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Selenium deficiency may increase risk of chronic disease: Study

4 commentsBy Stephen Daniells in Oakland , 16-Mar-2011
Last updated on 16-Mar-2011 at 17:23 GMT2011-03-16T17:23:54Z

“I’m sure my triage theory is right” - Bruce Ames
“I’m sure my triage theory is right” - Bruce Ames

Ensuring adequate intakes of selenium may reduce the risk of age-related diseases such as cancer and heart disease, says a new review that supports Bruce Ames’ triage theory.

By analyzing data from hundreds of published articles, Joyce McCann, PhD, and Bruce Ames, PhD, from Children's Hospital Oakland Research Institute (CHORI) report that selenium-dependent proteins considered essential to ensuring an organism survives until it reaches reproductive age are largely more resistant to selenium deficiency than non-essential selenoproteins.

Speaking with NutraIngredients-USA at his office in Oakland, Dr Ames called the new paper a “gorgeous review”, and said it adds to an earlier analysis of triage theory with vitamin K, published in the American Journal of Clinical Nutrition (2009, Vol. 90, pp. 889-907).

Evolutionary mechanisms

Triage – from the French word trier meaning to sort, separate, or select – works on the battlefield by military doctors prioritizing treatments depending on the probable survival of the wounded.

Dr Ames’ theory works in much the same way: By appreciating that natural selection favors short-term survival over the long-term, Dr Ames’ hypothesized that our short-term survival is achieved by prioritizing the allocation of scarce micronutrients. In other words, to stop us falling over from a lack of iron in the heart, for example, iron is pulled from non-essential sources.

The triage theory is a way of “measuring the insidious damage going on over time”, he said.

The theory was first proposed in 2006 (PNAS, Vol. 103, Pages 17589-94) to explain why age-related diseases like heart disease, cancer, and dementia may be unintended consequences of mechanisms developed during evolution to protect against episodic vitamin/mineral shortages.

“I’m trying to put nutrition on a firm foundation,” Dr Ames told NutraIngredients-USA, “and I’m sure the triage theory is right.”

New insights

By analyzing the activity and concentrations of 12 selenoproteins, five of which were classified as essential and seven as non-essential, Drs McCann and Ames found that the activity and levels of non-essential selenoproteins were preferentially lost when the organism was moderately selenium deficient.

“Results of the analysis are largely supportive of the theory, suggesting that, among all selenoproteins, dysfunction of those that are nonessential is likely to be the major contributor to increased disease risk due to selenium deficiency,” wrote the Oakland-based scientists.

Indeed, the non-essential selenoprotein Dio2 has previously been linked to a wide range of diseases or conditions, including osteoarthritis, while Gpx1 may protect against DNA damage, and ultimately cancer risk, Gpx2 may exert ant-inflammatory effects, and Gpx3 has been implicated in improved cardiovascular health.

Implications for intakes

Drs McCann and Ames also report that current recommendations for selenium intake – based on maximizing blood activities of the selenium enzyme glutathione peroxidase (GPx) – may be insufficient, given that an essential selenium-dependent protein called Sepp1 was found to be more sensitive to selenium deficiency than Gpx3.

“The fact that Sepp1 is more sensitive to Se deficiency than Gpx3 in human plasma has important implications for estimating the percentage of the population that is modestly selenium deficient,” wrote Drs McCann and Ames.

“Since the current [US] RDA (55 micrograms per day, roughly corresponding to 100 micrograms per liter of plasma selenium) is based on the sensitivity of Gpx3 in plasma, Sepp1 is expected to be at suboptimal levels, even in some individuals meeting current selenium intake recommendations.

“Based on these findings, it recently was suggested that recommended selenium intake levels should be raised from 55 to 75 micrograms per day,” they added.

Speaking with NutraIngredients-USA, Dr Ames Dr Ames added that the vitamin K review had highlighted a ‘protein hierarchy’; while the new selenium review shows that there is also a ‘tissue hierarchy’.

Selenium and cancer

Selenium is a trace element that occurs naturally in the soil and is absorbed by plants and crops, from where it enters the human food chain - either directly or through consumption of meat and other products from grazing animals.

The mineral is included in between 50 and 100 different proteins in the body, with multifarious roles including building heart muscles and healthy sperm. However, cancer prevention remains one of the major benefits of selenium, and it is the only mineral that qualifies for a Food and Drug Administration (FDA)-approved qualified health claim for general cancer reduction incidence.

Europe versus America

The study is of added importance in Europe where selenium levels have been falling since the EU imposed levies on wheat imports from the US, where soil selenium levels are high.

As a result, average intake of selenium in the UK has fallen from 60 to 34 micrograms per day, leading to calls from some to enrich soil and fertilizers with selenium to boost public consumption. Selenium-enriched fertilizers are used in Finland.

The European recommended daily intake (RDI) is 65 micrograms. The recommended EC Tolerable Upper Intake Level for selenium is 300 micrograms per day.

Source: FASEB Journal
Published online ahead of print March 14, 2011, doi:10.1096/fj.11-180885
“Adaptive dysfunction of selenoproteins from the perspective of the triage theory: why modest selenium deficiency may increase risk of diseases of aging”
Authors: J.C. McCann, B.N. Ames

4 comments (Comments are now closed)

Amazing theory!

Miguel De Zayas says:
September 5, 2015 at 1:53 pm
Amazing theory! It grabbed the essences of the most primitive yet most sophisticated function of every living organism in this planet: cannibalism. Missing nutrients (vitamins, minerals or coenzymes) are delocalized, in extreme cases even forcefully removed from body’s organs in detrimental collateral damage ways to compensate for key bodily systems involved in short term survival.
I would go even further… It’s my deepest belief that the body keeps hidden an “inventory” of what, when and where were those vitamins taken allowing for a fast pace recovery (damage control) once the needed nutrients become available once again. Just as our brain keeps count on the hours of sleep deprivation, our DNA’s “memory bank” does it with vitamins.
REPLY
Miguel De Zayas says:
September 5, 2015 at 3:03 pm
What is cancer?
Scientists have been trying to unveil the nature of this fatal illness (if left untreated). The blame falls in so many different and unrelated factors that left us back to where we started.
One thing is clear: a strong immune system and an active and effective antioxidant response “team” could protect us from its devastating attack.
I’m convinced today that the Triage Theory has provided us with the basic understanding of the hidden roots of cancer…I’ll explain it:
My first comment in this page covered a belief I cherish about the ability of our DNA to keep a (sort of an) inventory of the missing vitamins, minerals and coenzymes being “self-cannibalized” providing us with a chance for a short term survival in spite of a potential damage to other body systems due to an eventual failure in case those nutrients are never replaced or provided.

It’s precisely that ABILITY (imbedded in our DNA) that allows to “cannibalize” and “resupply” essential resources from one place to another in our bodies what helps us to fight aging related diseases but also (in the scenario characterized by a long term nutritional missing) the same DNA mechanism involved in cancer.
Let’s take insulin’s in diabetes as an example, a wrong diet favoring simple sugars and carbohydrates could be handled if the time exposing our body to it is relatively short. The same thing happens with our sophisticated DNA mechanism too. However, when a long term of lacking key vitamins or minerals causes this survival mechanism (Triage) to go out of control then just as seen before with the insulin in diabetes melitus type 2, the control system gets out of control and our bodies is incapable of regulating it.
This is precisely what lies at the very roots of cancer… Our DNA’s innate (inherent) cannibalistic attempt to compensate for the lack of functions key to provide a short term survival.

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Posted by Miguel De Zayas
05 September 2015 | 17h202015-09-05T17:20:07Z

dry AMD (macular degeneration

I have dry AMD and have heard that the use of Selenium would help my eyesight, would this be correct or could you give ma path on reversing my AMD

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Posted by David spears
26 August 2015 | 08h352015-08-26T08:35:41Z

Nutrition Deficiencies in Disease

Clinical evidence in Chronic diseases displays a high level of nutritional deficiencies especially in Cancers. Including in non-infectious acute diseases. The application of drugs may increase this deficiency. As the deficiencies increase the benefits of the drugs reduce and may increase toxicity. This affect is not limited to just nutrition. The need for all herbs is paramount.

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Posted by Harry Simpson
24 April 2011 | 10h302011-04-24T10:30:13Z

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