The studies focus on the effects of omega-3 on levels of inflammatory biomarkers that are involved in damage to cells called soluble adhesion molecules, particularly soluble intercellular adhesion molecule-1 (sICAM-1). It is generally accepted that low circulating level of sICAM-1 is good.
The first of the two new studies is a meta-analysis by Yang et al.from the Bethune First Hospital of Jilin University in China. The analysis indicated that omega-3 supplements were associated with reduced levels of sICAM-1, which may contribute to a decrease in the risk of atherosclerosis.
The second study, by Touvier et al. from the National Institute of Health and Medical Research in Paris, indicated that increased levels of omega-3 may counteract the pro-carcinogenic action of sICAM-1.
Multiple health benefits
The results were welcomed by Harry Rice, PhD, VP of regulatory & scientific affairs for the Global Organization for EPA and DHA Omega-3s (GOED).
Dr Rice told NutraIngredients-USA: “Without getting into the limitations of the investigations, taken together, the studies support reducing or minimizing sICAM-1 via omega-3 supplementation for multiple health benefits including, but not necessarily limited to, atherosclerosis treatment and prevention, as well as reducing the risk of certain cancers.”
For the meta-analysis Yang et al. analyzed 18 randomized clinical trials involving omega-3 supplements and providing data on sICAM-1 concentrations.
Results showed that omega-3 supplements were associated with sICAM-1 reductions in both healthy people and subjects with abnormal blood lipid levels.
“This finding suggests that omega-3 PUFA reduces inflammation by selectively inhibiting monocyte activation rather than endothelial activation,” wrote the researchers.
“This protective effect was identified in both healthy subjects and in subjects with dyslipidemia, which supports the notion that omega-3 PUFA can be supplemented to prevent the development and progression of atherosclerosis.”
The Touvier et al. study investigated how omega-3 intakes could alter sICAM-1 levels and cancer risk by comparing data from 408 people with cancer (so-called cases) and 760 healthy people with similar characteristics (the controls).
Results showed that sICAM-1 levels were indeed related to omega-3 levels, and that this association was seen for different types of cancer, including breast and prostate cancer.
In addition, sICAM-1 concentrations were positively associated with cancer risk in people with below average omega-3 intakes, added the Paris-based researchers.
“For the first time, the results of this nested case-control study suggest that omega-3 PUFAs modulate the prospective association between plasma ICAM-1 and cancer risk,” they wrote.
“sICAM-1 was associated with an increased cancer risk among subjects with low omega-3 PUFA intakes, whereas no association was observed for subjects with higher omega-3 PUFA intakes.”
Commenting on the potential mechanism by which omega-3 may modulate cancer risk, the researchers note that there are two potential mechanisms that merit attention.
The first is that omega-3s may decrease the expression of adhesion molecules like sICAM-1, while the second may be that omega-3s intervene in the pro-cancer pathway stimulated by ICAM-1, “but with an anticarcinogenic action”.
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi:10.3945/ajcn.111.027805
“Modulation of the association between plasma intercellular adhesion molecule-1 and cancer risk by n−3 PUFA intake: a nested case-control study”
Authors: M. Touvier, E. Kesse-Guyot, V.A. Andreeva, et al.
American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.111.025924
“Effects of n–3 PUFA supplementation on plasma soluble adhesion molecules: a meta-analysis of randomized controlled trials”
Authors: Y. Yang, N. Lu, D. Chen