The aim of the present work was to study how dietary olive and linseed oils modulate the rat metabolic responses to cafeteria diet during aging. Male older rats (ten months aged) weighing 350 to 400g were fed a standard chow or a cafeteria diet containing either olive oil (5%) or olive-linseed oils (2.5% olive, 2.5% linseed) for two months. Changes in serum glucose, cholesterol and triglyceride levels, liver and adipose tissue lipids and fatty acid composition, hepatic triglyceride lipase (HTGL), adipose tissue lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) activities and intracellular redox status (glutathione, malondialdehyde and carbonyl proteins) were determined at the end of the experiment. The cafeteria diet intake led to higher energy intake with higher body weight, hyperglycemia, hyperinsulinemia, hyperleptinemia and hyperlipidemia, liver and adipose lipid accumulation, alterations in lipolytic enzyme activities (high HSL and low HTGL activities) and intracellular oxidative stress (high malondialdehyde and carbonyl protein levels) in older rats. Olive oil and olive-linseed oils supplementation modulated liver and adipose tissue protein, cholesterol and triglyceride contents in both control and obese older rats, with beneficial effects resulting in lower energy intake and lower body weight, lower adipose fat deposition, decreased lipids, upregulated lipolytic enzyme activities and reduced intracellular oxidative stress. The combination olive-linseed oils appeared to be more effective in metabolic improvements especially in obese older rats. In conclusion, olive-linseed oils supplementation induced lower energy intake associated to an improvement of metabolic alterations observed in obesity during aging in rats.
