The Nutrition Debate #78: Metabolic Syndrome and Risk of Cancer

If you have Metabolic Syndrome there is a greater risk that you will develop certain types of cancer, according to a systematic review and meta-analysis reported in Medscape on November 18, 2012. The retrospective study was performed by a group of physician-researchers and was published in Diabetes Care, the magazine of the American Diabetes Association. To be clear, the study reports an association with cancer risk, not a causal relationship.

If you are unfamiliar with Metabolic Syndrome, it is defined by a cluster of risk factors: 1) obesity, particularly central obesity, 2) dysglycemia (i.e. pre-diabetes or Type 2), 3) elevated blood pressure, 4) and dyslipidemia, specifically high triglycerides and low HDL. Between 35% and 40% of the adult population of the U. S. today has Metabolic Syndrome. The higher percentage applies if the criterion for inclusion is a smaller waist measurement:  37”vs 40” for men and 31.5”vs 35” for women.

In 1986, when I was first diagnosed as a Type 2 diabetic, I had the full cluster of risk factors for Metabolic Syndrome, but no one told me I had it, or Syndrome X as it was then called. In fact, to this day no one has told me. Why is that, I wonder? Especially since the implications go far beyond cancer risk. The risks of virtually all the so-called Diseases of Civilization (heart disease, stroke, Alzheimer’s, etc.) are associated with a diagnosis of Metabolic Syndrome. Do you have Metabolic Syndrome? If you don’t know or aren’t sure, take a look at the specific criteria in Nutrition Debate #9 here.

The results of the study (pg.1): “We analyzed 116 datasets from 43 articles, including 38,940 cases of cancer. In cohort studies in men, the presence of Metabolic Syndrome was associated with liver, colorectal and bladder cancer. In cohort studies in women, the presence of Metabolic Syndrome was associated with endometrial, pancreatic, breast postmenopausal, rectal and colorectal cancers. Associations with Metabolic Syndrome were stronger in women than in men for pancreatic and rectal cancers. Associations were different between ethnic groups: we recorded stronger associations in Asia populations for liver cancer, in European populations for colorectal cancer in women, and in U. S. populations (whites) for prostate cancer.”

The conclusions (pg. 1): “Metabolic Syndrome is associated with increased risk of common cancers; for some cancers the risk differs between sexes, populations and definitions of metabolic syndrome.”

Furthermore detailed conclusions from page 28 drive home the findings: “Our results from meta-analyses of prospective cohort studies indicate that metabolic syndrome is consistently associated with an increased risk of several cancers in adults. However, many of the reported associations are small (relative risk between 1.1 and 1.6) and might differ between sexes for some sites and also across populations. In particular, the associations were stronger in women for some cancers (pancreas and rectal), and the magnitude of the association was highest for sex specific cancers (endometrial and breast postmenopausal). Moreover, from analyses in which sufficient datasets existed, the association was stronger for colorectal cancer in European populations (relative risk 1.64).”

And this hit: “Given the widespread diffusion of Metabolic Syndrome and the increased cancer mortality associated with Metabolic Syndrome, the findings of the present meta-analysis may have clinical significance. At least for some common cancer sites (colorectal cancer in both sexes, liver cancer in men, and pancreas cancer in women), we are confident that the results are real, as the grading for study quality was moderate to high and overall risk of bias was low” ( pg. 28).

Finally this blow (pg. 28): “Findings from this meta-analysis, which includes many recently published studies, suggest that Metabolic Syndrome is associated with increased risk of common cancers. The excess risk of cancer conferred by Metabolic Syndrome is low to moderate and in part explained by accompanying obesity and hyperglycemia. Neverthe-less, the increasing prevalence of Metabolic Syndrome worldwide and the high incidence of some malignancies, particu-larly colorectal and breast cancers, imply that every year many cases of cancer are attributable to Metabolic Syndrome” (emphasis mine). Remember, this is a retrospective, meta-analysis – not a prospective double-blind clinical trial, but to use the words “attributable to” is pretty strong language to be sure. It certainly should give one pause for thought.

Thoughts like, “What can I do about it?” Well, you can change your diet, that’s what. You can lose weight easily and keep it off permanently by eating a Very Low Carb, ketogenic diet. With this diet your blood sugars will normalize, and with weight loss your blood pressure will come down. And this diet will raise your HDL and lower your triglycerides. These are all the risk factors for Metabolic Syndrome, and they can all go away. You will be free of Metabolic Syndrome. Ipso facto!

© Dan Brown 12/8/12