 210mg anthocyanins, or acute 900mg dosing in performance trials.

Brands should not borrow the credibility of this science while using an undisclosed, underdosed or unverified blackcurrant ingredient.

A new US concern is a probiotic supplement marketed to runners claiming to be 'the first supplement created specifically for runners to stop bathroom issues before they start'.

Its product page references the CurraNZ New Zealand blackcurrant research on gastrointestinal symptoms in the heat and exertional heat stress, and claims the formula uses “clinically effective ingredients scientifically shown to improve gut health & reduce gastric distress.” 

However, the page does not appear to disclose the amount of New Zealand blackcurrant extract used per serving.

That matters because the GI heat-protective effects being referenced are not generic “blackcurrant” effects. They are based on specific New Zealand blackcurrant science, using researched doses and defined bioactive profiles.

If a product cites that science but does not show a comparable ingredient specification or researched dose, consumers may assume they are getting benefits the formula is not equipped to deliver.

In independent laboratory testing of a sample of the supplement showed the total and key anthocyanins associated with New Zealand blackcurrant were reported below the laboratory’s detection limit of 10mg/100g. Because we do not hold a retained unopened sample from the same batch, we are not presenting this as a batch-wide finding. However, the result raises legitimate questions about whether the product contains any New Zealand blackcurrant - and is listed as the second-largest ingredient in the product.

This concern is part of a wider issue. Recent analyses of “New Zealand” blackcurrant products in the US, UK and New Zealand have found the majority of products fail label claims, showing negligible anthocyanins, or containing unverified or unidentifiable extracts.

In one international investigation, supposedly New Zealand-sourced blackcurrant extracts showed up to 437% variation in anthocyanin content, with pesticide residues inconsistent with New Zealand origin.

For US consumers, the question is simple: does the product prove its ingredient, dose, anthocyanin content and traceability? If the science is being used to sell the product, the product should meet the science.

CurraNZ and Enzans® stand apart through traceability, batch testing and clinically researched New Zealand blackcurrant bioactives. For real results, look for the trademarks that prove the provenance - and the science.