Controversy is no stranger to vitamins and herbs, albeit
there are periods of more and of less attention. Popular
news sources recently have been making much of a couple
of issues: To start, there has been a regular drumbeat
regarding the uselessness of vitamins, either alone or in
combination, for either preserving or improving health.
Multi-vitamin/mineral supplements are common targets,
but so are vitamins such as vitamin D and a number of
popular herbs. Next, we are warned routinely of possible
interactions between various supplements, especially herbal extracts, and prescription drugs. In particular, blood-thinning
medications and certain immuno-suppressants used
to treat HIV have been emphasized as being incompatible with
a number of popular plant products, including St. John's wort
and Chinese ginseng. Both sets of issues are real, to be sure,
and need to be considered for safety's sake. Nevertheless,
the ensuing controversy over supplements is perhaps just
as important for what it reveals about American dietary and
other habits as for what it reveals about the safety of vitamins
and herbs.
In point of fact, many common foods have as great or
greater an impact upon numerous medical conditions as do
the vitamins and herbs that have been singled out. Examples
of this will be given shortly. In considering these examples, the
reader should be aware they are not exhaustive. They are being
offered as evidence for a number of points worth pondering.
First, what is revealed by the current focus upon the medical
interactions of popular supplements? Second, if quite a
number of foods pose the threat of similar interactions, does
a lack of focus on or concern with dietary factors suggest that
the diet of the average American is highly restricted in terms
of food choices? Third, is it the case that many conditions
for which drugs are readily prescribed for chronic use in this
culture might be better treated by simple changes in the diet
and/or the use, as first choice, of vitamins, herbs and other
supplements which have negligible side effects?
Vitamin D One More Time
TotalHealth magazine over the past few years has been vigilant
in examining controversial attacks on vitamin supplements
and it is disappointing to many of us that wrong-headed
analyses continue to be picked up and presented uncritically
by both professional journals and the popular press. USA
Today (January 23, 2014) is a good example of this as it
states unambiguously that studies and reviews of vitamin D
have found no "significant benefits for heart health, cancer
prevention or even bone health in healthy people." The
journal article that prompted these comments, large meta-analysis
just published in the British medical journal Lancet
is blunt in its assessment of vitamin D:1 "Available evidence
does not lend support to vitamin D supplementation and it
is very unlikely that the results of a future single randomized
clinical trial will materially alter the results from current meta-analyses."
The response from a number of primary vitamin D researchers
to this and other recent meta-analyses has been
withering. This includes the remarks of Dr. Michael Hollick,
the scientist responsible for identifying the major circulating
form of vitamin D in serum —25-hydroxyvitamin D3—which
is the form of vitamin D measured medically to assess vitamin
D status. Dr. Hollick terms the recent papers flawed
and "silly." Dr. Hollick's views are reported by Dr. Mercola
at his website (http://articles.mercola.com/sites/articles/archive/2014/02/17/vitamin-d-supplements.aspx) which provides
an elaborate critique of the recent vitamin D papers. Another
researcher who roundly dismisses the recent studies is
Dr. Cedric Garland of the University of California at San Diego
Moores Cancer Center. His comments cover both the Lancet
paper already mentioned and another recent meta-analysis:
This meta-analysis is nothing new and is already obsolete
since it is mainly based on old papers that used too little
vitamin D to expect any effect. A New Zealand study saying
we should only supplement people with vitamin D deficiency
and evidence of bone loss is equally wrong. Virtually everyone
in New Zealand, and most adults in the U.S., are vitamin D
deficient by modern criteria, being below 32 ng/ml.
The reality is that we now know that they are deficient with
regard to extraskeletal effects of 25(OH)D if their serum level
is below 40 ng/ml. These papers should be disregarded as
obsolete work. We are moving into a new era of using vitamin
D3 in doses no less that 4,000 IU/day for people aged 9 years
and older... Studies using less than 4,000 IU/day are on the
verge of obsolescence.
In other words, the studies culled and used as the basis
of the recent meta-analyses of vitamin D were themselves
inadequate because designed around totally inadequate
vitamin D daily dosages. Moreover, one does not need to
look far for at least one very major review that disagrees with
the conclusions of the negative meta-analyses in the most
fundamental way. A Cochrane review published just this year
on vitamin D and mortality gives an answer that seems more
than sufficient to warrant another look at vitamin D, at least
in its D3 form:2
Vitamin D3 seemed to decrease mortality in elderly
people living independently or in institutional care. Vitamin
D2, alfacalcidol and calcitriol had no statistically significant
beneficial effects on mortality.
Blood Thinning Drugs
Another point of current controversy involves both vitamins/
vitamin-like compounds and various herbs. Many aging
individuals are treated with anti-coagulants or "blood
thinners" to reduce the risks of stroke and blood clots. One
popularly prescribed such drug is Coumadin (warfarin). Drug
interactions with any of the anticoagulants are quite common,
including with such everyday items as alcohol and aspirin.
The usual side effects involve too free bleeding and show up
as such things as easy bruising, frequent nosebleeds, dark
urine and tarry stools. Needless to say, excessive bleeding can
be life-threatening under certain conditions. Interactions with
anticoagulants are so common that some pharmaceutical
experts caution against taking any new drug, including overthe-
counter items such as aspirin, without first speaking with
a doctor or pharmacist.
Ginkgo biloba extracts, particular examples of which in
a number of clinical trials currently are being reaffirmed for
cognitive health (but only in the case of certain extracts)3,
possibly present a problem for those taking anticoagulant
drugs largely because these extracts perform many of the
same tasks as those drugs and much more. Ginkgo extracts
improve the blood flow through the artery which serves the
heart, improve circulation in the brain and more generally
throughout the body, increase the clearance of toxins from
the system, and protect the body against what is known as
platelet-activating factor (PAF). PAF was only discovered in
1972, and since that time scientists have come to realize that it is involved in disturbances ranging from internal blood
clots (often leading to heart attacks and strokes) to allergic
reactions and asthma.4
Problems with excessively "sticky" blood are much
more common in the United States than they are in many
other countries around the world, such as in Japan. Diet
appears to be by far and away the most significant factor in
this. A quite large number of foods "thin" the blood. Food
sources of omega-3 fatty acids, which include many coldwater
ocean fish as well as walnuts and a few other items,
all tend to increase clotting time. All members of the onion
and garlic families act as blood thinners, especially if eaten
regularly and in quantity. The same is true of the mo-er (black
tree fungus) and reishi mushrooms, both of which can be
purchased in markets, which carry specialty mushroom and
Asian vegetables. Another natural blood thinner is hawthorn.
Hawthorne, which is found primarily as an extract in this
country, is the basis for some popular beverages in Asia and
often taken as a tea in Europe. Red wine, especially if it is high
in the antioxidant resveratrol, may increase coagulation time.
The quinine found in tonic water will increase or prolong the
actions of Coumadin and may have its own blood thinning
effects. Grapefruit is notorious for reducing the clearance of
warfarin-like compounds and therefore increasing the risk of
hemorrhage.5,6
A great many herbs, spices and digestive aids can
exercise significant anticoagulant effects. These include
cayenne pepper, bromelain from eating pineapple fruit and
stem, papain from papaya, and likely paprika and most chili
peppers. Ginger root, which is eaten in quantity in Indian
and Oriental cuisines, can strongly inhibit clotting. So can its
relative, tumeric, which is used widely in curries and a source
for purified curcumin. Vitamins and vitamin-like compounds,
as mentioned above, can lead to similar problems. These
compounds include vitamin E, tocotrienols, omega-3 fatty
acids, lipoic acid and many more.
Both Chinese and Indian (Ayurvedic) medicine would
greatly expand these lists of foods and herbs which can
increase clotting time, but, even as things stand, it should
be clear that diet likely is the predominant factor by far in
determining the activity of several elements in the blood
which control clotting time. Of course, there are at least as
many dietary factors which can influence blood coagulation in
opposition to Coumadin as those which are additive.
Changing the Rate of Drug Clearance
Many drugs (including some protease inhibitors, calcium
channel blockers, and oral contraceptives) are metabolized by
the cytochrome P450 3A4 (CYP3A4) metabolic pathway, which
is active in the liver. Grapefruit has already been mentioned as
influencing this pathway; it contains the compound naringenin,
which is one of the most powerful of common compounds in
affecting CYP3A4. The herbal supplements, which presently
are the most strongly implicated are goldenseal (Hydrastis
canadensis), St. John's wort (Hypericum perforatum), and cat's
claw (Uncaria tomentosa).7 Black pepper extracts, similarly,
influence cytochrome P450 and other elements involved in
drug clearance.
The ability to zero-in on this enzyme system through
special research techniques, unfortunately, in many ways is a
bit misleading. How much difference does it make in practice
whether the clearance of a drug is delayed as opposed to its
absorption being greatly enhanced? Black pepper, cayenne
pepper, ginger and long pepper all either strongly increase
absorption of other compounds and/or influence cytochrome
P450. Some sources of lecithin, such as eggs, may similarly
increase the uptake of certain drugs. Alcohol typically enhances
the effects of many drugs, whether by increasing absorption,
producing its own additive effects, or delaying clearance.
Quite a remarkable number of items in the diet can
interfere with many drugs. Some interfere directly with
absorption, as do the tannins and fibers found in many fruits
and vegetables. Others do so indirectly by activating overall
metabolism, liver and/or kidney functions.
Why Look to Dietary Choices Last?
Herbs, of course, do have many powerful effects upon the
body and should not be treated as if they are innocuous merely
because they are "natural." However, also missing in American
culture at large is an awareness that it is relatively easy to
intervene in many common conditions without resorting to
prescription drugs. In point of fact, other than a quite narrow
range public health messages regarding primarily fats and
fiber in the diet, we do not tend to think of diet as having
much of an impact upon health at all. There is no reservoir of
knowledge in everyday American culture regarding the health
uses of foods and herbs, unlike the cultures of Asia and even
Europe. Moreover, the U.S. heavily subsidizes the growth and
production of many foodstuffs used in "fast foods" (corn,
wheat, sugar beets, etc.) while doing nothing to reduce the
cost to consumers for fresh fruit and vegetables, i.e., items
that are healthful rather than being merely sources of calories.
Indeed, there are entire classes of medications sold
extremely widely in the United States for which there
appears to be no need in many other cultures. One class
which immediately comes to mind is that of the acid reflux /
heartburn /antacid medications, whether over-the-counter or
prescription. The entire notion that there are health problems
stemming from the production of excess stomach acid is
surely an odd one given the fact that we typically have no such
problems when we are young and produce plenty of stomach
acid, yet such problems in this culture are common in middle
age and later, i.e., at the point at which the ability to produce
stomach acid has already begun to decline markedly. What
has really happened is that the muscle that closes off the
top of the stomach and prevents its contents from flowing
back up the esophagus has weakened. Items that reduce the
production of stomach acid at the same time prevent the
complete digestion of proteins in the stomach, but, again,
do nothing to strengthen the muscle that controls acid reflux.
Interestingly enough, acid reflux is virtually unknown in much
of Asia where ginger is commonly used as a part of meals.
Ginger just happens to strengthen the esophageal sphincter.
In truth, the American diet tends to be extremely narrow
in the range of the foods eaten. "Fast foods" such as a burger
and fries garnished with a little bit of cold slaw have become increasingly important sources of dinner
and supper for the average American,
and therefore it is hard to argue that our
range of foods consumed daily is large.
Some authorities estimate that one
half of all meals are eaten outside the
home, mostly at fast food restaurants.
Aside from the obviously poor nutrition
supplied by such choices, it is also the
case that most of the otherwise readily
available foods that might be used to
influence many health conditions are
either missing or very badly represented.
We grow these foods, we just don't eat
them. Hence the observation by one
Tibetan doctor to the effect that we
seemed to have only two flavors in this
culture, salty and sweet.8
This returns us to our starting point.
Were the average American consuming
a truly varied diet, the American
medical profession likely would be
more aware of the impact of foods upon
health. Likewise, there is the curiously
dichotomous thinking of many of those
who are medically trained to the effect
that herbs are either without any benefit,
on the one hand, or likely to be a threat
to prescribed pharmaceutical drugs,
on the other hand. According to this
way of thinking, items are either foods
or drugs. Foods support the structure
and functions of the body, whereas
drugs intervene. As long as herbs could
be seen as being without effect, they
could be relegated largely to the foods
category, i.e., at best innocuous and
a waste of money in terms of health
benefits. Once it is admitted that herbs
might have benefits, they must be treated
like drugs and viewed as possessing a
host of powerful side effects and drug
interactions.
The problem is that even everyday
foods can have quite powerful effects
upon the body. So why not make use
of these food effects as a first line of
treatment, herbs as a second line, and
drugs only when all else fails?
References
- Reid IR, Bolland MJ, Grey A. Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysis. Lancet. 2014 Jan 11;383(9912):146-55.
- Bjelakovic G, Gluud LL, Nikolova D, Whitfield K, Wetterslev J, Simonetti RG, Bjelakovic M, Gluud C. Vitamin D supplementation for prevention of mortality in adults. Cochrane Database Syst Rev. 2014 Jan 10;1:CD007470.
- Lewis JE, Melillo AB, Tiozzo E, Chen L, Leonard S, Howell M, Diaz J, Gonzalez K, Woolger JM, Konefal J, Paterson E, Barnes D. A double-blind, randomized clinical trial of dietary supplementation on cognitive and immune functioning in healthy older adults. BMC Complement Altern Med. 2014 Feb 4;14(1):43.
- Murray, Michael T. "The Healing Power of Herbs," 2nd edition (Prima Publishing, Rocklin, California: 1995.)
- Brinker, Francis. "Herb Contraindications and Drug Interactions." Revised 2nd edition. (Eclectic Medical Publications, 1998.)
- Mindell, Earl and Hopkins, Virginia. "Prescription Alternatives." (Keats Publishing, 1998.)
- Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine. 2000;7(4):273-82.
- Yeshi Donden. "Health Through Balance." Snow Lion Publications, 1986.)