Common diabetes drug, metformin, appears to reduce cancer risk

Metformin, a commonly prescribed drug for the treatment of
type 2 diabetes, has been touted in several recent studies as having the potential
to reduce the risk of cancer in people taking it to control their disease.

Metformin (Glucophage) helps control both insulin levels and
the amount of glucose produced by the liver. It’s given to people with type 2
diabetes who have not been able to control the disease through lifestyle
changes – diet and exercise.

Since type 2 diabetes affects millions of people and those
numbers continue to rise – even among children and teenagers – there is a lot
of scientific interest directed toward this population. It has been observed that
those taking metformin to control their disease also seemed to have less risk
for certain cancers.

Moreover, lab studies have shown an association between
metformin and its ability to cause the death of cancer cells.

Research from the University of Montreal, published in the
March 23 online edition of Aging Cell, found that metformin reduces the body’s
production of inflammatory cytokines, which can not only accelerate aging, but
also promote the growth of cancer.

In addition, Dr. Diego Espinoza-Peralta, with Mexico’s
National Institute of Medical Sciences and Nutrition, presented the findings of
their study “Cancer Risk in Diabetes Type 2 Patients Receiving Metformin.
Systematic Review and Meta-Analysis,” on June 24, 2012, at the Endocrine
society’s 94 th Annual meeting in Houston.

Seven studies, encompassing more than 32, 000 patients were
reviewed. Researchers concluded that those using metformin on a daily basis to
control diabetes were 38% less likely to get any type of cancer relative to
those not taking the diabetes drug. This adds to the growing evidence that
metformin brings more benefits to diabetic patients beyond glucose control.

This presentation follows other studies and articles about
metformin and cancer. The June 11, 2012 issue of the Journal of Clinical
Oncology contained a study by Rowan T. Chlebowski et al, “Diabetes, Metformin
and Breast Cancer in Postmenopausal Women” that looked at the long-studied
population of the Women’s Health Initiative. Of 68,019 post-menopausal women in
the study, 3,401 had been diagnosed with diabetes. They were observed for
nearly 12 years. The researchers compared breast cancer that developed in women
with diabetes who used metformin, to the same patient population who did not use
metformin. They also compared these groups to women who developed breast cancer
and were not diabetic and therefore, were not using metformin. This research
showed an association between lowered risk among women with diabetes taking
metformin, and the development of invasive breast cancer.

An editorial in the same issue of JCO by Pamela J. Goodwin,
and colleagues noted that these and other studies point to a need for further
research of both the relationship of diabetes to cancer risk, as well as the
use of metformin in lowering risk and as a potential treatment.

A preclinical study presented by Christopher Heeschen, MD,
PhD, at the American Association for Cancer Research’s Pancreatic Cancer:
Progress and Challenges conference held last month showed that treatment with
metformin caused the death of pancreatic stem cells.

So why is this research important?

Cancer stem cells appear
to be the primordial cancer cells that not only survive most treatments but are
responsible for recurrent and progressive disease. To date, there is a very
limited number of known compounds able to inhibit or kill these critical
malignant survival cells.

Additionally, the research suggests that not only does
metformin appear to reduce the risk for developing cancer in diabetic patients
who take the drug, but that it might also help control cancer in this patient population
once it has developed. We have known for a long time, that high glucose levels
and insulin resistance not only increase a person’s risk for cancer, but can
fuel the growth of existing disease.

At the Block Center, our dietary recommendations include
eliminating refined carbohydrates, including white sugar, honey, molasses, white
bread, white rice, etc., from your diet because research shows that cancer
cells have a sweet tooth. We know that they consume 10 – 50 times more glucose
than normal healthy cells. In addition, the faster a tumor proliferates, the
more glucose it consumes. Experiments have shown that when lab animals are
injected with an aggressive cancer, they have much higher survival rates if
they have low or normal blood sugar than if they have high blood sugar; glucose
enables the cancers to grow with reckless abandon. 

We also recommend a diet low in saturated fats, high in
plant-based sources of protein, cold water fish rich in omega-3 fatty acids,
complex carbohydrates, fruits and berries rich in antioxidants, nuts, seeds, cruciferous
vegetables and complex carbohydrates such as buckwheat, whole grain bread, wild
rice, rye, quinoa, and whole wheat pasta. Their high fiber helps dilute, bind,
and remove various toxins from the body. In addition, high-fiber foods and
whole- grain products prevent the inflammatory and growth-stimulating effects
of surges in blood sugar and insulin.

Patients who come to us with a diagnosis of cancer and who
are also battling type 2 diabetes are encouraged to adhere both to our diet
recommendations and their medication regimen to best prepare them to fight
their disease. While the research on metformin suggests it may one day be a
widely used adjunct to cancer treatment – and is an off-label treatment strategy
we have implemented for certain patients for many years – its current role in
keeping diabetes in check and maintaining optimal blood glucose and insulin
levels plays an important role in their treatment regimen.

So as we cheer the latest metformin studies and
know the medication is helping those with type 2 diabetes lower their cancer
risk, we must not forget that eliminating refined foods in the first place can not
only lower cancer risk, it can also help prevent type 2 diabetes. At the Block
Center, our dietary recommendations play an important role in helping boost
your natural defenses, curtail inflammation, reduce free-radical damage,
minimize platelet activation (which can lead to dangerous blood clotting), and
reduce serum levels of insulin-like growth factor 1, (IGF-1), which stimulates
cell multiplication and inhibits cell death.

For more information on The Block Center for Integrative Cancer Treatment, call (847) 230-9107 or visit BlockMD.com.