The heart muscle tissue is frequently the first tissue in humans to suffer damage caused by selenium deficiency. When the cell membranes in the heart muscle tissue are damaged by the action of harmful free radicals (this is called oxidative damage), many of the healthy heart muscle cells are replaced by fibrous tissue. The resulting condition is called cardiomyopathy.
Cardiomyopathy is a disease of the heart muscle in which the heart is enlarged, thick, and rigid [Mayo Clinic]. As the cardiomyopathy worsens, the weakened heart muscle is less and less able to pump adequate quantities of blood to carry oxygen and nutrients to the cells and tissues throughout the body. Eventually, symptoms such as shortness of breath, early fatigue, and swelling in the legs and feet and abdomen appear, the symptoms of chronic heart failure.
Statin medications and selenium
Statin medications: good news and bad news? On the one hand, statin medications are effective at reducing cholesterol levels, and, are good, apparently, at reducing the number of deaths from heart attacks. On the other hand, we have seen a very considerable rise in the number of cases of chronic heart failure … in the same period that statin medications have been prescribed. Drs. Okuyama and Langsjoen and their colleagues have explained the pharmacological mechanisms by which this medical paradox may be occurring [Okuyama].
Statins inhibit the body’s production of Coenzyme Q10
Okay, I was aware of the evidence from well-designed studies linking the taking of statin medications to decreased plasma levels of Coenzyme Q10. Coenzyme Q10 is an important factor in cellular energy production and is an important lipid-soluble antioxidant [Folkers, Littarru, McMurray]. And I knew that the energy-deprived heart is a failing heart [Folkers, Molyneux, Mortensen]. So, I knew that anyone taking a statin medication needs to talk to his or her cardiologist about taking a good Coenzyme Q10 supplement.
Daily intakes of selenium
How much selenium from food and supplements do we need on a daily basis? Which bio-markers of optimal selenium status seem to be most useful to answer this question? Dr. Rachel Hurst and Dr. Susan J. Fairweather-Tait, Norwich Medical School, United Kingdom, and their colleagues set out to find answers. The design of their study is very interesting.
They enrolled 119 healthy British men and women aged 50 – 64 years in a randomized, double-blind, placebo-controlled study that lasted 12 weeks [Hurst]. They excluded the following persons from the study:
- smokers
- overweight people
- people with already high plasma selenium status
- people with long-term illnesses
- people on various medications
- people unwilling to discontinue taking vitamins and herbal remedies at least one month prior to the start of the study
The 119 study participants received either placebo or one of the following treatments:
- selenium-enriched yeast tablets containing 50, 100, or 200 micrograms of a patented organic selenium (SelenoPrecise® preparation delivered by Pharma Nord, Denmark)
- selenium-enriched onion meals that provided the equivalent of 50 micrograms of selenium per day
- unenriched onion meals that provided the equivalent of less than 4 micrograms of selenium per day
Measurements of selenium
Remember: Selenium is a trace element. We measure its intake in micrograms per day, not milligrams. We measure selenium status in plasma and serum in terms of micrograms per liter (or equivalently, in nanograms per milliliter). Selenium in toenails or hair, then, we measure in micrograms per gram.
A basic guide to selenium
Selenium is an important micronutrient. It is essential for life for both people and animals. The body cannot synthesize selenium and is dependent upon the selenium that it can get from food. In many regions of the world, there is too little selenium in the soil and in the food, and supplementation is necessary for optimal health.
Regions with selenium-poor soil
In many regions of the world, the content of selenium in the soil is quite low. In large parts of Asia, China in particular, and in much of Europe and the Middle East, there are low levels of selenium in the soil.
Plants accumulate inorganic selenium from the soil and convert it to organic selenium. In that way, the selenium enters the food chain. For example, cows eat grass containing selenium, and the some of the selenium enters the meat and the milk of the cows. People eat the meat and drink the milk. Too little selenium in the soil means too little selenium in the food.
What is a high selenium yeast supplement?
The trace element selenium is an essential component of the selenium-dependent enzymes called selenoproteins. We need these selenoproteins for the optimal biological functioning of our cells. Specifically, we need adequate daily intakes of selenium for the protection of cellular DNA, for successful reproduction, for proper thyroid gland function, for protection against infections, for anti-oxidative protection against the damage caused by free radicals, and for the prevention of cancer and heart disease.
What form of selenium is best?
Many of us cannot get enough selenium in our diets, especially if we do not regularly eat Brazil nuts (very high in selenium) or if we eat relatively little meat and fish. However, there are various supplemental forms of selenium available to us as consumers.
Our bodies cannot make selenium for us
Daily selenium intakes? We need to get this essential trace element – selenium — in our diets and in our supplements because our bodies cannot make it for us. The work of Dr. Gerhard N. Schrauzer, Dr. Raymond J. Shamberger, and Dr. Douglas V. Frost has shown that there is an inverse relationship between our selenium status and the risk of cancer mortality. Animal studies show an inverse correlation between selenium status and incidence of cancer. Observational studies show lower risk of various types of cancer with higher selenium status.
Intervention studies of selenium supplementation and cancer
Clinical studies in China
Large interventional studies in China, a region of the world with selenium-poor soils and foodstuffs, have shown that selenium supplements protect against hepatitis B virus and primary liver cancer [Yu] and that supplementation with a combination of selenium and other antioxidants reduces cancer incidence and mortality in a region characterized by high cancer mortality rates [Blot].
Selenium and colorectal cancer: The Bonelli study
Dr. Luigina Bonelli and a team of researchers in Genoa, Italy, were motivated by the following set of compelling facts:
- Colorectal cancer was the second leading cause of cancer death in Europe.
- Adenomas in the colon (adenomas are benign tumors, which sometimes transform to malignant tumors) were known to be precursors of colorectal cancer.
- Patients who had undergone a colonic polypectomy (removal of an adenomatous polyp) had an increased risk of developing colorectal cancer and needed to have periodic follow-up colonoscopies.
- Increased risk of developing adenomas was equated with increased risk of developing colorectal cancers.
- Observational studies indicated that there was an association between the plasma or serum concentrations of several antioxidant substances including selenium and the risk of colorectal cancer.
- In some intervention studies, supplementation with selenium was associated with reductions in the incidence of colorectal cancer.
The time was right to start a large study of the effectiveness of selenium and other antioxidants in reducing the risk of colorectal cancer.
Selenium to reduce the risk of colorectal cancer
Dr. Bonelli and her colleagues wanted to see if daily supplementation with a combination of antioxidants including selenium could reduce the risk of recurrent adenomas in patients who had had one or more adenomatous polyps removed. The researchers designed a randomized, double-blind, placebo-controlled clinical trial and, over the period of many years, they enrolled a total of 411 patients who had undergone a polypectomy.
How we know that selenium supplementation is important
Selenium? A trace element? You might well ask: How do we know that adequate amounts of dietary and supplemental selenium are important to us?
The first answer is: because we can see that selenium deficiency makes people sick.
A further answer is that we now know that selenium is an essential component of antioxidant enzymes.
And, on the basis of the results of randomized controlled trials, we know that selenium supplementation reduces the risk of cancer, reduces the risk of heart disease, and improves immune function.
Selenium is also very useful for reducing the toxic effects of heavy metals in the body.
Reason number one: Selenium-deficiency diseases
Keshan disease
In the 1960’s and 1970’s, thousands of people living in a region of China with selenium-poor soil, and, consequently, with selenium-poor food, died from the effects of a form of heart disease. The disease, which took its name from Keshan county in the afflicted region of China, is characterized by inflammation and enlargement of the heart muscle and excess fluid in the lungs. The primary cause of the disease was selenium deficiency.
Dr. Gerhard N. Schrauzer – renowned selenium researcher
Dr. Gerhard N. Schrauzer was the grand old man of selenium science. Actually, he was the grand old man of trace element research in the United States for 30 years or more. He was one of the pioneers and one of the major figures in selenium research. Let’s take a look at the useful contributions of information to the selenium supplementation knowledge base that Dr. Schrauzer made.
First, who was Dr. Schrauzer in the context of selenium research?
Dr. Schrauzer did his graduate study in chemistry at the University in Munich, Germany. He was awarded his Ph.D. summa cum laude. From 1966 to 1994, he was a chemistry and biochemistry professor at the University of California in San Diego (UCSD). After his retirement, he was a professor emeritus at UCSD.
The functions of selenium supplements
Why the interest in selenium facts? Here, at the beginning of the seleniumfacts.com website, we want to review in broad terms what we know about the functions of selenium supplementation. We are especially interested in selenium’s antioxidant and anti-inflammatory effects in the human body.
Selenium is an essential trace element in the human diet, and, in many regions of the world, it is an absolutely necessary nutritional supplement. It has many and diverse functions in the human body.
One of the interesting things about selenium is that it does not perform its functions as an element or an ion. Instead, it functions as a component of more complex compounds. In particular, it is an essential component of the 21st amino acid, selenocysteine.