Higher vitamin E levels predict improved prostate cancer survival
An article published in the May 1, 2009 issue of the journal Cancer Research reported the discovery of researchers at the National Cancer Institute of an improvement in prostate cancer survival among men with high vitamin E levels. The effect was particularly strong among those who supplemented with the vitamin.
Joanne L. Watters and colleagues analyzed data from 29,133 participants in the Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention Study, which evaluated the effect of vitamin E and beta-carotene on the risk of cancer in male Finnish smokers enrolled between 1985 and 1988. Blood samples collected upon enrollment and at three years were analyzed for serum levels of beta-carotene, retinol (vitamin A), and alpha-tocopherol (vitamin E). Although the trial concluded in April, 1993, on-going follow-up documented 1,891 prostate cancer cases and 395 deaths due to the disease through April, 2005.
Men whose serum alpha-tocopherol levels at the beginning of the study were among the top one-fifth of participants were found to have a 33 percent lower risk of dying of prostate cancer compared with those whose levels were in the lowest fifth. For those whose levels were highest at the third year of the study, a 20 percent lower risk existed. Men who received alpha-tocopherol supplements in the trial and whose baseline levels of vitamin E were highest experienced the lowest risk of prostate cancer mortality, which was 49 percent less than the risk experienced by those in the lowest 20 percent of serum alpha-tocopherol levels. This risk declined after three years to 74 percent less than the risk of those among the lowest fifth.
When all-cause mortality was analyzed among those diagnosed with prostate cancer, participants in the top one-fifth of serum vitamin E levels were shown to have a 33 percent lower risk of death over the course of follow-up, suggesting, according to the authors, "a possible effect for alpha-tocopherol on other causes of death in men with prostate cancer."
In their discussion, the authors note that the current study's findings are at odds with those of the Physician's Health Study II and the Selenium and Vitamin E Cancer Prevention Trial which failed to find a benefit for vitamin E on prostate cancer survival and incidence. The current study's analysis of serum alpha-tocopherol levels and longer follow-up period could account, in part, for the variance.
"These findings build upon previous research showing a 41 percent reduction of prostate cancer mortality in response to alpha-tocopherol supplementation in the controlled trial component of the ATBC Study from 1985 to 1993," the authors write. "In summary, our results suggest dietary and supplemental alpha-tocopherol may improve prostate cancer survival. Considering the large number of men diagnosed with prostate cancer, such nutritional modifications could have a significant effect if subsequent randomized trials in men with newly diagnosed prostate cancer prove a benefit," they conclude.
A study of over 29,000 male smokers in Finland, ages 50-69, disclosed a 32% decrease in the incidence of prostate cancer (PC) (95% confidence interval [CI] = -47% to -12%). This was observed among the subjects who had received 50 mg a day of alpha-tocopherol (n = 14,564) in contrast with those not receiving it (n = 14,569). Mortality from PC was 41% lower among men receiving alpha-tocopherol (95% CI = -65% to -1%). Among subjects receiving beta-carotene (n = 14,560), PC incidence was 23% higher (95% CI = -4% to 59%) and mortality was 15% higher (95% CI = -30% to 89%) compared with those not receiving it (n = 14,573). In this study, long-term supplementation with alpha-tocopherol substantially reduced PC incidence and mortality in male smokers.
An important issue is whether this benefit of alpha-tocopherol, and possibly other tocopherols, is limited to smokers or those who have recently quit smoking. A report by Chan et al. (1999) showed significant benefit only to smokers or those recently quitting smoking in a study involving 47,780 U.S. male health professionals who received at least 100 IU of supplemental alpha-tocopherol. In this population, the risk of metastatic or fatal PC was reduced 56%. In the nonsmoking population, there were no beneficial findings of statistical significance.
Research studies have shown that vitamin E reduces growth rates of PCs resulting from a high fat diet. Tumor growth rates were highest in the animals fed a 40.5%-kcal fat diet (the typical American diet). Tumors in animals fed 40.5%-kcal fat plus vitamin E were the same as those fed a 21.2%- kcal fat diet (an ideal fat level).
Hunger is the factor that often precludes most people from even considering a low-calorie diet. The remarkable news is that pinolenic acid, a polyunsaturated fatty acid found in Korean pine, has been shown to suppress appetite dramatically without causing any stimulatory effect.*
Life Extension’s Natural Appetite Control formula was developed for adults seeking to lower their calorie intake and maintain a successful, long-term weight management program. Each softgel of Natural Appetite Control provides 1000 mg of a standardized extract of Korean pine nuts containing the highest concentration of pinolenic acid found in any pine nut species.
This supplement should be taken in conjunction with a healthy diet and regular exercise program. Results may vary.
A common complaint among older adults is loss of physical and mental energy. As people age, their cells’ ability to produce energy is diminished. Many scientists believe that cellular energy deficit is a critical factor in the onset of many degenerative problems.
The Russian herb Rhodiola (Rhodiola rosea) has demonstrated a remarkable ability to support cellular energy metabolism. Rhodiola promotes higher levels of ATP (adenosine triphosphate) and CP (creatine phosphate) in the cellular power plants known as the mitochondria, thus providing more of the energy molecules needed to perform many daily activities.
In a human clinical trial, rhodiola aided exercise endurance after just a single dose. In another double-blind crossover human trial, rhodiola increased several measures of mental performance, including associative thinking, short-term memory, concentration, calculation and speed of audiovisual perception. Statistically significant improvements were reported after just two weeks of supplementation.