Lifestyle-related diseases

Excessive accumulation of fat in adipose tissue, especially in visceral adipose tissue, which is the origin of the onset of lifestyle-related diseases, is considered to be the main cause. Adipose tissue with moderate accumulation of fat secretes a large amount of useful cytokines such as adiponectin, and plays an important role in suppressing arteriosclerosis and cancer. However, in adipose tissue with excessive accumulation of fat, the secretion of useful cytokines such as adiponectin decreases, while the secretion of inflammatory cytokines such as TNF-α and PAI-1 increases. If this condition continues, it will eventually progress to a systemic disease.

 

Initially, research was focused on adipocytes, but it was reported that slight inflammation persisted when visceral adipose tissue accumulated excess fat, and then it was found in adipose tissue. It has been shown that the state of macrophages (inflammatory macrophages (M1) and non-inflammatory macrophages (M2)) is important in the development of lifestyle-related diseases. In other words, it has been found that a large number of inflammatory macrophages are present in excessively accumulated adipose tissue, sustaining mild inflammation.

Recently, it has become clear that the host's intestinal flora (intestinal flora) is one of the environmental factors involved in metabolic syndrome. In fact, differences in intestinal flora between obese and normal-weight individuals have been observed in experimental animals and humans. Further elucidation of the causal relationship between intestinal flora and lifestyle-related diseases is expected in the future.

In terms of metabolism of ingested energy, partial browning of white adipocytes is attracting attention. Originally, visceral fat, etc. belonged to white adipose tissue and its main role was to accumulate fat, but it was found that white adipose tissue also partially browns depending on the conditions in vivo . As a result, the idea that the browning of white adipocytes, which exist in large quantities in the body, is more important for controlling obesity than the suppression of fat accumulation by activating brown adipocytes, which is considered to be a very small amount in adults, has emerged. rice field. In addition, in the primary cell line in which adipocytes were differentiated in vitro without the use of forced differentiation agents such as dexamethasone and indomethacin, the expression of UCP-1, a protein responsible for fever and a marker of brown adipocytes, was observed. , has also been confirmed to be significantly increased by the addition of noradrenaline. Furthermore, some functional food ingredients have been found to enhance this response.

Adipose tissue has been considered as a temporary storage site for energy obtained from meals, but it is believed that its position as an organ that secretes cytokines such as adiponectin, which is essential for maintaining biological functions, will continue to grow.