Pro-Oxidants vs. Anti-Oxidants

A similar relationship exists in pro- vs. anti-oxidants. It seems we are overwhelmed with information about the importance of increasing anti-oxidants in our diet; the truth be told: we cancer care without pro-oxidation would prove fruitless. To understand this, let’s discuss the mechanisms.

A free radical is a reactive molecule that tends to damage cell parts so we tend to think that this is always ‘bad’… NOT true.  However, when DNA is damaged, this can mean damaged genes but this is precisely why our body replicates cells and the ‘old’ cell dies.  If the genes controlling cell multiplication are harmed, cell growth can get stuck in the “on” position and cause cancer – this is an example of imbalance.

Cancer cells are very active reproducing and growing causing an increased load of free radicals within the cancer cell. Cancer cells are not good at handling more free radicals, since they already have more in them than normal cells and they tend to spew them out of the cells forming a slime layer that makes it more difficult to penetrate. At first thought, maybe it would be wise to flood the cancer with anti-oxidants. Until we understand that, at the root, the cancer is growing without oxygen, fermenting its energy, we then arrive at a different solution.

Normally the body makes energy through oxidation and is able to quench free radicals produced with substances called antioxidants. Antioxidants lessen the amount of free radical-induced injury and bring balance. This ‘tug-o-war’ continues and may be illustrated in exercise. We go to the gym and work our muscles, breaking tissue down in the presence of a depleting supply of oxygen (almost a semi-cancerous state) for muscles to ‘recover’ stronger, bigger, more thrifty in their use of oxygen, healthier in what we call ‘better shape’.

Cancer is similar in that the cells have created a survival mechanism to grow and thrive in a hypoxic environment. Since pro-oxidant strategies increase free radicals, it may better seem that the way to kill cancer cells is by bombarding them with pro-oxidants. This would lead to more free radicals within cancer cells, and injury and eventual death to the cancer cells.

The mechanism of many chemotherapy drugs, as well as radiation, in destroying cancer cells is by causing free radical increase within cancer cells. This is the same mechanism in many of the apoptogens (cancer killers) in a nutritional approach.

Many nutraceuticals that are normally considered to be anti-oxidants actually have a pro-oxidant, cancer-killing effect on cancer cells.  Curcumin, for example is just one anti-oxidant that acts as a pro-oxidant to a cancer cell. It also elicits anti-inflammatory benefits that aide in breaking down the barrier for an immune assault on the growing cancer mass.  Selenium, EGCG (from Green Tea Extract), high dose Vitamin C and others also act like this. Some so-called antioxidants at high levels have other ways of killing cancer cells, like inhibiting certain enzymes (Curcumin inhibits topoisomerase II) that hinder normal apoptosis.

We have to be careful taking dogmatic stances in our nutritional approach.  The “anti-oxidants are good for you so excess amounts of anti-oxidants must be better” ignores the very principles of health that regulate homeostasis – balance.  Mixing different nutrition can be counterproductive as well; for instance, use of Curcumin along with Glutathione has shown to be a very wrong approach. Extensive research within the past half-century has indicated that Curcumin, the yellow pigment in curry powder, exhibits antioxidant, anti-inflammatory, and pro-apoptotic (aiding in normal cell death) activities.

Recent studies have investigated whether the anti-inflammatory and pro-apoptotic activities assigned to Curcumin are mediated through its pro-oxidant/anti-oxidant mechanism. Much data has revealed that TNF-mediated NF-κB (markers found to accelerate cancer) activation was inhibited by Curcumin – therefore Curcumin acts to slow cancer growth.  Glutathione, normally a great anti-oxidant (some would argue that it is the body’s greatest) reversed the inhibition – that means that Glutathione negated the cancer stopping benefits of Curcumin. This is just one example of what can go wrong with taking too many supplements!

Cellular pro-oxidants, called reactive oxygen species (ROS), are constantly produced in our body. As stated, excessive ROS can induce oxidative damage in the cell and promote a number of degenerative diseases including accelerated aging. Cellular antioxidants protect against the damaging effects of ROS and have long been the sales-pitch of health practitioners. However, we cannot ignore normal balance; in moderate concentrations, ROS are necessary for a number of protective reactions. ROS are essential mediators of antimicrobial phagocytosis (killing bio-toxins), detoxification reactions carried out by the cytochrome P-450 complex (the main liver detox pathway), and apoptosis which eliminates cancerous and other life-threatening cells. Can you say ‘balance’ again?

Excessive ingestion of antioxidants could dangerously interfere with these protective functions, while temporary depletion of antioxidants can enhance anti-cancer effects of apoptosis. This is just another lesson against ‘cookbook nutrition’. This is where practitioners educated in Kinesiology may have an advantage in determining the correct approach for the patient.  Functional medicine testing measuring ROS baselines may also prove effective on determining a nutraceutical attack, as each patient is different.