News Briefs:
Crucifers, Lung & Stomach Health;
Magnesium & Bone Strength;
Selenium & Joint Vitality
Crucifers May Help Lower Lung Cancer Risk
Studies have consistently linked consumption of green cruciferous vegetables - broccoli, cabbage and Brussels sprouts - with reduced rates of lung cancer. Crucifers contain protective compounds called isothiocyanates (eye-so-thigh-o-SIGH-en-ates). Newly published research confirms the importance of these compounds. The findings also suggest that many of us would benefit from eating more crucifers, though their protective effect appears to be stronger for some individuals.
Protective isothiocyanates are normally eliminated from the body by enzymes produced by two genes named GSTM1 and GSTT1. People with inactive forms of these genes have higher levels of the protective compounds. Researchers wanted to know whether people with the inactive genes might be more shielded from lung cancer risk since they retain more of these protective compounds in the body.
The study found that regular crucifer consumers (weekly vs. infrequently) who had the inactive form of "M1" or "T1"lowered their risk of lung cancer by 33% and 37% respectively. For those with both genes inactive, risk was cut by 72%. While people with the active form of both genes received no added protection, it's important to note that the non-active gene forms are fairly common. They occur in 50% (GSTMI) and 20% (GSTT1) of the population.
Broccoli Sprouts May Also Calm Gastritis
At a cancer conference in October, Japanese investigators reported that eating broccoli sprouts daily improves chronic bacterial gastritis (inflamed stomach lining) by fighting H. pylori - the bacteria responsible for many cases of bacterial gastritis and stomach ulcers. These sprouts contain sulfuraphane (sul-FOR-a-fain), an isothiocyanate that may protect cells from injury and slow H. pylori.
Subjects infected with H. pylori consumed about 1� cups of broccoli sprouts daily or the same amount of alfalfa sprouts, which contain no sulfuraphane. Only the broccoli group had lower markers of H. pylori and gastritis after 2 months, which returned to their initial levels several months after the study ended.
More Magnesium for Stronger Bones
Though less well studied than calcium, magnesium is also believed to play a role in bone strength. The Health ABC Study was conducted in over 2000 older men and women to examine whether magnesium intake is associated with bone mineral density (BMD). People with higher BMD are less likely to experience bone fractures.
BMD was reported to be significantly greater in men and women getting the most magnesium (394 mg on average) compared to those getting the least (about 248 mg). Magnesium supplements appeared to be an important contributor to overall intake. Nearly 58% of those in the highest magnesium group took supplements compared to less than 2% in the lowest group. The magnesium-BMD association was not observed among Afro-Americans who tend to have higher bone mineral densities.
Low Selenium May Increase Arthritis Risk
Older people may also benefit from a more adequate intake of the trace mineral selenium. At the American College of Rheumatology Annual Meeting in San Diego last month, investigators from University of North Carolina reported that low levels of selenium is strongly linked to arthritis of the knee. Selenium content was measured in toenails, an indicator of body stores.
The risk for knee osteoarthritis was 40% lower in those with the highest selenium stores compared to the lowest. In addition, the chance of having severe disease was nearly halved in this group. And in this study, some of the benefits of having adequate selenium stores were even stronger for Afro-Americans. These researchers will now try to learn whether selenium affects knee cartilage or whether the benefits are from selenium's antioxidant role.
- Brennan P, et al. Effect of cruciferous vegetables on lung cancer in patients stratified by genetic status. Lancet 366:1558-60, 2005.
- Yanaka A, et al. American Association for Cancer Res 4th International Conference Oct 31, 2005, Baltimore, MD.
- Ryder KM, et al. Magnesium intake from food and supplements is associated with bone mineral density in healthy older white subjects. J Am Geriatr Soc 53:1875-80, 2005.