What is inflammaging?

Inflammaging is a chronic, systemic, low-grade state of inflammation that is associated with the normal ageing process in mammals, including humans. The term is a contraction of 'inflammation' and 'aging'. What makes it remarkable is that this inflammation produces no noticeable symptoms for a long time, yet all the while it drives the ageing process and raises the risk of disease and premature death in older people. Inflammaging is considered one of the central mechanisms underlying biological ageing.

A significant part of inflammaging arises because cells become less capable of clearing their own waste at older ages. This process is called autophagy. When that clean-up mechanism falls short, damaged proteins accumulate, the energy-producing units in the cell (mitochondria) begin to function less efficiently, and oxidative stress increases. All of these disruptions further fuel the low-grade inflammation, creating a self-reinforcing cycle.

Inflammaging is associated with an increased risk of many common age-related diseases, such as cardiovascular disease, type 2 diabetes, and cancer. It also contributes to sarcopenia, the loss of muscle mass and muscle strength that makes older people frail and less mobile. In addition, there is limited evidence that inflammaging can accelerate the development and progression of osteoarthritis through the ageing of cartilage cells, a process called chondrosenescence.

It is important to emphasise that the precise causal role of inflammaging in most age-related diseases has not yet been fully clarified. Most associations are still observational: we see that inflammaging and these diseases occur together, but it has not always been proven that the inflammation is the direct cause. Furthermore, a standardised method for reliably measuring inflammaging in clinical practice is still lacking.

In the area of nutrition, there is some evidence that certain dietary fibres, particularly inulin and resistant starch, have short-term anti-inflammatory effects that may be relevant to inflammaging. For other fibres such as pectins, beta-glucans, and psyllium, the results are less convincing. Because studies differ considerably from one another, no unambiguous dietary recommendations can yet be made on the basis of the current evidence.