Blog Post

New Zealand Blackcurrants: Benefits for Athletes

New Zealand Blackcurrants Benefits for Athletes Featured Image

New Zealand Blackcurrants are not exactly the most well-known nutrition strategy for improving performance, but there is some solid research indicating benefits.

They can potentially help with a wide range of things including:

  • Improving race times
  • Helping with recovery
  • Improving blood flow
  • Increasing fat oxidation

In this post, the research will be summarised, and some practical interpretations will be made.

Mechanism of Action

 Anthocyanins appear to be the main component of blackcurrants that drive the benefits for athletes that we are looking at.

These are the pigments responsible for the blue, purple, red and orange colours of certain fruits and vegetables.

There are different forms of anthocyanins. Blackcurrant anthocyanins in particular have been shown to reduce inflammation and oxidative stress.

Anthocyanins have also been shown to improve blood flow. This can be particularly beneficial for endurance sports.

Why New Zealand Blackcurrants Specifically?

CurraNZ Supplement

Blackcurrants in general have a high anthocyanin content. New Zealand Blackcurrants have an even higher anthocyanin content than ones grown elsewhere though.

A study on this found that 100ml of juice from New Zealand Blackcurrants contained between 336 and 850mg of anthocyanins. Meanwhile, non-NZ blackcurrant juice contained 170-310mg.

Recovery

A systematic review containing 16 studies on NZ Blackcurrants found that markers of inflammation and oxidative stress had less of an increase due to exercise in comparison to placebo.

This was based mostly on studies involving blackcurrant extract being taken for 7 days leading up to exercise, with the final dosage being 2 hours before.

Research has also found that muscle damage is reduced and recovery of muscle function is improved.

This is an unsurprising finding since we have seen a lot of other options that have antioxidant and vasodilatory properties reduce delayed onset muscle soreness.

Vasodilation and Blood Flow

Vasodilation

New Zealand Blackcurrants can also help with vasodilation.

A seven-day study looking at this found increases in blood flow of 45% on the final day. This involved increases starting at 8% on day one and 25% on day 4.

A common theme among research on blackcurrants for athletes is that studies are often only a week long. Would benefits be greater if it was supplemented for longer?

We can also make some interpretations from other areas of research. Both beetroot juice and citrulline are well-known for their ability to improve blood flow.

Using beetroot juice as an example, it is common to see 1-2% improvements in race times in endurance events.

Performance improvement

People Running

A review of all the research on NZ blackcurrants and performance found a 0.45% improvement in performance on average.

That sounds small. But the authors of that paper highlighted that this is actually about half the improvements in performance seen with caffeine, which is commonly accepted as a performance enhancer.

Of the nine studies included in the performance data, eight used protocols of 7 days. The other one involved supplementing for 3 weeks. But as mentioned earlier, what if they had taken this for longer?

The studies included in this review looked were:

StudySubjectsBC anthocyanin doseFinal dosePerformance ProtocolPerformance Outcome
Braakhuis, 201423 females300 mg/d for 3-wk2–3 h before testRun time during a 5 km run time trial (25 min)Peak running speed improved by 1.9%, but total improvements in time were not noticeable.
Cook, 201514 males105 mg/d for 7-d2 h before testCycle time during a 16.1 km cycle time trial (28 min)Race time improved by 2.4%.
Godwin, 201724 males210 mg/d for 7-d2 h before testSprint time during a repeated run sprint interval test to fatigue (average of sprint 3–6, 22 s)Improved sprint time by 0.56 seconds by the 5th sprint.
Murphy, 201710 males105 mg/d for 7-d2 h before testCycle time during a twice repeated 4-km cycle time trial (12 min)Total time was 0.82% faster, although the difference was larger on the second time trial.
Perkins, 201513 males; crossover105 mg/d for 7-d3 h before testDistance covered during a repeated sprint test to fatigue (4 km)Increased total running distance by 10.6%.
Perkins, 201916 males210 mg/d for 7-dNot reportedDistance covered during a repeated sprint test to fatigue (4.7 km)Distance covered during high-intensity running increased by 6.8-10%.
Potter, 202018 males, 2 females210 mg/d for 7-dNot reportedHang time during a simulated rock climbing test to fatigue (30 s)No effect on pull-ups, but provided a trend for higher HT and significantly improved total climbing time by 23%.
Willems, 20158 males, 5 females138.6 mg/d for 7-d2–3 h before testPower output at set lactate level during a cycle test (225 watts)Power output was 6% higher.
Willems, 201613 males105 mg/d for 7-d3 h before testRun time during a run test to fatigue following a sprint test (14 min)Time to exhaustion was 15.78 minutes in the NZ BC group and 13.44 minutes in the placebo.

One thing you will notice is that in most of those studies, the performance improvement was significantly more than the 0.45% reported.

Personally, I think 0.45% is a fairer representation though. Studies based on things like “time to exhaustion” do not really translate as well to most real-world activities. An improvement of 10% for time to exhaustion is not anywhere near a 10% improvement in race times.

The way the authors came to a 0.45% improvement is through statistical techniques, but I think it is a fair summary.

Fat Metabolism

While not a lot of research has looked specifically at this, NZ blackcurrants have evidence of increasing fat oxidation during exercise.

In a 16km cycling time trial study where performance was improved by 2.4%, fat oxidation increased substantially. Other research has also found similar outcomes.

It is worth mentioning, but how much does this really matter?

Fat loss and fat oxidation are not necessarily the same thing. If you are interested, you can read another post we have on that topic.

A lot of people propose that improving fat oxidisation could help spare glycogen stores better for endurance performance. This idea has been challenged by a lot of research finding that when strategies are implemented to achieve this, performance often does not improve any further.

Antioxidants and Training Adaptations

As a quick note, there is a bit of controversy around antioxidants and training adaptations.

While we clearly see benefits, such as the stuff we see from NZ blackcurrants, there is another side to the argument.

Antioxidant supplementation around the time of resistance training has a bit of evidence that it can blunt training adaptations. The logic behind this is that potentially the inflammation and oxidative stress is part of the thing that causes the response and adaptations to training.

It is a complex topic though and not overly clear-cut. For a thorough breakdown, I recommend reading this article from Stronger by Science.

Stronger by science banner

One thing that is worth noting is that we have not really ever seen this issue arise through food. It is always due to high-dose antioxidant supplements.

We also have not seen any research on it directly linked to blackcurrant extract either. It is an idea worth being aware of, but I also would not focus on it too much at this stage.

Dosage and How to Use

Blackcurrant Supplement

The dosage that has been linked with performance benefits so far is a dosage containing 105–210mg of anthocyanins per day.

Less than 300mg per day is recommended to reduce the risk of gastrointestinal distress.

Research so far has mainly looked at short-term usage of 7 days.

If the antioxidant issue mentioned above is not a concern, then I personally see no issue with supplementing it daily or long-term. I would actually wager the benefits would be a bit larger than what we have seen in the research so far.

If the antioxidant issue mentioned above is an issue, there still is a place for blackcurrant extract. It might not make sense to consume year-round. But in the lead-up to an important event, it can make sense to take it since it clearly improves performance.

The easiest way to take it appears to be in either capsule or powder form.

Summary and Practical Interpretation

Blackcurrants

New Zealand Blackcurrants are a little-known performance enhancer, but they are worth being aware of.

Are they worth taking?

It is hard to say.

If the benefits mentioned in this article are relevant to you, then it could be worth it.

The most common place to buy it from in Australia sells 30 capsules for $38.95 AUD. It is not the cheapest supplement, but also not the most expensive.

I would not prioritise this above other things if money is tight. It could be worth taking if you have the money and inclination to have it though.

By Aidan Muir

Aidan is a Brisbane based dietitian who prides himself on staying up-to-date with evidence-based approaches to dietetic intervention. He has long been interested in all things nutrition, particularly the effects of different dietary approaches on body composition and sports performance. Due to this passion, he has built up an extensive knowledge base and experience in multiple areas of nutrition and is able to help clients with a variety of conditions. One of Aidan’s main strengths is his ability to adapt plans based on the client's desires. By having such a thorough understanding of optimal nutrition for different situations he is able to develop detailed meal plans and guidance for clients that can contribute to improving the clients overall quality of life and performance. He offers services both in-person and online.