Antioxidants are all the rage these days, seemingly good for
whatever ails you or your pet. The good news is that much of the
hype actually is true, and the better news is that herbs are
excellent sources of antioxidants. Even better, herbs not only
provide a wide variety of antioxidants (as we’ll see, an important
part of how they should be used), but they also are among the
safest sources known.
How do Antioxidants Work?
During the process of healthy metabolism, carbohydrates and
sugars are “burned” in the presence of oxygen to provide the animal
with energy. Most of the raw materials involved in metabolism are
converted to energy.
In all energy reactions in the body, however, there are some
molecular fragments that aren’t totally used up, and some of these
are chemically active fragments that have an electrical charge due
to an excess or deficient number of electrons. These charged
molecules are called free radicals.
Because they have one or more unpaired electrons, free radicals
are highly unstable. They scavenge the animal’s body to grab or
donate electrons, thereby damaging cells, proteins and DNA itself.
This same oxidative process also causes oils to become rancid,
peeled fruits to brown and iron to rust.
Normal aerobic respiration and food metabolism create a constant
source of free radicals, but a host of other activities produce
excessive free radicals as well, among them excessive exercise;
inflammatory diseases, such as arthritis; and the abnormal cell
growth that’s associated with most types of cancer. Free radicals
also can come from outside factors including pollution, sunlight,
tobacco smoke and X-rays.
Most animals are capable of dealing with a normal amount of free
radicals, but excessive free radicals can produce disease. In
addition, animals that are stressed, or aging animals with organ
systems and immune functions that are beginning to wane, may need
some help to eliminate free radicals.
Antioxidants are the antidote for an excess of free radicals in
the body. The term “antioxidant” refers to the activity of numerous
vitamins, minerals and other phytochemicals to serve as protection
against the damaging effects of free radicals.
There are many claims for the benefits of antioxidants for our
pets, including helping maintain long-term wellness through their
anti-aging activities; cancer prevention; promoting healthy vision
and eyesight; prevention of heart disease; preventing and treating
arthritis; enhancing the body’s immune functions; and providing the
animal with a degree of exercise tolerance.
Three vitamins—A, C and E—are the primary dietary antioxidants,
although there are hundreds of other substances that have
antioxidant activity. These essential vitamins are manufactured by
plants, and many commonly used herbs are especially high in vitamin
activity. In addition, many herbs have additional,
non-vitamin-related, antioxidant activity, and in fact, herbs and
spices often are the very best sources of both vitamins and
How to Dose Antioxidants
The majority of the popular antioxidants appear to be extremely
safe; the main area where problems might occur is when we try to
use therapeutic megadoses of vitamins and minerals. Megadoses, in
extreme cases, may be toxic, or the higher level of one vitamin may
create an imbalance between substances that need to be kept in
balance to be effective. An example here is that vitamin E dosages
need to be balanced with selenium levels in order for either to be
However, when we are using fresh or dried herbs to supply our
pets with antioxidants (and vitamins), there is much less to worry
about—herbs typically contain only small amounts of any one
substance, and the dosages you would add to a pet’s diet would
typically be far below any potentially toxic level.
The science of how to best provide antioxidants has given us
some tips for application for our pets:
• Whenever possible, use natural food sources known to be high
in antioxidants. There is considerable evidence to indicate that
antioxidants from a natural, dietary food source are more effective
than those taken in supplement form. If it helps make the food more
palatable for your pet’s taste buds, go ahead and chop up
vegetables, fruits and herbs, heat them naturally, and hide them in
some of your pet’s favorite foods, such as a chunk of meat.
• Many antioxidants found in foods are made more readily
available in foods that have been pureed and/or naturally
heated—the antioxidant lycopene, found in tomatoes, is an example
here. One exception to this rule is vitamin C, which is destroyed
by heating. Drying foods usually diminishes the amount of vitamins
and antioxidants available to the animal. It also is thought that
microwaving destroys many nutrients, including most, if not all,
• Use several sources to provide a mix of antioxidants—herbs,
vegetables and fruits are excellent sources. These and fruits
provide a good variety.
• A mix of antioxidants is important because many of them work
synergistically—the sum of the activities of several different
antioxidants often is many times higher than would be obtained by
adding the sum of their accumulated effects together.
Following are several examples of antioxidant-rich herbs that
you can sprinkle over your pet’s food, both to increase nutrition
and to provide your pet with some necessary spice in his diet. Note
that most of the herbs, in addition to being abundant in vitamin
and antioxidant activity, contain other ingredients that provide
specific medicinal activity and/or help to maintain healthy
function of one or more organ systems.
In a recent analysis, oregano was named “king of antioxidants.”
Some types of oregano tested as having higher amounts of
antioxidants than others—the highest score went to Mexican oregano
(Poliomintha bustamanta), which tested just slightly higher than
Italian oregano (Origanum ×majoricum). The third highest score was
Greek mountain oregano (Origanum vulgare ssp. hirtum), which is the
most commonly available variety in the United States.
In this same analysis, other herbs that tested high included
dill (Anethum graveolens), thyme (Thymus vulgaris), rosemary
(Rosmarinus officinalis), peppermint (Mentha ×piperita), sage
(Salvia officinalis), lemon balm (Melissa officinalis) and cinnamon
(Cinnamomum verum). That’s a pretty good handful to select from
when trying to please your pet’s taste buds.
But this was only one assay of a small number of herbs. Other
studies have found healthy levels of antioxidants in astragalus
(Astragalus membranaceus), basil (Ocimum basilicum), bilberry
(Vaccinium myrtillus), burdock (Arctium lappa), ginkgo (Ginkgo
biloba), ginger (Zingiber officinale), green tea (Camellia
sinensis), milk thistle (Silybum marianum) and a host of others.
Some of my favorite herbs, the common backyard weeds, also have
been shown to have significant antioxidant activity. For example,
purslane (Portulaca oleracea) outdid spinach in many measurements
of antioxidant activity. In fact, the list of herbs and weeds
proven to be rich in antioxidants is limited only by the assays
that have been performed—once again, herbs, no matter their
species, are almost invariably heavy-duty antioxidant (and vitamin)
It’s important to step back and realize that much of the hype on
specific plants that contain antioxidants depends on what herb is
under scrutiny at any given time. This month’s herb is likely being
ballyhooed because some lab just ran tests on it and had them
published where the media could pick up and run with the data. Next
month there will likely be another “herb of the month,” and we’ll
all think that this one is the “silver bullet” cure for
There is almost no limit to the repertory you can draw from to
provide your pet with a healthy dose of antioxidants. In the end,
with our pets, it’s not so much which source of antioxidants we
use; rather, it is that we find the antioxidant sources that our
pets enjoy eating, and then use them routinely. Experiment. Try
several herbs, fruits and berries … until you and your pet come to
an agreement on which ones he thinks are an acceptable part of his
diet. And, keep trying a variety of herbs, greens and fruits to
keep your pet’s diet interesting.•
Randy Kidd holds doctorates in veterinary medicine and clinical
pathology. After practicing traditional veterinary medicine for 10
years, he opened Honoring the Animals, a holistic practice in
Kansas City, Missouri. Visit our website, www.HerbsForHealth.com,
to order Dr. Kidd’s pet-care books.
Information provided in “Pet Corner” is not intended to replace
the advice of a qualified veterinarian.