ANTHOCYANINS are the marvellous pigments that give fruit and vegetables their red, blue, or purple or black colours. Cherries, strawberries, raspberries, blueberries, blackberries and raisins are some great examples of berries that are protective against multiple chronic diseases
ANTHOCYANINS exert anti-inflammatory effects on the body and help oxidative stress. ANTHOCYANINS are also capable of affecting signalling pathways. The nuclear factor erythroid 2-related pathway or Nrf2, is a transcription factor that regulates gene expression of antioxidant proteins.
ANTHOCYANINS have been shown to have a protective effect for CARDIOVASCULAR FUNCTION vital for healthy ageing and certainly for optimal sports performance.
SPORTS PERFORMANCE is highly dependent on blood flow, which is the limiting factor for muscle oxygenation. (Bassett DR & Howie ET. 2000. Med Sci Sports Exerc.32. & Foster C et al. 1999. Med Sci Exerc.31) ) The ability of anthocyanins to increase peripheral blood flow, cardiac output, and vasodilation has resulted in many areas of research and some great information.
ALL BERRIES contain anthocyanins and offer health benefits, however, each berry has a specific make-up of anthocyanins and these specific anthocyanins also provide different physiological effect. This means that NOT ALL berries will improve exercise performance.
In general, blackcurrants contain the highest percentage of anthocyanins (delphinidin glycosides) in comparison with blueberries (malvidin glycosides) and blackberries.
NEW ZEALAND BLACKCURRANTS (NZBC)
Location and climate also affect the anthocyanin content of berries and research has revealed that New Zealand blackcurrants have the highest bioavailable anthocyanin content.
Studies have observed increased blood flow due to vasodilation, increased femoral artery diameter, increased cardiac output and stroke volume, lowered blood pressure during muscle contraction, and muscles worked to the same intensity with less stress.
Rock climbing creates a high workload on the forearm flexors and increases reliance on blood flow during short recovery periods. A fascinating study (Potter J.A et al. Eur. J Physiol. 2020 ) done on sport climbers showed an increase in hang time 8%, total climbing time 11%, and climbing endurance.
For athletic performance, supplementation is often more viable than trying to get the optimal dosage using fresh fruit. Cook et al. showed that supplementation with a NZBC extract of 600mg per day for 7 days was optimal and if using fresh berries that would have required eating 450 blackcurrants per day. A bit tricky for the gut!
A lower dose of 120mg for 7 days with a final dose 1-2 hrs prior to an event is also adequate with less gastric stress reported.
Researchers A.J. Braakhuis et al wrote ''A 1% difference in athletic performance is relevant to athletes and of sufficient magnitude to affect medal rankings in an Olympic-level competition, with the potential to elevate a medal from fourth to a podium position'
TART CHERRY JUICE
Tart cherry juice using Montmorency cherry cultivar, has been shown to aid recovery in both strength and endurance athletes. Recovery is hugely important for athletes with high-load training schedules and for busy competition schedules. Tart cherry has also demonstrated benefits for improved sleep which is a vital component for all athletes.
Howatson G, et al (2010 Scand J Med Sci Sports) concluded that tart cherry juice appears to provide a viable means to recovery following strenuous exercise by increasing total antioxidant capacity, reducing inflammation, lipid peroxidation and it may aid recovery of muscle function. These researchers found that a cherry juice supplement did not prevent or protect against muscle damage, but rather, blunted the secondary muscle damage in response to inflammation.
BLUEBERRIES
Strenuous exercise is known to acutely generate oxidative stress and an inflammatory state.
Lisa Mcanulty et al (2011 Applied Phys Nutr and Metabolism) performed a study on whether eating 250g of blueberries per day for 6 weeks, and 375g given 1 hour prior to running 2.5 hours at > 70%max would counter oxidative stress, inflammation and affect immune changes.
The study concluded that Natural Killer (NK) cells count was increased and that oxidative stress was reduced and inflammatory cytokines were also reduced.
This is an awful lot of blueberries to eat and pretty pricey as well!
McLeay et al found that a blueberry smoothie appeared to up-regulate adaptive processes such as the up regulation of the endogenous antioxidant enzymes and thereby increase the antioxidant activity on a cellular level.
In conclusion, all berries have antioxidant properties, but some have the potential to exert a larger effect.
Overeating random berries everyday will probably cause gut issues and losing focus on all the other micronutrients should be avoided. Don't fixate on one particular food, you may be missing out on other important nutrients. A diet high in a large variety of antioxidants, minerals, vitamins, fatty acids, and protein is essential for overall optimal sports performance.