January 02, 2012
Trace Elements And Pancreatic Cancer Risk
A diagnosis of pancreatic cancer basically represents a notice you're going to be checking out of the Life Hotel. Bad cancer. So it is very desirable to find ways to lower the odds of getting pancreatic cancer. A new report finds some trace elements raise and lower the risk of pancreatic cancer.
A new study has found that high bodily levels of the trace elements nickel and selenium may be associated with reduced risk for pancreatic cancer, and that high levels of arsenic, cadmium and lead may increase the risk.
Avoiding toxins is usually a good idea unless you are training your body to detoxify some toxin because you expect someone to try to poison you.
I did some poking around about arsenic. In a fairly small number of areas arsenic in the water supply is a problem. Odds are you aren't in one of those areas. Arsenic comes into the diet in quite a few different ways. For example, arsenic was used to kill boll weevils in the Old South in the United States. So rice from some areas of the US has much higher arsenic in it. Louisiana rice appears to be worst with California rice as best. Imported Basmati and Jasmine rice have the lowest arsenic. But there's some dispute over how much of the arsenic in rice is of the more toxic inorganic kind. I'd like to know where some of the brand name rices come from btw. Anyone know?
In Britain fish is the biggest source of dietary arsenic.
Fish is the main source of arsenic in the UK diet.
I do not have details on which types of fish are especially high in arsenic. However, sounds like rainbow trout have pretty low arsenic levels.
In Europe arsenic shows up in a number of foodstuffs.
The main sources of inorganic arsenic intake are cereal grains and cereal based products, food for special dietary uses (e.g. algae), bottled water, coffee and beer, rice and rice-based products, fish and vegetables.
Next we come to chickens fed arsenic. It is not clear to me how much Pfizer's pulling of Roxarsone from the market cut the use of arsenic in chicken feed. Did other arsenic suppliers just replace Pfizer's product? My advice: do not eat chicken liver (where the arsenic concentrates) unless you can be certain the chicken you eat wasn't fed arsenic.
It is not clear to me what to cut out of the diet to do the easiest reduction in consumed arsenic.
Chinese food imports should be suspect.
I wouldn't get too excited about that arsenic finding. First, the Confidence Interval was only 1.08 to 3.78. 1.08 is risible, practically the same as no effect at all. Most statisticians recommend ignoring any finding that doesn't double or triple risk levels (ie, bring you up to a confidence interval of 2.00 to x or 3.0 to x. Anything lower than 2.0 on the lower end, (or .5 on the upper end) should definitely be ignored.
And second, the whole study is pretty iffy. It is a retrospective study and only looks at recent levels of trace elements found in the body (toenail clippings). As we all need to remind ourselves (constantly), correlation is not causation. Pancreatic cancer could just as easily be causing the skewed levels as be being caused by them, especially the deficiencies, as the pancreas is important in food metabolism. I'd say best to wait until someone actually does a double blind intervention study where they deliberately feed rats high and low levels of these trace elements and see if it has any impact on their cancer rates in general or on pancreatic cancer in particular before actually engaging in any lifestyle changes.
Does fish contain a lot of arsenic? Let's recall that Steve Jobs was addicted to sushi and he had pancreas cancer.
There are metal detoxification pills that you can buy from the vitamin store.
@dlr: using your stringent heuristic for hazard ratios would require tossing out most of what's published (including for example the recent paper on sodium/potassium and heart disease). I think you need to look at such results and see whether they make sense in the context of what else is known. I wouldn't be as conservative as you suggest except when looking at entirely novel and unexpected claims.
As for this finding, very interesting. I was unaware that nickel was considered a dietary mineral and see on brief search that it is still a matter of some controversy whether it is actually essential. It would be interesting indeed if there were an element that the body found useful in fighting cancer, but didn't really need for anything else.
Well those confidence levels just say this study is completely bogus. Chow down on that arsenic guys. You're good to go!
My big question:
What tests for mineral levels are reliable? Hair? nail clippings? Do we know that these tests can be trusted? What exactly do they tell us about levels in blood and cells?