Researchers have studied an alternative approach to regulate immune cell function to treat obesity
Obesity is a chronic illness which affects 30% of the world’s total population. The main cause of obesity is higher consumption of fat rich food and limited physical activity or exercise. The surplus amount of high energy consumed (mainly from fat and sugars) is then stored as fat in the body leading to high body weight. The Body Mass Index (BMI) of an obese person is between 25 and 30 which is very high. Many factors affect and contribute to obesity like genetics, body’s metabolism rate, lifestyle, environmental factors etc. Obesity or high body weight then leads to other negative outcomes in the body by causing harmful inflammation. Obese or overweight people are at a higher risk of developing severe illnesses or conditions, including heart disease because of clogged arteries, Type 2 diabetes and serious bone and joint conditions.
A study published in Proceedings of National Academy of Sciences USA sheds light on the reason why immune cells inside our fat tissue become harmful when someone is suffering from obesity. These immune cells in our body otherwise considered to be useful start to cause undesired inflammation and changes in the metabolic system. Free radicals are produced in our body during normal metabolic processes or due to exposure to outside sources like harmful radiation, smoking, environmental pollution etc. These free radicals are unstable and harmful atoms which can damage cells in our body and cause ageing and illness. Researchers of the current study from University of Virginia School of Medicine say that these free radicals are highly reactive and in an obese person as they react with lipids inside the fat tissue. Once lipids - which are considered an attractive target by the free radicals - combine with free radicals, normal immune response occurs in the body causing inflammation and results in ‘lipid oxidation’. The small oxidized lipids are pretty harmless and are found in healthy cells. However, longer full length oxidized lipids, found generally in obese tissue, cause excessive harmful inflammation which propagates the obesity disease within the fat tissue.
The knowledge of these problematic oxidized lipids can be used to devise a method to block them which can then prevent harmful inflammation. Example, a drug which could either diminish or completely eliminate the longer and damaging oxidized lipids. Such a therapy would be extremely beneficial for a chronic disease like obesity. However, as scientists point out, eradicating all inflammation may not be the right approach because some of it is useful for the body. Such targeting of the metabolic of immune cells in our immune system is an approach which is already being used for cancer.
Vlad Serbulea et al. 2018, ‘Macrophage phenotype and bioenergetics are controlled by oxidized phospholipids identified in lean and obese adipose tissue’, Proceedings of the National Academy of Sciences, vol. 115, no. 27,