How altered intercellular communication affects aging
Our cells are in constant communication using a series of chemical pathways. As we age, those pathways can become inflamed, distorting the messages they carry. This leads to many of the common signs of aging, as well as age-related diseases. The whole process is known as altered intercellular communication. But what causes it, and how can we reduce inflammation and keep our cells healthier for longer? Find out now.
What is altered intercellular communication?
Altered intercellular communication is the scientific name for age-related changes in how our cells speak to each other. Every day, our cells transmit billions of signals to help our bodies function. They tell cells when to grow, and when to stop growing. They send warnings about damage or infection. They provide feedback about the nutrients they need, the molecules we need to generate, and all the tiny processes that keep us alive and healthy.
When these communication pathways break down, the result is cell damage and age-related disorders. In fact, altered intercellular communication is defined by changes to endocrine, neuroendocrine, or neuronal pathways.
What causes altered intercellular communication?
There are many causes responsible for changes in how our cells signal each other. As we grow older, cellular damage accumulates in our systems, as does debris from inflammation and metabolic processes. This buildup of tiny particles of unwanted material eventually begins to have a noticeable effect on our bodies. And often the damage they do is compounding, meaning the effects can start to snowball.
One example is seen in our immune system. Over time, our immune systems function less effectively. Most young people can shake off a bout of influenza in a few days or a week. Older people are far more susceptible to suffering a serious or even fatal infection. The mortality rate for influenza in the United States in 2019 was less than 0.002% (1.8 people per 100,000) for 18-49 year olds. That number quadrupled for 50-64 year olds, and for over 65s, almost 49 people in 100,000 (0.05%) died of the flu.
A declining immune system is itself a hallmark of aging, and is often caused by age-related damage to our bodies. However it also contributes to the accumulation of that damage. A weaker immune system is less able to fight infections. This leads to ongoing, low-level inflammation throughout our bodies. This decline in our immune system is known as immunosenescence.
Another kind of senescence also affects intercellular communication — cellular senescence. Senescence means a cell has stopped replicating. It isn’t dead, but it isn’t fully functional either. These “zombie cells” contribute to signs of aging we see on our skin like uneven structure and a dull, tired complexion.
They also send out disruptive signals to surrounding cells, prompting them to also turn senescence. Think of their messages like zombie bites, spreading their infection through healthy cells. These signals are called senescence-associated secretory phenotype (SASP). SASP is a mixture of growth factors, immune modulators, and inflammatory cytokines. Not only does SASP make other cells also enter senescence, it is also immunosuppressive, meaning it harms the immune system. As SASP levels rise, it switches to become pro-inflammatory. That means it causes and spreads even more inflammation throughout the body.
All of this inflammation leads to a condition known as inflammaging. This is a state of ongoing inflammation that isn’t ever resolved. It both contributes to, and worsens the effects of, all kinds of age-related conditions, as well as opportunistic infections.
Treatments for altered intercellular communication
Once enough damage has accumulated in our systems to cause altered intercellular communication, it’s very difficult to turn back the clock. Experiments with animals have shown some success — one study demonstrated that caloric restriction increased the lifespan of mouse lemurs. However while the lemurs on a restricted diet lived on average 50% longer, they also suffered accelerated brain degeneration.
When it comes to humans, fewer studies exist on how calorie restriction impacts longevity. Certainly the results are more dramatic for shorter-lived animals. It’s unlikely that any diet alone will help somebody live to 150! What we do know is that calorie restriction reduces the metabolic processes that contribute to a lot of age-related damage in our bodies. That means eating a balanced, calorie controlled diet can improve your health and contribute to longevity. However it’s not a magic bullet, or an effective treatment for damage that has already occurred. Instead, we should focus on avoiding that damage to begin with.
How to avoid altered intercellular communication?
Prevention is always better than cure, and one of the most important causes of altered intercellular communication to prevent is cellular senescence. Several factors cause senescence, including infections, inflammation, and DNA damage from UV light. However one of the primary causes of cellular senescence is oxidative stress.
We need oxygen to survive, but it’s a very corrosive element. Inside our bodies, unstable oxygen molecules known as reactive oxygen species (ROS) cause cascading damage to our cells and DNA. Some of these ROS come from our environment in the form of free radicals. We are exposed to them through pollution, ozone, x-rays, tobacco smoke, and industrial chemicals.
Another common source of ROS in our bodies is from our diets. Our cells metabolize whatever we eat to provide fuel for our bodies. When we eat diets rich in high-fat fried foods, we increase the number of ROS produced as byproducts.
All of the sources of ROS contribute to oxidative stress building up in our bodies. And the more ROS we have, the higher the likelihood of cells entering senescence. The simplest way to avoid this is to avoid sources of free radicals and ROS. That means eating a healthy diet, not smoking, and avoiding exposure to UV light and pollution. Additionally, we can combat some of the damage that ROS do with antioxidants. These are molecules that neutralize ROS, preventing them from harming our cells. You can get antioxidants from fresh fruit and vegetables, dark chocolate, and green tea. Antioxidants are also available as dietary supplements.
Many of the hallmarks of aging have a cause-and-effect relationship with each other. Altered intercellular communication is no different. It is caused by the accumulation of debris and damage in our bodies throughout our lives, and once it starts the effects can snowball. There aren’t currently any known cures for altered intercellular communication. Instead it’s important to focus on preventing the damage that is the underlying cause. Eating a balanced diet that contains plenty of antioxidants is a great way to support your cellular health and promote longevity.