Blackcurrants have long been regarded as having remarkable health benefits. Early European folklore has blackcurrants being used for treating general fatigue, arthritis, kidney stones, gout, inflammation of the mouth, stomach and bowel, lung and cough aliments, and as a diuretic.

 

Recent scientific research from eight clinical trials has shown direct effects of Blackcurrants on health and well being. A clinical trial is a comparison test of a treatment versus a placebo (inactive look-a-like), and provides the most compelling evidence that the treatment causes the expected effect on human health.

 

We now know that it is the high concentrations of anthocyanins, other antioxidants and bioactives in blackcurrants that give these fruit their wonderful properties.

 

Recent work has shown that the anthocyanins contained in blackcurrants can be seen as free radical “scavengers” capable of combating the ageing of blood vessel walls. In addition, blackcurrant berries are often used for their phlebotonic properties. Vitamin C and anthocyanins increase the strength of capillaries and reduce their permeability, thus improving microcirculation. Blackcurrant can also be used to improve circulation, particularly in the legs. The anthocyanins contained in blackcurrant also help to combat problems associated with work on screens (visual fatigue). Lastly, blackcurrant is recognised and used for draining uric acid. 

 

A summary of the health benefits that have been studied during these clinical trials is outlined here, for more detailed information on the results please click here.

 

INCREASES BLOODFLOW

Subjects consumed anthocyanin (100mg) equivalent to two tablespoons of blackcurrant berries.

→ Anthocyanin content of plasma reached a maximum after 1 hour, and decreased to 50% by 4 hours.

→ After 1 hour the forearm blood flow increased significantly (about 40%) compared to placebo.

In another study 50mg of anthocyanin was shown to improve blood circulation in cold hands.

→ Hands were soaked in cold water at 10°C for 1 minute. For subjects who had consumed blackcurrants hand temperature returned to normal after 7 minutes, compared to 13 minutes for the placebo group.

                             

AUGMENTS BENEFITS OF EXERCISE

 A 2009 New Zealand study looked at the effectiveness of blackcurrant to augment the ability of regular exercise to enhance the immune responsiveness of the body.

Subjects consumed blackcurrant capsules, pre and post exercise equivalent to about 1/3 cup berries, for three weeks.

-significantly lower levels of bio markers of oxidative stress in plasma.

-significantly increased ability of plasma to suppress inflammatory responses.

 

REDUCES MUSCLE STIFFENING

Blackcurrants reduce muscle stiffness by increasing peripheral blood flow and reducing muscle fatigue.

Subjects consumed anthocyanin (50mg) equivalent to one tablespoon of blackcurrant berries and carried out keyboard work for 30 minutes.

→Total haemoglobin was significantly higher (about 40%) in the blackcurrant intake group. Oxygenated haemoglobin was significantly higher in the blackcurrant intake group.

→There was significant stiffening of the trapezius (shoulder) muscle during typing in the placebo but not the blackcurrant intake group. However, final stiffness was not significantly different between the two.

Anthocyanins from berry and grape extracts had a positive effect on chronic musculo skeletal pain (fibromyalgia). Subjects consumed anthocyanin powders for three months with the following significant effects:

→Reduced fatigue.

→Reduced sleep disturbance.

→Increased general health.

 

DECREASES VASCULAR INFLAMMATION

Increased intake of blackcurrant and orange juice decreased vascular inflammation and the risk of cardiovascular disorder.

A daily drink of 250 mls of blackcurrant juice and 250 mls of orange juice gave highly significant results after four weeks.

-11% decrease in C-reactive protein.

-3% decrease fibrinogen.

Lower levels of both markers indicate lower risk.

 

IMPROVES EYE FUNCTION AND RECOVERY

The eye takes approximately 30 minutes to fully adapt from bright sunlight to complete darkness and become one million times more sensitive than at full daylight.

→ Subjects consumed the equivalent of one tablespoon of blackcurrant berries or less.

→ Dark adaptation was significantly improved at the highest level of 50 mg anthocyanin, and two hours after consumption.

In another study, the same dose of blackcurrants was shown to greatly reduce visual fatigue following prolonged Visual Display Terminal work 2 hours after consumption.

 

IMPROVES KIDNEY FUNCTION

Consumption of 330 ml Blackcurrant juice daily for five days increased the

→ urinary pH

→ excretion of citric acid

→ excretion of oxalic acid.

 

This observation suggests that regular blackcurrant consumption could reduce the likelihood of kidney stone development as persistently low urinary pH is a significant factor for uric acid kidney stone formation.

In another study residents of a nursing home were given a daily glass of blackcurrant juice for 3 months. Residents reported reduced symptoms of urinary scalding, urgency and odour. Staff noted improvements in white cell count on urinalysis and reduced likelihood of recurrent urinary tract infection over a three month period.

 

References

 

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  94: 36-45 2005.

 

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  5: 553-562 2000.

 

Takenami,E. Kurashige,K.I. Matsumoto, H. Honma,T. Osada, T. Okubo, M. Hamaoka,T. Improvement of cold water immersion induced circulation impairment by blackcurrant extract intake-the investigation on cold constitutional women. The journal of the japanese society of thermology 23, 194-201 2004.

 

Kebler, T.; Jansen, B.; Hesse, A. Effect of blackcurrant, cranberry and plum juice consumption on risk factors associated with kidney stone formation. European journal of clinical nutrition 56: 1020-1023 2002.

 

Boyle, L.; Martin, J.; Tilley A.; Ager, C.; Payne, B. Study of use of Blackcurrant Juice

in Nursing Home Residents to Alleviate Urinary Infection and Associated Problems. Aged care Unit, Julia Farr Services, Flinders University Australia Nov 1996

 

Dalgard,C., Nielsen, F., Morrow, J.D., Enghusen-Poulsen,H., Jonung,T., Hørder, M., de Maat, M.P.M

Supplementation with orange and blackcurrant juice, but not vitamin E, improves inflammatory markers in patients with peripheral arterial disease. BRITISH JOURNAL OF NUTRITION 2009 101, 263-269.

 

Lyall, K. A., Hurst, S. M., Cooney, J., Jensen, D., Lo, K., Hurst, R. D., Stevenson L. M. Short-term blackcurrant extract consumption modulates exercise-induced oxidative stress and lipopolysaccharide-stimulated inflammatory responses. AM J PHYSIOL REGUL INTEGR COMP PHYSIOL 2009.297: 70-81.

 

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 NUTRITIONAL & ENVIRONMENTAL MEDICINE 2000 10, 189-199.