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Potential Health Benefits of Berries

January 2005
Current Nutrition & Food Science 1(1):71-86

Authors:

University of Aberdeen

Fruit and vegetable consumption is inversely related to the incidence of heart disease and several cancers. However, many people in countries in Northern latitudes do not eat the recommended “5-a-day” of fruit and vegetables. For such populations, a potentially important source of fruit may be locally grown soft fruits (eg. raspberries, blackberries, blueberries, blackcurrants). Such berries contain micronutrients such as vitamin C and folic acid which are essential for health. However, berries may have additional health benefits as they are also rich in phytochemicals such as anthocyanins which are glycosidic-linked flavonoids responsible for their red, violet, purple and blue colours. In vitro studies indicate that anthocyanins and other polyphenols in berries have a range of potential anti-cancer and heart disease properties including antioxidant, anti-inflammatory, and cell regulatory effects. Such experimental data has lead to numerous health claims on the internet implying that “berries are edible superstars that may protect against heart disease, cancers and ageing”. However, the bioavailabilty of polyphenols such as anthocyanins would appear to be limited, thus compromising their nutritional relevance. Consequently the aim of the article is to assess the current scientific evidence for claims that berries may have additional health benefits to those normally associated with consuming fruit and vegetables.

Structures of flavonol glycosides.

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Flavonol metabolites detected in human plasma.

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(-)-Epicatechin metabolites that are produced in humans (H) and rats (R).

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Content uploaded by Garry G Duthie

Content may be subject to copyright.

Current Nutrition & Food Science, 2005, 1, 71-86 71

Potential Health Benefits of Berries

Julie Beattie1, Alan Crozier2 and Garry G. Duthie3,*

1Centre for Public Health Nutrition Research, Department of Medicine, University of Dundee, Ninewells Hospital &

Medical School, Dundee DD1 9SY, UK. 2Graham Kerr Building, Division of Biochemistry and Molecular Biology,

Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK. 3Rowett Research Institute,

Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK.

Abstract: Fruit and vegetable consumption is inversely related to the incidence of heart disease and several cancers.

However, many people in countries in Northern latitudes do not eat the recommended “5-a-day” of fruit and vegetables.

For such populations, a potentially important source of fruit may be locally grown soft fruits (eg. raspberries, blackberries,

blueberries, blackcurrants). Such berries contain micronutrients such as vitamin C and folic acid which are essential for

health. However, berries may have additional health benefits as they are also rich in phytochemicals such as anthocyanins

which are glycosidic-linked flavonoids responsible for their red, violet, purple and blue colours. In vitro studies indicate

that anthocyanins and other polyphenols in berries have a range of potential anti-cancer and heart disease properties

including antioxidant, anti-inflammatory, and cell regulatory effects. Such experimental data has lead to numerous health

claims on the internet implying that “berries are edible superstars that may protect against heart disease, cancers and

ageing”. However, the bioavailabilty of polyphenols such as anthocyanins would appear to be limited, thus compromising

their nutritional relevance. Consequently the aim of the article is to assess the current scientific evidence for claims that

berries may have additional health benefits to those normally associated with consuming fruit and vegetables.

Keywords: Berries, soft fruit, micronutrients, anthocyanins, cancer, heart disease.

1. INTRODUCTION

In the United Kingdom ischemic heart disease (31%),

cancer (30%) and stroke (15%) were the principal causes of

death during 2001 [1]. A major contributing factor to the

aetiology of these chronic diseases is a poor diet [2-4]. Diet

in the developed world is a complex mixture of foods with

highly variable consumption patterns. For example, a review

of the “Scottish diet” highlighted poor dietary habits and

recommended reducing intake of cakes and pastries, fats,

sugar and confectionery, while increasing fruit, vegetable

and cereal consumption [5]. However, despite recommenda-

tions to eat an average of 400g of fruit and vegetables per

day, actual daily consumption in Scotland between 1993 and

2000 only rose from 190g to 200g [6]. This is unfortunate as

considerable evidence indicates that adequate fruit and

vegetable consumption has a role in preventing many

chronic diseases, including heart disease, stroke and several

cancers, [3, 7-12], long term consumption also being

associated with decreased premature mortality rates [13].

Reasons why some populations appear reluctant to

increase intakes of fruit and vegetables are complex.

However, the persistence of traditional dietary patterns may

reflect, in part, the historical expense and lack of availability

of fresh fruit and vegetables in Northern latitudes. For such

populations, a potentially important source of plant-based

food may be locally grown soft fruits (e.g. raspberries,

strawberries, blueberries, cranberries and blackcurrants). As

with other fruit and vegetables, berries are important dietary

*Address correspondence to this author at the Rowett Research Institute,

Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK; Tel: (0) 1224

716623; Fax: (0) 1224 716629; E-mail: ggd@rri.sari.ac.uk

sources of fibre and essential vitamins and minerals. They

also contain a vast number of other phytochemicals for

which there are no known deficiency conditions but which

may have marked bioactivities in mammalian cells of

potential health benefit. These include effects on oxidative

damage, detoxification enzymes, the immune system, blood

pressure, platelet aggregation, and anti-inflammatory, anti-

bacterial and anti-viral responses [14]. Compared with most

fruit, berries are unusual in that they are rich in

anthocyanins. These are glycosidic-linked flavonoids

responsible for their red, violet, purple and blue colours.

Therefore the aim of this review is to assess whether there is

a putative role for berries and in particular the anthocyanins

and other phytochemicals they contain, in the prevention of

chronic diseases.

2. SOFT FRUITS (BERRIES AND CURRANTS)

The most commonly consumed berries are strawberries

(Fragaria x ananassa), raspberries (Rubus idaeus),

blackberries (Rubus spp.), blueberries (Vaccinium

corymbosum), black currants (Ribes nigrum) and red currants

(Ribes rubrum). There are also a number of crosses between

raspberries and blackberries available such as the loganberry

(Rubus loganbaccuus). Edible berries have been a part of

man’s diet for centuries. The modern cultivated strawberry,

for example, is a descendent of a woodland variety grown by

the Romans which was then subsequently crossed with

American and Chilean varieties around 1750. Raspberries

have been cultivated in Europe since the Middle Ages and

blackberries may have been eaten since Neolithic times [15].

Despite this historical longevity most types of berries have

never been developed beyond local markets [16], reflecting

in part their susceptibility to decay post-harvesting. A

72 Current Nutrition & Food Science, 2005, Vol. 1, No. 1 Duthie et al.

notable exception is the American cranberry (Vaccinium

macrocarpon) which is exported worldwide both as the berry

and as a juice.

3. ESSENTIAL MICRONUTRIENTS IN BERRIES

As with other fruits, berries contain a range of

micronutrients which are essential for health. In particular,

many types of berries contain a high level of vitamin C

(ascorbic acid), so much so that often only a handful of the

fruit can provide the recommended daily allowance (RDA).

As this vitamin has antioxidant activity, acts as a cofactor in

hydroxylation reactions which are required for collagen

synthesis, has a role in hormone synthesis, the immune

system, iron absorption, platelet aggregation, thrombus

formation and may have a role in preventing heart disease,

osteoporosis and a range of cancers, [17-22] berries are an

obvious dietary source for populations with sub-optimal

vitamin C status. The biological roles of vitamin C are

reviewed in detail in [23].

Berries can also be significant dietary sources of folic

acid, a water soluble B vitamin which as well as being

essential to prevent neural tube defects in new-borne babies

also may play a role in reducing risk of heart disease and

cancer through a range of mechanisms including lowering

homocysteine levels, catalysing nitric oxide formation and

maintaining DNA stability [24, 25]. For a recent review of

the physiology of folate and vitamin B12 in health and

disease, see [26].

4. PHYTOCHEMICALS IN BERRIES

Phytochemicals are not required for normal functioning

of the body and their absence does not result in a deficiency

condition. However, they may have bioactivity in

mammalian cells which could impact on health and disease.

Berries are a rich source of such phytochemicals, in

particular anthocyanins and flavonols. Concentrations in

berries will be influenced by many factors including

environmental conditions, degree of ripeness, cultivar,

cultivation site, processing and storage of the fruit [27-29].

The anthocyanins are conjugated anthocyanidins, which

provide the distinctive and vibrant palate of colours found in

dark berries. There are six anthocyanidins distributed

throughout the plant kingdom; cyanidin, malvidin,

delphinidin, peonidin, petunidin and pelargonidin (Fig. 1).

They form conjugates with a number of sugars, in particular

glucose, sophorose, rutinose, rhamnose, galactose, arabinose

and xylose (Fig. 2). The structures of the main anthocyanins

in berries are summarised in Figure 2 and listed in more

detail along with other phenolics in (Table 1). There is much

variety and while some fruits, such as cranberry (Vaccinium

macrocarpon) and elderberry (Sambucus nigra), contain

derivatives of only one type of anthocyanin (i.e. cyanidin), a

wide array of anthocyanins is found in blueberry (Vaccinium

corymbosum) and blackcurrant (Ribes nigrum). In general

the anthocyanin profile of a tissue is characteristic, and it has

been used in taxonomy, and for the detection of adulteration

of juices and wines. Blackcurrants are characterised by the

presence of the rutinosides and glucosides of delphinidin and

cyanidin [30], with the rutinosides being the most abundant.

Other anthocyanins and flavonol conjugates have been

Anthocyanidin R1R2Colour

Pelargonidin H H orang-red

Cyanidin OH H red

Delphinidin OH OH pink

Peonidin OCH3H bluish purple

Petunidin OCH3OH purple

Malvidin OCH3OCH3redish purple

Fig. (1). Structures of the major anthocyanins

noted, but at much lower concentrations [31, 32]. Whilst

redcurrants (Ribes rubrum) are very closely related to

blackcurrants, they contain mainly cyanidin diglycosides

with cyanidin monoglucosides present only as minor

components [33]. Strawberries (Fragaria x ananassa),

blackberries (Rubus spp.), and red raspberries (Rubus idaeus)

are all from the Rosaceae family but they have a diverse

anthocyanin content. The major anthocyanins in raspberries

and blackberries are derivatives of cyanidin, while in

strawberries pelargonidin glycosides predominate [33]. The

major components in blueberries are delphinidin-3-

galactoside and petunidin-3-glucoside, however, many minor

anthocyanins are also present [34, 33]. Cranberries belong to

the Ericaceae, the same family as blueberries, but have

cyanidin-based compounds as their major anthocyanins [35].

As with cranberries, blackberries and raspberries, the major

anthocyanins in elderberries are cyanidin-based, with

cyanidin-3-sambubioside and cyanidin-3-glucoside predo-

minating [36] (Table 1, Fig. 2).

Flavonols and other flavonoids are commonly quantified

as the aglycone after acid or enzyme hydrolysis to remove

sugar residues [37, 38]. Using this approach the myricetin,

quercetin and kaempferol content (Fig. 3) of edible berries

had been estimated [39]. Quercetin was found to be highest

in bog whortleberry (Vaccinium uliginosum) (15.8 mg/100

g), bilberry (Vaccinium myrtillus) (1.7 – 3.0 mg/100 g) and

in elderberries. In blackcurrant cultivars, myricetin was the

most abundant flavonol (8.9 – 20.3 mg/100 g), followed by

quercetin (7.0 – 12.2 mg/100 g) and kaempferol (0.9 – 2.3

mg/100 g) [40]. In comparison, the total anthocyanin content

of red raspberries is ca. 60mg/100g [41]. Specific flavonol

glycosides that have been identified in berries include

quercetin-3-glucoside, quercetin-3-rutinoside quercetin-3-

galactoside and quercetin-3-xylosylglucuronide, myricetin-3-

glucoside, myricetin-3-galactoside and myricetin-3-

rutinoside (Fig. 4, Table 1) [42-45].

Berries can contain substantial amounts of the flavan-3-ol

monomers (+)-catechin and (-)-epicatechin as well as dimers,

trimers and polymeric proanthocyanidins (Fig. 5). The

Potential Health Benefits of Berries Current Nutrition & Food Science, 2005, Vol. 1, No. 1 73

Fig. (2). Structures of the major anthocyanins in berries.

OHO

CH3

OHO

CH3

OHO

CH3

OHO

CH3

OHO

Cyanidin-3-O-sambubioside

(Elderberry)

Cyanidin-3-O-sophoroside

(Raspberry)

Cyanidin-3-O-(2G-O-xylosylrutinoside)

(Redcurrant, Raspberr y)

Delphinidin-3-O-rutinoside

(Blakcurrant)

Cyanidin-3-O-rutinoside

(Blakcurrant, Blackberry)

Cyani din-3-O-arabinoside

(Cra nberry)

Dephinidin-3-O-galactoside

(Blueberry)

Cyanidin-3-O-gal actoside

(Cra nberry)

Petunidin-3-O-glucoside

(Blueberry)

Pelargo nidin-3-O-glucoside

(Strawberry)

Cyanidin-3-O-g lucoside

(Blac kberry, Strawberr y, Elderb erry)

74 Current Nutrition & Food Science, 2005, Vol. 1, No. 1 Duthie et al.

concentration of the polymers is usually greater than the

monomers, dimers and trimers and overall, cranberries are a

particularly rich source of these compounds [46, 47]

(Table 2).

The hydroxybenzoate, ellagic acid (Fig. 6) has been

reported to be present in berries, particularly raspberries

(0.58 mg/100 g), strawberries (1.8 mg/100 g) and

blackberries (8.8 mg/100 g) [48]. Indeed ellagic acid has

been described as being responsible for > 50% of total

phenolics quantified in strawberries and raspberries [49]. In

reality, however, free ellagic acid levels are generally low,

although substantial quantities are detected along with gallic

acid after acid hydrolysis of extracts as a product of

ellagitannin breakdown (Fig. 6). For instance, red

raspberries, the health benefits of which are often promoted

Table 1. Endogenous Phenolics in Berries. Major Components Indicated in Bold Font

Common name Genus and species Family Phenolics Reference

Blackcurrant Ribes nigrum Grossulariaceae Del-3-Rut; Cy-3-Rut; Del-3-Glc; Cy-3-Glc

Peo-3-Rut, Mal-3-Rut

Mal-3-Rut, Mal-3-Glc, Myr-3-Rut, Myr-3-Glc,

Q-3-Rut, K-3-Glc

Matsumoto et al., 2001a

Frøytlog et al., 1998

Hakkinen and Auriola, 1998

Määttä et al., 2003

Redcurrant Ribes rubrum Grossulariaceae Cy-3-Glc-Rut, Cy-3-Soph, Cy-3-Glc, Cy-3-Xyl-Rut,

Cy-3-Rut Goiffon et al., 1999

Strawberry Fragaria ×

ananassa Rosaceae Pel-3-Glc, Cy-3-Glc, Pel-3-Ara

Ellagic acid Goiffon et al., 1999, Bridle

and Garcia-Viguera, 1997

Amakura et al., 2000

Blackberry Rubus spp. Rosaceae Cy-3-Sop, Cy-3-Glc-Rut, Cy-3-Glc, Cy-3-Rut, Q-3-Gal,

Q-3-Glc, Q-3-Rut, Q-3-XylGlcAC, lambertianin C Hong and Wrolstad, 1990

Cho et al., 2004,

Degénéve 2004

Red raspberry Rubus idaeus Rosaceae Cy-3-Sop, Cy-3-Glc-Rut, Cy-3-Rut, Cy-3-Glc,

Pel-3-Sop, Pel-3-Glc-Rut, Cy-3,5-DiGlc, Cy-3-Samb,

Pel-3-Glc, Pel-3-Rut, sanguiin H-6, lambertianin C, Q-

3-Rut, Q-3-Glc, Q-3-GlcAC

Boyles and Wrolstad, 1993

Mullen et al., 2002

Blueberry Vaccinium

corymbosum Ericaceae Del-3-Gal, Del-3-Glc, Cy-3-Gal, Del-3-Ara,

Cy-3-Glc, Pet-3-Gal, Cy-3-Arab, Pet-3-Glc,

Peo-3-Gal, Pet-3-Arab, Peo-3-Glc, Mal-3-Gal, Peo-3-

Arab, Mal-3-Glc, Mal-3-Arab, caffeoylquinic acids,

Q-3-Gal, Q-3-Glc, Q-3-Rut

Kader et al., 1996;

Goiffon et al., 1999;

Prior et al., 2001,

Cho et al., 2004

Cranberry Vaccinium

macrocarpum Ericaceae Cy-3-Gal, Cy-3-Ara, Cy-3-Gal, Cy-3-Ara, Myr-3-Gal,

Q-3-Gal, Q-3-Rham Huopalahti et al., 2000;

Prior et al., 2001;

Vvedenskaya et al., 2004

Elderberry Sambucus nigra Caprifoliaceae Cy-3-Samb-5-Glc, Cy-3,5-DiGlc,

Cy-3-Samb, Cy-3-Glc Bridle and Garcia-Viguera,

1997

Abbreviations: Cyanidin (Cy); Pelargonidin (Pel); Peonidin (Peo), Petunidin (Pet), Malvidin (Mal), Quercetin (Q), Myricetin (Myr), Kaempferol (K); Glucoside (Glc), Diglucoside

(DiGlc); Sophoroside (Sop); Xyloside (Xyl); Acetylxyloside (XylAc); Arabinoside (Ara); Acetylarabinoside (AraAc); Glucuronide (GlcAC); Xylosylglucuronide (XylGlcAC);

Acetylglucoside (GlcAc); Galactoside (Gal); Rhamnoside (Rham), Rutinoside (Rut); Sambubioside (Samb).

Fig. (3). Structures of the flavonol aglycones kaempferol, quercetin, isorhamnetin and myricetin.

OOH

HO O

OOH

Kaempferol Quercetin Myricetin

Potential Health Benefits of Berries Current Nutrition & Food Science, 2005, Vol. 1, No. 1 75

on the basis of a high ellagic acid content, contain ca. 100

µg/100 g of ellagic acid compared to ca. 30 mg/100g of

ellagitannins, mainly in the form of sanguiin H-6 and

lambertianin C (Fig. 6) [41]. Berries also contain a variety of

hydroxycinnamates including caffeoyl/feruloyl esters but

usually they are present in low concentrations [50] although

in other fruits compounds such as 5-caffeoylquinic acid

(chlorogenic acid) can accumulate in substantial

concentrations.

5. POTENTIAL HEALTH PROPERTIES OF BERRY

PHYTOCHEMICALS

There is a lack of epidemiological studies relating

consumption of berries to disease risk. However, flavonoid

intake and risk of CHD mortality was first investigated using

the 7-Countries Study – a cross-cultural correlation study

composed of 16 cohorts followed-up for 25 years after initial

baseline measurements collected around 1960 [51]. The

average intake of flavonols and flavones combined was

found to be inversely associated with CHD mortality,

statistically explaining 25% of the variability in CHD rates

across the cohorts. There have subsequently been at least 7

epidemiological studies that appear to corroborate Hertog’s

original findings although weak but inverse relationships

between intake and CHD have also been described [14].

Similarly, flavonoid intake has also been associated with

decreased risk of cancer in some but not all studies [52, 53].

Numerous in vitro studies also indicate that plant secondary

metabolites can potentially affect diverse processes in

mammalian cells which, if also occurring in vivo, could have

Fig. (4). Structures of flavonol glycosides.

OHO

OH O

CH3

OHO

OH O

OHO

OH O

OHO

OH O

OHO

OH O

OHO

HO O

HO OH

OHO

OH O

HO OH

Quercetin-3-glucoside Quercetin-3-galactoside Quercetin-3-xyloglucoside

Quercetin-3-rutinoside Myricetin-3-glucoside

Quercetin-3,4'-O-diglucoside Quercetin-4'-O-glucoside

76 Current Nutrition & Food Science, 2005, Vol. 1, No. 1 Duthie et al.

anti-carcinogenic and anti-atherogenic implications. These

processes include gene expression, apoptosis, platelet

aggregation, LDL oxidation, blood vessel dilation, intercellu-

lar signalling, P-glycoprotein activation and the modulation

of enzyme activities associated with carcinogen activation

and detoxification (reviewed in [54]). For example, extracts

of bilberry, rich in delphinidin and malvidin glycosides

induce apoptosis in human leukaemia HL60 cells, the former

also inhibiting the growth of colon cancer HCT116 cells

[55]. Similarly, anthocyanins and hydroxycinnamic acids

from blueberry and cranberry protect endothelial cells

against TNFα induced inflammatory responses [56].

Other flavonols found in fruit including berries, such as

quercetin, have been shown to inhibit cyclooxygenase and

lipoxygenase activities [57]; both enzymes are involved in

the release of arachidonic acid, the initiator of a general

inflammatory response. Quercetin also exerts a preferential

Fig. (5). Structures of the flavan-3-ol monomers (+)-catechin and (-)-epicatechin and oligomeric proanthocyanidins.

Table 2. Concentration of Flavan-3-ol Monomers, Dimers and Trimers and Total Proanthocyanidins in Berries. Data Expressed as

mg/100g Fresh Weight ± Standard Deviation. n.d. – Not Detected; n.a. – Not Analysed; PA – Proanthocyanidins

Berry Monomers Dimers Trimers Total PAs Source

Blackcurrant 0.9 ± 0.2 2.9 ± 0.4 3.0 ± 0.3 122 ± 28 Gu et al., (2004)

Redcurrant 3.2 1.9 n.d. n.a de Pascual-Teresa et al., (2000)

Strawberry 4.2 ± 0.7 6.5 ± 1.3 6.5 ± 1.2 145 ± 25 Gu et al., (2004)

Blackberry 3.7 ± 2.2 6.7 ± 2.9 3.6 ± 1.9 27 ± 17 Gu et al., (2004)

Red raspberry 4.4 ± 3.4 11 ± 10 5.5 ± 5.7 30 ± 23 Gu et al., (2004)

Blueberry 4.0 ± 1.5 7.2 ± 1.8 5.4 ± 1.2 180 ± 51 Gu et al., (2004)

Cranberry 7.3 ± 1.5 26 ± 6.1 70 ± 13 419 ± 75 Gu et al., (2004)

OH O

HO OH

(-)-Epicatechin (+)-Catechin

Oligomeric Procyanidins

n = 0, dimeric

n = 1, trimeric

n = 2, tetrameric

Potential Health Benefits of Berries Current Nutrition & Food Science, 2005, Vol. 1, No. 1 77

cytotoxic effect on dividing colon carcinoma HT29 and

CACO2 cells [58] and induces apoptosis in human

leukaemia HL60 cells following inhibition of growth.

Possible mechanisms of action could include, increased

expression of wild type p53 [59], reduction of Ki ras levels

[60] or p21 upregulation [61]. Quercetin also inhibited DNA

synthesis in human leukaemia HL60 cells [61, 62] and

animal studies indicate that the incidence of carcinogen

induced mammary tumours and lung tumours were

decreased by dietary administration of quercetin [63, 64].

Extensive research has been carried out on the potential anti-

cancer properties of ellagic acid, mediated in a number of

mechanisms [65] such as the inhibition of metabolic

activation of carcinogens [66], protection of DNA from

alkylation by binding sites that may react with carcinogens

[67] and the regulation of cell cycle progression and cell

death (apoptosis) in cancer cells.

Potential cardiovascular protective effects of

ellagitannins have also been reported as vasorelaxation assays

on rabbit aorta found that sanguin H-6 and lambertianin C,

were the active components of raspberry extracts responsible

for vasorelaxation activity [68]. The flavonols quercetin and

catechin were found to act synergistically to inhibit platelet

aggregation and adhesion to collagen [69], atherosclerotic

Fig. (6). Raspberries contain high concentrations of two ellagitannins, sanguiin H-6 and lambertianin C. When extracts are treated with acid

the ellagitannins are hydrolysed releasing substantial quantities of ellagic acid.

C OCO

HO OH

C O

HO OH

C OCO

OH OH

C OCO

OH OH

C O

OH OH

OOH

HO O

Sanguiin H-6

Lambertianin C

Ellagic acid

78 Current Nutrition & Food Science, 2005, Vol. 1, No. 1 Duthie et al.

lesions being reduced by 46% in apolipoprotein E deficient

mice when added to the diet [70].

Much attention has focussed on the ability of compounds

such as anthocyanins and flavonols to act as antioxidants.

This is possibly unsurprising as there is a substantial body of

epidemiological and experimental literature suggesting that

inadequate intakes of recognised nutritional antioxidants

such as vitamin E, vitamin C and carotenoids can lead to

oxidative damage of proteins, lipids and DNA in vivo. This,

in turn, may predispose the development of many chronic

diseases [71]. The antioxidant effectiveness of anthocyanins

and other polyphenols in vitro is essentially due to the ease

with which a hydrogen atom from an aromatic hydroxyl

group is donated to a free radical [72]. In addition, their

ability to chelate transition metal ions involved in radical-

forming processes such as Fenton reactions [73, 74] and the

induction of endogenous antioxidants [75] could also

contribute to antioxidant efficacy of the compounds.

Consequently, numerous studies have shown that many

phenolic compounds found in fruits and vegetables,

including berries, inhibit the oxidation of LDL and DNA in

vitro e.g. [76, 77].

6. ABSORPTION OF BERRY PHYTOCHEMICALS

Although phytochemicals found in berries may exert

numerous effects in vitro, they have to be absorbed from the

gut if they are to exert a similar effect in systemic cells and

tissues. This absorption will depend on numerous factors

including molecular structure, the amount consumed, the

food matrix, degree of bioconversion in the gut and tissues,

the nutrient status of the host and genetic factors. Ingestion

of fresh strawberries (240g), freeze dried blueberries (100g)

and berry juices have all been reported to increase the

antioxidant capacity of blood plasma by 14-30%. [78, 79]

[80-82] which suggests that some phytochemicals with

antioxidant properties are absorbed [83, 84]. However, this

view has recently been challenged as any change in plasma

antioxidant capacity after fruit consumption may be mainly

due to fructose mediated increases in uric acid rather than

fruit-derived antioxidants [85]. This is compatible with the

observation that the absorbtion of anthocyanins and other

flavonoids from the diet is relatively low.

Anthocyanins

A variety of anthocyanins appear in urine after

supplementation with berries or berry extracts but in very

low concentrations, usually 0.1%, or less, of the ingested

dose [86]. Anthocyanins have also been found in human

plasma in very low concentrations 0.5-1 h after consumption,

falling to near baseline levels within 6-8 h. After the

consumption of an elderberry extract by elderly women, the

main elderberry anthocyanins, cyanidin-3-glucoside and

cyanidin-3-sambubioside, were detected in plasma. [87].

Thus, glycosylated anthocyanins, unlike flavonol glycosides,

appear in the bloodstream. This may be a consequence of the

fact that, in contrast to quercetin glucosides, anthocyanin

glucosides are not hydrolysed by human small intestine β-

glucosidases [88]. Studies with rats indicate that anthocyanin

absorption occurs in the stomach as well as the small

intestine [89-91].

Although only unmodified anthocyanins have been

usually detected in urine after supplementation [86],

improved analytical techniques are now beginning to reveal

the presence of lower levels of methylated, glucuronidated

and sulphated metabolites. For instance after consumption of

elderberries, as well as cyanidin-3-glucoside and cyanidin-3-

sambubioside, urine was found to contain four metabolites,

peonidin-3-glucoside, peonidin-3-sambubioside, a peonidin

glucuronide and a cyanidin-3-glucosylglucuronide. This

demonstrates that methylation of the 3'-hydroxyl group had

occurred as well as glucuronidation at an as yet undetermi-

ned position (Fig. 8) [92]. In a study with strawberries,

which contain pelargonidin-3-glucoside, the predominant

anthocyanin to appear in urine was not the parent glucoside

but three pelargonidin glucuronides, a pelargonidin sulphate

and the aglycone pelargonidin [93].

Flavonols

The absorption and excretion of flavonols in humans and

model animal systems has been studied extensively.

Although these investigations have not involved berries,

flavonols that occur in berries such as quercetin-3-glucoside

and the disaccharide quercetin-3-rutinoside (Fig. 5) have

been extensively investigated. Flavonol aglycones, such as

quercetin (Fig. 3) are hydrophilic and can passively diffuse

across biological membranes. Flavonol glycosides, in

contrast, are more water-soluble molecules which greatly

limits their rate of diffusion through cell membranes. Thus, if

the glycosides, which occur in berries and are the major

components in other fruits and vegetables, are to be absorbed

into the circulatory system some form of transport system is

likely to be involved. On the basis of indirect evidence it has

been proposed that flavonol glucosides, such as quercetin-3-

glucoside, can be absorbed intact into the small intestine

using the sodium-dependent glucose transporter (SGLT1)

[94]. There is evidence that supports the involvement of

SGLT1 in the uptake of flavonol glucosides [95] [96].

However, other studies with human intestinal Caco-2 cell

monolayers have shown that quercetin-4'-glucoside is not

absorbed despite the operation of SGLT1 which was

demonstrated by the active transport of glucose [97]. Further

research is required to determine the mechanism(s) by which

flavonols and other flavonoids are transported from the

lumen of the gastrointestinal (GI) tract into the bloodstream.

Studies with human volunteers have been carried out

following consumption of lightly fried onions, which contain

especially high concentrations of flavonol conjugates, princi-

pally quercetin-4'-glucoside and quercetin-3,4'-diglucoside

(Fig. 4). Aziz et al. (1998) [98] reported that following

ingestion of 300g of lightly fried onions by human volunteers,

conjugatedquercetin (quercetin released by acid hydrolysis,

therefore probably originating from quercetin glucuronide

and sulphate metabolites – see below) appeared in plasma. A

peak plasma concentration of almost 2 µM was reached after

1 h and levels declined ca. 3-fold over the next 4 hours and

only trace quantities remained at 24 hours (Fig. 10A).

Subsequently Day et al. (2001) [99] used HPLC with MS

and diode array detection to analyse human plasma collected

1.5 h after ingestion of onions. A mixture of glucuronidated

and sulphated conjugates of quercetin and methylquercetin

were identified. In total 12 quercetin conjugates were

Potential Health Benefits of Berries Current Nutrition & Food Science, 2005, Vol. 1, No. 1 79

detected, the major components being quercetin-3-O-

glucuronide, its 3'-methylated derivative, isorhamnetin-3-

glucuronide, a quercetin diglucuronide and quercetin-3'-

sulphate (Fig. 7). There was, therefore, extensive metabolism

of the parent flavonol glucosides involving deglycosylation,

glucuronidation, sulphation and methylation. In a further

study a total of twenty three flavonol metabolites,

comprising a mixed range of sulphate, methyl, glucuronide

and glucoside derivatives of quercetin, were detected in

plasma and urine after the consumption of onions [100].

Quercetin glucosides are deglycosylated by β-

glucosidases in the small intestine, namely broad specific

cytosolic β-glucosidase (CBG) and lactase phloridzin

hydrolase (LPH) [101]. The aglycone does not accumulate

but is metabolised by uridine-5'-diphosphate glucuronyl-

transferases, sulphotransferases and/or catechol-O-

methyltransferases [102]. Studies with rats following

ingestion of [2-14C]quercetin-4'-glucoside indicate that as

well as transport in the bloodstream there is a substantial

efflux of the various quercetin metabolites back into the

lumen of the GI tract [103]. Quercetin metabolites which do

enter the circulatory system and gain access to the liver may

then be further methylated, glucuronidated or sulphated

[102]. Although there is evidence that enterohepatic

circulation returns quercetin metabolites to small intestine,

the extent to which this occurs is as yet unknown. The

disaccharide, quercetin-3-rutinoside, which is found in

berries, as well as apples and tea, is not a substrate for either

LPH or CBG. In addition, it has a lower and delayed peak

plasma concentration than quercetin-4'-glucoside [104]

indicating that it may be absorbed in the distal section of the

small intestine and/or the large intestine where it is probably

degraded by colonic bacteria [88].

Flavan-3-ols

Monomeric flavan-3-ols as well as dimers, trimers and

oligomers are present in berries (Table 2) but information on

the absorption and metabolism of these compounds comes

primarily from studies with (-)-epicatechin, (+)-catechin,

procyanidin-rich chocolate and grape seed extracts. (-)-

Epicatechin and (+)-catechin are absorbed in humans and

animals appearing in plasma and urine primarily as

glucuronidated, methylated and sulphated metabolites [105]

[106-110]. Peak plasma concentrations typically occur 1-2 h

after ingestion. Identified human plasma and urinary

metabolites include (-)-epicatechin-3'-glucuronide, 4'-methyl-

(-)-epicatechin-3'-glucuronide while in rats formation of 3'-

methyl-(-)-epicatechin, (-)-epicatechin-7-glucuronide, 3'-

methyl-(-)-epicatechin-7-glucuronide occurs (Fig. 9) [111].

There is conflicting evidence on the absorption and

metabolism of the oligomeric and polymeric flavan-3-ols in

humans and animals. Koga et al. (1999) [112] observed the

presence of (+)-catechin and (-)-epicatechin and an absence

of dimers in the plasma of rats following ingestion of a grape

seed extract. Extending this study, Donovan et al. (2002)

[113] fed rats a GSE, (+) catechin and procyanidin B3 meals.

While conjugated metabolites of (+)-catechin were detected

in plasma and urine after both the (+)-catechin and GSE

meals there was no evidence of absorption for the

procyanidins. However, in another study (-)-epicatechin and

(+)-catechin and trace amounts of procyanidin dimer B2 were

detected in sulfatase- and β-glucuronidase-treated human

plasma collected 30 min after ingestion of a cocoa beverage

rich in flavan-3-ol monomers and procyanidins [114]. In

keeping with this report, it has been shown that after oral

administration of B2 to rats, the dimer was absorbed and

excreted in urine with a portion of the procyanidin being

converted to (-)-epicatechin which undergoes post-ingestion

conjugation and methylation [109]. On balance, however, the

available evidence indicates that flavan-3-ol dimers, trimers

and oligomers are, at best, poorly absorbed [115].

Sanguiin H-6 and lambertianin C (Fig. 6) occur in high

concentrations in raspberries [68] and both blackberries and

Fig. (7). Flavonol metabolites detected in human plasma.

HO O

HO OH

COOH

OCH3

HO O

HO OH

COOH

OSO3

HO O

HO OH

COOH

HO O

HO OH

COOH

OCH3

HO O

HO OH

COOH

Quercetin-3-glucuronide Isorhamnetin-3-glucuronide Quercetin-3'-sulphate

Quercetin-3'-O-glucuronide Quercetin-4'-O-glucuronide Isorhamnetin-4'-O-glucuronide

80 Current Nutrition & Food Science, 2005, Vol. 1, No. 1 Duthie et al.

strawberries also contain substantial amounts of ellagitannins

[116]. These compounds which have a molecular weight in

excess of 1000 Da would appear to be too large to be

absorbed into the circulatory system. They are, however,

strong antioxidants [103] [116] and could exert protective

effects as they pass through the GI-tract. In addition, they

could also be depolymerised to some degree releasing gallic

acid and ellagic acid which would be absorbed more readily.

7. BIOAVAILABILITY OF BERRY PHENOLICS

In addition to absorption, the activity of phytochemicals

in vivo will also depend on the extent and manner of their

metabolism by liver and kidney, their rate of excretion and

the degree they are sequestered in body tissues. However,

generally the bioavailability of dietary flavonoids has been

difficult to assess. Quantitative analysis of quercetin in acid

hydrolysed urine collected over a 24 h period after ingestion

of onions accounted for 0.8% of the amount ingested and

extrapolations from the amounts present in the bloodstream

at peak plasma concentration also yielded a figure of 0.97%

(Fig. 10A) [98]. However, studies with ileostomy volunteers

in which ileal fluid was analysed after ingestion of onions

indicate that 50-75% of the onion flavonol glucosides are

absorbed [94] [117]. To what extent and in what form the

“missing” flavonols are bioavailable and sequestered in body

tissues remains to be determined.

Dietary phenolics and their metabolites which are not

absorbed in the small intestine pass into the large intestine

and there is currently much interest in their possible

catabolism by colonic bacteria resulting in ring fission and

the formation of low molecular weight catabolites such as

hippuric acid, benzoic acid and hydroxyphenylacetic acids

[118]. Some of these acidic urinary catabolites are also

products of other metabolic pathways unrelated to either

flavonoid or hydroxycinnamate breakdown and they are

present in substantial quantities in urine before

supplementation. The assumption that relatively minor

changes in the levels of these compounds are a direct

consequence of the breakdown of the ingested phenolic

compound is somewhat premature especially when, in the

absence of studies using isotopically labelled substrates,

detailed catabolic pathways are proposed [119-121].

Anthocyanins appear in plasma and are excreted in urine

in far smaller concentrations than flavonols. This is evident

in Figure 10 where the peak plasma concentration of the

cyanidin-3-glucoside and cyanidin-3-sambubioside was ca.

100 nM which is ca. 20-fold lower than the conjugated

quercetin that accumulated in plasma after eating onions.

Fig. (8). Elderberrries contain cyanidin-3-glucoside and cyandidn-3-sambubioside which are converted to a number of metabolites including

peonidin-3-glucoside and peonidin-3-sambubioside prior to excretion in urine.

HO OH

HO O

HO OH

OCH3

HO OH

OCH3

HO O

HO OH

Cyanidin-3-glucoside

Cyanidin-3-sambubioside

Peonidin-3-glucoside

Peonidin-3-sambubioside

Potential Health Benefits of Berries Current Nutrition & Food Science, 2005, Vol. 1, No. 1 81

Conjugated quercetin excreted after eating onions

corresponded to 0.98% of the amount ingested [98] while

figures for anthocyanins are typically 0.1% or less [86] with

one exception, the urinary excretion of anthocyanins from

strawberries which corresponded to 1.8% of the amount

consumed [93]. This was accredited to analysing the urine

immediately after collection as opposed to after storage of

frozen samples. However, studies with urine collected after

dosing with raspberries have failed to detect any differences

in the anthocyanin content of fresh or thawed frozen urine

with the recovery in both instances being ca. 0.1% (Borges

and Crozier, unpublished). The higher urinary recovery of

anthocyanins occurring after the ingestion of strawberries

may, therefore, be a special feature of pelargonidin-3-

glucoside.

It is unclear why plasma and urinary levels of

anthocyanins are usually much lower than those of flavonols

after supplementation. There are two possible factors that

may have an influence on absorption. As mentioned earlier,

anthocyanins are not hydrolysed by GI tract β-glucosidases

[88] and this may reduce the amounts that pass through the

gut wall into the bloodstream. However, a recent study in

which anthocyanin absorption was investigated after in situ

perfusion of the jejunum + ileum found that absorption

ranged from 10.7% for malvidin-3-glucoside to 22.4 % for

cyanidin-3-glucoside [90]. This is much higher than indirect

estimates of anthocyanin absorption based on either plasma

content or urinary excretion levels. A further factor to

consider, in addition to catabolism to hydroxyphenylacetic

acids and related compounds, is that at low pH anthocyanins

exist as flavylium cations but can undergo pH-dependent

structural changes [122]. They will be at ca. pH 6 in the GI

tract, the circulatory system and body tissues so there may be

conversion to other forms such as chalcones which are not so

readily detected as the red coloured flavylium ion.

Fig. (9). (-)-Epicatechin metabolites that are produced in humans (H) and rats (R).

Fig. (10). Pharmacokinetics of (A) conjugated quercetin levels in plasma after the consumption of onions by human volunteers (n = 5) (Aziz

et al. 1998) and (B) cyanidin-3-O-glycosides after the ingestion of an elderberry extract by elderly women (n = 4) (Cao et al. 2001). Data

presented as mean values ± standard error.

HO OH

COOH

OCH3

HO OH

COOH

HO OH

HOOC

OCH3

HO OH

HOOC

(-)-Epicatechin-3'-glucoronide (H) 4'-Methyl-(-)-epicatechin-3'-glucuronide (H)

(-)-Epicatechin-7'-glucuronide (R) 3'-O-Methyl-(-)-epicatechin (R) 3'-Methyl-(-)-epicatechin-7-glucoronide (R)

82 Current Nutrition & Food Science, 2005, Vol. 1, No. 1 Duthie et al.

Flavan-3-ol monomers appear to be efficiently absorbed

into the bloodstream as Donovan et al. (2002) [113] fed rats

a single 20 mg (+)-catechin supplement and observed that

urinary excretion of (+)-catechin metabolites over a 24 h

period corresponded to 37% of the ingested dose. This is

much higher than equivalent figures obtained with flavonols

and anthocyanins and indicates that flavan-3-ol monomers

are efficiently absorbed from the GI-tract into the circulatory

system.

Although the term bioavailability is used freely in the

literature, information is only beginning to emerge on the

levels and identity of phenolic compounds and their in vivo

metabolites that appear in the circulatory system after

ingestion of berries and other fruits and vegetables.

Saturation of metabolic pathways by “pharmacological”

doses appear to be required to obtain the free form in the

blood [123]. Ingestion of nutritionally relevant amounts

results in extensive deglycosylation, glucuronidation,

sulphation and methylation reactions mediated by a range of

enzymes in the small intestine, liver and colon. The extent

and identity of these in vivo metabolites that accumulate in

body tissues is very poorly understood although information

is beginning to be obtained from feeding radiolabelled

flavonoids to model animal systems [103]. It is, however,

clear that in most instances once flavonoids and other

phenolics enter the circulatory system they undergo

extensive metabolism. Thus, if physiological studies, with

cell cultures and in vitro test systems, investigating potential

protective effects are to be of any relevance they should be

making use of genuine in vivo metabolites, like quercetin-3-

glucuronide and quercetin-3'-sulphate, and not aglycones or

glycosides which do not accumulate in the body [124]. This

should be borne in mind in relation to the following section

on possible health benefits of consuming berries.

8. STUDIES SUGGESTING HEALTH BENEFITS OF

BERRIES

8.1. Cancer

Cancer development is commonly recognised as a

microevolutionary process that requires the cumulative

action of multiple events. (1) initiation: induction of DNA

mutation in a somatic cell, (2) promotion: stimulation of

tumourigenic expansion of the cell clone, (3) progression:

malignant conversion of the tumour into cancer [125]. In

vitro studies suggest that certain berry extracts can moderate

such processes in particular by inhibiting the growth and

proliferation of cancer cells, inducing cell death [126], [55]

and impairing angiogenesis through inhibition of expression

of vascular endothelial growth factor VEGF [127]. Results

from animal models, however, are equivocal. For example,

inclusion of freeze dried black raspberries and strawberries

[128] in the diets of rats given a tumour initiator resulted in

decreased progression, incidence and multiplicity of

oesophageal tumours. However, similar effects were not

observed with blueberries [129]. A human intervention study

did find that after 5 weeks consumption of berry juice

(aronia, blueberry and boysenberry), there was a decrease in

oxidised DNA bases in peripheral blood mononuclear cells

[81] although whether this implies a decrease in risk of

developing cancer is uncertain.

8.2 Heart Disease

Uptake of oxidised low density lipoprotein cholesterol by

monocytes and macrophages in the vascular endothelium

may be a key event in the development of the plaque which

occludes the coronary arteries [130, 131]. Although in vitro

studies have shown that extracts from blackberry, cherry,

raspberry, blueberry and bilberry can inhibit LDL oxidation

[132, 133], results from intervention studies have been

disappointing. For example, no significant inhibition of LDL

oxidation was observed after volunteers had consumed 100g

of berries per day (blackcurrants, bilberries and

lingonberries) for 8 weeks [134]. Similarly, consumption of

berry juice did not affect plasma lipids, LDL oxidation,

platelet aggregation and adhesion molecule concentration in

a healthy population [135].

8.3. Immune System

Consumption of 330ml berry juice per day for 2 weeks is

reported to increase lymphocyte responsiveness to mitogen

activation, enhanced natural killer cell lytic activity and T-

lymphocyte specific cytokine secretion by human volunteers

suggesting enhanced immune function [81]. Whether such

potentially beneficial effects are specific to berries or reflect

a more general response to increased fruit intake is unclear.

8.4. Neurological Function

Diet may play a role in improving age-related

neurological dysfunction [136] and studies with aged rats

have reported that dietary berry extracts can protect against

and even reverse certain age-induced declines in brain

function such as those in learning, memory, motor

performance and neuronal signal transduction [137, 138],

[139, 140].

8.5. Urinary Tract Health

The effects of cranberries on urinary tract health have

been widely investigated since the 1920’s. It was previously

thought that acidification of the urine as a result of

consuming cranberries was responsible for the ameliorative

effects on urinary tract infections (UTI). However

cranberries contain proanthocyanidins which appear to

prevent adherence of p-fimbriated E.coli to the uroepithelial

cells [141], [142]. Other types of berries may have similar

properties e.g. the blueberry, which is also a Vaccinium

species. Several clinical trials of cranberry juice and

cranberry tablets have been published. Although a Cochrane

review [143], [144] found insufficient evidence to

recommend cranberry juice for treatment or prevention of

UTI, there are now more trials suggesting that cranberry

juice or tablets do have some protective effect [145]. For

example, women who consumed 50ml of a cranberry-

lingonberry concentrate for 6 months had a UTI recurrence

rate of 16% compared with 36% in the control group [146]

and Stothers (2002) [147] found absolute risk reductions of

12% for cranberry juice and 14% for cranberry juice tablets

for recurrence of UTI.

9. EFFECTS OF FOOD PROCESSING ON BERRIES

Advances in horticultural techniques and international

trade means it is often possible to obtain fresh berries out of

the traditional summer and autumn seasons. However,

Potential Health Benefits of Berries Current Nutrition & Food Science, 2005, Vol. 1, No. 1 83

berries generally have a short shelf life and as a result, they

are often preserved before eating. In addition, they are

widely used in juices, wines, liquors, jam, ice-cream yoghurt

and confectionery. Therefore, the effects of processing and

storage methods on micronutrient and phytochemicals

content needs to be considered when assessing potential

health benefits.

In general, vitamin C content of berries declines during

storage by up to 56% depending on duration and

temperature. However, concentrations of other phenolics

such as anthocyanins and ellagic acid remain relatively

unchanged and ellagitannin levels may actually increase

possibly indicating some endogenous metabolism post-

harvest [41, 148, 149]. However, losses in vitamin C (36%)

and flavonols (6-50%) have been reported during jam-

making and subsequent storage [29, 150-152]. In contrast,

concentrations of free ellagic acid initially increase after

manufacture due to thermal decomposition of the

ellagitannins in the berries [150]). Large losses in flavonols

and vitamin C may also occur during the manufacture of

berry juices although cold pressing methods may be less

destructive than those involving steam extractions [29].

10. CONCLUSIONS

Berries are rich sources of essential micronutrients,

particularly vitamin C and folic acid. They also contain

numerous phytochemicals. These have diverse effects in

vitro which suggest potential health benefits. However, until

more is known about the absorption and metabolic fate of

berry anthocyanins and flavonols in vivo, it would be unwise

to ascribe additional health promoting properties to berries

beyond those recognized for fruit and vegetables in general.

However, in populations with habitually low intakes of

plant-based foods, locally grown fresh or frozen berries are

an underused and potentially valuable dietary resource.

ACKNOWLEDGEMENTS

Julie Beattie was funded by the Scottish Executive

Health Department and the Scottish Executive

Environmental and Rural Affairs Department (SEERAD).

Garry Duthie is also grateful to SEERAD for financial

support.

REFERENCES

[1] National Statistics, 2004. National Statistics Online. Last updated:

9th September 2004, accessed on 11 September 2004. Available

from http: //www.statistics.gov.uk/

[2] Doll R, Peto R. The causes of cancer: quantitative estimates of

avoidable risks of cancer in the United States today. Journal of the

National Cancer Institute 1981; 66(6): 1191-1308.

[3] WCRF. Food nutrition and the prevention on cancer - a global

perspective; 1997.

[4] Joint WHO/FAO Expert Consultation. Diet, Nutrition and the

Prevention of Chronic Diseases. Geneva; 2003.

[5] The Scottish Office Department of Health. Scotland's Health A

Challenge To Us All: The Scottish Diet. Edinburgh: HMSO; 1993.

[6] MAFF. The National Food Survey 1999. London: HMSO; 2000.

[7] Ness A, R., Powles JW. Fruit and vegetables, and cardiovascular

disease : A review. International Journal of Epidemiology 1997;

26(1): 1-13.

[8] Joshipura KJ, Ascherio A, Mansun J, et al. Fruit and vegetable

intake in relation to risk of ischaemic stroke. Journal of the

American Medical Association 1999; 282(13): 1233-1239.

[9] Johnsen SP, Overvad K, Stripp C, Tjonneland A, Husted SE,

Sorensen HT. Intake of fruit and vegetables and the risk of

ischaemic stroke in a cohort of Danish men and women. American

Journal of Clinical Nutrition 2003; 78: 57-64.

[10] Appel LJ, Moore TJ, Obarzanek E, et al. A clinical trial of the

effects of dietary patterns on blood pressure. New England Journal

of Medicine 1997; 336: 1117-1124.

[11] Block G, Patterson B, Subar A. Fruit, vegetables and cancer

prevention: a review of the epidemiological evidence. Nutrition and

Cancer 1992; 18(1): 1-29.

[12] Hertog MG, Bueno de Mesquita HB, Fehily A, Sweetnam PM,

Elwood PC, Kromhout D. Fruit and vegetable consumption and

cancer mortality in the Caerphilly study. Cancer Epidemiology

Biomarkers and Prevention 1996; 5(9): 673-677.

[13] Rissanen TH, Voutilainen S, Virtanen JK, et al. Low intake of

fruits, berries and vegetables is associated with excess mortaility in

men: the Kuopio Ischaemic Heart Disease Risk Factor (KIHD)

Study. Journal of Nutrition 2003; 133(1): 199-204.

[14] Duthie GG, Gardner PT, Kyle JA. Plant polyphenols: Are they the

new magic bullet? Proceedings of the Nutrition Society 2003;

62(3): 599-603.

[15] Saltmarch M, Crozier A, Ratcliffe B. Fruit and Vegetables. In:

Goldberg G, editor. Plants: Diet and Health. Oxford: British

Nutrition Foundation / Blackwell Publishing; 2003. p. 107-133.

[16] Finn CE. Temperate berry crops. In: Janick J, editor. Perspectives

on new crops and new uses. Alexandria, VA: ASHA Press; 1999. p.

324-334.

[17] Davey MW, VanMontagu M, Inze D, et al. Plant L-ascorbic acid:

chemistry, function, metabolism, bioavailability and effects of

processing. Journal of the Science of Food and Agriculture 2000;

80: 825-860.

[18] Khaw KT, Bingham S, Welch A, et al. Relation between plasma

ascorbic acid and mortaility in men and women in EPIC-Norfolk

prospective study: a prospective population study. The Lancet

2001; 357: 657-663.

[19] Jacobs EJ, Connell CJ, Patel Av, et al. Vitamin C and vitamin E

supplement use and colorectal cancer mortality in a large American

Cancer Society cohort. Cancer Epidemiology Biomarkers and

Prevention 2001; 10(1): 17-23.

[20] Jacobs EJ, Henion AK, Briggs PJ, et al. Vitamin C and vitamin E

supplement use and bladder cancer mortality in a large cohort of US

men and women. American Journal of Epidemiology 2002;

156(11): 1002-1010.

[21] Enstrom JE, Kanim LE, Klein MA. Vitamin C intake and mortality

among sample of the united states population. Epidemiology 1992;

3(3): 194-202.

[22] Byers T, Guerrero N. Epidemiological evicence for vitamin C and

vitamin E in cancer prevention. American Journal of Clinical

Nutrition 1995; 62: S1385.

[23] Thurnham DI, Bender DA, Scott JA, Halstead CH. Water Soluble

Vitamins. In: Garrow JR, James WPT, Ralph A, editors. Human

Nutrition and Dietetics. London: Churchill Livingston; 2000. p.

249-288.

[24] Verhaar MC, Stroes E, Rabelink TJ. Folates and cardiovascular

disease. Arteriosclerosis Thrombosis and Vascular Biology 2002;

22(1): 6-13.

[25] Key TJA, Allen NE, Spencer EA, Travis RC. The effect of diet on

risk of cancer. The Lancet 2002; 360: 861-868.

[26] Scott JA. Folate. In: Garrow JR, James WPT, Ralph A, editors.

Human Nutrition and Dietetics. London: Churchill Livingstone;

2000. p. 271-276.

[27] Hakkinen SH, Torronen AR. Content of flavonols and selected

phenolic acids in strawberries and vaccinium species: influence of

cultivar, cultivation site and technique. Food Research International

2000a; 33: 517-524.

[28] Boyles MJ, Wrolstad RE. Anthocyanin composition of red

raspberry juice: Influences of cultivar processing and environmental

factors. Journal of Food Science 1993; 58(5): 1135-1141.

[29] Hakkinen SH, Karenlampi SO, Mykkanen HM, Torronen AR.

Influence of domestic processing and storage on flavonol contents

in berries. Journal of Agricultural and Food Chemistry 2000; 48:

2960-2965.

[30] Matsumoto H, Hanamura S, Kawakami T, Sato Y, Hirayama M.

Preparative-scale isolation of four anthocyanin components of

blackcurrant (Ribes nigrum L.) fruits. Journal of Agricultural and

Food Chemistry 2001; 49(3): 1454-1545.

[31] Froytlog C, Slimestad R, Andersen OM. Combination of

chromatographic techniques for the preparative isolation of

84 Current Nutrition & Food Science, 2005, Vol. 1, No. 1 Duthie et al.

anthocyanins - applied on blackcurrant (Ribes nigrum) fruits.

Journal of Chromatography A 1998; 825: 89-95.

[32] Hakkinen SH, Auriola S. High performance liquid chromatography

with electrospray ionisation mass spectrometry and diode array

detection in the identification of flavonol aglycones and glycosides

in berries. Journal of Chromatography A 1998; 829: 91-100.

[33] Goiffon J-P, Mouly PP, Gaydou EM. Anthocyanin pigment

determination in red fruit juices, concentrated juices and syrups

using liquid chromatography. Analytica Chimica Acta 1999; 382:

39-50.

[34] Kader F, Rovel B, Girardin M, Metche M. Fractionation and

identification of the phenolic compounds of highbush blueberries

(Vaccinium corymbosum, L.). Food Chemistry 1996; 55: 35-40.

[35] Huopalahti R, Jarvvenpaa E, Katina K. A novel solid phase HPLC

method for the analysis of anthocyanin and organic acid

composition of Finnish cranberry. Journal of Liquid

Chromatography and Related Technologies 2000; 23: 2695-2701.

[36] Bridle P, Garcia-Viguera C. Analysis of anthocyanins in

strawberries and elderberries. A comparison of capillary zone

electropheresis and HPLC. Food Chemistry 1997; 59: 299-304.

[37] Hertog MGL, Hollman PCH, Venema DP. Optimization of

quantative HPLC determination of potentially anticarcinogenic

flavonoids in fruit and vegetables. Journal of Agricultural and Food

Chemistry 1992; 40: 1591-1598.

[38] Hertog MGL, Hollman PCH, Katain MB. Content of potentially

anticarcinogenic flavonoids of 28 vegetables and 9 fruits commonly

consumed in The Netherlands. Journal of Agricultural and Food

Chemistry 1992; 40: 2379-2383.

[39] Hakkinen SH, Heinonen IM, Karenlampi SO, Mykkanen HM,

Ruuskanen J, Torronen AR. Screening of selected flavonoids and

phenolic acids in 19 berries. Food Research International 1999; 32:

345-353.

[40] Mikkonen TP, Maatta KR, Hukkanen AT, et al. Flavonol content

varies among black currant cultivars. Journal of Agricultural and

Food Chemistry 2001; 49: 3274-3277.

[41] Mullen W, Stewart AJ, Lean MEJ, Gardner P, Duthie GG, Crozier

A. Effect of freezing and storage on the phenolics, ellagitannins,

flavonoids and antioxidant capacity of red raspberries. Journal of

Agricultural and Food Chemistry 2002; 50: 5197-5201.

[42] Maatta KR, Kamal-Eldin A, Torronen AR. High performance liquid

chromatography (HPLC) analysis of phenolic compounds in berries

with diode array and electrospray ionisation mass spectrometric

(MS) detection: Ribes species. Journal of Agricultural and Food

Chemistry 2003; 51: 6736-6744.

[43] Mullen W, Yokota T, Lean MEJ, Crozier A. Analysis of

ellagitannins and conjugates of ellagic acid and quercetin in

raspberry fruit by LC-MS. Phytochemistry 2003; 64: 617-624.

[44] Cho MJ, Howard LR, Prior RL, Clark JR. Flavonoid glycosides and

antioxidant capacity of various blackberry, blueberry and red grape

genotypes determined by high-performance liquid chromatography/

mass spectrometry. Journal of the Science of Food and Agriculture

2004; 84: 1771-1782.

[45] Vvedenskaya IO, Rosen RT, Guido J E, Russell DJ, Mills KA,

Vorsa N. Characterisation of flavonols in cranberry (Vaccinium

macrocarpon) powder. Journal of Agricultural and Food Chemistry

2004; 52: 188-195.

[46] Pascual-Teresa de S, Santos-Buelga C, Rivas-Gonzalo JC.

Quantitative analysis of flavan-3-ols in Spanish foodstuffs and

beverages. Journal of Agricultural and Food Chemistry 2000; 48:

5331-5337.

[47] Gu L, Kelm MA, Hammerstone JF, et al. Concentration of

proanthocyanidins in common foods and estimates of normal

consumption. Journal of Nutrition 2004; 134: 613-617.

[48] Amakura Y, Okada M, Tsuji S, Tonagai Y. High performance

liquid chromatographic determination with photo diode array

detection of ellagic acid in fresh and processed fruits. Journal of

Chromatography A 2000; 896: 87-93.

[49] Hakkinen SH, Karenlampi SO, Heinonen M, Mykkanen HM,

Torronen AR. Content of the flavonols Quercetin, Myricetin and

Kaempferol in 25 edible berries. Journal of Agricultural and Food

Chemistry 1999; 47: 2274-2279.

[50] Maatta KR, Kamal-Eldin A, Torronen AR. Identification and

quantification of phenolic compounds in berries of Fragaria and

Rubus species (Family Rosaceae). Journal of Agricultural and Food

Chemistry 2004; in press.

[51] Hertog MGL, Kromhout D, Aravanis C, et al. Flavonoids intake

and long-term risk of coronary heart disease and cancer in the 7

countries study. Archives of Internal Medicine 1995; 155: 381-386.

[52] Knekt P, Jarvinen R, Seppanen R, et al. Dietary flavonoids and the

risk of lung cancer and other malignent neoplasms. American

Journal of Epidemiology 1997; 146(3): 223-230.

[53] Arts ICW, Jacobs Jr DR, Gross M, Harnack LJ, Folsom AR.

Dietary catechins and cancer incidence among postmenopausal

women: the Iowa Women's Health Study (United States). Cancer

Causes and Control 2002; 13(4): 373-382.

[54] Duthie GG, Duthie SJ, Kyle JAM. Plant polyphenols in cancer and

heart disease: implications as nutritional antioxidants. Nutrition

Research Reviews 2000; 13: 79-106.

[55] Katsube N, Iwashita K, Tsushida T, Yamaki K, Kobori M.

Induction of apoptosis in cancer cells by bilberry (vaccinium

myrtillus) and the anthocyanins. Journal of Agricultural and Food

Chemistry 2003; 51(1): 68-75.

[56] Youdim KA, McDonald J, Kalt W, Joseph JA. Potential role of

dietary flavonoids in reducing microvascular endothelium

vulnerability to oxidative and inflammatory insults. Journal of

Nutritional Biochemistry 2002; 13: 282-288.

[57] Nijveldt RJ, van Nood E, van Hoorn DEC, Boelens PG, van Norren

K, van Leeuwen PAM. Flavonoids: a review of probable

mechanisms of action and potential applications. American Journal

of Clinical Nutrition 2001; 74: 418-425.

[58] Agullo G, Gamet L, Besson C, Demigne C, Remesy C. Quercetin

exerts a preferential cytotoxic effect on active dividing colon

carcinoma HT29 and CACO2 cells. Cancer Letters 1994; 87(1): 55-

63.

[59] Plaumann B, Fritsche M, Rimpler H, Brandner G, Hess RD.

Flavonoids activate wild type p53. Oncogene 1996; 13: 1065-1614.

[60] Csokay B, Pradja N, Weber G, Olah E. Molecular mechanisms in

the antiproliferative action of quercetin. Life Sciences 1997; 60:

2157-2163.

[61] Narayanan BA, Geoffroy O, Willingham MC, Re GG, Nixon DW.

p53/p21 (WAF1/CIP1 expression and its possible role in G1 arrest

and apoptosis in ellagic acid treated cancer cells. Cancer Letters

1999; 136: 215-221.

[62] Uddin S, Choudhry MA. Quercetin, a bioflavonoid, inhibits the

DNA synthesis of human leukemia cells. Biochemistry and

Molecular Biology International 1995; 36: 545-550.

[63] Verma AK, Johnson JA, Gould MN, Tanner MA. Inhibition of

induced rat mammary cancer by dietary flavonol quercetin. Cancer

Research 1988; 48: 5754-5758.

[64] Khanduja KL, Gandhi RK, Pathania V, Syal N. Prevention of N-

nitrosodiethylamine-induced lung tumorigenesis by ellagic acid and

quercetin in mice. Food Chemistry and Toxicology 1999; 37(4):

313-318.

[65] Maas JL, Galletta GJ, Stoner GD. Ellagic Acid, an anticarcinogen

in fruits, especially in strawberries: A review. HortScience 1991;

26(1): 10-14.

[66] Das M, Bickers DR, Mukhtar H. Effects of ellagic acid on hepatic

and pulmonary xenobiotic metabolism in mice - studies on the

mechanism of its anticarcinogenic action. Carcinogenesis 1985;

6(10): 1409-1413.

[67] Barch DH, Fox CC. Selective inhibition of

methylbenzylnitrosamine induced formation of esophageal O6

methylguanine by dietary ellagic acid in rats. Cancer Research

1988; 48(24): 7088-7092.

[68] Mullen W, McGinn J, Lean MEJ, et al. Ellagitannins, flavonoids,

and other phenolics in red raspberries and their contribution to

antioxidant capacity and vasorelaxation properties. Journal of

Agricultural and Food Chemistry 2002; 50: 5191-5196.

[69] Pignatelli P, Pulcinelle FM, Celestini A, Lenti L, Ghiselli A,

Gazzaniga PP. The flavonoids quercetin and catechin

synergistically inhibit platelet function by antagonising the

intracellular production of hydrogen peroxide. American Journal of

Clinical Nutrition 2000; 72: 1150-1155.

[70] Hayek T, Fuhrman B, Vaya J, et al. Reduced progression of

atherosclerosis in apolipoprotein E deficient mice following

consumption of red wine or its polyphenols quercetin or catechin is

associated with reduced susceptibility of LDL to oxidation and

aggregation. Arteriosclerosis Thrombosis and Vascular Biology

1997; 17: 2744-2752.

[71] Diplock AT, Charleux J-L, Crozier-Willi G, Kok FJ, Rice-Evans C,

Roberfroid M, et al. Functional food science and defence against

Potential Health Benefits of Berries Current Nutrition & Food Science, 2005, Vol. 1, No. 1 85

reactive oxidative species. British Journal of Nutrition 1998;

80(S1): S77-S112.

[72] Rice-Evans C, Miller NJ, Paganga G. Antioxidant properties of

phenolic compounds. Trends in Plant Science 1997; 2(4): 152-159.

[73] Ferrali M, Signorini C, Caciotti B, et al. Protection against

oxidative damage of erythroyte membrane by the flavonoid

quercetin and its relation to iron chelating activity. FEBS letters

1997; 416(2): 129-129.

[74] Morel I, Lescoat G, Cogrel P, et al. Antioxidant and iron chelating

activities of the flavonoids catechin, quercetin and diosmetin on

iron loaded rat hepatocyte cultures. Biochemical Pharmacology

1993; 45(1): 13-19.

[75] Fiander H, Schneider H. Dietary orthophenols that induce

glutathione S transferase and increase the resistance of cells to

hydrogen peroxide are potential cancer chemoproventives that act

by two mechanisms : the alleviation of oxidative stress and the

detoxification of mutagenic xenobiotics. Cancer Letters 2000; 156:

17-24.

[76] Meyer AS, Donovan JL, Pearson DA, Waterhouse AL, Frankel EN.

Fruit hydroxycinnamic acids inhibit human low density lipoprotein

oxidation in vitro. Journal of Agricultural and Food Chemistry

1998; 46: 1783-1787.

[77] Kasai H, Fukada S, Yamaizumi Z, Sugie S, Mori H. Action of

chlorogenic acid in vegetables in fruits as an inhibitor of 8-

hydroxydeoxyguanosine formation in vitro and in a rat

carcinogenesis model. Food Chemistry and Toxicology 2000;

38(5): 467-471.

[78] Cao G, Russell RM, Lischner N, Prior RL. Serum antioxidant

capacity is increased by consumption of strawberries, spinach, red

wine or vitamin C in elderly women. Journal of Nutrition 1998;

128: 2383-2390.

[79] Kay CD, Holub BJ. The effect of wild blueberry (Vaccinium

angustifolium) consumption on postprandial serum antioxidant

status in human subjects. British Journal of Nutrition 2002; 88: 389-

397.

[80] Netzel M, Strass G, Kaul C, Bitsch I, Dietrich H, Bitsch R. In vivo

antioxidative capacity of a composite berry juice. Food Research

International 2002; 35: 213-216.

[81] Bub A, Watzl B, Blockhaus M, et al. Fruit juice consumption

modulates antioxidative status, immune status and DNA damage.

Journal of Nutritional Biochemistry 2003; 14: 90-98.

[82] Pedersen CB, J. K, Jenkinson AM, Gardner PT, McPhail DB,

Duthie GG. Effects of blueberry and cranberry juice consumption

on the plasma antioxidant capacity of healthy female volunteers.

European Journal of Clinical Nutrition 2000; 54: 405-408.

[83] Strain JJ, Elwood PC, Davis A, et al. Frequency of fruit and

vegetable consumption and blood antioxidants in the Caerphilly

cohort of older men. European Journal of Clinical Nutrition 2000;

54: 828-833.

[84] Cao G, Booth SL, Sadowski JA, Prior RL. Increases in human

antioxidant capacity after consumption of controlled diets high in

fruit and vegetables. American Journal of Clinical Nutrition 1998b;

68: 1081-1087.

[85] Lotito S, Frei B. The increase in human plasma antioxidant capacity

after apple consumption is due to the metabolic effect of fructose on

urate, not apple-derived antioxidant flavonoids. Free Radical

Biology and Medicine 2004; 37: 251-258.

[86] McGhie TK, Ainge GD, Barnett LE, Cooney JM, Jensen DJ.

Anthocyanin glycosides from berry fruit are absorbed and excreted

unmetabolized by both humans and rats. Journal of Agricultural and

Food Chemistry 2003; 51: 4539-4548.

[87] Cao G, Muccitelli HU, Sanchez-Moreno C, Prior RL. Anthocyanins

are absorbed in glycated forms in elderly women: a

pharmacokinetic study. American Journal of Clinical Nutrition

2001; 73: 920-926.

[88] Nemeth K, Plumb GW, Berrin J-G, et al. Deglycosylation by small

intestine epithelial cell β-glucosidases is a critical step in the

absoption and metabolism of dietary flavonoid glycosides in

humans. European Journal of Nutrition 2003; 42: 29-42.

[89] Passamonti S, Vrhovsek U, Vanzo A, Mattivi F. The stomach as a

site for anthocyanins absorption from food. FEBS letters 2003; 544:

210-213.

[90] Talavera S, Felgines C, Texier O, et al. Anthocyanins are efficiently

absorbed in the small intestine of rats. Journal of Nutrition 2004;

134: 2275-2279.

[91] Talavera S, Felgines C, Texier O, Besson C, Lamaison J-L, Remesy

C. Anthocyanins are efficiently absorbed from the stomach in

anesthetized rats. Journal of Nutrition 2003; 133: 4178-4182.

[92] Wu X, Cao G, Prior RL. Absorption and metabolism of

anthocyanins in elderly women after consumption of elderberry or

blueberry. Journal of Nutrition 2002; 132: 1865-1871.

[93] Felgines C, Talavera S, Gonthier M-P, et al. Strawberry

anthocyanins are recovered in urine as glucuro- and sulfoconjugates

in humans. Journal of Nutrition 2003; 133: 1296-1301.

[94] Hollman PCH, de Vries JHM, van Leeuwen PAM, Mengelers MJB,

Katan MB. Absorption of dietary quercetin glycosides and

quercetin in heathy ileostomy volunteers. American Journal of

Clinical Nutrition 1995; 62: 1276-82.

[95] Walgren RA, Lin J-T, Kinne RK-H, Walle T. Cellular uptake of

dietary flavonoid quercetin-4'-β-glucoside by sodium-dependent

glucose transporter SGLT1. Journal of Pharmacology and

Experimental Therapeutics 2000; 294: 837-843.

[96] Wolffram S, Block M, Ader P. Quercetin-3-glucoside is transported

by the glucose carrier SGLT1 across the brush border membrane of

rat small intestine. Journal of Nutrition 2002; 132: 630-635.

[97] Walgren RA, Walle UK, Walle T. Transport of quercetin and its

glucosides across human intestinal epithelial Caco-2 cells.

Biochemical Pharmacology 1998; 55: 1721-1727.

[98] Aziz AA, Edwards CA, Lean MEJ, Crozier A. Absorption and

excretion of conjugated flavonols, including quercetin-4'ο-β-

glucoside and isorhamnetin-4'-ο-β-glucoside by human volunteers.

Free Radical Research 1998; 29: 257-269.

[99] Day AJ, Mellon F, Barron D, Sarrazin G, Morgan MRA,

Williamson. Human metabolism of dietary flavonoids:

identification of plasma metabolites of quercetin. Free Radical

Research 2001; 35(6): 941-952.

[100] Mullen W, Boitier A, Stewart AJ, Crozier A. Flavonoid metabolites

in human plasma and urine after consumption of red onions:

analysis by HPLC with photodiode array and full scan tandem mass

spectrometric detection. Journal of Chromatography A 2004; in

press.

[101] Day AJ, Dupont S, Ridley S, et al. Deglycosylation of flavonoid

and isoflavonoid glycosides by human small intestine and liver β-

glucosidase activity. FEBS letters 1998; 436: 71-75.

[102] O'Leary KA, Day AJ, Needs PW, Mellon FA, O'Brien NM,

Williamson G. Metabolism of quercetin-7-and quercetin-3-

glucuronides by an in vitro hepatic model: the role of human β-

glucuronidase, sulfotransferase, catechol-O-methyltransferase and

multi-resistant protein 2 (MRP2) in flavonoid metabolism.

Biochemical Pharmacology 2003; 65: 479-491.

[103] Mullen W, Graf BA, Caldwell ST, et al. Determination of flavonol

metabolites in plasma and tissues of rats by HPLC-radiocounting

and tandem mass spectrometry following oral ingestion of [2-

14C]quercetin-4'-glucoside. Journal of Agricultural and Food

Chemistry 2002; 50: 6902-6909.

[104] Graefe EU, Wittig J, Mueller S, et al. Pharmacokinetics and

bioavailability of quercetin glycosides in humans. Journal of

Clinical Pharmacology 2001; 41: 492-499.

[105] Piskula MK, Terao J. Accumulation of (-)-epicatechin metabolites

in rat plasma after oral administration and distribution of

conjugation enzymes in rat tissues. Journal of Nutrition 1998; 128:

1172-1178.

[106] Yang CS, Chen L, Lee MJ, Balentine D, Kuo MC, Schantz SP.

Blood and urine levels of tea catechins after ingestion of different

amounts of green tea by human bolunteers. Cancer Epidemiology

Biomarkers and Prevention 1998; 7: 351-354.

[107] Rein D, Lotito S, Holt RR, Keen CL, Schmitz HH, Fraga CG. (-)-

Epicatechin in human plasma: in vivo determination and effect of

chocolate consumption on plasma oxidation status. Journal of

Nutrition 2000; 130: 2109-2114.

[108] Wang JF, Schramm DD, Holt RR, et al. A dose-response effect

from chocolate consumption on plasma (-)-epicatechin and

oxidative damage. Journal of Nutrition 2000; 130: 2115-2119.

[109] Baba S, Osakabe N, Natsume M, Terao J. Absorption and urinary

excretion of procyanidin B2 [epicatechin-(4β-8)-epicatechin] in rats.

Free Radical Biology and Medicine 2002; 33: 142-148.

[110] Warden BA, Smith LS, Beecher GR, Balentine DA, Clevidence

BA. Catechins are bioavailable in men and women drinking black

tea throughout the day. Journal of Nutrition 2001; 131: 1731-1737.

[111] Natsume M, Osakabe N, Oyama M, et al. Structures of (-)-

epicatechin glucuronide identified from plasma and urine after oral

86 Current Nutrition & Food Science, 2005, Vol. 1, No. 1 Duthie et al.

ingestion of (-)-epicatechin: differences between human and rat.

Free Radical Biology and Medicine 2003; 34: 840-849.

[112] Koga T, Moro K, Nakamori K, et al. Increase in oxidative potential

of rat plasma by oral administration of proanthocyanidin-rich

extract from grape seeds. Journal of Agricultural and Food

Chemistry 1999; 47: 1892-1897.

[113] Donovan JL, Manach C, Rios L, Morand C, Scalbert A, Remesy C.

Procyanidins are not bioavailable in rats fed a single meal

containing a grape seed extract or the procyanidin dimer B3. British

Journal of Nutrition 2002; 87: 299-306.

[114] Holt RR, Lazarus AA, Sullards MC, et al. Procyanidin dimer B2

[epicatechin-(4 beta-8)-epicatechin] in human plasma after the

consumption of a flavanol-rich cocoa beverage. American Journal

of Clinical Nutrition 2002; 76(4): 798-804.

[115] Gonthier M-P, Donovan JL, Texier O, Felgines C, Remesy C,

Scalbert A. Metabolism of dietary procyanidins in rats. Free

Radical Biology and Medicine 2003; 35: 837-844.

[116] Degeneve A. Antioxidants in fruits and vegetables [MSc]. Glasgow:

University of Glasgow; 2004.

[117] Walle T, Otake Y, Walle K, Wilson FA. Quercetin glucosides are

completely hydrolyzed in ileostomy patients before absoprtion.

Journal of Nutrition 2000; 130: 2658-2661.

[118] Manach C, Scalbert A, Morand C, Remesy C, Jimenez L.

Polyphenols: food sources and bioavailability. American Journal of

Clinical Nutrition 2004; 79: 727-747.

[119] Rechner AR, Kuhnle G, Bremner P, Hubbard GP, Moore KP, Rice-

Evans C. The metabolic fate of dietary polyphenols in humans. Free

Radical Biology and Medicine 2002; 33(2): 220-235.

[120] Rechner AR, Smith MA, Kuhnle G, et al. Colonic metabolism of

dietary polyphenols: influence of structure on microbial

fermenation products. Free Radical Biology and Medicine 2004;

36: 212-225.

[121] Olthof MR, Hollman PCH, Buijsman MNCP, van Amelsvoort

JMM, Katan MG. Chlorogenic acid, quercetin-3-rutinoside and

black tea phenolics are extensively metabolised in humans. Journal

of Nutrition 2003; 133: 1806-1814.

[122] Clifford MN. Anthocyanins - nature, occurrence and dietary

burden. Journal of the Science of Food and Agriculture 2000; 80:

1063-1072.

[123] Scalbert A, Williamson G. Dietary intake and bioavailability of

polyphenols. Journal of Nutrition 2000; 130(S): 2073-2085.

[124] Kroon PA, Clifford MN, Crozier A, et al. Based on in vivo data,

how do we assess the effects of exposure to dietary polyphenols in

vitro? American Journal of Clinical Nutrition 2004; 80: 15-21.

[125] Dreher D, Junod AF. Role of oxygen free radicals in cancer

development. European Journal of Cancer 1996; 32A(1): 30-38.

[126] Liu M, Li XQ, Weber C, Lee CY, Brown J, Liu RH. Antioxidant

and antiproliferative activities of raspberries. Journal of

Agricultural and Food Chemistry 2002; 50: 2926-2930.

[127] Roy S, Khanna S, Alessio HM, et al. Anti-angiogenic property of

edible berries. Free Radical Research 2002; 36: 1023-1031.

[128] Kresty LA, Morse MA, Morgan C, et al. Chemoprevention of

esophageal tumourigenesis by dietary administration of lyophilized

black raspberries. Cancer Research 2001; 61: 6112-6119.

[129] Aziz RM, Nines R, Rodrigo K, et al. The effect of freeze dried

blueberries on N-nitrosomethylbenzylamine tumourigenesis in the

rat eosophagus. Pharmaceutical Biology 2002; 40: 43-49.

[130] Steinberg D, Parthasarthy S, Carew TE, Khoo JC, Witztum JL.

Beyond Cholesterol - modifications of low density lipoprotein that

increase it antherogenicity. New England Journal of Medicine

1989; 320(14): 915-924.

[131] Esterbauer H, Gebicki J, Puhl H. The role of lipid peroxidation and

antioxidants in oxidative modification of LDL. Free Radical

Biology and Medicine 1992; 13(4): 341-390.

[132] Heinonen IM, Meyer AS, Frankel EN. Antioxidant activity of berry

phenolics on human low-density lipoprotein and liposome

oxidation. Journal of Agricultural and Food Chemistry 1998; 46:

4107-4112.

[133] Laplaud PM, Lelubre A, Chapman MJ. Antioxidant action of

Vaccinium myrtillus extract on human low density lipoproteins in

vitro: initial observations. Fundamentals of Clinical Pharmacology

1997; 11(1): 35-40.

[134] Marniemi J, Hakala P, Maki J, Ahotupa M. Partial resistance of low

density lipoprotein to oxidation in vivo after increased intake of

berries. Nutrition Metabolism and Cardiovascular Disease 2000; 10:

331-337.

[135] Eccleston C, Baoru Y, Tahvonen R, Kallio H, Rimbach GH,

Minihane AM. Effects of an antioxidant rich juice (sea buckthorn)

on risk of factors for coronary heart disease in humans. Journal of

Nutritional Biochemistry 2002; 13: 346-354.

[136] Youdim KA, Joseph JA. A possible role in phytochemicals in

improving age-related neurological dysfunctions: a multiplicity of

effects. Free Radical Biology and Medicine 2001; 30(6): 583-594.

[137] Youdim KA, Shukitt -HB, Martin A, et al. Short term dietary

supplementation of blueberry polyphenolics: beneficial effects on

aging brain performance and peripheral tissue function. Nutritional

Neuroscience 2000; 3(6): 383-397.

[138] Joseph JA, Shukitt -HB, Denisova NA, et al. Long-term dietary

strawberry, spinach or vitamin E supplemetation retards the onset of

age related neuronal signal transduction and cognitive behavioural

deficits. Journal of Neuroscience 1998; 18: 8047-8055.

[139] Joseph JA, Shukitt -HB, Denisova NA, et al. Reversals of age

related declines in neuronal signal transduction, cognitive and

motor behavioural deficits with blueberry spinach or strawberry

dietary supplementation. Journal of Neuroscience 1999; 19(18):

8114-8121.

[140] Bickford PC, Gould T, Briederick L, et al. Antioxidant rich diets

improve cerebellar physiology and motor learning in aged rats.

Brain Research 2000; 866: 211-217.

[141] Howell AB, Vorsa N, Der Marderosian A, Foo LY. Inhibition of

the adherence of P-Fimbriated E Coli to uroepithelial cell surfaces

by proanthocyanidin extracts from cranberries. New England

Journal of Medicine 1998; 339(15): 1085.

[142] Sobota AE. Inhibition of bacterial adherence by cranberry juice:

potential use for the treatment oif urinary tract infections. Journal of

Urology 1984; 131: 1013-1016.

[143] Jepson RG, Mihaljevic L, Craig J. Cranberries for preventing

urinary tract infections: The Cochrane Library; 2002.

[144] Jepson RG, Mihaljevic L, Craig J. Cranberries for treating urinary

tract infections: The Cochrane Library; 2002.

[145] Kiel RJ, Nashelsky J. Does cranberry juice prevent or treat urinary

tract infection? The Journal of Family Practice 2003; 52(2): 154-

155.

[146] Kontiokari T, Sundqvist K, Nuutinen M, Pokka T, Kaskela M,

Uhari M. Randomised trial of cranberry-lingonberry juice and

Lactobacillus GG drink for the prevention of urinary tract infections

in women. British Medical Journal 2001; 322: 1571-1573.

[147] Stothers L. A randomized control trial to evaluate effectiveness and

cost effectiveness of naturopathic cranberry products as prophylaxis

against urinary tract infection in women. Canadian Journal of

Urology 2002; 9(3): 1558-1562.

[148] Ancos de B, Ibanez E, Reglero G, Cano MP. Frozen storage effects

on anthocyanins and volatile compounds of raspberry fruit. Journal

of Agricultural and Food Chemistry 2000; 48: 873-879.

[149] Kalt W, Forney CF, Martin A, Prior RL. Antioxidant capacity,

vitamin C, phenolcs and anthocyanins after fresh storage of small

fruits. Journal of Agricultural and Food Chemistry 1999; 47: 4638-

4644.

[150] Zafrilla P, Ferreres F, Tomas-Barberan FA. Effect of processing

and storage on the antioxidant Ellagic Acid derivatives and

flavonoids of red raspberry (Rubus idaeus) jams. Journal of

Agricultural and Food Chemistry 2001; 49: 3651-3655.

[151] Amakura Y, Umino Y, Tsuji S, Tonogai Y. Influence of jam

processing on the radical scavenging activity and phenolic content

in berries. Journal of Agricultural and Food Chemistry 2000;

48(12): 6292-6297.

[152] Garcia-Viguera C, Zafrilla P, Artes F, Romero F, Abellan P,

Tomas-Barberan FA. Colour and anthocyanin stability of red

raspberry jam. Journal of Agricultural and Food Chemistry 1998;

78: 565-573.

Received: October 19, 2004 Accepted: December 01, 2004

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Sep 2024

will provide an outline of the nutritional and therapeutic benefits of several berries. It will focus on the major vitamins, minerals, antioxidants, and phytochemicals found in berries, as well as how these compounds can benefit overall health and well-being. The study will also look into the possible therapeutic applications of berries in the prevention and treatment of several health disorders, including cardiovascular disease, diabetes, and cancer. It will discuss the differences in nutrient profiles and bioactive chemicals found in various berry species, as well as how these variances may influence their distinct health-promoting properties. Furthermore, the abstract will discuss any potential safety risks or contraindications related with berry eating, particularly for people who have certain medical problems or are taking specific drugs.

Therapeutic potential of berries in age-related neurological disorders

Article

May 2024

Aging significantly impacts several age-related neurological problems, such as stroke, brain tumors, oxidative stress, neurodegenerative diseases (Alzheimer's, Parkinson's, and dementia), neuroinflammation, and neurotoxicity. Current treatments for these conditions often come with side effects like hallucinations, dyskinesia, nausea, diarrhea, and gastrointestinal distress. Given the widespread availability and cultural acceptance of natural remedies, research is exploring the potential effectiveness of plants in common medicines. The ancient medical system used many botanical drugs and medicinal plants to treat a wide range of diseases, including age-related neurological problems. According to current clinical investigations, berries improve motor and cognitive functions and protect against age-related neurodegenerative diseases. Additionally, berries may influence signaling pathways critical to neurotransmission, cell survival, inflammation regulation, and neuroplasticity. The abundance of phytochemicals in berries is believed to contribute to these potentially

Therapeutic potential of berries in age-related neurological disorders

Article

Full-text available

May 2024

Aging significantly impacts several age-related neurological problems, such as stroke, brain tumors, oxidative stress, neurodegenerative diseases (Alzheimer’s, Parkinson’s, and dementia), neuroinflammation, and neurotoxicity. Current treatments for these conditions often come with side effects like hallucinations, dyskinesia, nausea, diarrhea, and gastrointestinal distress. Given the widespread availability and cultural acceptance of natural remedies, research is exploring the potential effectiveness of plants in common medicines. The ancient medical system used many botanical drugs and medicinal plants to treat a wide range of diseases, including age-related neurological problems. According to current clinical investigations, berries improve motor and cognitive functions and protect against age-related neurodegenerative diseases. Additionally, berries may influence signaling pathways critical to neurotransmission, cell survival, inflammation regulation, and neuroplasticity. The abundance of phytochemicals in berries is believed to contribute to these potentially neuroprotective effects. This review aimed to explore the potential benefits of berries as a source of natural neuroprotective agents for age-related neurological disorders.

Chapter 8: Berries and Their Promising Potential Health Benefits ByJudith Boateng, Rawan Al Hazaimeh Boateng, J., & Al Hazaimeh, R. (2024). Berries and Their Promising Potential Health Benefits. In Plant Food Phytochemicals and Bioactive Compounds in Nutrition and Health (pp. 147-201). CRC Press.

Chapter

Jun 2024

Berries consumption is on the rise due to consumer awareness of their health benefits. Berries are abundant in polyphenols and phenolic compounds, which include phenolic acids, tannins, stilbenes, and flavonoids (anthocyanins, flavonols, flavanones, flavones and flavanols). Several in vivo and in vitro studies, as well as controlled clinical trials, indicated their consumption could improve health by exerting antiinflammatory, antioxidant, antiproliferative, antilipidemia, antiinsulinemia, and antihypertensive effects against cancer, obesity, cardiovascular diseases, and diabetes. Berries are presently regarded as functional foods with prebiotics effects to benefit the gut microbiota and improve overall health. This chapter will discuss the current research on berries and their potential health benefits.

Osmotic dehydration of waxy skinned berries-a review

Article

May 2024
DRY TECHNOL

Waxy skinned berry fruits contain essential nutrients and play an important role in human health and nutrition. However, these fruits encounter two major problems; firstly, they are extremely perishable in nature that limits their consumption throughout the year and to address this bottleneck, osmotic dehydration (OD) can be an efficient way which brings the second problem associated with berries. The waxy skin of some valuable berries acts like a barrier and reduces the mass transfer (MT) during OD. The restricted MT during OD can be improved by applying pretreatments, accelerators during OD as well as optimizing OD parameters. Therefore, this review is first of its kind aims to provide a comprehensive discussion on the concept of OD, pretreatments and processing parameters associated with the improved MT in the waxy skinned berries. In terms of maintaining the sensory attributes, innovative non-thermal pretreatments are found better than classical thermal, mechanical, and chemical/enzymatic pretreatments. Moreover, factors affecting the MT rate and efficiency of OD processes, along with mathematical and computational models to optimize OD of waxy skinned berries are given. The advantages of OD processes on the quality of the products, in terms of bioactive compounds, texture, sensory properties, and color, were additionally summarized. The novelty of this review lies in its exclusive focus on the OD of berry fruits with a waxy layer on their surface and the strategies to ease off the process. ARTICLE HISTORY

Reversals of Age-Related Declines in Neuronal Signal Transduction, Cognitive, and Motor Behavioral Deficits with Blueberry, Spinach, or Strawberry Dietary Supplementation

Article

Full-text available

Sep 1999

Short-Term Dietary Supplementation of Blueberry Polyphenolics: Beneficial Effects on Aging Brain Performance and Peripheral Tissue Function

Article

Full-text available

Jan 2000
NUTR NEUROSCI

Emerging evidence from our lab indicate that fruits and vegetables, in particular blueberry (BB) extracts, are able to ameliorate age-related declines in neuronal and cognitive function, common in disorders such as Alzheimer disease. The current study examined if the beneficial effects were also discernable with supplementation of BB extracts, in an already well balanced diet. Indeed, following an 8 week supplementation regime, age-related declines in several behavioral parameters such as balance, coordination, working memory and reference memory were still protected against. Similarly, BB extracts also potentiated oxotremorine enhancement of K+-evoked release of dopamine from striatal slices. Decline in the dopaminergic system have been shown to have a profound effect on cognitive functions. The improvement in dopamine release may have been due in part to the observed increase in striatal vitamin C levels. Although assessment of serum transaminase levels in BB supplemented animals appeared to suggest improved liver function, this was not thought to be the reason for the elevated vitamin C levels. The underlying mechanism for this is unclear. Together these findings highlight the diverse in vivo actions of dietary polyphenolics, a number of which may be important against age-related declines in certain brain functions. Furthermore they are to be able to mediate protective effects despite the diet containing sufficient concentrations of antioxidants.

Colour and anthocyanin stability of red raspberry jam

Article

Dec 1998
J SCI FOOD AGR

Anthocyanin and colour stability of red raspberry jams made from two different varieties (‘Zeva’ and ‘Heritage’) were analysed during 6 months, stored at three temperatures (20, 30 and 37°C). Also the influence of freezing the fruit, previously to jam manufacture, was evaluated. Different anthocyanin composition was detected for both cultivars and while ‘Zeva’ fruit had a higher total anthocyanin content, Heritage variety produced jams with a higher redness hue. The development of browning was directly related to storage temperature but not to thawing or the variety of fruit used. © 1998 Society of Chemical Industry.

Flavonoids: A review of probable mechanisms of action and potential applications

Article

Oct 2001

The aim of this review, a summary of the putative biological actions of flavonoids, was to obtain a further understanding of the reported beneficial health effects of these substances. Flavonoids occur naturally in fruit, vegetables, and beverages such as tea and wine. Research in the field of flavonoids has increased since the discovery of the French paradox,ie, the low cardiovascular mortality rate observed in Mediterranean populations in association with red wine consumption and a high saturated fat intake. Several other potential beneficial properties of flavonoids have since been ascertained. We review the different groups of known flavonoids, the probable mechanisms by which they act, and the potential clinical applications of these fascinating natural substances.

Partial resistance of low density lipoprotein to oxidation in vivo after increased intake of berries

Article

Dec 2000
NUTR METAB CARDIOVAS

Background and aim: The health-promoting effects of fruit- and vegetable-based diets are known to be associated with their antioxidative components. We found in our preliminary in vitro laboratory tests that extracts of many common Finnish edible berries are potent scavengers of peroxyl radicals and inhibitors of lipid peroxidation. We therefore designed the current study to evaluate both the long-term (8 weeks) and short-term (5 hours) effects of increased intake of three berries on antioxidant potential and lipid peroxidation. Methods and results: Healthy 60-year-old men were randomized to berry, supplement and control groups (20 men in each group). The berry group ate, in addition to their normal diet, a 100 g portion of deep-frozen berries (bilberries, lingonberries, or black currants) daily for 8 weeks. The other groups ingested daily 100 mg of alpha-tocopherol and 500 mg of ascorbic acid (supplement group) or 500 mg of calcium gluconate (control group). In the short-term experiment 6 men ate 80 g of each of the three berries in one go. Serum ascorbate concentrations increased significantly in both the berry and the supplement group. Serum alpha-tocopherol levels and the antioxidant potential (TRAP) in low density lipoprotein (LDL) increased in the supplement group only. In the berry group, slightly lowered LDL diene conjugation (p = 0.074) and slightly increased total serum TRAP (p = 0.084) values were observed. No changes were found in these measures in the supplement or the control group. In the short-term experiment, LDL TRAP showed a small increase (about 10%, p = 0.039) during five hours after the intake of 240 g berries. Conclusions: The effects of consumption of berries on antioxidant potential and diene conjugation in LDL particles in vivo appear to be small.

Antioxidants in fruits, berries and vegetables

Chapter

Aug 2002

Water soluble vitamins

Article

Jan 1991

David Thurnham

Ellagic Acid, an Anticarcinogen in Fruits, Especially in Strawberries: A Review

Article

Jan 1991

Antioxidant and anti proliferative activities of raspberries

Article

May 2002

Raspberries are rich in phenolic phytochemicals. To study the health benefits of raspberries, four fresh raspberry varieties (Heritage, Kiwigold, Goldie, and Anne) were evaluated for total antioxidant and antiproliferative activities. The total amount of phenolics and flavonoids for each of the four raspberry varieties was determined. The Heritage raspberry variety had the highest total phenolic content (512.7 +/- 4.7 mg/100 g of raspberry) of the varieties measured followed by Kiwigold (451.1 +/- 4.5 mg/100 g of raspberry), Goldie (427.5 +/- 7.5 mg/100 g of raspberry), and Anne (359.2 +/- 3.4 mg/100 g of raspberry). Similarly, the Heritage raspberry variety contained the highest total flavonoids (103.4 +/- 2.0 mg/100 g of raspberry) of the varieties tested, followed by Kiwigold (87.3 +/- 1.8 mg/100 g of raspberry), Goldie (84.2 +/- 1.8 mg/100 g of raspberry), and Anne (63.5 +/- 0.7 mg/100 g of raspberry). The color of the raspberry juice correlated well to the total phenolic, flavonoid, and anthocyanin contents of the raspberry. Heritage had the highest a/b ratio and the darkest colored juice, and the Anne variety showed the lowest phytochemical content and the palest color. Heritage raspberry variety had the highest total antioxidant activity, followed by Kiwigold and Goldie, and the Anne raspberry variety had the lowest antioxidant activity of the varieties tested. The proliferation of HepG(2) human liver cancer cells was significantly inhibited in a dose-dependent manner after exposure to the raspberry extracts. The extract equivalent to 50 mg of Goldie, Heritage, and Kiwigold fruit inhibited the proliferation of those cells by 89.4 +/- 0.1, 88 +/- 0.2, and 87.6 +/- 1.0%, respectively. Anne had the lowest antiproliferative activity of the varieties measured but still exhibited a significant inhibition of 70.3 +/- 1.2% with an extract equivalent to 50 mg of fruit. The antioxidant activity of the raspberry was directly related to the total amount of phenolics and flavonoids found in the raspberry (p < 0.01). No relationship was found between antiproliferative activity and the total amount of phenolics/flavonoids found in the same raspberry (p > 0.05).

Fractionation and identification of the phenolic compounds of Highbush blueberries (Vaccinium corymbosum, L.)

Article

Dec 1996
FOOD CHEM

A scheme for the fractionation of flavonoid and nonflavonoid compounds is presented. The phenolic compounds of Highbush blueberries (cultivar ‘Coville’) were analysed by high performance liquid chromatography and thin-layer chromatography. Fifteen anthocyanins were identified as the 3-monoglucoside, 3-monogalactoside and 3-monoarabinoside of delphinidin, cyanidin, malvidin, peonidin and petunidin. No acyl anthocyanin was detected. Derivatives of malvidin and delphinidin were the most abundant; the 3-monogalactoside constituted 41% of the anthocyanin. Four flavonol glycosides were also identified as the kaempferol-3-O-glucoside, 3-O-glucoside, 3-O-galactoside and 3-O-rhamno-side of quercetin. The major phenolic acid was chlorogenic acid. After hydrolysis of the phenolic neutral fraction (FA), gallic, syringic and vanillic acids were identified by TLC. These acids appeared to be present in their ester forms, probably as glucoside esters.