The Effect of Diet and Exercise on Tobacco Carcinogen-induced Lung Cancer
Menée sur des souris femelles, cette étude analyse l'effet d'un régime pauvre en glucides et d'une activité physique sur le risque de cancer du poumon induit par le tabac, en fonction du type et de la quantité de glucides, de protéines et de lipides
In previous studies we found that low carbohydrate (CHO) diets reduced the incidence of tumors in mice genetically predisposed to cancer. However, since more than 90% of human cancers arise via carcinogen-induced somatic mutations we investigated, herein, the role that different types and levels of CHO, protein and lipid play in lung cancer induced by the tobacco-specific carcinogen, nicotine-derived nitrosamine ketone (NNK) in A/J mice. We found lowering CHO levels significantly reduced lung nodules and blood glucose levels. We also found that soy protein was superior to casein and that coconut oil was ineffective at reducing lung nodules. Diets containing amylose or inulin (at 15% of total calories), soy protein (at 35%), and fat (at 50%, 30% being fish oil) were the most effective at reducing lung nodules. These fish oil-containing diets increased plasma levels of the ketone body, β-hydroxybutyrate, while reducing both insulin and 8-isoprostane in plasma and bronchoalveolar IL-12 and lung PGE2 levels. After only 2 weeks on this diet, the levels of γ-H2AX were significantly reduced, 24 hours after NNK treatment. Housing these mice in two-tiered rat cages with exercise wheels led to similar mouse weights on the different diets, while keeping mice in standard mouse cages led to both significant weight differences between the low CHO, soy protein, fish oil diet and Western diet and substantially more lung nodules than in the two-tiered cages. Our results suggest that low CHO, soy protein, fish oil containing diets, together with exercise, may reduce the incidence of lung cancer.