Omega 3 Deficiency: Increased Risk of Hereditary Obesity

A deficiency of Omega-3 in the diet, combined with a chronic excess of Omega-6, can lead to a form of hereditary obesity. This was demonstrated by a study published in the Journal of Lipid Research, where researchers from 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 towards obesity, the authors explain, worsens from generation to generation. Moreover, the researchers showed that these mice develop a series of metabolic disorders, such as insulin resistance that increases the risk of diabetes. Also, the expression of genes involved in inflammation processes associated with obesity increases over generations. According to the researchers, these results demonstrate that a fat-rich diet, combined with a high ratio of Omega-6 fatty acids to Omega-3 fatty acids, promotes a gradual increase in inflammatory stimuli and fat mass.

A Matter of Balance

An unbalanced ratio between Omega-6 and Omega-3 fatty acids can lead to weight gain associated with serious long-term effects on human health. Unfortunately, changes in Western societies’ diets over the last forty years have caused a significant shift in this ratio. Indeed, new eating habits have led to a 250% increase in Omega-6 intake. Conversely, Omega-3 consumption has decreased by 40%. This has caused the balance between Omega-6 and Omega-3, which should be around a 5 to 1 ratio, to shift to 15 to 1 typical of a European citizen, and even up to 40 to 1 as can be found in the United States. Along with this phenomenon, changes in diet have also led to a gradual increase in obesity levels.

Low Omega-3 Promote Obesity

The French researchers, led by Gérard Ailhaud, demonstrated a strong link between the Western diet and the increase in obesity using mice models. The animals were allowed to eat freely from foods chosen to mimic a typical Western diet, rich in Omega-6 and poor in Omega-3. The experiment continued for four parent-offspring generations. During this time, the scientists observed a gradual increase in fat mass. Additionally, 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.

Hypothesis of a Mechanism

Based on the obtained data, the researchers hypothesized that the CSF-3 gene stimulates the growth of progenitor cells of adipose cells. The heredity of obesity would thus 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 verify the accuracy 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