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Rodriguez-Leyva and Pierce Nutrition & Metabolism 2010, 7:32
http://www.nutritionandmetabolism.com/content/7/1/32
Open Access
REVIEW
BioMed Central
© 2010 Rodriguez-Leyva and Pierce; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Cre-
ative Commons Attribution Licens e (http://creativecommons.org/licenses/by/ 2.0), which permits unrestricted use, distri bution, and re-
production in any medium, provided the original work is properly cited.
Review
The cardiac and haemostatic effects of dietary
hempseed
Delfin Rodriguez-Leyva
1,2
and Grant N Pierce*
1
Abstract
Despite its use in our diet for hundreds of years, hempseed has surprisingly little research published on its physiological
effects. This may have been in the past because the psychotropic properties wrongly attributed to hemp would
complicate any conclusions obtained through its study. Hemp has a botanical relationship to drug/medicinal varieties
of Cannabis. However, hempseed no longer contains psychotropic action and instead may provide significant health
benefits. Hempseed has an excellent content of omega-3 and omega-6 fatty acids. These compounds have beneficial
effects on our cardiovascular health. Recent studies, mostly in animals, have examined the effects of these fatty acids
and dietary hempseed itself on platelet aggregation, ischemic heart disease and other aspects of our cardiovascular
health. The purpose of this article is to review the latest developments in this rapidly emerging research field with a
focus on the cardiac and vascular effects of dietary hempseed.
Introduction
Cannabis sativa L. is an annual plant in the Cannabaceae
family. It has been an important source of food, fiber,
medicine and psychoactive/religious drug since prehis-
toric times [1]. Cannabis is mentioned as a medication in
ancient Egyptian medical texts: Ramesseum III Papyrus
(1700 B.C.), Eber's Papyrus (1600 B.C.), the Berlin Papy-
rus (1300 B.C.), and the Chester Beatty VI Papyrus (1300
B.C.) [1,2].
Two main types of Cannabis Sativa L. must be distin-
guished, the drug and non-drug types. The first is also
known as marijuana, hashish or Cannabis tincture and
contains Δ9-Tetrahydrocannabinol (THC) in concentra-
tions between 1-20%, high enough to exhibit psychoactiv-
ity. The second type of Cannabis Sativa L. is industrial
hemp with THC concentrations < 0.3% so it has no psy-
choactive properties [3,4].
Canada, Australia, Austria, China, Great Britain,
France and Spain are among the most important agricul-
tural producers of hempseed. In the United States, it is
not legal to cultivate hempseed. This is primarily because
many believe that by legalizing hemp they may lead to a
legalization of marijuana [5]. Other governments have
accepted the distinction between the two types of Canna-
bis and, while continuing to penalize the growing of mar-
ijuana, have legalized the growing of industrial hemp [5].
Hempseed possesses excellent nutritional value. It is
very rich in essential fatty acids (EFAs) and other polyun-
saturated fatty acids (PUFAs). It has almost as much pro-
tein as soybean and is also rich in Vitamin E and minerals
such as phosphorus, potassium, sodium, magnesium, sul-
fur, calcium, iron, and zinc [6,7]. The nutrient profile of
hempseed is shown in Table 1. Hempseed oil contains all
of the essential amino acids and also contains surprisingly
high levels of the amino acid arginine, a metabolic pre-
cursor for the production of nitric oxide (NO), a molecule
now recognized as a pivotal signaling messenger in the
cardiovascular system that participates in the control of
hemostasis, fibrinolysis, platelet and leukocyte interac-
tions with the arterial wall, regulation of vascular tone,
proliferation of vascular smooth muscle cells, and
homeostasis of blood pressure [8]. In a study that
included 13 401 participants, 25 years and older from the
Third National Health Nutrition and Examination Sur-
vey, an independent relationship was shown between the
dietary intake of L-arginine and levels of C-Reactive pro-
tein [9], a marker strongly correlated with the risk of car-
diovascular disease (CVD) [10]. The results of this
populated-based study suggested that individuals may be
able to decrease their risk for CVD by following a diet
that is high in arginine-rich foods [9]. Dietary hempseed
* Correspondence: gpierce@sbrc.ca
1 Department of Physiology, University of Manitoba and Institute of
Cardiovascular Sciences, St Boniface Hospital Research Centre, 351 Tache
Avenue, Winnipeg, Manitoba, R2H 2A6, Canada
Full list of author information is available at the end of the article
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Table 1: Nutrient profile of hempseed*.
Nutrient Units Value per 100
grams
Nutrient Units Value per 100
grams
Proximates
Energy kcal 567 Lipids
Energy kJ 2200 Saturated fat g 3.3
Protein g 24.8 16:0 g 3.44
Total lipid (fat) g 35.5 18:0 g 1.46
Ash g 5.6 20:0 g 0.28
Carbohydrates g 27.6 Monounsaturated
fat
g5.8
Fiber, total dietary g 27.6 18:1n9 g 9
Digestable fiber g 5.4 Total
polyunsaturated
g36.2
Non-digestable
fiber
g 22.2 18:2n6 g 56
Moisture g 6.5 18:3n6 g 4
Glucose g 0.30 18:3n3 g 22
Fructose g 0.45 18:4n3 g 2
Lactose g <0.1 Cholesterol mg 0
Maltose g <0.1 Amino acids
Tryptophan g 0.20
Minerals Threonine g 0.88
Calcium, Ca mg 145 Isoleucine g 0.98
Iron, Fe mg 14 Leucine g 1.72
Magnesium, Mg mg 483 Lysine g 1.03
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is also particularly rich in the omega-6 fatty acid linoleic
acid (LA) and also contains elevated concentrations of
the omega-3 fatty acid α-linolenic acid (ALA). The
LA:ALA ratio normally exists in hempseed at between
2:1 and 3:1 levels. This proportion has been proposed to
be ideal for a healthy diet [11]. Other rich sources of LA
[12,13] are listed in Table 2.
The long chain PUFA that is found in the body ulti-
mately originates from the diet and through elongation
and desaturation of their dietary precursors, ALA and
LA. Both families of fatty acids, n-3 and n-6, share and
compete for the same enzymes (Δ6-desaturase, Δ5-desat-
urase, and elongases) in their biosynthetic pathways. The
Δ6-desaturase enzyme is the rate-limiting step [9]. Fol-
lowing its metabolism, LA can be converted into arachi-
donic acid whereas ALA will be converted into the long
chain fatty acids, eicosapentaenoic acid (EPA) and doco-
sahexaenoic acid (DHA) (Figure 1). A high LA intake
interferes with the desaturation and elongation of ALA
[14]. Therefore, theorically, a lower ratio of omega-6/
omega-3 fatty acids is more advantageous in reducing the
risk of many of the chronic diseases of high prevalence in
Western societies. The ratio of ω-6 to ω-3 fatty acids
ranges from 20-30:1 in Western societies instead of the
traditional (historic) range of 1-2:1 on which human
beings evolved [15]. This is thought to be closely associ-
ated with chronic diseases like coronary artery disease,
hypertension, diabetes, arthritis, osteoporosis, inflamma-
tory and autoimmune disorders and cancer.
Phosphorus, P mg 1160 Methionine g 0.58
Potassium, K mg 859 Cystine g 0.41
Sodium, Na mg 12 Phenylalanine g 1.17
Zinc, Zn mg 7 Tyrosine g 0.82
Copper, Cu mg 2 Valine g 1.28
Manganese, Mn mg 7 Arginine g 3.10
Selenium, Se mcg <0.02 Histidine g 0.71
Vitamins Alanine g 1.28
Vitamin C mg 1.0 Aspartic acid g 2.78
Thiamin mg 0.4 Glutamic acid g 4.57
Riboflavin mg 0.11 Glycine g 1.14
Niacin mg 2.8 Proline g 1.15
Vitamin B-6 mg 0.12 Serine g 1.27
Vitamin A IU 3800
Vitamin D UI 2277.5
Vitamin E mg 90.00
* Adapted from reference 6 and 7. Data based on Finola variety of hempseed.
Table 1: Nutrient profile of hempseed*. (Continued)
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Hempseed is also a rich and unusual source of the poly-
unsaturated fatty acid gamma linolenic acid (GLA)
(18:3n6) to the body. Additionally, another important
biological metabolite of ALA and LA, stearidonic acid
(18:4n3; SDA) is also present in hempseed oil (Figure 1).
Both can inhibit inflammatory responses [16,17].
Recently, many studies have demonstrated that dietary
interventions can play a central role in the primary and
secondary prevention of several diseases. The PUFAs
derived from fish, EPA and DHA, have been extensively
studied. Based on the close relation between the path-
ways that metabolize ALA and LA, and the capacity of
both to be converted into long chain fatty acids, plant
sources of ALA (i.e. flaxseed, canola and others) have
begun to attract more scientific attention for their poten-
tial to improve our health. However, because of legal reg-
ulations, lack of knowledge and some confusion about the
differences between fiber hemp and marijuana, the
growth of hempseed research has been slower than
expected. In view of its long history of dietary usage, it is
surprising that research on the effects of dietary hemp-
seed in animal and humans has been limited. Further-
more, because of its expected nutritional value and the
hypothetical benefits of LA and ALA against a variety of
health disorders, a better understanding of the appropri-
ate doses and presentation (oil, seed, etc) of hempseed
should represent useful health-related information. It is
important to point out that dietary hempseed as an
energy containing food item introduces changes in the
fatty acid composition of the diet and will inevitably
replace other dietary components under an isocaloric
condition. Previously some [18] but not all authors [19]
have found differences in body weight after the adminis-
tration of 30 ml/d of hempseed oil for four to eight weeks
in humans. Finally, an identification of the target patient
population (age, clinical condition, co-morbidities, etc)
that may benefit the most from a supplementation of
hempseed in the diet would also be important informa-
tion.
Animal Data
The biochemical metabolism of omega-6 fatty acids like
LA produces eicosanoids in the body. Eicosanoids are
biologically active and contribute to the formation of
thrombi and atheromas and shifts the physiological state
to one that is prothrombotic and proaggregatory, with
increases in blood viscosity, vasospasm, and vasocontric-
tion and decreases in bleeding time [15]. Hempseed is
rich in LA content. Therefore, hempseed has received
research attention for its effects on platelet aggregation.
Richard et al [20] reported that diets supplemented
with 5% and 10% hempseed (wt/wt) for 12 weeks resulted
in a significant increase in total plasma PUFAs in rats.
ALA and LA levels increased significantly in a concentra-
tion-dependent manner [20]. Dietary hempseed supple-
mentation also resulted in a significant inhibition of
platelet aggregation and a lower rate of aggregation. This
is an important result with physiological and pathological
implications. As we have become increasingly aware of
the importance of blood clots to the initiation of myocar-
Table 2: Rich sources of the essential fatty acid linoleic acid*.
Source of LA LA (g/100 g) ALA (g/100 g) Ratio n6/n3
Safflower oil 73 0.4 >100
Corn oil 57 1 57
Hempseed Oil 56 22 2.5
Cottonseed oil 50 0.2 >100
Soybean oil 50 8 6.2
Sesame oil 40 0.3 >100
Black walnuts 37 2 18.5
English walnuts 35 6.8 5.1
Sunflower seeds 30 0.06 >100
Brazil nuts 25 0.01 >100
Margarine 22 2.1 10.4
Pumpkin and squash seeds 20 0.12 >100
Spanish peanuts 16 0.01 >100
Peanut butter 15 0.08 >100
Almonds 10 0.06 >100
*Adapted from reference [12] and [13]
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dial infarctions and strokes, the capacity of a dietary
intervention like hempseed to inhibit clot formation has
obvious appeal. However, if excessive bleeding is an
expected event (as would be the case during surgery), it
becomes essential for the physician/surgeon to know of a
prior history of dietary hempseed usage.
These data on the effects of dietary hempseed on plate-
let aggregation have been extended into hypercholester-
olemic conditions by Prociuk and colleagues [21]. They
have shown that rabbits fed a high cholesterol diet for
eight weeks exhibit an enhanced platelet aggregation [21].
However, when 10% hempseed was supplemented to the
diet together with the high cholesterol diet, these hyperc-
holesterolemic animals displayed normal platelet aggre-
gation values. This normalization was not related to any
correction of the elevated plasma cholesterol levels but
was related in part to the increased levels of plasma
gamma-linolenic acid [21]. Because most patients at high
risk for coronary heart disease are hypercholesterolemic,
these findings have important potential for treating or
preventing cardiovascular diseases.
Two other studies have been focused on the capacity of
hempseed for altering cardiac function before and after
an ischemic event [22,23]. Both studies have shown no
effects of a hempseed-supplemented diet on basal cardiac
contractile function or electrical activity before ischemia
[22,23]. However, the data on the effects of dietary hemp-
seed on cardiac performance post-ischemia is less consis-
tent. Al-Khalifa and colleagues [23] reported that hearts
from rats fed a 5% or 10% hempseed supplemented diet
for 12 weeks exhibited significantly better post-ischemic
recovery of maximal contractile function and enhanced
rates of tension development and relaxation during rep-
erfusion than hearts from the control group. The authors
found that these hearts were not protected from the
occurrence of premature contractions, nor were the
increases in resting tension altered during ischemia or
reperfusion [23]. This beneficial effect of hempseed on
post-ischemic cardiac performance may be species spe-
cific. The same lab found that supplementation of the diet
with 10% hempseed in rabbits did not show any beneficial
effects on left ventricular end-diastolic pressure
(LVEDP), left ventricular developed pressure (LVDP),
arrhythmia incidence and arrhythmia duration during
ischemia and reperfusion [22]. Some limitations of the
study related to the duration of the dietary intervention
(8 weeks as opposed to 12 weeks) and sample size may
have influenced the capacity for the dietary hempseed to
protect the heart during ischemic insult [22].
Clinical Data
The actions of dietary hempseed in humans have only
been studied to a limited extent. Fatty acid bioavailability
from hempseed oil was recently studied in comparison to
two other dietary oils (fish and flaxseed) [24]. Hempseed
and hempseed oil is enriched in LA and GLA. Eighty-six
healthy subjects completed a 12 week dietary supplemen-
tation with 2 g/day of these oils. The hempseed interven-
tion did not significantly increase the concentration of
LA, GLA or any other fatty acid in the plasma of the sub-
jects, nor did it change the level of plasma total choles-
terol (TC), high density cholesterol (HDL-C), low density
cholesterol (LDL-C) or triglycerides (TG) [24]. Both flax-
seed and fish oils did induce significant changes in circu-
lating fatty acid species associated with their respective
oils (ALA for flaxseed; EPA and DHA for fish oil) [24].
Supplementation with hempseed oil also did not induce
any change in collagen- or thrombin-stimulated platelet
aggregation or in the levels of circulating inflammatory
markers [24]. It was suggested that the lack of effects may
be related to the dose used [24]. This hypothesis has been
supported by data obtained in another dietary interven-
tion that used higher doses of hempseed (30 ml/day) [18].
In this randomized, double-blinded, crossover design
trial, hempseed and flaxseed oils were compared at the
same doses. After 4 weeks of supplementation, the hemp-
seed intervention increased the concentrations of both
LA and GLA in serum cholesteryl esters (CE) and TG.
The flaxseed intervention resulted in higher serum CE
Figure 1 Biochemical pathway for linolenic acid and α-linolenic
acid transformation. ALA = α-linolenic acid; ARA = arachidonic acid;
DGLA = dihomo γ-linolenic acid; DHA = docosahexaenoic acid; DPA =
docosapentaenoic acid; EPA = eicosapentaenoic acid; GLA = γ-linolen-
ic acid; LA = linoleic acid.
18:3 (GLA) 18:4
20:3(DGLA)
20:4
22:4
22:5 (DPA)
24:4 24:5
24:5
24:6
6-desaturase
5-desaturase
elongase
elongase
6-desaturase
elon
g
ase
18:3 (ALA)
COOH
COOH
20:5 (EPA)
22:6 (DHA)
COOH
n-6 n-3
COOH
18:2 (LA)
COOH
20:4 (ARA)
COOH
22:5 (DPA)
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and TG concentrations of ALA. However, a statistically
significant decrease in GLA concentrations was observed
during this period of intervention. Importantly, the pro-
portion of arachidonic acid in CE was lower after the
flaxseed diet than after the hempseed supplementation
but this was not statistically significant. However, the
hempseed supplements resulted in a lower total choles-
terol:HDL cholesterol ratio. A higher total-to-HDL cho-
lesterol ratio has been found in association with coronary
heart disease [25]. However, no significant differences
were found between the effects of flaxseed and hempseed
oils in terms the fasting serum total or lipoprotein lipid
levels, plasma glucose levels, or insulin or hemostatic fac-
tors [18]. Callaway and colleagues [19], using 30 ml/day of
hempseed oil, conducted a 20-week randomized, single-
blind crossover study in 20 patients with atopic dermati-
tis, and found that the levels of both essential fatty acids,
LA and ALA, and GLA increased in all lipid fractions
after using hempseed oil, with no significant increases of
arachidonic acid in any lipid fractions. Moreover, atopic
dermatitis symptoms were improved after the interven-
tion with hempseed oil [19].
These results emphasize the importance of using
higher doses of hempseed oil if significant increases in
fatty acid species are to be achieved. Clearly, the ingestion
of two large capsules of hempseed daily (as most people
in the general public may ingest), is insufficient to achieve
a desired increase in LA or GLA levels in the plasma [24].
Much larger doses are required to induce beneficial phys-
iological effects. However, this may not be possible to
achieve currently in the general population. If 10-15
times the amount used by Kaul and co-workers [24] is
required to achieve a significant increase in plasma fatty
acid levels, it would be unpractical to expect the general
public to ingest 20-30 capsules of hempseed per day. This
is a significant problem that the food and supplement
industry must address in the future if hempseed is to be
considered a realistic dietary approach to healthy living.
Supplementing the diet with tablespoons of hemp oil in
addition to hemp capsules as well as ingesting foods that
contain these omega-3 fatty acids may be the optimal way
to obtain them.
Linoleic acid and heart disease: New research fields
for hempseed
Hempseed is a rich source of LA and others nutrients.
The specific pathologies or conditions in which it can be
used effectively are in need of more research but the data
presently available suggest that LA may have beneficial
effects in certain cardiovascular circumstances.
Effects on cholesterol levels
Iacono et al [26] reported that a high LA based diet
(10.8%) decreased total cholesterol by 15% and LDL-C by
22%, without producing significant changes in plasma
HDL-C after 6 weeks of dietary intervention in 11 healthy
middle aged, male subjects. Apolipoprotein B decreased
by 37% whereas apolipoprotein A-I increased by 24% in
the group of individuals supplemented with this diet [26].
In a multiple crossover design that included 56 normo-
lipemic, healthy subjects, Zock and colleagues [27] found
that those who received the LA supplemented dietary
intervention for three weeks (2.0% of total energy intake
as LA) obtained lower levels of serum LDL-C, and higher
HDL-C levels when compared with subjects who received
its hydrogenation products elaidic (trans-Cl8:ln9) and
stearic acid (C18:O). Recently, Mensink et al [28]
employed a meta-analysis that included 60 controlled tri-
als to show that polyunsaturated fat (mainly LA) reduces
LDL-C, triglycerides and increases HDL-C. However,
others have shown that healthy individuals supplemented
for 4 weeks with hempseed exhibited a lower total-to-
HDL cholesterol ratio [24]. A higher total:HDL choles-
terol ratio is associated with coronary heart disease and
has a worse prognosis after a myocardial infarction
[29,30]. Clearly, the issue is not resolved yet. The popula-
tion studied (healthy vs clinically compromised), the dos-
ages of hempseed used, the presentation administered
(whole hempseed vs milled hempseed vs hemp oil vs
purified LA), the duration of the dietary intervention, the
composition of the diet, are all factors that may be critical
in producing the effects (of lack of effects) in these stud-
ies. More research is needed in order to understand if
these specific conditions influence cardiovascular effi-
cacy and to understand which metabolic factors are most
sensitive (hypertriglyceridemia, hypercholesterolemia,
low HDL-C, or other hyperlipoproteinemias) to this kind
of dietary intervention.
Effects on high blood pressure
Results reported by The International Study of Macro-
Micronutrients and Blood Pressure, a cross-sectional epi-
demiological study that included 4680 individuals, sug-
gested that dietary LA intake may contribute to
prevention and control of high blood pressure [31]. Other
small studies have found that supplementation with LA (4
g-23 g/day) decreased blood pressure after 4 weeks of
dietary intervention [32,33]. However, these promising
results are in conflict with another study that reported no
association between LA intake and lower blood pressure
levels [34]. Studies using hempseed as a source of LA for
hypertensive patients have not been conducted. It is also
important to note that the consequences of these kinds of
diets on arterial stiffness and vascular perfusion charac-
teristics are unknown. The additional effects of these
diets on ventricular hypertrophy that develops secondary
to high blood pressure is not known nor are the effects
when hempseed is supplemented with an antihyperten-
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sive medication. The potential for hempseed to alter drug
kinetics in the body has not been studied.
Effects on atherosclerosis
Almost three decades ago, Cornwell and Panganamala
postulated that an intracellular deficiency in essential
fatty acids plays a central role in the atherogenic process
[35]. Recently, Das [36] showed how a defect in the activ-
ity of Δ6 and Δ5 desaturases may be a factor in the initia-
tion and progression of atherosclerosis. He also provided
evidence that low-grade systemic inflammatory condi-
tions are also essential fatty acids deficient states [36].
With our current understanding of the close relationship
that infectious disease and inflammation has with athero-
genesis [37,38], it is not difficult to predict that foods with
an optimal LA-ALA ratio will reduce inflammation under
ideal dietary conditions and it may thereby attenuate ath-
erosclerotic heart disease. Unfortunately, the effects of
LA on atherosclerosis are not completely clear. Arachi-
donic acid can be derived from LA. This can be con-
verted to prothrombotic and proinflammatory
prostaglandins. However, changes in dietary LA within
the usual dietary range do not appreciably alter arachi-
donic acid levels [39,40]. Consistent with this, some have
suggested that LA could have anti-inflammatory effects
mediated by biochemical pathways that do not involve
the cyclooxygenase pathway [41]. Presently, the random-
ized, controlled trials that address this topic have not
been able to distinguish between the effects of omega-3
and omega-6 fatty acids [42]. Both have had beneficial
effects by decreasing plasma levels of soluble TNF recep-
tor 1 and 2, indicators of TNF activity [42].
Surprisingly, studies of the effects on atherosclerotic
heart disease of dietary hempseed supplementation in
animals or humans have not been completed. This type of
study has been successfully completed using flaxseed as a
dietary intervention [43,44]. It would also be important to
determine if the LA content of hempseed (and not its
ALA content) is responsible for decreasing inflammatory
markers and the systemic atherosclerotic process in gen-
eral.
Coronary heart disease
A meta-analysis of data from 25 case-control studies
strongly suggested that a lower tissue content of LA is
associated with increased coronary heart disease risk
[45]. More importantly, this study did not show an associ-
ation between AA tissue content and the risk for coro-
nary artery disease. The results from randomized
controlled trials have not been consistent either. Some
[46,47] but not all [48,49] have found reductions in coro-
nary risk with the use of an LA diet intervention. In a
recent review, Harris [45] states that reducing LA intakes
to less than 5% energy would be likely to increase the risk
for coronary heart disease whereas higher intakes should
be beneficial even in conditions without clinical evidence
of adverse effects.
What we do not know about the effects of dietary
hempseed
As discussed earlier in this paper, there is a lack of knowl-
edge regarding the usefulness of hempseed or LA in dif-
ferent aspects related to cardiovascular diseases. It is
important to identify not only what we presently know
about dietary hempseed but also what is not known. The
animal data lacks systematic information about the action
of hempseed on myocardial infarctions, hypertension,
atherosclerosis, markers of inflammation and arrhyth-
mias. Similarly, we need to know more about the effects
of this plant on the circulating lipid profile. Primary and
secondary cardiovascular prevention trials using hemp-
seed as a source of LA have not been performed. In gen-
eral, we need to understand better the bioavailability of
fatty acids like LA and GLA from dietary hempseed as a
function of the age or sex of the subject, or as a function
of the dosage of hempseed employed. Other dietary inter-
ventions (i.e. flaxseed) are sensitive to these variables
[50,51] so it is not unrealistic to hypothesize that the
delivery of hempseed will be influenced by these variables
as well. It will also be important to identify if the hypoten-
sive effects attributed to LA can be reproduced by dietary
hempseed. As discussed previously, the capacity of LA
and/or hempseed to affect ventricular hypertrophy sec-
ondary to high blood pressure, human atherosclerosis,
inflammation, as well as the co-morbidities associated
with cardiovascular diseases (like metabolic syndrome,
diabetes mellitus, insulin resistance, obesity, heart failure
or arrhythmias) still need to be determined in carefully
controlled clinical trials.
Conclusions
The data discussed above supports the hypothesis that
hempseed has the potential to beneficially influence heart
disease. A mix of legal issues and misunderstandings has
slowed research progress in this area but enough data
presently exists to argue strongly for the continued inves-
tigation into the therapeutic efficacy of dietary hemp-
seed. There remain many questions regarding the
cardiovascular effects of hempseed that demand scien-
tific answers in order to definitively establish this food as
a preventive or therapeutic dietary intervention. Cardio-
vascular patients may not be the only subjects who bene-
fit from this research. Furthermore, only time will tell if
other diseases that have an immunological, dermatologi-
cal, neurodegenerative basis may also benefit from this
new nutritional intervention.
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Competing interests
The authors declare that they have no competing interests.
Authors' contributions
Both authors contributed to the creation, literature review and writing of this
manuscript.
Acknowledgements
The work was supported through a grant from the Canadian Institutes for
Health Research. The indirect costs of this research were supported by the St
Boniface Hospital and Research Foundation. Dr Rodriguez Leyva was a Visiting
Scientist of the Heart and Stroke Foundation of Canada.
Author Details
1Department of Physiology, University of Manitoba and Institute of
Cardiovascular Sciences, St Boniface Hospital Research Centre, 351 Tache
Avenue, Winnipeg, Manitoba, R2H 2A6, Canada and 2Cardiovascular Research
Division, V.I. Lenin Universitary Hospital, s/n Lenin Avenue, Holguin, 80100,
Cuba
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Received: 10 September 2009 Accepted: 21 April 2010
Published: 21 April 2010
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doi: 10.1186/1743-7075-7-32
Cite this article as: Rodriguez-Leyva and Pierce, The cardiac and haemo-
static effects of dietary hempseed Nutrition & Metabolism 2010, 7:32
