The ratios and amounts of the fats you eat ultimately alters the structure of the membranes of the cells. Changes in the the structure of the cell membrane alters their function. Polyunsaturated fats make cell membranes more flexible.
For example skin is made of cells, and cells are enclosed by membranes. Women make more long chain Omega 3 DHA than men and this may be part of the explanation for softer skin etc
Cell membranes have different composition in different parts, in a sense in the same way as our skin, our membrane with the outside world, differs in composition according to its functions. Lipid rafts are areas with a different composition within the main membrane.
The body also uses the cell membrane as a 'larder' for fats, and draws down on them when they are needed as ingredients to make chemical messengers.
The the type and amount of Omega 3 and 6 you eat really does matter, in that it has significant effect on the function of cells and so the body.
Cell Biochem Biophys. 2012 May 24. [Epub ahead of print]
Chemical-Physical Changes in Cell Membrane Microdomains of Breast Cancer Cells After Omega-3 PUFA Incorporation.
Corsetto PA, Cremona A, Montorfano G, Jovenitti IE, Orsini F, Arosio P, Rizzo AM.
Source
Dipartimento di Scienze Farmacologiche e Biomolecolari, UniversitÃ* degli Studi di Milano, Via D. Trentacoste 2, 20134, Milan, Italy,
paola.corsetto@unimi.it.
Abstract
Epidemiologic and experimental studies suggest that dietary fatty acids influence the development and progression of breast cancer. However, no clear data are present in literature that could demonstrate how n - 3 PUFA can interfere with breast cancer growth. It is suggested that these fatty acids might change the structure of cell membrane, especially of lipid rafts. During this study we treated MCF-7 and MDA-MB-231 cells with AA, EPA, and DHA to assess if they are incorporated in lipid raft phospholipids and are able to change chemical and physical properties of these structures. Our data demonstrate that PUFA and their metabolites are inserted with different yield in cell membrane microdomains and are able to alter fatty acid composition without decreasing the total percentage of saturated fatty acids that characterize these structures. In particular in MDA-MB-231 cells, that displays the highest content of Chol and saturated fatty acids, we observed the lowest incorporation of DHA, probably for sterical reasons; nevertheless DHA was able to decrease Chol and SM content. Moreover, PUFA are incorporated in breast cancer lipid rafts with different specificity for the phospholipid moiety, in particular PUFA are incorporated in PI, PS, and PC phospholipids that may be relevant to the formation of PUFA metabolites (prostaglandins, prostacyclins, leukotrienes, resolvines, and protectines) of phospholipids deriving second messengers and signal transduction activation. The bio-physical changes after n - 3 PUFA incubation have also been highlighted by atomic force microscopy. In particular, for both cell lines the DHA treatment produced a decrease of the lipid rafts in the order of about 20-30 %. It is worth noticing that after DHA incorporation lipid rafts exhibit two different height ranges. In fact, some lipid rafts have a higher height of 6-6.5 nm.
In conclusion n - 3 PUFA are able to modify lipid raft biochemical and biophysical features leading to decrease of breast cancer cell proliferation probably through different mechanisms related to acyl chain length and unsaturation.
While EPA may contribute to cell apoptosis mainly through decrease of AA concentration in lipid raft phospholipids, DHA may change the biophysical properties of lipid rafts decreasing the content of cholesterol and probably the distribution of key proteins.