Abstract Perilla
frutescens seeds are a good source of polyunsaturated omega 3 6 9 fatty acids
(PUFAs). The seeds of perilla are small end globular weight about 4 g/1000,
contained approximately 35–45% oil. However the leaves are a very poor source
of oil, since they contain only 0.2%. In addition, only the seed oil contains
the omega
3 fatty acids alpha-linolenic acid (ALA). In comparing to other plant
oils, perilla seed oil consistently contains the one of the highest proportion
of omega 3 (ALA) fatty acids, at 54–64%. The omega 6 (linoleic acid) component
is usually around 14% and omega 9 (Oleic acid) is also present in perilla oil.
These polyunsaturated fatty acids are most beneficial to human health and in
prevention of different diseases like cardiovascular disorders, cancer,
inflammatory, rheumatoid arthritis etc.
Introduction
General description of Perilla frutescencs
Perilla frutescens, is a member of the Lamiaceae/Labiatae
family and commonly called perilla. The crop is annual and is native to India
and China. Major producing countries of perilla are China, India, Japan, Korea,
Thailand, other East Asian countries. The herb is about 1 m high with small
flowers, a gray-brown fruit, and glossy, downy-haired leaves. Cultivation of
the crop is grown from seed and sown in May. Harvesting is usually between the
end of September and beginning of October. The applicable parts of perilla
plants are the leaves and seeds.
There are two main types: red and green perilla. Perilla
seeds, also called EBARA seed. This oil is a kind of light yellow clear and
transparent liquid, with aromatic odor and slight soluble in ethanol. Major
fatty acids of the oil are unsaturated fatty acids like Oleic acid 14–23%,
linoleic acid 11–16%, linolenic acid 54–64% (Graph 1). This oil also contains
saturated fatty acids 6.7–7.6%. Perilla seeds contain different polyphenols or
flavones (rosemarinic acid, luteolin, chrysoeriol, quercetin, catcehin,
apegenin and shishonin). Perilla seed oil is used as cooking oil, fuel. It is
dry oil used as in paint, varnish and ink manufacturing or as a substitute for
linseed oil. The seed cakes are used as animals and birds feed (Gediminas et
al. 2008; Talbott and Hughes 2006; Longvah et al. 2000; Borchers et al. 1997;
Narisawa et al. 1994).
Source and uses of omega fatty acids
Perilla is used for oil production as a rich source of
omega-3 polyunsaturated fatty acids (PUFAs), specifically alpha-linolenic acid
(ALA). It also contains omega 6 and omega 9 fatty acids. Omega fatty acids are
the essential for our health, so the omega-3s and 6s must be obtained through
our diet or by supplementation. It is the best resources for additional human
omega-3 polyunsaturated fatty acids (PUFAs). ALA (omega 3 fatty acid), is found
in some other plant oils sources such as flaxseed (linseed), with lower amounts
in walnut, canola, soy and animal sources like fish oil (cold water fish as
salmon, cod and mackerel).
Perilla oil suppresses the production of chemical mediator
in the allergy and inflammatory responses. These essential fatty acids have
been associated with benefits in a wide range of inflammatory conditions, heart
diseases, colitis/Crohn’s disease, asthma, allergies, antimicrobial, anticancer
etc. Perilla is also used for nausea, sunstroke, to induce sweating and as an
antispasmodic. In vivo metabolism of polyunsaturated omega-3 fatty acids, it
mainly exists in the form of DHA (docosahexaenoic acid) and EPA
(eicosapentaenoic acid). These two specific omega-3 fatty acids metabolites are
inserted in cell membranes throughout the body, where cellular machinery
converts them into substances which prevent abnormal clotting, reduce
inflammation, and relax blood vessels and improved ventilatory parameters
(Lewis 2008; Talbott and Hughes 2006; Calder 2004; James et al. 2000; Chin et
al. 1992; Mattson and Grundy 1985).
Other dietary sources of omega-3 fatty acids
Botanical sources
Flax seeds produce linseed oil, which has a very high
omega−3 fatty acid content Six times richer than most fish oils in n−3, flax
(or linseed) (Linum usitatissimum) and its oil are perhaps the most widely
available botanical source of n−3. Flaxseed oil consists of approximately 55%
ALA (alpha-linolenic acid). Flax, like chia, contains approximately three times
as much n−3 as n−6. 15 g of flaxseed
oil provides 8 g of ALA, which is converted in the body to EPA and then
DHA at efficiency of 5–10% and 2–5%, respectively (Azcona et al. 2008; Lewis
2008; Albert et al. 2002; Schacky and Dyerberg 2001; James et al. 2000; Mattson
and Grundy 1985) (Tables 1 and 2).
Animal sources
Fish
The most widely available source of EPA and DHA is cold
water oily fish such as salmon, herring, mackerel, anchovies and sardines. Oils
from these fish have a profile of around seven times as much omega 3 fish oil
as omega 6. Other oily fish such as tuna also contain omega
3 fish oil in somewhat lesser amounts. Consumers of oily fish should be
aware of the potential presence of heavy metals and fat-soluble pollutants like
PCBs and dioxin which may accumulate up the food chain. Although fish is a
dietary source of n−3 fatty acids, fish do not synthesize them; they obtain
them from the algae or plankton in their diet (James et al. 2000; Renaud 2002;
Chin et al. 1992).
Eggs
Eggs produced by chickens fed a diet of greens and insects
produce higher levels of n−3 fatty acids (mostly ALA) than chickens fed corn or
soybeans. In addition to feeding chickens insects and greens, fish oils may be
added to their diet to increase the amount of fatty acid concentrations in
eggs. The addition of flax and canola seeds to the diet of chickens, both good
sources of alpha-linolenic acid, increases the omega-3 content of the eggs
(Azcona et al. 2008; Trebunová et al. 2007).
Meat
The n−6 to n−3 ratio of grass-fed beef is about 2:1, making
it a more useful source of n−3 than grain-fed beef, which usually has a ratio
of 4:1. In most countries, commercially available lamb is typically grass-fed,
and thus higher in n−3 than other grain-fed or grain-finished meat sources. The
omega 3 content of chicken meat may be enhanced by increasing the animals’
dietary intake of grains that are high in n−3, such as flax, chia, and canola
(Azcona et al. 2008; Trebunová et al. 2007).
Seal oil
Seal oil is a source of EPA, DPH, and DPA. According to
Health Canada, it helps to support the development of the brain, eyes and
nerves in children up to 12 years of age (Azcona et al. 2008; Trebunová et al.
2007).
Other sources
Milk and cheese from grass-fed cows may also be good sources
of n−3. The microalgae Crypthecodinium cohnii and Schizochytrium are rich
sources of DHA (22:6 n−3) and can be produced commercially in bioreactors. This
is the only source of DHA acceptable to vegans. Oil from brown algae (kelp) is
a source of EPA. Walnuts are one of few nuts that contain appreciable n−3 fat,
with approximately a 1:4 ratio of n−3 to n−6. Acai palm fruit also contains n−3
fatty acids. Omega-3 is also found in soft gels in pharmacies and nowadays it
is also found in combination with omega
6, omega 9 and shark liver oil(Azcona et al. 2008; Trebunová et al.
2007).
Chemistry of fatty acids
Perilla is an alternative source of fatty acids that
contains both saturated and unsaturated (monosaturated and polyunsaturated)
fatty acids. Fatty acids having more than one double bonds are termed as PUFAs.
It contains saturated fatty acids mainly palmitic acid 5–7%, stearic acid 1–3%,
monosaturated oleic acid 12–22%, and poly saturated fatty acids linoleic acid
13–20%, γ-linolenic acid 0–1%, α-linolenic acid 52–64%, icosanoic acid 0–1%.
Increase in the number of double bonds progressively decreases the melting
point. Unsaturated fatty acids are lower melting point than saturated fatty
acids. Plant triglycerides have a large portion of unsaturated fatty acids such
as oleic, lenoleic and linolenic acids. Animal triglycerides have high
proportion of saturated fatty acids such as palmitic and stearic acids (Tables
3 and 4).
Nomenclature of fatty acids
The systemic nomenclature of fatty acids is derived from the
name of its parent hydrocarbon by replacing its final e by oleic acid. Thus the
names of saturated fatty acids end with the suffix anoic acid and those of
unsaturated fatty acids with the suffix enoic acid. The numbering of carbon
atoms in fatty acids is started at the carboxyl terminus and end methyl carbon
is known as omega carbon atom (Figs. 4 and 5).
Various conventions are adopted for indicating the position
of the double bonds. The most widely used are involve the use of the symbol Δ
fallowed by superscript number. For example Δ9 means that there is a double
bound between carbon 9 and carbon 10. Alternatively the position of the double
bond is indicated by the numerals as in case simple alkenes. Lastly note that
total number of carbon atoms and number of position(s) of double bond(s) is
again indicated by convention. Examples, the symbol 18;0 denote a C18 fatty
acid with no double bonds, the symbol 18: 1; 9 denote a C 18 fatty acid with a
double bond between carbon 9 and carbon 10 and the symbol 18: 2; 9,12 denote a
C 18 fatty acid with two double bonds between C9 and C10 and between C12 and 13
(Renaud 2002; Mattson and Grundy 1985) (Table 5).
Definition of omega fatty acids
The names “omega 3” or “omega 6” or “omega 9” fatty acids
refer to where a double bond occurs in the fatty acid molecule. The terms
“omega” or “n minus” refer to the position of the double bond of the fatty acid
closest to the methyl end of the molecule. Thus, oleic acid, which has its
double bond 9 carbons from the methyl end, is considered an omega
9 (or an n–9) fatty acid. Similarly, linoleic acid, common in vegetable
oils, is an omega-6 (n–6) fatty acid because its second double bond is 6
carbons from the methyl end of the molecule (i.e., between carbons 12 and 13
from the carboxyl end). Omega 3 and omega 6 fatty acids are “essential fatty
acids”, meaning that these fatty acids cannot synthesized by body itself.
Instead, we must include them in our diet or through supplements to meet our
body demands. Omega 9 fatty acids are “conditionally essential”, which means
that if we have the other fatty acids in our diet, then our body can
manufacture omega 9 fatty acids. Otherwise, omega 9 fatty acids must be
consumed or supplemented as well. DHA (docosahexaenoic acid) and EPA
(eicosapentaenoic acid) are the two specific omega 3 fatty acids found in fish
oil such as cold water fish as salmon, cod and mackerel (Green et al. 2007; Calder
2004; Renaud 2002; Chin et al. 1992; Ip et al. 1996; Mattson and Grundy 1985).
Importance of omega fatty acids
Among plant oils, the balance between omega
3 omega 6 omega 9 fatty acids must dictate which oil is chosen. Oils
which predominate in omega 3 component would be most likely to promote health,
only perilla and flax seed (vegetable) oil predominate in omega 3 fatty acid.
Most would actually contribute to the imbalance of omega-6 fatty acids because
they contain more omega-6 than omega-3. Any amount of omega 9 is beneficial,
but in balancing these fatty acids, the omega-3 component is the most
important.
The most common omega 6 fatty acid is linoleic acid. When
omega 6 fatty acids are consumed in the diet, they are inserted in the cell
membranes, where the same cellular machinery converts them into substances
which promote abnormal clotting and increase inflammation. While Omega-3 fatty
acids are beneficial to improved cardiovascular health, and certain types of
cancers, as well as enhancing the immune system (Lewis 2008; Reisman et al.
2006; Talbott and Hughes 2006; Calder 2004; Albert et al. 2002; James et al.
2000; Longvah et al. 2000; Lee et al. 1994; Narisawa et al. 1994; Thompson et
al. 1997; Chin et al. 1992; Kromann and Green 1980).
Balance of omega-3 & 6 is key for normal immune function
Many health issues depend on a proper balance of omega 3 and
omega 6 fatty acids. While omega 6 fatty acids are necessary for normal immune
function and clotting, too much omega 6 fatty acid may promote abnormal
clotting and an overactive immune system. It is believed that our ancestors
evolved on a diet where these two omega fatty acids were approximately equal.
However, modern diets usually have up to 20 times more omega 6 fatty acids than
omega 3 fatty acids. Many of the chronic degenerative diseases we experience
today are believed to have their origins in an imbalance of omega 3 and omega 6
fatty acids in our diet. This necessitates that n−3 and n−6 be consumed in a
balanced proportion; healthy ratios of n−6: n−3 range from 1:1 to 4:1. (Renaud
2002; Mattson and Grundy 1985).
Cardio-vascular benefits
Heart disease is the one of the most common diseases
nowadays due to current life style and eating habits. Certain population
studies have shown that a diet high in omega-3 fatty acids, specifically EPA
and DHA found in fish
oil or metabolized product of ALA (perilla oil) can help to prevent
heart disease. Omega-3 fatty acid (ALA), through the body’s metabolic pathway,
can be converted into EPA and DHA at a rate of roughly 7–10%. The research
proved that when using omega 3 rich perilla oil instead of soybean oil, the
subjects increased omega-3 levels in their blood, which may lead to prevention
of coronary heart disease and decrease blood clotting (Lewis 2008; Calder 2004;
Schacky and Dyerberg 2001).
In different cells of the body, the cellular machinery makes
different things. In platelets, the cell products in the blood which aid in
clotting, omega 6 fatty acids are converted to thromboxane A2 (TXA2). This
makes the platelets more likely to burst (degranulate), releasing their
clotting substances and cell messengers. These cell messengers constrict blood
vessels and tell other platelets to burst—causing a clotting cascade. On the
other hand, when omega 3 fatty acids are used in the same machinery in
platelets, thromboxane A3 (TXA3) is made, which is inactive. If you have been
cut or injured, you want the bleeding to stop with the help of platelets.
However, if you have not been cut or injured, clotting is abnormal and may
block flow to areas which need it—causing a heart attack or stroke. In white
blood cells (WBC’s), the infection fighting cells of the body, omega 6 fatty
acids make more inflammatory substances. These substances include leukotriene
B4, (LTB4), which is a cell messenger responsible for inflammation throughout
the body. It is a “call to arms” for other WBC’s. LTB4 even tells certain WBC’s
to get into the wall of the blood vessel. LTB4 actually causes these WBC’s to
absorb oxidized LDL cholesterol (cholesterol plaque is formed). In contrast,
when omega 3 fatty acids are used in the same cellular machinery, leukotriene
B5 (LTB5) is made. LTB5 is anti-inflammatory. Health demands normal functioning
of both systems (Bemelmans et al. 2002; de Lorgeril et al. 1999; Thompson et
al. 1997; Lee et al. 1994).
Anti-inflammatory and rheumatoid arthritis benefits
Perilla oil is rich in the omega 3 fatty acids, on
metabolism gives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA),
which can displace arachidonic acid (AA) from cell membranes. These omega-3
fatty acids are also released with AA by phospholipases and act as substrate
inhibitors of conversion of AA by cyclo-oxygenases (COX) and the terminal
synthases to the pro-inflammatory oxygenated inflammatory mediators known as
eicosanoids. EPA is structurally identical to AA with the exception of its
additional n−3 double bond and can be converted to eicosanoids that resemble
eicosanoids. In addition to these effects on inflammatory eicosanoid synthesis,
perilla oils have been shown to reduce the production of the inflammatory
cytokines IL-1β and TNFα by monocytes stimulated in vitro. These cytokines are
important effector molecules in inflammatory responses and TNFα blocking agents
are now used widely to treat rheumatoid disease that has proven refractory to
less expensive therapies. In vitro studies have also shown inhibition of
release of the metalloproteinases that are implicated in the tissue damage that
is the hallmark of rheumatoid arthritis and other inflammatory diseases
(Osakabe et al. 2005, 2004; Banno et al. 2004; James et al. 2000).
It has been reported that conversion of ALA to EPA and
further to DHA in humans is limited, but varies with individuals. Women have
higher ALA conversion efficiency than men, probably due to the lower rate of
utilization of dietary ALA for beta-oxidation.
Perilla oil reduces recourse to NSAIDs for analgesia in
rheumatoid arthritis and thereby reduces risk for upper GI haemorrhage. Perilla
oil contrasts with the highly selective COX-2 inhibitor rofecoxib, which has
been associated with increased serious cardiovascular events, by reducing risk
for these events. The result is fewer AA derived eicosanoids with production of
homologous metabolites products such as PGE1 (one less double bond than AA
derived PGE2). ALA rich oils appear to reduce symptoms in rheumatoid arthritis
but available evidence is far less than that for perilla oil in rheumatoid
arthritis (Osakabe et al. 2005; Banno et al. 2004; Calder 2004; James et al.
2000; Borchers et al. 1997).
Cancer benefits
Similarly, studies in animals have found that omega
3 fatty acids suppress cancer formation, but at this time there is no
direct evidence for protective effects in humans. A group of isomers of the essential
fatty acid linoleic acid, “conjugated linoleic acid” (CLA), appear to have both
anticarcinogenic and antiatherogenic properties and may affect body
composition. CLA differs from linoleic acid by the position and geometric
configuration of one of its double bonds (Chin et al. 1992). Animal studies
have indicated that CLA reduces the incidence of tumors induced by carcinogens
(Ip et al. 1996; Thompson et al. 1997). In addition to its anticarcinogenic
properties, CLA appears to be antiatherogenic as well (Lee et al. 1994).
Saturated fatty acids have not been found to have any specific effects on
carcinogenesis. On a positive note, recent studies have shown that conjugated
linoleic acid, appears to be unique among fatty acids because low levels in the
diet produce significant cancer protection (Banno et al. 2004; Osakabe et al.
2004; Caughey et al. 1996; Narisawa et al. 1994; Chin et al. 1992).
Antiallergic benefits
Numerous studies have shown that perilla seed oil suppressed
a wide range of allergic mediators in experimental animals. These findings
raise the potential for perilla oil to be effective in reducing allergic
hypersensitivity in humans. Allergic mediators were decreased in the perilla
oil (ALA). The perilla oil group also showed benefits in terms of lung
function, breathing parameters and may be useful for the treatment of asthma.
Perilla oil for reduction in asthma symptoms due to the alpha-lineolic acid
effects on leukotrienes as well as use of perilla extract for seasonal
allergies (Gediminas et al. 2008; Reisman et al. 2006; Osakabe et al. 2005,
2004; Ragažinskienė et al. 2004; Borchers et al. 1997).
Brain health benefits
PUFAs (n−3 and n−6, 3000 mg a day), PUFAs plus
multi-vitamins and minerals or placebo supplementation in children with
learning and behavioral problems (Green et al. 2007). Omega-3 exerts
neuroprotective action in Parkinson’s disease, exhibit a protective effect
(much like it did for Alzheimer’s disease as well). The high doses of omega-3
given to the experimental group completely prevented the neurotoxin-induced
decrease of dopamine that ordinarily occurs. Since Parkinson’s is a disease
caused by disruption of the dopamine system, this protective effect exhibited
could show promise for future research in the prevention of Parkinson’s disease
(Talbott and Hughes 2006).
Numerous applications
Not only does perilla contain the omega 3 ALA, but perilla is also a rich source of phenolic
compounds, flavanoids and anthocyanins known for their antioxidant properties.
Rosemarinic acid, luteolin, chrysoeriol, quercetin, catcehin and apigenin are a
few of the phenolic compounds found in perilla oil. These antioxidants may also
be involved in allergy, antimicrobial, cardiovascular and cancer prevention
along with the omega 3 fatty acids. Perilla seeds contain polyphenols luteolin
showed the strong antimicrobial effect than other phenolic compounds (Gediminas
et al. 2008; Yamamoto and Ogawa 2002).
Research has observes that populations consuming diets high
in ALA, reduction in the death rate due to coronary heart disease. As perilla
seed oil is one of the richest sources of ALA, the research is clear more
perilla equals improved heart health. Other studies suggest that omega-3 fatty
acids are useful in the treatment of cancer, inflammatory, colitis/Crohn’s
disease, arthritis and various skin conditions. Anti-inflammatory doses of
perilla oil have been shown to reduce the hypertensive and nephrotoxic effects
of cyclosporin. It prevent the formation of LTB4 have been used in treating
asthma, rheumatoid arthritis, colitis, lupus, multiple sclerosis, and psoriasis
(Osakabe et al. 2005; Banno et al. 2004; Calder 2004; Albert et al. 2002;
Bemelmans et al. 2002; de Lorgeril et al. 1999; Borchers et al. 1997; Caughey
et al. 1996).
Perilla oil can be used as a tasty addition to salad
dressings, dips, yogurt, hot cereal, blender drinks and other foods. Many
individuals enjoy the flavor of perilla oil taken by the teaspoonful. Perilla
oil is also available in an easy to swallow, soft gel form. The nourishment
supplied by 2.1 g α-linolenic acid equal that by 30 g fish oil. To receive the
numerous health benefits that perilla oil has to offer, a suggested dosage is 3
g per day (Green et al. 2007; Reisman et al. 2006; Talbott and Hughes 2006;
Yamamoto and Ogawa 2002; Longvah et al. 2000; Schacky and Dyerberg 2001; Lee et
al. 1994).
Health risks
Known or suspected risks of EPA and DHA omega−3 fatty acids
may include the possibility of: Increased bleeding if overused (normally over 3
g per day) by a patient who is also taking aspirin or warfarin. However, this
is disputed. Hemorrhagic stroke (only in case of very large doses). Reduced
glycemic control among diabetics (Lewis 2008; Kromann and Green 1980).
Cardiac risk
Persons with congestive heart failure, chronic recurrent
angina pectoris or evidence that their heart is receiving insufficient blood
flow are advised to talk to their doctor before taking n−3 fatty acids. There
have been concerns if such persons take n−3 fatty acids or eating foods that
contain them in substantial amounts. In a recent large study, n−3 fatty acids
on top of standard heart failure therapy produced a small but statistically
significant benefit in terms of mortality and hospitalization (Ornish 2006).
Daily values
According to food and nutrition Board (2005) acceptable
intake (AI) for n−3 is 1.6 g/day for men and 1.1 g/day for women while the
acceptable macronutrient distribution range AMDR is 0.6% to 1.2% of total
energy. “A growing body of literature suggests that higher intakes of
α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid
(DHA) may afford some degree of protection against coronary heart disease.
Because the physiological potency of EPA and DHA is much greater than that for
α-linolenic acid, it is not possible to estimate one AMDR for all n−3 fatty
acids. Approximately 10% of the AMDR can be consumed as EPA and/or DHA.” The
FDA recommends that total dietary intake of n−3 fatty acids from fish not
exceed 3 g per day, of which no more than 2 g per day are from nutritional omega
3 fish oil supplements (Lewis 2008; Talbott and Hughes 2006; Bemelmans
et al. 2002; Schacky and Dyerberg 2001; Chin et al. 1992; Mattson and Grundy
1985).
Discussion
Research showed that the low incidence of heart attacks even
their diet was so high in fat. When the fats in the diet were studied, it
appeared that omega 3 fatty acids, found in high levels in their food, provided
protection from heart attacks. Perilla oil to be potentially benefits include
protecting the heart (reduced blood clotting), reducing allergic symptoms and
asthma, acting as a pain reliever and anti-inflammatory, stimulating immune
function, intestinal dryness and constipation. Perilla oil to be potentially
benefits to prevent and cure different ailments but little health risk was also
reported.
Perilla is used as culinary and medicinal herb in many part
of Asia. Perilla seed supplies the polyphenolic ingredients luteolin and
rosmarinic acid- two substances that have a powerful impact on decreasing
allergy symptoms. ALA in vivo decreases the blood pressure and reduced the
cholesterol and glyceride contents in the blood. It controls hematoblastic
aggregation and thrombi reduction. ALA has definite inhibitory action on the
growth and metabolism of breast and colon cancer.
Conclusion
Yet if we increase our intake of omega-3 fatty acids, we may
prevent the formation of these inflammatory substances and actually increase
the production of anti-inflammatory substances. Most important to people
concerned about cardiovascular disease, omega 3 fatty acids have been shown to
improve blood pressure and vascular resistance, lower triglycerides, prevent
abnormal heart rhythm and sudden cardiac death, and may reduce the risk of
heart attack. The high content of omega-3 fatty acids, the absence of mercury
risk from fish sources, and the beneficial effects of perilla oil is the best
supplement to achieve balance in these valuable fatty acids. Although perilla
has been around for centuries, is has recently as a viable vegan omega 3
alternative for nutrition and health. Linolenic acid is also a precursor of a
special group of prostaglandins.
Person, those who are vegetarian or dislike the
taste of fish, have a fish allergy or are just unable to tolerate fish oil due
to reflux, vegetarian sources (Perilla oil) of omega-3 fatty acids are
preferable. Plant based omega-3s including perilla, flax, purslane, and walnut
will provide essential fats for necessity of our body. Now that the low fat
diet craze is over, healthy fats from sources such as perilla oil, fish oils, flaxseed
oil, hemp oil, and evening primrose oil are making their way back into the
diets. More clinical evidence is required before recommendations can be made
for any clinical usage of perilla.
