Herbs, spices and cardiovascular disease 127
(Scalbert and Williamson, 2000). This approach makes the connection that in most
chronic diseases there is a component of oxidative stress, which can lead to the
production of damaging reactive oxygen and free radicals. In response to such damage
a complex antioxidant defence has developed in which dietary oxidants provide an
important role (Halliwell, 1996, 2000). Already it is possible to buy concentrated
extracts of individual herbs and spices that claim to have specific medical benefits.
Research is being undertaken to examine these claims (Vivekananthan et al., 2003)
and also how the crude herbs and spices may achieve their effect specifically in
cardiovascular disease (Blomhoff, 2005). The following is a discussion of the role
selected herbs and spices play in delaying the onset of this important disease.
8.2 Chemical composition of herbs and spices...................................
The chemical composition of selected herbs and spices that are thought to have a role
in the delay or prevention of the onset of cardiovascular disease is described. For
further details of these plants see herbals by Grieve (1998) and by Bellamy (2003).
8.2.1 Rosemary
Rosemary herb (Rosmarinus officinalus L.) is grown in many parts of the world as a
six-feet-high evergreen shrub. Leaves and twigs are used as a flavouring as well as
a treatment for a variety of medical conditions. It has pronounced anti-oxidant properties
that may extend to the reduction of total cholesterol levels in serum and also in
tissues such as the liver, heart and fatty tissue. The likely active compounds include
six compounds with three different polyphenol skeletons, phenolic diterpenes (carnosic
acid, carnosal, and 12-O-methylcarnosic acid), caffeoyl derivatives (rosmarinic acid)
and flavones (isoscutellarein 7-0-glucoside and genkwanin). Only in the leaves are
all six compounds present at the same time. Of the polyphenol compounds, rosmarinic
acid showed the highest concentration and had the highest antioxidant activity (del
Baňo et al., 2003).
8.2.2 Oregano
Oregano (Origanum vulgare L.) is native to northern Europe where it is cultivated
commercially. Both fresh and dried leaves are used as a source of flavouring. At the
same time it has been shown to have the highest anti-oxidant activity compared to the
same amounts of fresh dill, thyme, sage and parsley. In general, fresh oregano on a
weight for weight basis had three to 20 times higher antioxidant activity than the
other herbs studied and in comparison to vegetables, oregano has 42 times more
antioxidant activity than apples, 30 times more than potatoes, 12 times more than
oranges and four times more than blueberries (Zheng and Wang, 2001). The most
active component appears to be rosmarinic acid and thymol. As a measure of its
antioxidant power oregano has demonstrated stronger antioxidant capacity than either
of the two synthetic antioxidants commonly added to processed foods – BHT (butylated
hydroxytoluene) and BHA (butylated hydroxyanisole) (Zheng and Wang, 2001). Kulisic
et al., (2004) in an assessment of the components of the oregano essential oil, confirmed
that the oil had remarkable antioxidant properties. It was suggested that the oil could
be used as a potential source of antioxidants for the food industry.