Consumption of fatty fish reduces lipophilic index and improves cardiovascular health

Finland: The consumption of fatty fish decreases lipophilic index (LI), indicating better membrane fluidity in people with coronary heart disease or impaired glucose metabolism, a recent study in Nutrition, Metabolism & Cardiovascular Diseases has revealed. 

The lipophilic scale is regarded as an indicator of cell membrane flexibility, and a reduced lipophilic scale signifies enhanced membrane flexibility. In the study, a diminished lipophilic scale was additionally linked to increased mean HDL particle size and heightened abundance of sizable HDL particles, implying advantages for cardiovascular health.

The lipophilic metric has been introduced to depict the flexibility of membranes, which can potentially alter the functionality of cells and proteins bound to the membrane. The length and saturation of fatty acids in membranes impact membrane flexibility. To illustrate, the fatty acids found in serum lipids or erythrocyte membranes can be utilized to compute the lipophilic index. Previous investigations have indicated that omega-3 fatty acids with long carbon chains in fish offer advantages in terms of cardiovascular risk. However, further research on the underlying mechanisms is still required. On the contrary, camelina oil is abundant in alpha-linolenic acid, an essential omega-3 fatty acid whose relationship with membrane flexibility remains unknown.

The investigators leveraged data from two randomized clinical trials to examine the impact of consuming fish and camelina sativa oil on the lipophilic index. The initial study involved 79 individuals (both men and women) with impaired glucose tolerance, while the second study included 33 men and women with cardiovascular disease. To conduct a 12-week intervention, participants were randomly assigned to one of four groups: the camelina oil group, the fatty fish group, the lean fish group, or the control group in the first study. In the second study, subjects were randomly allocated to the fatty fish group, the lean fish group, or the control group for an 8-week intervention. The lipophilic index was determined by analyzing erythrocyte membrane fatty acids in the first study and serum phospholipid fatty acids in the second study.

In both the aforementioned studies, consuming four weekly meals of fatty fish reduced the lipophilic index, indicating improved membrane fluidity. This enhancement in membrane fluidity has been linked to a decreased risk of cardiovascular issues. An improved lipophilic index, indicative of better membrane fluidity, was also associated with larger high-density lipoprotein (HDL) particles. These larger HDL particles have also been associated with a reduced risk of cardiovascular problems. However, consuming lean fish or camelina sativa oil did not exhibit any notable effects on the lipophilic index.

Reference:

Arja T. Lyytinen, Monira Yesmean, Suvi Manninen, Maria Lankinen, Monika Bhalke, Linda Fredrikson, Reijo T. Käkelä, Katariina Öörni, Ursula S. Schwab, Fatty fish consumption reduces lipophilic index in erythrocyte membranes and serum phospholipids, Published:April 17, 2023 DOI:https://doi.org/10.1016/j.numecd.2023.04.011.