Selenium yeast kept bad fats from forming in the blood after a fatty meal, according to results from a new study.

Doctors from the Free Radical Research Group, National Research Institute for Food and Nutrition, Rome, Italy, reported that eight healthy men and six healthy women, aged 25 to 40, ate a special high-fat meal before and after taking 110 mcg of selenium yeast per day for 10 days. There was no placebo group in the study. The meals contained an especially toxic—but common—fat byproduct called a lipid hydroperoxide (LH) which forms when natural polyunsaturated fatty acids overheat during manufacture, cooking, or frying. LH can attach to low-density lipoprotein (LDL, the "bad" cholesterol) in the blood, damage (oxidize) cells on arterial walls, and form the plaque that doctors believe leads to hardening of the arteries, a type of atherosclerosis.

Immediately before, and three hours after each meal, researchers measured blood-fluid (plasma) levels of selenium, antioxidants, LH-LDL, and an unstable compound that results from oxidized fat called malondialdehyde, or MDA. After the first meal, LH-LDL levels increased 2% and MDA levels increased 10%. After taking selenium yeast for 10 days and eating the second high-fat meal, levels of LH-LDL and MDA did not increase significantly. Researchers noted that throughout the study, plasma levels of selenium were adequate, and did not change significantly, and concluded that supplementing with selenium to adequate levels reduces risk for chronic and degenerative diseases such as atherosclerosis.

People with higher blood-fluid (serum) levels of selenium, the essential trace mineral, had significantly lower risk for bladder cancer, according to findings from a new Belgian study. Doctors conducted a case-control study that examined 178 persons with bladder cancer (cases) and 362 persons without bladder cancer (controls). The researchers took into account age, sex, smoking habits, and occupational hazards, and measured fruits and vegetables in the diet, as well as levels of vitamins A (retinol), C, and E, and total antioxidants in the blood.

After adjusting for these factors, scientists determined that those who had the highest levels of selenium—more than 96 mcg per liter of blood (mcg/l)—were 70% less likely to develop bladder cancer as were those who had the lowest levels of selenium; less than 82.4 mcg/l. Doctors also found that those in the middle group, whose selenium levels were between 82.4 mcg/l and 96 mcg/l, had 52% less risk of developing bladder cancer compared to those with the lowest levels. The researchers pointed out that, for each 10 mcg/l increase in the selenium level, the risk for bladder cancer dropped by 14%. The average person has about one liter of blood per 30 pounds of body weight.

According to the September, 2006, issue of Lancet Oncology, researchers first noticed the connection between selenium and cancer 40 years ago, when geographic studies reported lower death rates for cancer in regions of the U.S. with high levels of selenium. The first double-blind selenium-cancer study began in 1983 when researchers recruited 1,312 patients with histories of skin cancer at seven dermatology clinics located in low-selenium areas of the U.S. Doctors administered 200 mcg of selenium per day—about twice the average amount Americans consume—or a placebo, and followed up 10 years later. While results were not significant for skin cancer, there were 41% fewer total cancers, and 18% fewer deaths from cancer for selenium users compared to placebo.

Reference: International Journal of Urology; 2006, Vol. 13, No. 9, 1180-4.

     People with adequate levels of the essential trace mineral selenium live longer, healthier lives, and have better mental function compared to those with lower levels, according to three new findings from the Study of Aging Anatomy (Etude du Vieillissement Artériel, or EVA). French researchers recruited 1,389 men and women, aged 59 to 71, from 1991 to 1993, and followed up for nine years, during which time 109 participants died.

     In the first finding from the study, published in Clinical Chemistry, researchers measured selenium levels and found that those who survived the nine-year follow-up period had started the study with higher blood-fluid (plasma) levels of selenium than those who died. The researchers took into account diet, health, and lifestyle, and found that those with the lowest selenium levels were most likely to have died, and that cancer was more likely to be the cause of death than other causes.

     In the second finding, published in the Journal of Nutritional Biochemistry, compared to all other participants, those who were oldest, those who were obese, and those who had heart or blood-vessel disease during the nine-year follow-up period had lost the most selenium by the end of the study. Doctors found that other risk factors—such as gender, education, smoking, drinking alcohol, high cholesterol and other blood fats, diabetes, and high blood pressure—did not appear to decrease selenium levels, and suggested that nutrition and metabolism may affect selenium levels.

     In the third finding, among those whose selenium levels decreased over the nine-year period, those with the largest decrease had more mental decline than those with the smallest decrease. Among those whose selenium levels increased during the study, those with the smallest increase had more mental decline than those with the largest increase.

The EVA scientists concluded that selenium levels decline with age, low selenium levels make it difficult to maintain optimum health, and selenium may protect against cardiovascular diseases and mental decline.

Reference: Epidemiology: 2007; Vol. 18, No. 1, 52-8.