Blackcurrants – the answer to endurance sports muscle cramp and fatigue?

A Canterbury blackcurrant farmer cum practicing science consultant, Jane Lancaster, might have uncovered a way

…to reduce lactic acid build up leading to muscle cramp and hence assist endurance athletes to improve performance.

The NZ Blackcurrant Cooperative asked Lancaster to review international scientific evidence from clinical trials using blackcurrants in order to understand how an extract of NZ blackcurrants was so effective in reducing dark rings under the eyes of young Japanese women.

Lancaster looked at all research regarding blackcurrants and anthocyanins – powerful antioxidants found in large amounts in blackcurrants, where clinical trials proved effectiveness on humans and where results were based on the method used to prove medicines for major health issues.

“I was intrigued by the Japanese focus on using blackcurrants to make the eyes more beautiful,” says Lancaster. “The excellent research done by the Japanese showed that the cause is primarily from a special class of antioxidants in Blackcurrants called anthocyanins. These are what makes the Blackcurrants skin and juice that incredibly rich black-purple-red colour. And because of the NZ climate and type of varieties grown, NZ Blackcurrants have the highest levels of these antioxidants than those grown elsewhere,” says Lancaster.

But although the study started looking at eye beauty, the research showed some other values which could be far more important for the NZ lifestyle.

The studies showed that taking an ordinary serving of Blackcurrants (approximately two dessertspoonfuls) dramatically improved blood circulation by as much as a factor of 40% and led to reduced muscle stiffness, cramp and fatigue symptoms.

“This is because the anthocyanins seem to improve blood circulation in stressed muscle tissue. In the tests this was measured on forearms and shoulders, but the effect, a relaxation of blood vessels, applies across the whole body. Continuous muscle contraction shrinks blood vessels in the muscle group concerned and stifles the body’s ability to remove metabolites such as lactic acid. And muscle stiffness, pain and cramping can result. This lactic acid build-up is what defeats most endurance athletes,” say Lancaster

“The idea that taking a pleasant shooter glass of a totally natural, drug-free blackcurrant smoothie will reduce that build-up, is quite exciting. We’ll now look at initiating collaborative research with, for example, a sports fitness centre.”  says Floyd.

Blackcurrants may be a way to reduce lactic acid build up leading to muscle cramp and hence for endurance athletes to improve performance.

  • Attached: Full review of scientific papers prepared by Jane Lancaster under a research grant funded by the NZ Blackcurrant Cooperative.
  • Matsumoto, H., Takenami, E., Iwasaki-Kurashige, K., Osado, T., Katsumura, T., Hamaoka, T.  Effects of blackcurrant anthocyanin intake on peripheral muscle circulation during typing work in humans. EUROPEAN JOURNAL APPLIED PHYSIOLOGY 2005 94: 36-45  
  • Nakaishi, H., Matsumoto, H.,  Tominaga,S., Hirayama, M. Effects of blackcurrant anthocyanoside intake on dark adaptation and VDT work induced transient refractive alteration in healthy humans.  ALTERNATIVE MEDICINE REVIEW 2000 5: 553-562  
  • (Title and author in Kanji) THE JOURNAL OF THE JAPANESE SOCIETY OF THERMOLOGY, 2004 23, 194-201   
  • Edwards,A.M., Blackburn, L., Townsend,S., David, J. Food supplements in the treatment of primary fibromyalgia: a double-blind, crossover trial of anthocyanidins and placebo. JOURNAL OF NUTIRTIONAL & ENVIRONMENTAL MEDICINE 2000 10, 189-199.