A new study confirms the suspicion that increasing vegetable intake lowers the risk of developing aggressive prostate cancers – the kind that spread beyond the prostate into surrounding tissues. (Kirsh VA, et al., “Prospective study of fruit and vegetable intake and risk of prostate cancer,” J Natl Cancer Inst. 2007 Aug 1;99(15):1200-9.) In this study of 29,361 men over four years, those who consumed more than one serving per week of cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, and cabbage) reduced their risk by 59%, compared to those men who ate these vegetables less than once per month. Cruciferous vegetables, also known as the Brassica family, include other vegetables as well, such as kale, collards, broccoli rabe (rapini), turnip greens, mustard greens, bok choy, Chinese cabbage, mizuna, tat soi, and others. Non-brassica cruciferous veggies include arugula, radish, watercress, daikon, and horseradish.



Researchers have shown that in mice implanted with human cancer cells, the antioxidants Vitamin C and N-acetyl-cysteine inhibit the growth of the tumors. (Gao P, et al., “HIF-Dependent antitumor-genic effect of antioxidants in vivo,” Cancer Cell. 2007 Sep;12(3):230-8.) These effects appear to be independent of the antioxidant effects of these nutrients that protect DNA from damage. The benefits are related instead to the inhibition of a substance called hypoxia-inducible factor, or HIF-1. HIF-1 appears to protect tumor cells from attack, and the diminished levels caused by the nutrients results in growth inhibition. This information is an important addition to our understanding of how nutrients can work in many different ways. Unlike side effects of drugs, the unexpected effects of nutrients are almost always beneficial. The researchers suggested that this effect might also block colon-cancer and cervical-cancer growth. For some inexplicable reason, the researchers cautioned (!) against taking large doses of Vitamin C. Increasing evidence supports the value of very high doses of Vitamin C in cancer prevention and treatment, as was reported by Linus Pauling decades ago. His position is now being vindicated by the latest research.



Lutein and zeaxanthin are two antioxidant carotenoids that appear to protect the retina from age-related decline. These nutrients are plant pigments that protect the plants and impart to them a yellow to yellow-orange color. A study of 4519 subjects from 60-80 years old showed that over six years, those with the highest level of consumption of these two nutrients had a 35% lower risk of macular degeneration than those with the lowest level of intake. (SanGiovanni JP, et al., “The relationship of dietary carotenoid and vitamin A, E, and C intake with age-related macular degeneration in a case-control study: AREDS Report No. 22,” Arch Ophthalmol. 2007 Sep;125(9):1225-32.) Some of the atrophic retinal changes were reduced by 65%. Lutein and zeaxanthin are found in dark green vegetables such as spinach and broccoli, corn, peas, zucchini, eggs, and romaine lettuce. Supplements of lutein are often derived from the yellow pigment in marigolds, and they usually contain small amounts of zeaxanthin.



Vitamin E has anti-inflammatory, antioxidant, and anti-platelet effects, all of which serve to reduce risks of heart disease, cancer, and inflammatory disorders. A new clinical study shows that supplements of Vitamin E help to prevent blood clots in the veins, also called venous thromboembolism, or VTE. (Glynn RJ, et al., “Effects of random allocation to vitamin E supplementation on the occurrence of venous thrombo-embolism: report from the Women's Health Study,” Circulation. 2007 Sep 25;116(13): 1497-503.) VTE can lead to strokes and lung blood clots with potentially lethal consequences. Researchers evaluated 39,686 women in the Women’s Health Study, half of whom were given 600 IU of Vitamin E on alternate days, and half a placebo. Over 10 years, the Vitamin E group had a 21% lower risk of VTE than the control group (perhaps they should have taken their Vitamin E every day to further lower the risk). Among the subgroup of women who had a prior history of VTE, the benefits were even greater. Those Vitamin-E takers had a 44% reduced risk of recurrence of the VTE during the same time period. A specific subgroup of women with a genetic propensity to excessive blood clotting had a 49% reduction in risk. Nonetheless, Reuters Health reported that the American Heart Association does not recommend Vitamin E supplements to reduce cardiovascular risks. I wonder what they would recommend instead.



The value of lifestyle changes (diet and exercise) in the prevention and management of diabetes is even more important in light of a recent report on two commonly prescribed diabetes medications, Avandia (rosiglitazone) and Actos (pioglitazone). This meta-analysis of other studies on 14,291 patients taking these drugs showed that they had double the risk of developing heart failure and a 42% greater risk of heart attacks compared to those not taking the drugs. (Singh S, et al., “Long-term risk of cardiovascular events with rosiglitazone: a meta-analysis,” JAMA 2007 Sep 12;298(10):1189-95.) Surprisingly, the cardiac risks were present even in younger patients, within a very short time (26 months on the drugs), and even at low doses. Lifestyle changes are free of side effects, and unlike the medications, they are without cost.



Even mild exercise is beneficial when it comes to preventing diabetes. Japanese researchers studied 8600 men who worked for the same company, evaluated the amount of walking they did to get to work, and then followed them for four years. The study found that those who walked 21 minutes or more per day to get to work had a 25% lower risk of developing diabetes than those who reported walking less than 10 minutes per day. (Sato KK, et al., “Walking to work is an independent predictor of incidence of type 2 diabetes in Japanese men: the Kansai Healthcare Study,” Diabetes Care 2007 Sep;30(9):2296-8.) Exercise improves insulin sensitivity and helps with weight control, both of which are potential contributors to the prevention of diabetes. Of course, exercise has numerous other benefits in prevention of heart disease, improving sleeping patterns, increasing energy and bone density, and elevating mood, and as this study shows, any extra activity helps.