The human body is such a complex structure
and is working all the time to keep us in balance. This requires the
coordination of thousands of different proteins and other natural chemicals
interacting on a moment-by-moment basis. When something goes wrong in the body,
this typically manifests as symptoms and a subsequent disease. Enter the
medical profession!
Much of medical teaching is based around the therapeutic value of
pharmaceutical drugs and a variety of surgical procedures. Basically, if you
can't fix it with a prescription pad or a scalpel, then any other approach
doesn't work. I have been saying for many years that the five key lifestyle
principles are four times more powerful than anything a doctor can do for you,
but, when you have an established medical disease, it is also important to have
medical therapy.
There is no doubt many of the pharmaceutical treatments that are administered
to people may have significant interactions with other aspects of our life. One
very well-recognised scenario is the interaction between a variety of foods and
commonly prescribed pharmaceutical drugs. Let's focus purely on pills (I’m
leaving out intravenous therapies for the purpose of this article), which are
swallowed to have their therapeutic effects. The process of swallowing food,
pills, vitamin supplements and herbs, along with the variety of fluids people
ingest throughout the day, may lead to significant interactions that strangely
may either have no effect on the drug involved, increase or decrease its
activity, depending on a number of factors.
Certain foods and supplements may affect how well a drug is absorbed, either
increasing or reducing absorption based on the mechanism involved. At other
times, specific foods and supplements may affect a number of biochemical
mechanisms within the gastrointestinal tract and specifically the liver, where
all of our raw materials are metabolised and again may either increase or
decrease the activity of the prescribed pharmaceutical drug. Alternatively, a
number of drugs are excreted in the kidneys with a number of factors affecting
the efficiency of this mechanism.
Without getting too detailed, I thought I would list a number of commonly
prescribed medications and the potential foods and timing of the ingestion of
these foods and fluids that may affect the drugs.
1. Warfarin
This drug has been around for many years and has been the workhorse strong blood thinner for people with artificial heart valves, a specific cardiac abnormality-atrial fibrillation and recurrent clotting in veins known as deep venous thrombosis and/ or pulmonary emboli.
Thankfully, there are a handful of newer
drugs that don't require the diligence needed to achieve proper levels of
warfarin in the bloodstream. Unfortunately, these new drugs are not
replacements for people with artificial heart valves but are highly effective
for the management of atrial fibrillation and recurrent clotting.
When you’re on warfarin you have to be very careful with what you eat, what you
drink, other medications and certain supplements. The big interaction is with
certain medications such as some painkillers, a number of antibiotics and
specific food stuffs such as leafy green vegetables, which are loaded with
vitamin K which compete directly with the action of warfarin. Alcohol can also
affect the way warfarin is metabolised in the liver. The strong message here is
that if you need to be on warfarin, you need to be very careful and have a
strong line of communication with your doctor about all the above.
2. Calcium rich foods and antibiotics
The commonly prescribed antibiotics such
as the tetracycline group and another antibiotic-ciprofloxacin, are affected by
taking these with milk and other calcium rich products. The calcium binds the
drugs in the gut and there is a marked reduction in absorption.
3. Pickled, cured and fermented foods interact with some old-style anti-depressants,
which are not commonly prescribed these days known as monoamine oxidise
inhibitors. These foods, especially cheese, are loaded with tyramine, which can
markedly increase the activity of these drugs. Some drugs prescribed for
Parkinson’s disease can also be affected by this mechanism and it is very
important to discuss with your doctor what food you should eat if you are
prescribed any of these therapies.
4. Alcohol and a number of prescription medications: in particular
sedatives, painkillers and stimulants.
If you are prescribed any of these
medications, you should be very careful about your alcohol intake, limiting
this to no more than two small glasses per day, if at all. Alcohol can also
affect a number of other therapies such as antibiotics. If you enjoy a drink and
are prescribed medications, always discuss this with your doctor and
pharmacist.
5. Grapefruit juice and just about any medications.
As we all reach that milestone of 60, I’d
suggest it is more the exception than the norm that we are on medications for
something. Grapefruit juice is a strong inhibitor of the main enzyme system
that breaks down a number of commonly used drugs. It reminds me of the joke
when the little boy says to his mother, “When I grow up, I want to be a rock
musician”. His mother replies, “I'm sorry but you have to choose one or the
other”. In the same way, over the age of 60, I believe we should be avoiding
grapefruit juice if we are on any medications whatsoever and in particular
statin drugs, some BP medications and some drugs used for treating mental
health disorders.
6. Bananas and BP treatment.
There
are two commonly prescribed BP pills known as ACE inhibitors and ARBs. Bananas
have a relatively high concentration of potassium and these two blood pressure
groups may elevate your potassium somewhat. If you enjoy bananas, and your
blood pressure is high, it is important to have your potassium levels measured
(which should be done regardless because you have high blood pressure) along
with your kidney function. If your potassium is above the normal range you
should reduce your intake of potassium containing foods such as bananas and
tomatoes. This is not a particularly significant issue for most people.
In most cases, simply take your medications one hour before or two hours after
eating. And if you are on any of the medications I have mentioned such as
statins for cholesterol, blood pressure pills, treatment for diabetes, reflux
drugs, painkillers, sedatives and anti-depressants, ask your doctor and
pharmacist to give you a full list of the foods you can enjoy and the food you
should avoid.
This straightforward conversation may be the difference between the prescribed
medications working, having no effect or potentially very serious side-effects
based on the drugs and the food involved. We have long since passed the era
where doctors were dictators and we basically did what we were told. We are now
in the era of information that is available to us all and, in my view, doctors should be two things to patients:
educators and servants. The long-term management of any chronic condition
requires a careful analysis of all aspects of a person’s care, which includes
the food, fluid and supplements they take and the potential for interactions
for any medications that may be prescribed.