The kidneys cleanse our blood. Well-functioning kidneys are vital for the circulatory system and good health in general. Normal functioning of cells, including kidney cells, hinges on a host of different selenium-containing proteins and coenzyme Q10. Studies show that older people in many parts of the world, Europe included, have deficiencies of both substances. Therefore, a team of Swedish scientists conducted a study where they looked at selenium status and kidney function in a group of seniors. They gave selenium yeast and coenzyme Q10 or placebo to the participants for a period of four years. The results showed that the supplemented group as compared with the placebo group had improved kidney function according to several parameters. The positive effect on cellular energy metabolism, inflammation, and oxidative stress was attributed to the two supplements. The study is published in the science journal Nutrients.
Kidneys remove waste and toxins from the blood, for instance toxic substances from medicine. The kidneys have many other functions, including to regulate the body’s vital fluid balance and pH value. In addition, the kidneys are responsible for producing hormones such as renin that controls blood pressure and EPO that helps synthesize red blood cells. Our kidneys are therefore vital for our health by many accounts.
If you suffer from a mild degree of kidney disease you probably won’t even notice it. Still, it increases the risk of diseases in the heart and cardiovascular system such as atherosclerosis and blood clots. Chronic heart failure only occurs in few people with chronic kidney disease.
Because of the close relation between kidney function, heart function, and cardiovascular function, medical science uses a term known as cardiorenal syndrome.
It turns out that cardiovascular diseases and kidney diseases are characterized by chronic inflammation. Also, inflammation is seen in the early stages of kidney dysfunction and this inflammation can promote the development of kidney ailments, which is because inflammation generates free radicals. These are aggressive molecules that cause chain reactions that can damage cells and tissue. Our only source of protection against free radicals is the presence of various antioxidants, where selenium and coenzyme Q10 play a particularly vital role.
If, however, we lack antioxidants it increases our risk of oxidative stress, which is an imbalance between free radicals and antioxidants. Therefore, there is a close link between chronic inflammation and oxidative stress, a condition that is very harmful.
Facts about kidney functions:
Selenium’s important functions and its role in the kidneys and circulatory system
Selenium supports around 30 different selenium-containing enzymes (selenoproteins) that are of vital importance to our energy turnover, metabolic processes, immune defense, fertility and so on. Selenium also supports the important GPX antioxidants that protect cells and tissues against oxidative stress caused by free radicals. Studies show that selenium protects the kidneys against toxic damage caused by mercury, cadmium, lead, and chemotherapy with a compound called cisplatin.
Our thyroid gland and kidneys hold the largest selenium concentrations but the concentration of selenium in kidney patients is lower than in healthy individuals. In mice, selenium deficiency has been seen to cause damage to the kidneys due to oxidative stress and damage to the mitochondria, which are the microscopic powerhouses that produce energy inside our cells.
Low selenium is already known to increase the risk of cardiovascular disease. The agricultural soil in large parts of the world lacks selenium and that affects the entire food chain. An estimated one billion people worldwide are believed to be selenium-deficient. In Europe, the average selenium intake is well below 50 micrograms per day, which is far too little. According to studies, we need around 100 micrograms of selenium per day or more in order to properly saturate selenoprotein P that is used as a marker of selenium status in the blood.
Q10’s important functions and its role in kidney function and the circulatory system
Q10 is of great importance to cellular energy turnover that takes place inside the mitochondria. It is inside these powerhouses that Q10 is a part of the so-called electron transport chain. Once the energy has been extracted it is stored in molecular form as ATP (adenosine triphosphate). With help from Q10, the cells can then break down ATP and release the energy trapped inside. This energy is used for things like muscle contractions and kidney function.
Q10 is also a lipid-soluble antioxidant that protects cells and cholesterol against free radicals and oxidative stress.
Q10 occurs in two different forms. Thioredoxin reductase 1, one of many selenoproteins, is needed in order for Q10 to be able change from one form to another and vice versa.
In other words, there is an essential interplay between Q10 and selenium that is determining for normal cell function and good health.
We humans make most of our own Q10 but our endogenous synthesis of the compound begins to decrease with age. The Q10 content in the heart of an 80-year-old is around half of what you find in a person who is around 20 years of age.
Ways to measure kidney function
Supplements of selenium and Q10 improve kidney function by several parameters
Chief physician and cardiologist Urban Alehagen from the University of Linköping in Sweden headed the new study. He hypothesized that supplements of selenium and Q10 would have a positive impact on kidney function in older people living in regions that had selenium-depleted farmland, and where selenium deficiencies were therefore more common.
The science team started by looking at the relation between selenium status and creatinine levels in 589 older men and women. Afterwards, 215 of these individuals took part in a randomized, double-blind, placebo-controlled study. The average age was 71 years.
At baseline, all participants had low selenium levels in their blood. Kidney function was assessed using creatinine, cystatin-C, GFR and other advanced techniques.
One group got 200 micrograms of selenium yeast and 200 mg of Q10 every day, while the other group got matching placebo. Kidney function was measured at baseline and after 48 months. The study was evaluated after approximately five years.
The scientists found a clear link between low selenium and impaired kidney function. They also observed that supplements of selenium yeast and Q10 resulted in a significantly improved kidney function with regard to creatinine, cystatin-C, GFR and the other variables. The researchers assume that the two compounds affect kidney function positively by lowering inflammation and oxidative stress.
Q10 and selenium may also improve heart function and lower mortality
For many years, Urban Alehagen has conducted research with Q10 and selenium. Due to his role as a cardiologist, he has mainly focused on these two compounds and their role in the prevention of cardiovascular diseases. In the groundbreaking KiSel-10 study, which he also headed, the older participants were given placebo or daily supplements with 200 micrograms of selenium yeast and 200 mg of Q10. Both the selenium and the Q10 were pharmaceutical-grade products. The study lasted five years and showed that the supplemented group had a 54 percent lower cardiovascular mortality rate and a significantly lower hospitalization rate. Follow-up studies after 10 and 12 years respectively confirmed that Q10 and selenium supplements have a notable long-term effect on the cardiovascular system, the heart function, and lifespan.
Urban Alehagen et al. Selenium and Coenzyme Q 10 Supplementation Improves renal Function in Elderly deficient in Selenium: Observational Results and Results from a Subgroup Analysis of Prospective Randomised Double-Blind Placebo-Controlled trial. Nutrients. December 2020
Alehagen U et al. reduced Cardiovascular Mortality 10 Years after Supplementation with Selenium and Coenzyme Q10 for four years. Follow-Up Results of a Prospective Randomized Double-Blind Placebo-Controlled trial in Elderly Citizens. PLoS One 2015
Urban Alehagen et al. Still reduced cardiovascular mortality 12 years after supplementation with selenium and coenzyme Q10 for four years. A validation of previous 10-years follow-up results of a prospective randomized double-blind placebo-controlled trial in elderly. PLOS ONE 2018
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