Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 428

Selenium has been identified as a nutrient of concern in community‐dwelling older adults.⁸ According to a Cochrane Review, because of the use of selenium in enriched foods, supplements, and fertilizers in some countries, there could be an increased perception that selenium reduces the risk of cardiovascular disease and other chronic diseases.³⁰ However, the results of studies to date are equivocal. Based on the results of 12 RCTs that provided selenium supplements to adults considered primarily healthy and well‐nourished, it was concluded that selenium supplements did not influence all‐cause mortality, CVD mortality, non‐fatal CVD events, or all CVD events (fatal and non‐fatal). In agreement with other studies, adverse events associated with selenium supplementation included alopecia and dermatitis.

Cai et al.³¹ examined relationships of selenium and cancer from RCT, cohort, or case‐control studies that included selenium as baseline exposure and outcomes as cancer events (incidence and mortality). Sixty‐nine studies were identified that were assessed through meta‐analysis, meta‐regression, and dose‐response analyses. Overall, high serum/plasma or toenail selenium had some efficacy for cancer prevention, such that higher selenium exposure decreased the risk of breast cancer, lung cancer, oesophagal cancer, gastric cancer, and prostate cancer but not colorectal cancer, bladder cancer, or skin cancer.³¹ In contrast to this finding, Vincenti et al.³² conducted meta‐analyses of RCT and cohort studies of selenium in a Cochrane Review and found that the higher quality RCTs showed no benefit for selenium supplements in reducing the risk of cancer. Unexpectedly, some RCTs suggested that selenium supplementation may increase the risks of high‐grade prostate cancer and type 2 diabetes.³²

Based on the contradictory nature of the evidence, supplementation with selenium to reduce the risk of cancer or cardiovascular diseases does not appear warranted at this time. In the next section, comprehensive meta‐analyses of several vitamins and minerals, alone or in combination, are reviewed for their health benefits and risks regarding cardiovascular disease and cancer.