Omega 3 deficiency: increased risks of hereditary obesity

A deficiency of omega three in the diet, combined with a chronic excess of omega six, can lead to a form of hereditary obesity. This is demonstrated in a study published in the Journal of Lipid Research, in which researchers at the Université de Nice Sophia-Antipolis (Nice, France) found that mice fed a diet similar to that of the modern Western world tend to gain more and more weight. This tendency toward obesity, the authors explain, is exacerbated from generation to generation. Not only that, the researchers showed that these mice develop a number of metabolic disorders, such as insulin resistance that exposes them to the risk of diabetes. And the expression of genes involved in inflammation processes associated with obesity also increases as generations pass. According to the researchers, these findings show that a high-fat diet, associated with a high ratio of omega-6 fatty acids to omega-3 fatty acids, promotes a gradual increase in inflammatory stimuli and adipose mass.

A budgetary issue

An unbalanced ratio of omega-6 to omega-3 fatty acids can lead to weight gain with which serious long-term effects on human health are associated. Unfortunately, changes in the diets of Western societies over the past four decades have caused a significant change in this ratio. In fact, new dietary regimes have led to a 250% increase in the introduction of Omega-6. Conversely, Omega-3 consumption has decreased by 40%. This has meant that the balance between Omega-6 and Omega-3, which should settle around a ratio of 5 to 1, has shifted to the 15 to 1 typical for a European citizen and, even, to the 40 to 1 that can be reached in the United States. Hand in hand with this phenomenon, the change in diet has also led to a gradual increase in obesity levels.

Few omega-3s promote obesity

French researchers, led by Gérard Ailhaud, have demonstrated the existence of a close link between Western diet and increased obesity using mice as models. The animals were allowed to feed at will on foods chosen in such a way as to mimic the typical Western diet, rich in Omega-6 and low in Omega-3. The experiment continued until four parent-child generations were involved. During this time, the scientists observed a gradual increase in fat mass. In addition, the expression of some important genes involved in growth control and immune functions, such as colony stimulating factor-3 (CSF-3) and Nocturnin, also gradually increased.

The hypothesis of a mechanism

Based on the data obtained, the researchers hypothesized that the CSF-3 gene stimulates the growth of fat cell progenitor cells. The heritability of obesity would, therefore, be due to a gradual increase in CSF-3 expression from generation to generation. This increase would promote the proliferation of adipocyte progenitors. According to the authors, further research will allow them to verify the correctness of this hypothetical mechanism.

Source

1. Massiera F, Barbry P, Guesnet P, Joly A, Luquet S, Moreilhon-Brest C, Mohsen-Kanson T, Amri EZ, Ailhaud G, "A Western-like fat diet is sufficient to induce a gradual enhancement in fat mass over generations," J Lipid Res. 2010 Aug;51(8):2352-61. Epub 2010 Apr 20