Adipose tissue not only serves as an energy store, but is also an active endocrine organ, influencing the regulation of many physiological processes, such as metabolism, immune response and inflammation. The secretory products of adipocytes, known as adipokines, play a key role in aging processes, and their dysfunction with age can lead to many metabolic and inflammatory conditions. A better understanding of the impact of adipokines on the aging process may open up new therapeutic pathways to improve metabolic health and extend life.
Adipose tissue as an endocrine organ
There are different types of adipose tissue - white, brown and beige - with different functions in the body:
- White adipose tissue stores energy and secretes pro-inflammatory adipokines.
- Brown adipose tissue generates heat through thermogenesis, which is beneficial for metabolism.
- Beige adipose tissue exhibits characteristics of both types and can undergo transformation into brown tissue, promoting metabolic health.
Adipokines such as leptin, adiponectin, resistin and wisfatin play a key role in regulating metabolism and inflammatory processes. For example, leptin regulates hunger and energy metabolism, while adiponectin protects against insulin resistance by exhibiting anti-inflammatory properties.
The role of adipokines in the aging process
Aging changes the secretion profile of adipokines, which affects metabolic health:
- Leptin: With age, leptin levels increase, leading to leptin resistance, which leads to energy imbalances and the development of obesity. In the context of aging, leptin becomes a promoter of inflammation, which can accelerate cellular aging processes
- Adiponectin: Adiponectin levels tend to decline with age, increasing the risk of cardiovascular disease and diabetes. Changes in adiponectin levels can serve as indicators of healthy aging.
- Resistin and visfatin: They promote inflammation and are associated with chronic inflammatory diseases, which worsens the body's metabolic function.
Dysfunction of adipose tissue with age - known as adiposenescence
With age comes a gradual dysfunction of adipose tissue, known as adiposenescence, which manifests itself:
- Aging of adipocytes: Old fat cells secrete greater amounts of pro-inflammatory factors such as IL-6 and TNF-α, which contributes to increased inflammation in the body (inflammaging).
- An increase in the amount of visceral tissue: With age, adipose tissue changes its distribution, which promotes fat deposition around internal organs, increasing metabolic risk.
Adipokines as biomarkers of aging and longevity
Adipokines can be used as indicators of healthy aging. For example, higher levels of adiponectin are associated with better metabolic health and longer life, while elevated leptin levels may indicate the development of obesity and metabolic diseases. Monitoring adipokine profiles can be a key tool in assessing health and longevity.
Changes in the adipose tissue microenvironment and longevity
As we age, the adipose tissue microenvironment becomes more pro-inflammatory, which promotes cellular aging. Adipose tissue dysfunction is often the result of impaired angiogenesis and the accumulation of oxidative stress, which accelerates the aging process at the cellular level. Changes in M1/M2 macrophage ratios and abnormalities in the immune response are also influential.
Interventions to improve adipose tissue function
- Diet: Introducing a diet rich in polyphenols (e.g., resveratrol, curcumin) and omega-3 fatty acids can significantly improve adipocyte function.
- Physical activity: Regular exercise enhances the thermogenic capacity of adipose tissue and reduces inflammation, which promotes healthy aging
- Pharmacotherapy: The use of drugs such as metformin or thiazolidinediones can modulate adipokine secretion, improving metabolic health.
- Intermittent fasting: Calorie restriction and intermittent fasting have been shown to have anti-inflammatory effects and increase insulin sensitivity, which improves adipose tissue function
Future research directions
New therapies focus on eliminating aging adipocytes (senolytics) and regenerating dysfunctional adipose tissue with cell therapies. These approaches may contribute to better metabolic health and prolonged life.
Conclusions
Adipose tissue is a key regulator of metabolic health, and its dysfunction with age can significantly affect the aging process. Optimizing adipocyte function through diet, physical activity and pharmacotherapy is a promising strategy in the pursuit of healthy aging and longevity.
Sources:
- Estimating impact of food choices on life expectancy: A modeling study
- Aging research: A field grows up Hypertrophy and/or Hyperplasia: Dynamics of Adipose Tissue Growth
- Physical activity across midlife and health-related quality of life in Australian women: A target trial emulation using a longitudinal cohort