Last Updated on April 20, 2026 by Sanjana Kahol

Fatty liver disease is becoming more common. It mostly affects people who sit around a lot and consume a lot of fat. We often link it to being overweight and having cholesterol. New research says that the real cause might be something happening deep inside our cells.

Scientists at the University of California Los Angeles (UCLA) Health Sciences found a group of “zombie cells”. These cells may play a role in liver damage, inflammation and even aging.

These cells do not work properly. When they are damaged, there’s no need for them to stay in the body. They release inflammatory signals. Over time this can hurt tissues and lead to long-term diseases.

What are zombie cells?

Zombie immune cells are a type of cell. They enter a state called senescence. In this state the cells stop dividing. Do not die. They stay active in a way. They release chemicals that hurt nearby tissues.

In this study researchers looked at macrophages. These are cells that normally protect the body. They remove substances and dead cells. When these macrophages become senescent, they stop doing their protective job. They contribute to inflammation instead.

To find these cells scientists found a special molecular signature. It involves two proteins: p21 and TREM2. When both are present together it signals that the macrophage has become senescent. It is contributing to disease rather than preventing it.

How these cells affect the liver

The study found that the number of senescent macrophages increases with age. In people only about 5% of these cells are senescent. In older people this number can rise to as much as 60–80%. This increase matches the rise in inflammation seen in aging tissues.

The liver is especially vulnerable. In conditions like fatty liver disease excess cholesterol plays a role. It pushes these cells into a senescent state. They stop dividing and release proteins.

In real life this can be seen in people who eat a lot of high-fat high-cholesterol foods. For example, someone who often eats junk food, fried items and processed snacks may create an environment in their body. This environment promotes the formation of these cells. Over time this can lead to liver inflammation and damage. This happens before noticeable symptoms appear.

Can removing these cells reverse damage?

One of the surprising findings of the study was that removing these zombie cells could reverse liver damage. Researchers used a drug called ABT-263 in mice. This drug selectively eliminates cells.

The results were significant. Mice with fatty liver disease showed a reduction in liver size and weight. They had improved health even though their diet remained unhealthy. This suggests that these cells are not just associated with the disease. They may be the cause of it.

In terms this means that future treatments could focus on targeting these bad cells. They do not just have to change their diet or lifestyle. For example a person with early-stage fatty liver disease might receive treatment. This treatment removes these cells. It helps the liver recover effectively.

Real-life implications for everyday health

This research shows how everyday habits can influence our health at a level. For instance, someone working hours who relies on processed and high-cholesterol foods may increase their risk. They may develop fatty liver disease through the buildup of these zombie cells.

Aging people who already experience metabolism and higher cholesterol levels may be more vulnerable. This could explain why fatty liver disease is becoming more common. It is common among people who do not appear severely overweight.

The findings also suggest an impact beyond the liver. Researchers believe that similar processes may occur in parts of the body. These include the brain and heart. They may link these cells to diseases like Alzheimer’s and conditions.

What this means for the future

Although the drug used in the study is not yet safe for use the research opens the door to new treatments. These treatments target cells. Scientists are now working to develop alternatives. These alternatives can selectively remove these cells without side effects.

The study also supports the idea that aging and chronic diseases may share biological mechanisms. By understanding and targeting these mechanisms it may be possible to treat conditions at once.

For now the research reinforces the importance of maintaining a diet and healthy lifestyle. While future treatments may offer solutions, reducing excessive cholesterol intake and staying active remain key ways to protect the body from long-term damage.

Read the press release here: Source