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Several studies suggest that natural salicylates in plant-based foods may benefit health. However, large variation in published values of the salicylate content of foods means that relating dietary intakes to disease risk is problematical. Consequently, we have systematically reviewed the available literature using prescribed selection criteria. By combining these literature values with in-house analysis, we have constructed a food composition database describing median salicylate values for 27 different types of fruits, 21 vegetables, 28 herbs, spices and condiments, 2 soups and 11 beverages. Application of a validated food frequency questionnaire estimated median dietary intakes of 4.42 (range 2.90-6.27) and 3.16 (2.35-4.89) mg/day for Scottish males and females, respectively. Major dietary sources of salicylates were alcoholic beverages (22%), herbs and spices (17%), fruits (16%), non-alcoholic beverages including fruit juices (13%), tomato-based sauces (12%) and vegetables (9%). Application of the database to populations with differing dietary habits and disease risk profiles may provide further evidence for the role of dietary salicylates in the prevention of chronic diseases.
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REVIEW
A systematic review of salicylates in foods: Estimated
daily intake of a Scottish population
Adrian Wood
1
, Gwen Baxter
2
, Frank Thies
1
, Janet Kyle
1
and Garry Duthie
3
1
School of Medicine and Dentistry, Division of Applied Medicine, University of Aberdeen, Foresterhill, Aberdeen,
Scotland, UK
2
Research and Development, Dumfries and Galloway Royal Infirmary, Dumfries, Scotland, UK
3
Molecular Nutrition Group, Rowett Institute of Nutrition and Health, Aberdeen, Scotland, UK
Received: August 28, 2010
Revised: November 26, 2010
Accepted: December 15, 2010
Several studies suggest that natural salicylates in plant-based foods may benefit health.
However, large variation in published values of the salicylate content of foods means that
relating dietary intakes to disease risk is problematical. Consequently, we have systematically
reviewed the available literature using prescribed selection criteria. By combining these
literature values with in-house analysis, we have constructed a food composition database
describing median salicylate values for 27 different types of fruits, 21 vegetables, 28 herbs,
spices and condiments, 2 soups and 11 beverages. Application of a validated food frequency
questionnaire estimated median dietary intakes of 4.42 (range 2.90–6.27) and 3.16 (2.35–4.89)
mg/day for Scottish males and females, respectively. Major dietary sources of salicylates were
alcoholic beverages (22%), herbs and spices (17%), fruits (16%), non-alcoholic beverages
including fruit juices (13%), tomato-based sauces (12%) and vegetables (9%). Application of
the database to populations with differing dietary habits and disease risk profiles may provide
further evidence for the role of dietary salicylates in the prevention of chronic diseases.
Keywords:
Dietary intakes / Food composition / Salicylic acid
1 Introduction
Associations between human dietary patterns and risk of
chronic diseases are well documented. For example, high
dietary intakes of fruits and vegetables are associated with
reduced risk of developing heart disease and several
common types of cancer [1, 2]. Numerous epidemiological
and laboratory studies have suggested protective effects for a
variety of nutritionally essential plant-based dietary compo-
nents, such as fibre, antioxidant vitamins and trace elements
[3]. However, plants also contain more than 100 000
secondary metabolites ranging from structurally simple
alkaloids to more complex polyphenols and steroids. Many
such non-nutritive compounds exert biological activities in
mammalian systems that may have impact on health and
disease risk [4].
There is a growing interest in the role of salicylic acid
(2-hydroxybenzoic acid) (Fig. 1) as a dietary component with
beneficial effects on human health. Potential anti-inflam-
matory, anti-atherogenic and anti-neoplastic mechanisms in
human cells include the inhibition of cyclo-oxygenase 2
transcription, the stimulation of apoptosis, moderation of
DNA mismatch repair and stimulation of antioxidant
activity [5]. Moreover, several intervention studies indicate
that regular intake of acetylsalicylic acid (aspirin) decreases
the risk of developing cancer [6], rapid deacetylation
following consumption indicating that salicylic acid is the
biologically active component [7]. Salicylic acid and its salts
and esters are abundant in the plant kingdom functioning
as hormonal mediators of local and systemically acquired
resistance to pathogens and environmental stress [8].
They are therefore likely to be present in plant products of
dietary relevance such as fruits, vegetables, herbs and
spices [9]. This has led to the suggestion that the recognised
Correspondence: Professor Garry Duthie, Rowett Institute of
Nutrition and Health, University of Aberdeen, Greenburn Road,
Aberdeen AB21 9SB, Scotland, UK
E-mail: G.Duthie@abdn.ac.uk
Fax: 144-1224-716687
&2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.mnf-journal.com
Mol. Nutr. Food Res. 2011, 55, S7–S14 S7DOI 10.1002/mnfr.201000408
effects of plant-based diets on lowering disease risk may
be attributable, at least in part, to their salicylic acid content
[10, 11].
It is unclear whether sufficient salicylic acid can be
obtained from dietary sources to exert disease preventative
activity, estimated daily intakes ranging from 0.4 to 200
mg/day have been reported [9, 12, 13]. Such a difference
may be ascribed to the disparate information available on
the salicylic acid content of foods confounding estimation of
dietary intakes. Consequently, we set out to (i) construct a
comprehensive database on salicylate levels in plant-based
foods through both in-house analytical determinations and
rigorous systematic examination of available literature and
(ii) estimate dietary salicylate intake in a healthy Scottish
population. It is intended that the food composition data-
base can be used in population studies exploring dietary
salicylate intakes and disease risk.
2 Materials and methods
To ensure as comprehensive a database as possible, data
from the literature were critically and systematically eval-
uated and then augmented with additional values from in-
house analyses of foods commonly consumed in the UK.
2.1 Critical appraisal of available literature
The method of systematic review and subsequent accep-
tance or rejection of data followed the procedures previously
employed in the construction of a flavonoid food database
[14] using the selection criteria based on the Royal Society of
Chemistry food composition tables [15–18]. In brief, these
were (i) food items had to be randomly selected and
purchased from various commercial outlets during different
seasons of the year, (ii) food samples were prepared using
normal domestic practices, (iii) optimized sample extraction
and hydrolysis conditions were clearly described or cited and
(iv) salicylate determination was based on modern techni-
ques of high-pressure liquid chromatography and MS with
validation and quality assurance measures summarised.
Using this approach, the bibliography databases CAB
abstracts, BIDS and Medline were searched using the
keywords ‘‘salicylic acid, salicylates, food and diet.’’ Data
from nine publications [9, 12, 13, 19–23] satisfied the
selection criteria and were used in the construction of the
salicylate food composition database.
2.2 Analysis of salicylate in foods
Information on commonly consumed food items in northeast
Scotland was obtained from a previous survey [18]. The total
salicylate content of the edible portions of 19 fruits, 20
vegetables, 7 spices and 6 juices purchased from local
supermarkets were determined using high-performance
liquid chromatography (HPLC) with electrochemical detec-
tion as previously described [19, 20]. Six items of the same
food were homogenised together to minimise individual
variation within each food type. Duplicate portions (1.0 g fruit
and vegetables, 0.05 g spices and 0.5mL liquids) of homo-
genised foods were suspended in 3mL of 2.5mol/L sodium
hydroxide for 24 h at room temperature. Hydrochloric acid
(1 mL of 5.3 mol/L) was then used to adjust the mixtures
so that they contained a final concentration of 0.1 mol/L
HCl. Following addition of EDTA (final concentration
100 mmol/L), 4-methyl salicylic acid (internal standard, final
concentration of 2.0 mmol/L), vortexing (15 min) and centri-
fugation (3000 rpm, 10 min, 41C), the organic phases were
dried under oxygen free nitrogen and reconstituted in 0.5mL
of 30 mmol/L citrate (pH 3.8) containing 5% methanol.
Eluted substances were detected electrochemically at an
oxidation potential of 11.1V using a previously described
four-step program [19]. The presence of salicylic acid was
confirmed by peak disappearance following addition of sali-
cylate hydroxylase and by MS [19]. Intra-assay and inter-assay
coefficients of variation (CV) were 3 and 4% respectively.
2.3 Database construction
Data for total salicylates from the literature and the in-house
analysis were combined and total salicylates for 27 different
types of fruits, 21 vegetables, 28 herbs, spices and condi-
ments, 2 soups and 11 beverages were calculated as median
values to accommodate non-normal distribution of the
range of values available for each food item.
2.4 Estimating dietary salicylate intake
Dietary intake was assessed by applying the salicylate data-
base to the Scottish Collaborative Group (SCG) semi-quan-
titative Food Frequency Questionnaire (FFQ) version 6.5
[18], consisting of a list of 170 food items, and a supple-
mental questionnaire of similar format incorporating spices
and recipes. One hundred and sixteen healthy men, mean
age 31 years (range 19–72) and 121 healthy women, mean
age 31 years (range 17–64) from Aberdeen, Scotland, UK
completed the questionnaires. For each item, participants
were asked to report their average use over the preceding
three months for a specified serving size of each food and
beverage. Nine pre-specified frequency responses were
possible, ranging from rarely or never eaten to eaten
every day. Individual salicylate intakes were calculated by
Figure 1. Molecular structure of salicylic acid.
S8 A. Wood et al. Mol. Nutr. Food Res. 2011, 55, S7–S14
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multiplying the frequency of each food or beverage
consumed by the salicylate content of the specified portion
size and then summing the contributions from all foods and
beverages. The salicylate contents of 19 composite dishes
(e.g. pizzas and spaghetti bolognaise) were also calculated
from standard recipes using the values for individual
ingredients from the database with adjustment for weight
lost through cooking [24–32]. Median daily total salicylic acid
intakes were adjusted for energy intake. Dietary investiga-
tions were approved by the local research ethics committee
and informed consent was obtained.
3 Results
3.1 Total salicylate content of foods
Electrochemical determination following separation by
HPLC confirmed the presence of salicylates in a range of
plant-based food items readily available to the UK consumer
(Table 1). Herbs and spices were particularly rich sources
whereas salicylates were absent in some vegetables such as
aubergines, broccoli and courgettes.
Combining the values from the in-house analysis with
those from the systematic assessment of the literature
resulted in a dietary database containing the median sali-
cylate content of 27 different types of fruits, 21 vegetables,
28 herbs, spices and condiments, 2 soups and 11 beverages
(Table 2). The salicylate content ranged from 0 to 33.59
mg/kg in fruits, 0 to 6.01 mg/kg in vegetables, 5.74 to
450 mg/kg in spices and 0.10 to 4.06 mg/kg in juices. Esti-
mated salicylate contents of standard recipes [24–32] (Table
3) ranged from 0 mg/kg (oil and lemon dressing) to 8.5 mg/
kg (tomato chutney). Raisins were particularly rich sources
of salicylates (0.98–66.2 mg/kg), a likely relative concentra-
tion effect of water loss by the drying process.
3.2 Estimated daily intakes and main food sources
Estimated medial total salicylate intakes were 4.42 and
3.16 mg/day for males and females, respectively. Following
adjustment for energy, this gender difference was no longer
apparent (Table 4). Primary food sources of salicylates
(Fig. 2) were alcoholic beverages (22%), herbs and spices
(17%), fruits (16%), non-alcoholic beverages including fruit
juices (13%), tomato-based sauces (12%) and vegetables
(9%). Salicylate intake was significantly and positively
associated (po0.01) with intakes of fibre, potassium, vita-
min C and alcohol (data not shown).
4 Discussion
Food composition databases provide essential information
for research on the health effects of nutrients, nutritional
surveillance, clinical dietetic practice and food formulation
and processing. Compositional information on potentially
bioactive phytochemicals in foods is generally lacking
although several databases for polyphenols in foods are
now under construction [33]. The present study provides
the first comprehensive and systematic assessment of
the salicylate content of commonly consumed foods and
is the first estimation of the dietary intake of salicylates
by a Scottish population. The database can be updated
and estimates of intake improved as further literature
that satisfies the systematic selection criteria becomes
available.
A particular strength of the database is only accepting
salicylate values obtained using gas or LC with alkaline or
acid hydrolysis, compound validation by MS and stated
quality assurance procedures. Values obtained by older, less
specific and colorimetric procedures were excluded as being
potentially artefactually high. However, a limitation is the
Table 1. Total salicylate content of foods purchased from local
Scottish retailers as determined by HPLC with
electrochemical detection
Food item Salicylates
(mg/kg)
Food item Salicylates
(mg/kg)
Fruits Vegetables
Banana 0.34 Asparagus 1.29
Blackberries 0.81 Aubergine 0.0
Blueberries 0.57 Broccoli 0.0
Gala melon 0.62 Cabbage
green
0.0
Grapefruit 0.44 Carrots 0.16
Green apple 0.55 Cauliflower 0.01
Kiwi fruit 0.31 Celery 0.04
Lime 0.0 Courgette 0.0
Mango 0.03 Cucumber 0.02
Nectarine 3.29 Green bean 0.07
Orange 0.11 Green pepper 0.01
Peach 0.12 Lettuce
(iceberg)
0.05
Pear 0.23 Mange tout 0.20
Plum 0.01 Mushroom
(button)
0.13
Raspberry 0.09 Onion (white) 0.80
Red grape 0.02 Potato 0.02
Strawberry 0.61 Red pepper 0.09
White grape 0.02 Swede 0.07
Yellow
melon
0.11 Tomato 0.13
Yellow pepper 0.09
Juices Spices
Apple 0.83 Black cumin 25.05
Cranberry 0.99 Cumin 29.76
Grapefruit 0.10 Chat masala 5.74
Orange 0.68 Cinnamon 0.78
Pineapple 4.06 Garam masala 12.85
Tomato 1.32 Paprika 28.25
Turmeric 20.88
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Table 2. The total salicylate database: median values calculated from combining in-house determinations with systematically reviewed
literature values
Food item (n) State Median (mg/kg) Range (mg/kg) References
Fruits
Apple (5) Fresh 0.55 o0.02–5.9 [9, 12, 21, 22], Table 1
Apricot (3) Tinned 0.10 0.03–25.8 [9, 12, 22]
Banana (3) Fresh 0.40 0.34–18.6 [9, 21], Table 1
Blackberry (3) Fresh 0.81 0.07–18.6 [9, 23], Table 1
Black chokeberry (1) Fresh 1.20 1.2 [23]
Blueberry (3) Fresh 0.57 0.33–27.80 [9, 23], Table 1
Bramble (1) Fresh 8.30 8.3 [23]
Cherry (2) Fresh 4.43 0.36–8.5 [9, 12]
Crowberry (1) Fresh 2.80 2.8 [23]
Grapes red (2) Fresh 4.71 0.02–9.4 [9], Table 1
Grapes white (4) Fresh 0.04 0.02–0.6 [12, 21, 22], Table 1
Grapefruit (3) Fresh 0.44 0.2–6.8 [9, 21], Table 1
Kiwi fruit (3) Fresh 0.31 o0.2–3.2 [9, 21], Table 1
Lemon (2) Fresh 2.50 1.8–3.2 [9, 21]
Lime (1) Fresh 0 0 Table 1
Mango (2) Fresh 0.57 0.03–1.1 [9], Table 1
Melon gala (1) Fresh 0.62 0.62 Table 1
Melon honeydew (1) Fresh 0.11 0.11 Table 1
Nectarine (5) Fresh 0.87 0.04–4.9 [9, 12, 21, 22], Table 1
Orange (5) Fresh 0.11 o0.02–23.9 [9, 12, 21, 22], Table 1
Peach (2) Fresh 2.96 0.12–5.8 [9], Table 1
Pear (3) Fresh 1.46 o0.2–2.7 [9, 21], Table 1
Plum (3) Fresh 0.50 0.01–2.1 [9, 21], Table 1
Raspberries (3) Fresh 0.90 0.09–51.4 [9, 23], Table 1
Raisins (2) Fresh 33.59 0.98–66.2 [9, 12]
Sorbus (1) Fresh 0.28 0.28 [22]
Strawberry (4) Fresh 0.63 0.04–13.6 [9, 12, 22], Table 1
Vegetables
Asparagus (2) Fresh 1.35 1.29–1.4 [9], Table 1
Aubergine (2) Fresh 4.40 0–8.8 [9], Table 1
Broccoli (2) Fresh 3.25 0–6.5 [9], Table 1
Cabbage-green (2) Fresh 0 0 [9], Table 1
Carrot (3) Fresh 0.50 0.16–2.3 [9, 21], Table 1
Cauliflower (2) Fresh 0.80 0.01–1.6 [23], Table 1
Celery (2) Fresh 0.02 0–0.04 [9], Table1
Courgette (1) Fresh 0 0 Table 1
Cucumber (4) Fresh 0.24 0.02–7.8 [9, 12, 21], Table 1
Green beans (2) Fresh 0.59 0.07–1.1 [9], Table 1
Lettuce (2) Fresh 0.02 0–0.05 [9], Table 1
Mange tout (1) Fresh 0.20 0.2 Table 1
Mushroom (2) Fresh 1.27 0.13–2.4 [9], Table 1
Onion (2) Fresh 1.20 0.8–1.6 [9], Table 1
Peas frozen (2) Fresh 0.35 0.3–0.4 [9, 21]
Peppers-green (2) Fresh 6.01 0.01–12 [9], Table 1
Peppers-red (1) Fresh 0.1 0.1 Table 1
Pepper-yellow (1) Fresh 0.1 0.1 Table 1
Potato (2) Fresh 0.01 0–0.02 [9], Table 1
Swede (2) Fresh 0.04 0–0.07 [9], Table 1
Tomato (5) Fresh 0.36 0.05-1.3 [9, 12, 21, 23], Table 1
Herbs, spices and condiments
Asafoetida (1) Dried 38 38 [20]
Black cumin (1) Dried 25.05 25.05 Table 1
Cardamom black (2) Dried 173.5 77–270 [9, 20]
Cardamom green (1) Dried 132 132 [20]
Chat masala (1) Dried 5.74 5.74 Table 1
Chilli powder (3) Dried 13 o0.2–1466 [9, 20]
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lack of information on how locality, varietal and growing
conditions and the effects of processing and storage affect
the salicylate content of foods. For example, the salicylate
content of five brands of orange juice ranged from 0.47 to
3.01 mg/L. Such potential confounding affects have been
minimised by the computation of single, median salicylate
values for each food item. This may more likely reflect the
intake of a population exposed to a diverse range of products
over the longer term. In addition to seasonal and varietal
influences on salicylate contents of primary products, the
database would benefit from direct analysis of commonly
consumed meals. Calculated daily intakes included standard
recipes but no information is available on the salicylate
content of processed foods where some forms may be used
as flavouring agents or preservatives [34].
Estimated medial salicylate intakes of 4.42 and 3.16 mg/
day for males and females respectively are comparable with
Table 2. Continued
Food item (n) State Median (mg/kg) Range (mg/kg) References
Cinnamon (5) Dried 23.8 0.78–642 [9, 12, 20, 21], Table 1
Cloves (2) Dried 41.2 25–57.4 [9, 20]
Coriander (2) Fresh 14.5 2–27 [9, 20]
Cumin (3) Dried 450 29.8–16294 [9, 20], Table 1
Curry powder (3) Dried 15.2 5.55–2180 [9, 12, 21]
Fennel (2) Dried 14 8–20 [9, 20]
Fenugreek (2) Dried 61.5 1–122 [9, 20]
Garam masala (2) Dried 340.42 12.85–668 [9], Table 1
Garlic (3) Fresh 1 o0.2–56 [9, 19, 20]
Ginger (3) Fresh 35 o0.2–45 [9, 20, 21]
Honey (3) Liquid 0.66 o0.2–39 [9, 12, 21]
Mint (2) Fresh 54.2 14.4–94 [9, 21]
Mixed herbs (2) Dried 289.15 22.3–556 [9, 21]
Nutmeg (2) Dried 26.09 24–28.18 [9], Table 1
Oregano (3) Dried 26 19.9–660 [9, 12, 21]
Paprika hot (5) Dried 28.25 2.98–2030 [9, 12, 20, 21], Table1
Pepper black (4) Dried 33.85 3.05–90 [9, 12, 20, 21]
Tamarind (1) Fresh 96 96 [20]
Turmeric (4) Dried 392.44 17–3505 [9, 12, 20], Table 1
Thyme (3) Dried 28.6 12.8–1830 [9, 12, 21]
Malt vinegar (2) Liquid 0.03 0–0.05 [9, 21]
White vinegar (2) Liquid 6.73 0.15–13.3 [9, 21]
Soups
Lentil (2) Tinned, liquid 0.21 0.12–0.3 [19]
Tomato (3) Tinned, liquid 0.022 0.005–0.034 [19]
Drinks
Coffee-instant (3) Freeze dried, liquid 1.8 0.37–6.8 [9, 12, 21]
Tea (3) Tea bag, liquid 1.06 0.42–34.5 [9, 12, 21]
Beer (2) Liquid 1.63 0.06–3.2 [9, 21]
White wine (8) Liquid 0.44 0.01–12.9 [21, 23]
Red wine (13) Liquid 0.50 0–2.58 [12, 21, 23]
Apple juice (3) Liquid 0.83 0.73–3.81 Table 1
Cranberry juice (2) Liquid 0.99 0.91–1.07 Table 1
Grapefruit juice (1) Liquid 0.10 Table 1
Orange juice (5) Liquid 0.68 0.47–3.01 Table 1
Pineapple juice (1) Liquid 4.06 Table 1
Tomato juice (1) Liquid 1.32 Table 1
Table 3. Estimated total salicylate content of some standard
recipe dishes
Recipe dish Total salicylates
(mg/kg)
Bolognaise sauce 3.2
Pizza, tomato 0.7
Flan, cheese onion and potato 0.5
Flan, cheese and mushroom 0.2
Pancakes, savoury, stuffed with
vegetables
4.2
Nut roast 3.2
Dressing, oil and lemon 0.0
Chutney, tomato 8.5
Cornish pastie 4.9
Vegetable korma 7.3
Mol. Nutr. Food Res. 2011, 55, S7–S14 S11
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estimated intakes in a Scottish population of other phenolic
compounds including types of flavonols, flavones, flavo-
nones and proanthocyanins [35]. Fruits and vegetables are
major sources of salicylates accounting for approximately
25% of total intake. Fruits and vegetables are also rich
sources of fibre, vitamin C and potassium and, therefore,
significant associations between intakes of these nutrients
and salicylates are not unexpected. Spices also account for a
considerable proportion of total salicylate intake (14% in
males and 10% in females). Consequently, populations that
incorporate substantial amounts of spices in foods may have
markedly higher daily intakes of salicylates. Indeed, it has
been suggested that the low incidence of colorectal cancer
among Indian populations may be ascribed in part to high
exposure to dietary salicylates throughout life from spice
consumption [36]. In contrast, any potential cancer preven-
tative affects of dietary salicylates [37] in Scots may be
negated by the substantial proportion derived from bevera-
ges containing alcohol (22%), a recognised pro-carcinogenic
risk factor [38].
Serum and urinary salicylate concentrations of vegetar-
ians are higher than omnivores and overlap with individuals
who regularly take low-dose aspirin [39, 40]; this suggests
substantial absorption of salicylates from ingested plant-
based foods. Such serum concentrations are sufficient to
inhibit PGHS-2 mRNA synthesis and promoter activity
in vitro [41, 42] thus preventing the conversion of arachi-
donic acid to potentially tumour-promoting cyclic prosta-
noids. The Scottish population has a habitually low intake of
fruits and vegetables [43] and salicylate intakes in the
present study, therefore, may be insufficient to exert disease
preventative effects. Application of the database to popula-
tions with differing dietary habits and disease risk profiles
may provide further evidence for the role of dietary salicy-
lates in the prevention of chronic diseases.
A. W. was funded by the Food Standards Agency (UK)
Scholarship Scheme. G. D. is grateful for funding from the
Scottish Government. This paper is dedicated to the late John
Paterson.
The authors have declared no conflict of interest.
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... The derived amounts of salicylic acid in foods are small and depend on food production techniques, culturally linked diets, and geographic origin of the products [12]. According to a Scottish review, average daily intake of salicylic acid was 4.42 mg and 3.16 mg for men and women, respectively [13]. Dietary products containing relatively high amounts of salicylates are vegetables (tomato, asparagus, corn), fruits (apple, cherry, strawberry, currant, raisin, peach, nectarine, kiwi, melon), berries, spices, coffee, tea, and alcohol [11]. ...
... In the interaction model, diets were not significantly associated with gender, age, BMI, allergic diseases, or chronic diseases, indicating that diets could be an AERD-dependent phenomenon in this group. Physicians do not generally recommend low-salicylate diet due to both the lack of evidence-based efficacy and the resulting restriction of healthy fruit and vegetable consumption [11,13,14,38]. The salicylate intake in western-type of low-spice food is low [12,13] and the adherence to this diet is also difficult as it affects quality of life [14], further arguing against actively promoting low-salicylate diets. ...
... Physicians do not generally recommend low-salicylate diet due to both the lack of evidence-based efficacy and the resulting restriction of healthy fruit and vegetable consumption [11,13,14,38]. The salicylate intake in western-type of low-spice food is low [12,13] and the adherence to this diet is also difficult as it affects quality of life [14], further arguing against actively promoting low-salicylate diets. A strict diet, high in omega-3 and low in omega-6-fatty acids, has been shown to lead to improved upper respiratory symptoms and decreased production of arachidonic acidderived inflammatory lipids relevant to AERD [39]. ...
Article
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Background The adoption of avoidance diets by adult-onset asthmatics has not previously been studied. We hypothesized that avoidance diets would associate with adult-onset asthma, allergy, and aspirin-exacerbated respiratory disease (AERD). Methods A total of 1247 subjects with adult-onset asthma (age range: 31–91) from the Finnish national registry, and age- and sex-matched controls (n = 1970) participated in a questionnaire study in 1997. We estimated the association between asthma/allergy/AERD and avoidance diets, adjusting for potential confounding factors and validated the results in two retrospective cohorts of 5080 rhinitis/rhinosinusitis patients and 167 AERD patients from 2019 to 2020. Results The presence of asthma positively associated with adoption of any avoidance diet (adjusted OR [CI95%] 1.24 [1.02–1.51], p = 0.029) as did allergic disease and self-reported AERD within the asthmatic group (1.79 [1.29–2.48], p = 0.001 and 1.69 [1.15–2.49], p = 0.007, respectively). Asthmatics and allergic asthmatics were more likely to report avoidance of fish, fruits and vegetables, and spices (p ≤ 0.03) compared to controls and non-allergic asthmatics. The adjusted OR for multiple diets among AERD patients was 2.57 [1.34–4.95] p = 0.005. In the validation, 26.2% of the allergic asthmatics and 10.8% of AERD patients had documented avoidance diets. Conclusions Our study shows a positive association between avoidance diets and adult-onset asthma, and with allergic disease or AERD within asthmatic patients. Although we lack information on the reason patients chose to observe a specific diet, our results reinforce the importance of asking patients about their diet and if needed, giving dietary advice for adult asthma patients to help them avoid the adoption of unnecessarily restrictive diets.
... Phenolic acids are omnipresent in edible vegetables, fruits, and nuts, with an estimated average daily consumption of 1-2 g of these components in a human diet [7]. Salicylic acid, a secondary metabolite associated with plant disease resistance and abiotic stress response, exhibits higher levels in nectarines (3.29 mg/kg), asparagus (1.29 mg/kg), and spices like cumin (29.76 mg/kg), black cumin (25.05 mg/kg), and paprika (28.25 mg/kg) [8]. Protocatechuic acid is more abundant in traditional Chinese medicine and berries such as Eucommia ulmoides (1720 mg/100 g), black olives (21 mg/100 g), and black raspberries (8.35 mg/100 g) [9]. ...
... Cinnamic acid is found in high Phenolic acids are omnipresent in edible vegetables, fruits, and nuts, with an estimated average daily consumption of 1-2 g of these components in a human diet [7]. Salicylic acid, a secondary metabolite associated with plant disease resistance and abiotic stress response, exhibits higher levels in nectarines (3.29 mg/kg), asparagus (1.29 mg/kg), and spices like cumin (29.76 mg/kg), black cumin (25.05 mg/kg), and paprika (28.25 mg/kg) [8]. Protocatechuic acid is more abundant in traditional Chinese medicine and berries such as Eucommia ulmoides (1720 mg/100 g), black olives (21 mg/100 g), and black raspberries (8.35 mg/100 g) [9]. ...
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Inflammatory bowel disease (IBD) is a chronic inflammatory intestinal disorder, and its complex etiology makes prevention and treatment challenging. Research on new drugs and treatment strategies is currently a focal point. Phenolic acids are widely present in plant-based diets and have demonstrated the potential to alleviate colitis due to their powerful antioxidant and anti-inflammatory properties. In this review, we provide an overview of the structures and main dietary sources of phenolic acids, encompassing benzoic acid and cinnamic acid. Additionally, we explore the potential of phenolic acids as a nutritional therapy for preventing and treating IBD. In animal and cell experiments, phenolic acids effectively alleviate IBD induced by drug exposure or genetic defects. The mechanisms include improving intestinal mucosal barrier function, reducing oxidative stress, inhibiting excessive activation of the immune response, and regulating the balance of the intestinal microbiota. Our observation points towards the need for additional basic and clinical investigations on phenolic acids and their derivatives as potential novel therapeutic agents for IBD.
... In a systematic review, Wood et al. were able to establish the average of daily salicylate intake in the diet of Scottish population, making it possible to define what is a high or low salicylate diet (103). However, it is difficult to apply this information to other populations because of the diversity of food and types of food processing in each country. ...
Article
Full-text available
It has been estimated that Nonsteroidal Anti-inflammatory drug (NSAID) Exacerbated Respiratory Disease (N-ERD) previously named as Aspirin Exacerbated Respiratory Disease (A-ERD) affects around 1.4 million persons in the United States. Its prevalence in asthmatic patients has widely been underestimated, as a considerable number of patients would need an aspirin provocation test to confirm the diagnosis. N-ERD physiopathology is somehow complex, but basically involves an imbalance in the arachidonic acid metabolite pathway. The syndrome is characterized by the presence of asthma, chronic rhinosinusitis with nasal polyposis (CRSwNP) and NSAID and aspirin intolerance. Despite maximal and comprehensive medical treatment, the disease tends to be severe, with difficult to treat asthma and highly aggressive and recurrent ethmoidal polyposis. Recently, monoclonal antibodies aimed at reducing type 2 inflammation have demonstrated very promising results on disease control. The goal of this review is to provide the most recent published advances and evidence on physiopathology, diagnostic protocols and therapeutic strategies of N-ERD.
... Findings from systematic reviews can be viewed as independent scientific publications to document the state of the scientific evidence, identify knowledge gaps and research needs, provide input into program and policy decision-making processes, and serve as the foundation for later updates as new data emerge [34]. Although systematic reviews are well known in the broader scientific/medical fraternity, their use in food composition is relatively new [19,21,35,36]. This systematic review was thus conducted due to the gap in knowledge of available polyphenol data and the need for such data in the country, as well as to provide scientific evidence to inform the South African Food Data System. ...
Article
Full-text available
Comprehensively compiled dietary polyphenol data is required to compare polyphenol content between foods, calculate polyphenol intake and study its association with health and disease. The purpose of this review was to identify data on the presence and content of polyphenolic components in South African foods, with the aim of compiling the data into a database. An electronic literature search was conducted up until January 2020 using multiple databases. Additional literature was sourced from South African university repositories. A total of 7051 potentially eligible references were identified, of which 384 met the inclusion criteria. These studies provided information on food item name, geographical distribution, polyphenol type, quantity, and quantification method. Data for 1070 foods were identified, amounting to 4994 polyphenols. Spectrophotometry was the main method used for quantification of gross phenolic content in various assays such as total phenolic content (Folin–Ciocalteu assay), total flavonoid content (AlCl3 assay) and condensed tannin content (vanillin–HCl assay). Phenolic acids and flavonoids were the main polyphenol classes identified. This review highlights that South Africa has abundant information on the polyphenol content of foods, which could be utilised within a food composition database for the estimation of polyphenol intake for South Africa.
Article
Introduction: A particularly aggressive course of chronic sinusitis with nasal polyps is seen in patients with bronchial asthma and hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs). These patients often report exacerbation associated with consumption of foods reach in salicylates. Therefore, the authors analyzed the effect of a low-salicylate diet (LSD) on the course of chronic sinusitis with polyps in patients with NSAID-exacerbated respiratory disease (N-ERD) to answer the question: which patients would obtain the best therapeutic benefit? Methods: Adult patients with N-ERD were selected for dietary intervention with LSD. Patients were seen on two occasions: at an initial visit and a follow-up after 12 weeks of diet. At both visits, an evaluation was performed with total nasal symptom score (TNSS) and modified Lund-Kennedy (L-K) endoscopy score. Results: Forty patients (21 female, 52.5%, median and IQR of age 52; 43.5-61) used LSD for 12 weeks. Initial analysis of dietary intervention in the whole group revealed a significant decrease in TNSS and each symptom assessed separately, and the L-K score. The group was further divided into two subgroups based on the distance between NSAID intake and the beginning of symptoms: patients with immediate (n = 9; 22.5%) or non-immediate (n = 31; 77.5%) symptoms. The absolute change in nasal obstruction, itching, TNSS, and L-K scores were significantly higher in patients with immediate than with non-immediate symptoms. Conclusion: Results of the study indicate that patients with N-ERD and immediate symptoms may clinically benefit more from an LSD as an additional therapeutic option than patients with non-immediate symptoms.
Article
Salicylates are generally present in plants as part of their defense system against pathogens and environmental stress. Major dietary sources of salicylates were found in spices and herbs, such as curry and paprika (hot powder). Several studies suggest that these natural salicylates offer health benefits in the human body, such as antidiabetic, anticancer, antiviral, and anti-inflammatory properties. However, despite their advantages, salicylates can be harmful to people with allergies, and high doses of salicylates may cause respiratory alkalosis and gastrointestinal bleeding. Additionally, salicylates can interact with certain drugs, such as nonsteroidal anti-inflammatory drugs and warfarin. This narrative review aimed to consolidate recent information on the content of salicylates in food based on the literature, while also highlighting the benefits and risks associated with salicylate consumption in humans. Based on the literature review and analysis of results, it can be concluded that the dietary intake of salicylates in vegetarians can be relatively high, resulting in concentrations of salicylic acid in the blood and urine that are comparable to those observed in patients taking a low dose of aspirin (75 mg). This suggests that a diet rich in salicylates may have potential benefits in preventing and treating some diseases that require low doses of aspirin.
Article
The test of the association between dietary intake of specific carotenoids and disease incidence requires the availability of accurate and current food composition data for individual carotenoids. To generate a carotenoid database, an artificial intelligence system was developed to evaluate data for carotenoid content of food in five general categories, namely, number of samples, analytic method, sample handling, sampling plan, and analytic quality control. Within these categories, criteria have been created to rate analytic data for beta-carotene, alpha-carotene, lutein, lycopene, and beta-cryptoxanthin in fruits and vegetables. These carotenoids are also found in human blood. Following the evaluation of data, acceptable values for each carotenoid in the foods were combined to generate a database of 120 foods. The database includes the food description; median, minimum, and maximum values for the specific carotenoids in each food; the number of acceptable values and their references; and a confidence code, which is an indicator of the reliability of a specific carotenoid value for a food. The carotenoid database can be used to estimate the intake of specific carotenoids in order to examine the association between dietary carotenoids and disease incidence.
Chapter
Historical perspectiveDefinitions and terminologyConsumption patterns of plantderived foods and drinksSources, intakes and properties of constituents of plant-derived foods and drinksBioavailability and interactionsSummaryResearch recommendationsKey points
Article
Aim To compare amounts of salicyluric acid (SU) and salicylic acid (SA) excreted daily in the urine of non-vegetarians and vegetarians not taking salicylate drugs, and patients taking 75 or 150 mg aspirin/day. Methods Urine excreted over 24 hours was collected from volunteers in the four groups. The volumes were recorded and the concentrations of SU and SA were determined electrochemically after separation by high performance liquid chromatography. Results Significantly more SU was excreted daily by vegetarians (median, 11.01; range, 4.98–26.60 μmol/24 hours) than by non-vegetarians (median, 3.91; range, 0.87–12.23 μmol/24 hours), although amounts were significantly lower than those excreted by patients taking aspirin. Median amounts of SU excreted by patients taking 75 and 150 mg/day of low dose aspirin were 170.69 (range, 13.15–377.18) μmol/24 hours and 165.17 (range, 5.61–429.12) μmol/24 hours, respectively. The amount of SU excreted by patients taking either 75 or 150 mg of aspirin/day was not significantly different. Significantly more SA was excreted by vegetarians (median, 1.19; range, 0.02–3.55 μmol/24 hours) than by non-vegetarians (median, 0.31; range, 0.01–2.01 μmol/24 hours). The median amounts of SA excreted by vegetarians and the patients taking aspirin were not significantly different. Conclusions More SU and SA is excreted in the urine of vegetarians than in non-vegetarians, consistent with the observation that fruits and vegetables are important sources of dietary salicylates. However, significantly less SU was excreted by vegetarians than patients taking aspirin, indicating that the daily intake of bioavailable salicylates by vegetarians is considerably lower than that supplied by a single 75 or 150 mg dose of aspirin.
Article
The salicylic acid concentration in a range of fresh and canned fruit and vegetables was determined using a sensitive spectrofluorimetric technique. Concentrations in fresh fruit ranged from 0.02 mg kg-1 in kiwifruit to 0.10 mg kg-1 in New Zealand grapefruit, and in fresh vegetables from 0.01 mg kg-1 in cabbage to 0.10 mg kg-1 in whole kernel sweet corn. In canned products, salicylic acid levels ranged from 0.01 mg kg-1 in pears to 0.82 mg kg-1 in cream-style sweet corn. Canned sweet corn and some tomato products had higher levels than the corresponding fresh vegetables. Evidence was obtained to suggest that, in the case of whole kernel sweet corn, the application of heat increased the concentration of free salicylic acid.
Article
The oxidation of arachidonic acid in vertebrate tissues is briefly compared to the oxidation of linolenic acid in plants. Both give rise to bio-active molecules containing cyclopentane rings, the prostaglandins and jasmonic acid respectively. Both oxidations are inhibited by salicylic acid, aspirin and other non-steroidal, anti-inflammatory drugs. Aspirin is known to inhibit the cyclising enzyme, cyclo-oxygenase in animal tissues. By contrast it is thought to inhibit allene oxide synthase (AOS) rather than the analogous cyclising enzyme in plants. This conclusion is based on studies of an unusual isoform of AOS, and it is suggested that a search should be made for aspirin-acetylatable proteins in extracts of the leaves of temperate crop plants. The possible reaction of aspirin with the unusual AOS produced by sea corals is briefly considered.
Article
Background Salicylic acid is a chemical signal in plants infected by pathogens and it is responsible for the anti-inflammatory action of aspirin. Patients who take aspirin have a reduced risk of developing atherosclerosis and colorectal cancer, both of these pathologies having an inflammatory component. Dietary salicylic acid may help to prevent these conditions. We wondered if foods made from organically-reared plants might have a higher content of salicylic acid than those made from non-organic plants, since the latter are more likely to be protected from infection by the application of pesticides. Objective To determine if organic vegetable soups have a higher salicylic acid content than non-organic vegetable soups. Methods The contents of salicylic acid in organic and non-organic vegetable soups purchased from supermarkets were determined. Salicylic acid was identified by varying the chromatographic conditions and comparing the retention times of the unknown substance in the extracts with salicylic acid; by treating extracts of the soups with salicylate hydroxylase; and by using GCMS. Salicylic acid was determined by using HPLC with electrochemical detection. Results Salicylic acid was present in all of the organic and most of the non-organic vegetable soups. The median contents of salicylic acid in the organic and non-organic vegetable soups were 117 (range, 8–1040) ng · g−1 and 20 (range, 0–248) ng · g−1 respectively. The organic soups had a significantly higher content of salicylic acid (p=0.0032 Mann Whitney U test), with a median difference of 59 ng · g−1 (95 % confidence interval, 18–117ng · g−1). Conclusions Organic vegetable soups contained more salicylic acid than non-organic ones, suggesting that the vegetables and plants used to prepare them contained greater amounts of the phenolic acid than the corresponding non-organic ingredients. Consumption of organic foods may result in a greater intake of salicylic acid.
Article
Dietary salicylates inhibit cycloxygenase-2 and may therefore have anti-inflammatory properties similar to those of aspirin. Individuals that are sensitive to aspirin may also be intolerant to non-acetylated salicylates and could benefit from a low salicylate diet. A total of 76 foodstuffs comprising fruit (16), fresh and prepared vegetables (13), herbs and spices (12), flavourings and sauces (9), beverages (20) and miscellaneous foods (6) were analysed using gas chromatography with mass spectrometric detection and 13C carboxyl SA as internal standard. Thirty-seven of the samples contained detectable SA, the highest levels being found in dried herbs (up to 28.6 mg/kg), whereas only one sample (curry sauce) contained detectable ASA at 0.34 mg/kg. Limits of detection for both SA and ASA were matrix-dependent and ranged from 0.008 to 0.23 mg/kg. The results show many inconsistencies with previous data and highlight the need for analysis of a wider range of foods and drinks that are currently available.
Article
Considerable information on polyphenol content in foods is scattered in up to 1000 peer-reviewed publications and is therefore not easily exploited. Over 60000 food composition data have been collected from this literature and stored in the new Phenol-Explorer database ( www.phenol-explorer.eu ). Thirty-seven thousand data were selected after evaluation and aggregated separately according to 5 categories of analytical methods to generate mean content values for 502 compounds (glycosides, esters, or aglycones) in 452 foods. These data are exploited here in a first systematic analysis of the content in foods of these 502 polyphenols. These data will be useful for epidemiologists to determine polyphenol intake and associations with health and diseases in populations and for food scientitsts and food manufacturers to develop new products with optimized properties.
Article
We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn hydrolysis to salicylic acid. With the method for free acetylsalicylic acid and salicylic acid, recovery was 95-98␏or acetylsalicylic acid added to foods and 92-102␏or salicylic acid. Recovery of added salicylic acid was 79-94␏or the free-plus-bound salicylic acid method. The limit of detection was 0.02 mg/kg for fresh and 0.2 mg/kg for dried foods for all substances. We did not find acetylsalicylic acid in any of 30 foods previously thought to be high in salicylates. The contents of free-plus-bound salicylic acid and of free salicylic acid ranged from 0 to 1 mg/kg in vegetables and fruits and from 3 to 28 mg/kg in herbs and spices. Thus the tested foods did not contain acetylsalicylic acid and only small amounts of salicylic acid. Our data suggest that the average daily intake of acetylsalicylic acid from foods is nil and that of salicylic acid is 0-5 mg/day.