Alpha-linolenic acid and the risk of prostate cancer. What is the evidence?
Alpha-linolenic acid and the risk of prostate cancer. What is the evidence?
Year: 2004
Authors: N Attar-Bashi, A G Frauman, A J Sinclair.
Publication Name: The Journal of Urology/
Publication Details: Volume 171; Page 1402.
Abstract:
Several studies have examined the association between polyunsaturated fatty acids and prostate cancer risk. The role of alpha linolenic acid (ALA) in prostate cancer development has been investigated using various experimental designs and controversial findings have been published. In this review, the evidence on the association between ALA and the risk of prostate cancer in humans was assessed. The authors comprehensively reviewed a number of published studies on the association between ALA and the risk of prostate cancer using MEDLINE. Some studies suggest that ALA is associated with an increased risk of prostate cancer. Among eight case-control studies, six reported an association between dietary ALA and increased prostate cancer risk, while two reported no link between dietary ALA and prostate cancer. Among the cohort studies, one270 reported that ALA was linked with increased prostate cancer risk, while the other reported that ALA intake was inversely related to prostate cancer risk. Inconsistencies emerged when fatty acids were measured in the same cell type raising questions as to whether the ALA content of blood lipids or blood cells is a good indicator of the biology within the prostate tissue. Overall, the relationship between ALA levels in the prostate and ALA levels in the diet, blood and red blood cells has not been established. A recent meta-analysis showed that ALA consumption might reduce heart disease mortality, whereas ALA intake or blood ALA increased prostate cancer risk. It was noted that the results for relative risk of prostate cancer were quite heterogeneous and several factors were proposed: study design, differences in the background diets of the populations, random error and publication bias. These authors concluded in their recent review of the topic that it is unlikely that an important nutrient like ALA will be shown to increase prostate cancer risk while also decreasing heart disease risk. No consistent effect of ALA on prostrate cancer has emerged from the human cohort and case-control studies. Two dietary factors are the most likely contributors to prostate cancer development?excess calories and total fat. The dietary ratio of omega-6 to omega-3 fatty acids may also be important. In some studies eating red meat also emerged as a risk factor for prostate cancer. Even though meat contains only small amounts of ALA, it is a key source of ALA in some people’s diets, making it a marker for a diet rich in animal fat and meat. Fat from vegetable sources?also a source of ALA?was not linked with increased prostate cancer risk. These findings reveal the complexities of the diet and the relationships between nutrients and disease processes. The authors conclude that further research is needed in this area before it can be concluded that there is an association between ALA and prostate cancer. lyunsaturated fatty acids and prostate cancer risk. The role of alpha linolenic acid (ALA) in prostate cancer development has been investigated using various experimental designs and controversial findings have been published. In this review, the evidence on the association between ALA and the risk of prostate cancer in humans was assessed. The authors comprehensivey reviewed a number of published studies on the association between ALA and the risk of prostate cancer using MEDLINE. *. Some studies suggest that ALA is associated with an increased risk of prostate cancer. Among eight case-control studies, six reported an association between dietary ALA and increased prostate cancer risk, while two reported no link between dietary ALA and prostate cancer. Among the cohort studies, one270 reported that ALA was linked with increased prostate cancer risk, while the other reported that ALA intake was inversely related to prostate cancer risk. Inconsistencies emerged when fatty acids were measured in the same cell type raising questions as to whether the ALA content of blood lipids or blood cells is a good indicator of the biology within the prostate tissue. Overall, the relationship between ALA levels in the prostate and ALA levels in the diet, blood and red blood cells has not been established. A recent meta-analysis showed that ALA consumption might reduce heart disease mortality, whereas ALA intake or blood ALA increased prostate cancer risk. It was noted that the results for relative risk of prostate cancer were quite heterogeneous and several factors were proposed: study design, differences in the background diets of the populations, random error and publication bias. *These authors concluded in their recent review of the topic that it is unlikely that an important nutrient like ALA will be shown to increase prostate cancer risk while also decreasing heart disease risk. No consistent effect of ALA on prostrate cancer has emerged from the human cohort and case-control studies. Two dietary factors are the most likely contributors to prostate cancer development?excess calories and total fat. The dietary ratio of omega-6 to omega-3 fatty acids may also be important. In some studies eating red meat also emerged as a risk factor for prostate cancer. Even though meat contains only small amounts of ALA, it is a key source of ALA in some people’s diets, making it a marker for a diet rich in animal fat and meat. Fat from vegetable sources?also a source of ALA?was not linked with increased prostate cancer risk. These findings reveal the complexities of the diet and the relationships between nutrients and disease processes. The authors conclude that further research is needed in this area before it can be concluded that there is an association between ALA and prostate cancer.
