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Black currants
carry significantly high amounts of phenolic flavonoid phytochemicals called
anthocyanins. Scientific studies suggest that consumption of blackcurrants can
have potential health effects against cancer, aging, inflammation, and
neurological diseases.
Black currants
have anti-oxidant value (Oxygen radical absorbance capacity- ORAC) of 7950
Trolex Equivalents per 100g, which is one of the highest value for fruits after
chokeberries, elderberry, and cranberries. Red currants, however, possess
comparatively less ORAC value at 3387 TE.
They are an
excellent source of antioxidant vitamin, vitamin-C. 100 g of fresh currants
provide more than 300% of daily-recommended intake values of vitamin C.
Research studies have shown that consumption of fruits rich in vitamin C helps
the human body develop immunity against infectious agents and also help
scavenge harmful oxygen-free radicals from the body.
Black currants
carry small but significant amount of vitamin A, and flavonoid anti-oxidants
such as beta-carotene, zea-xanthin and cryptoxanthin levels. 100 g fresh
berries provide 230 IU of vitamin A. These compounds are known to have antioxidant
properties. Vitamin A is also required for maintaining integrity of mucus
membranes and skin, and essential for healthy vision. Furthermore, consumption
of natural fruits rich in flavonoid anti-oxidants helps to protect from lung
and oral cavity cancers.
Fresh
blackcurrants are also rich in many essential vitamins such as pantothenic acid
(vitamin B5), pyridoxine (vitamin B-6) and thiamin (vitamin B-1). These
vitamins are essential in the sense that human body requires them from external
sources to replenish and required for metabolism.
They also carry
good amounts of mineral iron. 100 g currant berries provide about 20% of daily
recommended levels. Iron is an important co-factor for cytochrome oxidase
guided cellular metabolism. It is also required for red blood cell (RBC)
production in the bone marrow.
Additionally, the
berries are also a very good source of other important minerals like copper,
calcium, phosphorus, manganese, magnesium, and potassium, which are very
essential for body metabolism.
Vision: Can blackcurrants help my eyesight? Scientists have
discovered that dietary antioxidants play an important role in maintaining eye
health and vision, particularly in preventing cataract.
Cataract is a common degenerative eye disease and is associated with getting
older. It results from the build-up of oxidised proteins in the lens of the
eye, which prevents light from entering. Some antioxidants like vitamin C have
been found to reduce the risk of cataract, but whether or not the other
blackcurrant antioxidants offer similar protection is not yet known.
In a scientific study on humans, blackcurrant juice
containing anthocyanins helped the volunteers' eyes to adjust to darkness
better.
Urinary Tract Health: What is a urinary tract infection or UTI? The urinary tract
is the name given to the organs in the body which produce and store urine; the
kidneys, the ureters, the bladder, and the urethra. Urinary tract infections
(UTIs) occur when bacteria, usually from faeces, enter the urethra, travel
upwards and stick to the walls of the urinary tract, where they multiply. Surprisingly,
urine is normally sterile, in other words it does not contain many bacteria at
all. The combination of a healthy immune system, specific personal care
practices and the flow of urine flushing bacteria out keeps it that way.
When the body detects the presence of bacteria in the
"wrong place" it responds by activating the immune system to try and
destroy them. Unfortunately, this causes inflammation at the place where our
bodies are fighting the invaders, which means that the area becomes swollen and
sensitive. This causes pain in the urinary tract, especially during urination.
Cystitis is another word commonly used to refer to a UTI.
How might blackcurrants help to stop me getting a UTI? Drinking
a lot of blackcurrant juice or squash may help to prevent UTIs, simply because
drinking lots of any fluid means that the urinary tract is regularly flushed out!
Whilst the best treatment for a UTI is a course of antibiotics, many people use
plants with antibiotic properties to help prevent the infections. Although the
most famous of these is the cranberry, scientists are beginning to think that
the blackcurrant may be just as beneficial.
In the laboratory, scientists looked at why cranberries were
effective against foreign bacteria in the urinary tract and discovered that
substances called proanthocyanidins from cranberries and blueberries stop
bacteria from sticking to the walls of the tract, preventing them from
remaining there and causing infection (a). Blackcurrants may also get rid of
bacteria from the urinary tract, because they too contain proanthocyanidins
(b), which can be found in urine after drinking blackcurrant juice (c).
Furthermore, blackcurrant juice, blackcurrant extracts and
single substances from blackcurrants have been tested in the laboratory and
were found to stop the growth of some species of harmful bacteria (d).In a
preliminary study on humans, blackcurrant juice was given to elderly volunteers
in a nursing home, and was effective in relieving some of the symptoms of a UTI
(e).
Interestingly, infection by Staphylococcus aureus (MRSA), a
gastroenteritis bug, has been shown to lead to other illness such as UTI (f),
but blackcurrant wins again since scientists have recently shown that it is
extremely effective at killing this bacteria (g). There can be few other fruit
capable of giving such a broad spectrum of benefits!
Ageing & Brain Function: What is ageing? People tend to think that ageing is only
associated with the elderly. However, it's truer to say that ageing begins from
birth. Adopting anti-ageing measures can never start too early. The rate of
ageing is due to a combination of factors: influences from our genes as well as
influences from our lifestyle and the environment. We cannot change our genes,
but we can change our lifestyle by looking at what we eat and what activities
we do. For instance, antioxidants, including those we get from our diet, play
an important role in slowing down the ageing process.
The earliest signs of ageing include wrinkles and grey hair.
Later on, tissues, organs and systems in the body, such as the heart and brain,
stop working as well as they used to. When the brain starts to age, we develop
a poorer memory and have less control over our body movement.
How might fruit help the ageing process? Emerging research
by Dr Ghosh and colleagues at the Horticulture and Food Research Institute of
New Zealand into the protective effect of food components on nerve cells
found that the phenolic components found in blackcurrant out-performed the
corresponding compounds found in other fruit such as blueberry and boysenberry.
Dr Ghosh’s studies suggest that the antioxidant ability of blackcurrant is such
that the anthocyanins and the other components such as the procyanidins not
only protected the nerve cells (neurons) from oxidative stress but also helped
to regenerate the body's own defence systems.
Dr Joseph and his colleagues at Tufts University recently
revealed that feeding older rats with blueberry, strawberry or spinach extracts
significantly improved short-term memory. They also found that blueberry extract
improved the rats' body balance, co-ordination and running speed.
Interestingly, a blackcurrant extract was found to significantly prolong the
life span of 'older, dying' mice.
Dr Joseph's group has been instrumental in many of the studies
focussed on the beneficial effect of fruit-derived polyphenolics with respect
to neural-related disease such as Alzheimer’s, Parkinson’s and Dementia.
Their detailed human cell studies have shown that supplementation with soft
fruit polyphenolics, such as anthocyanins, flavanol, catechins and hycroxy
cinnamic acids, resulted in the prevention of a variety of age-related deficits
including cognitive performance whilst increasing incidences of neurogenesis
(the creation of new nerve cells) and neuroplasticity, the brain's ability to
change with learning.
More recently, model studies were undertaken to look at the
effect that the polyphenolic components within soft fruit, such as blueberry
and boysenberry, had on memory, locomotion and anxiety . Interestingly, the
experiments with a rat model demonstrated that these components showed
significant improvements in short-term memory, one of the symptoms related to
Alzheimer’s disease. Further support as to the ability of the fruit
polyphenolic compounds to reduce oxidative stress and thereby reduce the effect
of associated diseases and pathologies comes from recent studies with
hippocampal cells (believed to play a central role in memory). Compounds
commonly found in blackcurrant, like catechin and anthocyanidins, were found to
exhibit protective effects when the cells were stressed.
Other researchers found that this protection extended to
nerve cells exposed to common products of ageing. Low density lipoproteins
are involved in cholesterol transport in the body but they are susceptible to
oxidation during our normal ageing processes leading to the production of
oxidise LDL (oxLDL). This was shown to enter nerve cells leading to DNA
breakdown and ultimately cell death. However, polyphenolic compounds similar to
those found in blackcurrant exerted a protective effect and reduced
neurodegeneration. Further to that, more detailed, studies by this group under
Prof Rice Evans in King’s College London showed that the procyanidins
(significant components of blackcurrants) and their metabolites inhibit cell
death induced by oxidative stress.
Corroboration of proanthocyanidins as beneficial dietary
components was reflected in the report by Bagchi et al who reported that
these compounds exhibit a broad scale protective effect in many different cell
types. An early patent claimed that blackcurrant juice may have the potential
to prevent neurodegenerative diseases (conditions due to brain ageing or
failing over time) such as Parkinson's disease .
Most of these studies have not been carried out in humans
because we take a long time to age, so laboratory models were used instead.
Whilst these studies give us an early indication of the anti-ageing properties
of blackcurrants and berry anthocyanins, more research in humans is required to
confirm these effects.
Cardiovascular Health: A high intake of fruit and vegetables
has been linked to a reduced risk of heart disease. For example, it is
well-known that the flavonoid-rich diet of the French, who drink a lot of red
wine, is good for you. Blackcurrants are a natural, readily available and rich
source of flavonoids.
How do flavonoids reduce the risk of cardiovascular disease?
Eating foods and drinks that are rich in flavonoids can
benefit the cardiovascular system in a number of ways. Studies have shown that
drinking wine or juices rich in flavonoids helps to improve the function of
your blood vessels. Scientists have also shown that flavonoids can reduce blood
stickiness in both laboratory tests and in humans. This means reducing the
chance of forming small blood clots which can injure the blood vessel lining
and stop them working. As well as stooping blood vessels working properly,
small blood clots release harmful chemicals that can increase the formation of
bad cholesterol (also known as oxidised low density lipoprotein), which sticks
to the blood vessel walls. Eventually, this can lead to a narrowing of the
arteries, which will prevent the blood flowing around the body efficiently and
could lead to increased blood pressure.
What scientific evidence is there?
Laboratory tests have found that flavonoids reduce the rate
at which bad cholesterol is formed. Whilst some volunteer studies have shown
that this occurs in the body after people have consumed wine or juices rich in
flavonoids, not all studies have shown this effect. When a mixture of
blackcurrants, lingonberries and bilberries were eaten by 20 men in Finland,
scientists observed that the rate of bad cholesterol formation was slightly
reduced. In another study, blackcurrant juice helped the function of blood
vessels in rats. A further study has shown improved blood flow in the forearm
after consumption of blackcurrant anthocyanins. This also led to some reduction
in shoulder muscle stiffness after a typing exercise.
Natural Brain Boost : Ground-breaking research reveals that
acute supplementation with blackcurrant extract can help to increase human
cognitive function and performance. What’s more, this new research also
suggests that blackcurrant juice can play an important role in slowing the
cognitive decline associated with ageing and disorders including dementia.
A randomised, double-blind, placebo-controlled, crossover
study was conducted using 36 healthy young participants (18–35 years). The
sample was given blackcurrant juice which was found to boost the ability to
undertake tasks requiring alertness, vigilance and sustained attention.
Findings from the intervention illustrate a cognitive benefit of acute
blackcurrant supplementation in healthy young humans. What’s more, mental
fatigue was found to be reduced in those consuming blackcurrant juices, further
proving that blackcurrants help you to get into the zone.
The new research suggests that the consumption of
blackcurrant juice may well play an important role not only in improving
cognitive performance, but also in slowing the cognitive decline associated
with natural ageing and disorders including dementia.
The Power of Polyphenols
Blackcurrant juice contains berry fruit polyphenols, natural
compounds renowned for playing an important role in reducing the progression of
neurodegenerative and cardiovascular diseases. These incredible polyphenols
have antioxidant properties which help to prevent and reduce the progression of
diabetes, cancer and neurodegenerative and cardiovascular diseases as well as
increasing the healthy bacteria (Bifidobacterium) in the gut. As this new
research has demonstrated, the consumption of berry fruit polyphenols also has
an effect in improving human cognitive performance.
“There has been much research undertaken to identify the
benefits of fruit intake on cognitive performance and their ability to reduce
the extent of cognitive decline and dementia. Generally the data suggests that
berries are the best fruit for this beneficial effect. Here, this new study
with healthy young participants confirms that blackcurrant juice intake is
associated with an increase in ability to perform multiple repetitions of attention
tasks requiring alertness, vigilance, sustained attention, mood and mental
fatigue.” Professor Derek Stewart of the James Hutton Institute in Scotland.
Digestion & Fighting Cancer: Ground-breaking new
research reveals that delicious blackcurrants can help to promote healthy
bacteria in the gut as well as having an ‘anti-tumour’ effect on some cancers.
Anthocyanins are the natural compounds which give blackcurrants
their characteristic colour. New research has demonstrated that these
anthocyanins help to increase levels of healthy bacteria (Bifidobacterium) in
the gut helping to maintain the healthy functioning of the digestive system.
Maintaining a healthy digestive system and reducing gut inflammation is
important for health, weight management and disease prevention. Results from an
April 2016 study testing the anti-cancer activity of blackcurrant polyphenol
extract, demonstrated that blackcurrant extract has an ‘anti-tumour’ effect and
helps to decrease the size of gastric and oesophagus cancers. Additionally, in
terms of fighting cancer, further fresh research has revealed that these
anthocyanins, particularly the purple anthocyanins found in blackcurrants, are
effective and potent at inhibiting tumour cell numbers and increasing cancer
cell death.
Reducing Erectile Dysfunction: Blackcurrants have long been
regarded as a super fruit, commonly renowned for their rich antioxidant content
which has been proven time and again to help keep us healthy. According to new ground-breaking
research, blackcurrants might even be beneficial for our health in ways
previously unexplored: scientists in the US and UK have found that a diet rich
in flavonoids, natural compounds found in fruit and vegetables, could
dramatically reduce the risk of erectile dysfunction.
Erectile dysfunction affects 322m men globally and, as well
as being distressing to the individual, it’s also an early indicator of poor
vascular function, a precursor of cardiovascular disease. Research published
earlier this year has revealed that men who look after themselves, take
physical activity and enjoy a diet rich in flavonoids (naturally occurring
compounds in fruit and vegetables), are less likely to suffer erectile
dysfunction.
The study, led by Professor Aedin Cassidy (University of
East Anglia), assessed flavonoid intake in ~ 25,000 men over a 10 year
period. Of the six main commonly
consumed flavonoids that were examined, three were found to be beneficial;
anthocyanins, flavanones and flavones – and men who regularly consumed foods
high in these flavonoids were 10 per cent less likely to suffer erectile
dysfunction. Blackcurrants contain the highest level of anthocyanins compared
to blueberries, red wine, apples and citrus fruits.
The study highlights that those who take some physical
activity and have a high flavonoid intake have a 21% lower risk than those with
a combined low intake and physical activity. It was also found that overall the
beneficial effects of these higher levels of flavonoid intake equate to two to
five hours of brisk walking.
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