The review was written by David Gems and Alexander Carver from University College London, along with Yuan Zhao from Queen Mary University of London. Their work combines ideas from evolutionary biology with findings from modern biomedical research to explain how early damage in the body may later contribute to diseases such as cancer, arthritis, and infections.

How Early-Life Damage May Shape Health Decades Later

According to the researchers, the first stage begins earlier in life when the body experiences various forms of disruption. These can include infections, physical injuries, or genetic mutations. While the body is often able to repair or contain much of this damage, some of it may remain hidden rather than being fully removed.

The second stage occurs later in life as normal genetic activity starts changing in ways that are no longer beneficial to the body. These late-life biological changes can weaken the body’s ability to keep earlier damage under control. As a result, previously contained problems may gradually develop into disease.

The scientists argue that this process helps explain why many illnesses appear mainly in older adults even though their origins may trace back much earlier.

Why Diseases Like Shingles and Arthritis Appear With Age

The review highlights aging as a multifactorial process, meaning it is driven by many interacting biological factors instead of a single cause. The proposed model suggests that the combination of earlier damage and later-life genetic changes plays a major role in age-related disease.

For example, dormant viruses that remain inactive for years can become active again when the immune system weakens with age, leading to conditions such as shingles. In a similar way, injuries sustained in youth may eventually contribute to osteoarthritis as aging tissues become less resilient over time.

Inherited genetic mutations may also stay silent for decades before increasing the risk of diseases such as cancer or fibrosis later in life.

Evolutionary Biology and Aging Research

The researchers say their model builds on long-standing evolutionary theories of aging. One influential idea is that natural selection becomes weaker later in life, allowing harmful biological processes to emerge with age because they have less impact on reproduction and survival earlier in life.

The review also references studies involving the roundworm Caenorhabditis elegans. In these experiments, early mechanical damage in the worms eventually led to fatal infections in old age. The scientists suggest similar patterns may also occur in humans.

A New Framework for Healthier Aging

Overall, the review presents aging as a process shaped by multiple interacting causes that unfold over time. By separating aging into two major stages, early-life damage and later-life genetic activity, the researchers believe their framework could help guide future strategies aimed at disease prevention and healthier aging.

The findings also raise the possibility that reducing damage earlier in life or targeting harmful late-life biological changes could help lower the risk of chronic disease in older adults.

We both work in languages education and recognize the real benefits that learning another language can bring. As well as myriad cognitive benefits, it brings with it cultural insights and empathetic awareness.

With that in mind, we’re here to dispel five myths about language learning that might be putting you off.

Myth one: it’s all about grammar and vocabulary

In fact, learning about people, history and culture is arguably the best part of learning a language. While grammar and vocabulary are undeniably important aspects of language learning, they don’t exist in isolation from how people communicate in everyday life.

Language learning can help us to have “intercultural agility”: the ability to engage empathically with people who have very different experiences from our own. To be able to do this means learning about people, history and culture.

Immersing yourself in a particular country or location, for example through studying or working, is a fantastic way to do this. But when this isn’t feasible, there are so many other options available. We can learn so much through music, books, films, musical theater and gaming.

Myth two: we should focus on avoiding mistakes – they’re embarrassing

One problem with formal language learning is that it encourages us to focus on accuracy at all costs. To pass exams, you need to get things “right”. And many of us feel nervous about getting things wrong.

But in real-life communication, even in our expert languages, we often make mistakes and get away with it. Think of the number of times you have misspelled something, or said the wrong word, and still been understood.

Less formal language learning can encourage us to think more about communication than accuracy.

One advocate of this approach is author Benny Lewis, who popularized a communicative learning approach he calls “language hacking” which focuses on the language skills needed for conversation. Language apps also encourage this, as does real-life travel and communication.

Myth three: it’s too much effort to start over with a new language

You can use languages in lots of ways, and the language you learn at school doesn’t have to be the only one you learn.

In England, most people learn one or more of French, Spanish or German at school. These languages can often serve as great apprenticeship languages, teaching us how to learn a language and about grammatical structures.

But they are not always the languages that we are most likely to use as adults, when family and work could take us anywhere. Our cultural interests might also lead us to want to know more about a new language.

Learning a language that you have a personal interest in can be very motivating and help you to keep going when things get a bit rocky.

Myth four: learning a language is an individual endeavor

You don’t have to learn alone. Learning with others, or having the support of others, can help motivate us to learn.

This might be through a multilingual marriage, joining a conversation group or chatting in a language learning forum online. Don’t feel that you have to have reached a certain proficiency before you start reaching out to others.

Language apps can also make language learning a collective endeavor. You can learn along with friends and family, and congratulate them on their language learning streaks.

This is something both of us do with multiple generations of our families, helping us engage with language learning in a lighthearted way.

Myth five: it’s a lot of hard graft

Learning a language in a systematic way can be challenging, whether in a classroom or from a self-study course. But some things make this easier. We have found that people are more motivated to engage when they have a personal reason to learn. This could be, for example, wanting to communicate with family or to travel to a particular country or region.

The growth in popularity and accessibility of language learning apps has made language learning possible from any location and at any time, often for free.

You can easily catch up on your Chinese from the comfort of your own armchair, at whatever time is most convenient for you. Apps can be fun and playful, and can help us maintain motivation, develop vocabulary and embed grammatical structures.

There are lots of reasons for learning a language, and lots of benefits. We encourage everyone to focus on these benefits, and give it a go.

Now, researchers at the University of Cologne have uncovered a new mechanism showing how the amino acid leucine can enhance mitochondrial performance. Their findings reveal that leucine helps preserve critical proteins involved in energy production, allowing cells to generate energy more efficiently. The study, led by Professor Dr. Thorsten Hoppe from the Institute for Genetics and the CECAD Cluster of Excellence on Aging Research, was published in Nature Cell Biology under the title “Leucine inhibits degradation of outer mitochondrial membrane proteins to adapt mitochondrial respiration.”

How Leucine Supports the Cell’s Power Plants

Leucine is an essential amino acid, meaning the body cannot produce it on its own and it must come from food. It is commonly found in protein rich foods including meat, dairy products, beans, and lentils. While leucine is already known for its role in building proteins, the new research uncovered another important function.

The team found that leucine prevents the breakdown of certain proteins located on the outer surface of mitochondria. These proteins help transport important metabolic molecules into the mitochondria so energy production can continue efficiently. By protecting those proteins from being degraded, leucine allows mitochondria to work at a higher level and helps cells meet increased energy demands.

“We were thrilled to discover that a cell’s nutrient status, especially its leucine levels, directly impacts energy production,” said Dr. Qiaochu Li, first author of the study. “This mechanism enables cells to swiftly adapt to increased energy demands during periods of nutrient abundance.”

The Role of SEL1L in Energy Production

The researchers also identified a key protein called SEL1L that helps regulate this process. Under normal conditions, SEL1L acts as part of the cell’s quality control system by identifying damaged or misfolded proteins and marking them for destruction.

According to the study, leucine appears to suppress SEL1L activity. As a result, fewer mitochondrial proteins are broken down, which improves mitochondrial efficiency and boosts cellular energy production.

“Modulating leucine and SEL1L levels could be a strategy to boost energy production,” Li added. “However, it is important to proceed with caution. SEL1L also plays a crucial role in preventing the accumulation of damaged proteins, which is essential for long-term cellular health.”

Potential Links to Cancer and Metabolic Disease

To better understand the broader impact of the discovery, the researchers studied the effects of leucine metabolism in the tiny roundworm Caenorhabditis elegans. They found that problems with leucine breakdown could damage mitochondrial function and even cause fertility issues.

The team also examined human lung cancer cells and discovered that some cancer related mutations affecting leucine metabolism appeared to improve cancer cell survival. The finding suggests that the pathway may play an important role in future cancer research and therapy development.

Overall, the study provides new evidence that nutrients do far more than simply fuel the body. They also actively influence how cells generate and manage energy at the molecular level. By uncovering how leucine regulates mitochondrial activity, the researchers believe their work could eventually help guide new treatments for metabolic disorders, cancer, and other diseases linked to impaired energy production.

The research was supported by Germany’s Excellence Strategy through CECAD, several Collaborative Research Centres funded by the German Research Foundation (DFG), the European Research Council Advanced Grant “Cellular Strategies of Protein Quality Control-Degradation” (CellularPQCD), and the Alexander von Humboldt Foundation.

The findings, which were observed in mice, could eventually lead to new ways to reduce intestinal damage caused by radiation therapy and chemotherapy. Researchers say cysteine-rich diets or supplements might one day help cancer patients recover more quickly from treatment-related injuries.

“The study suggests that if we give these patients a cysteine-rich diet or cysteine supplementation, perhaps we can dampen some of the chemotherapy or radiation-induced injury,” says Omer Yilmaz, director of the MIT Stem Cell Initiative, an associate professor of biology at MIT, and a member of MIT’s Koch Institute for Integrative Cancer Research. “The beauty here is we’re not using a synthetic molecule; we’re exploiting a natural dietary compound.”

The study, published in Nature, is the first to identify a single nutrient capable of directly enhancing intestinal stem cell regeneration. Previous research had shown that broader dietary patterns, such as fasting or calorie restriction, can influence stem cell activity, but scientists had not pinpointed one specific nutrient responsible for this type of repair response.

How Cysteine Activates Gut Repair

Yilmaz and his team wanted to better understand how individual nutrients affect stem cells and tissue health. To investigate, the researchers fed mice diets enriched with one of 20 different amino acids, which are the building blocks of proteins. They then measured how each amino acid influenced regeneration in intestinal stem cells.

Among all the amino acids tested, cysteine produced the strongest regenerative effect on both stem cells and progenitor cells, which eventually mature into adult intestinal cells.

The researchers later uncovered the biological chain reaction behind the effect. When intestinal cells absorb cysteine from food, they convert it into a molecule called CoA. That molecule is then released into the intestinal lining, where it is absorbed by immune cells known as CD8 T cells.

Once activated, these T cells begin multiplying and producing IL-22, a signaling protein called a cytokine that plays a major role in intestinal repair and stem cell regeneration.

Until now, scientists did not know that CD8 T cells could produce IL-22 in a way that supports intestinal stem cells.

“What’s really exciting here is that feeding mice a cysteine-rich diet leads to the expansion of an immune cell population that we typically don’t associate with IL-22 production and the regulation of intestinal stemness,” Yilmaz says. “What happens in a cysteine-rich diet is that the pool of cells that make IL-22 increases, particularly the CD8 T-cell fraction.”

Immune Cells Positioned for Rapid Healing

The researchers found that these activated T cells gather in the lining of the small intestine, placing them in an ideal position to respond quickly when damage occurs. The effect was largely limited to the small intestine because that is where most dietary protein is absorbed.

In the study, mice fed a cysteine-rich diet showed improved recovery from radiation-related intestinal damage. The team also reports that unpublished experiments found similar regenerative benefits after treatment with the chemotherapy drug 5-fluorouracil, which is commonly used against colon and pancreatic cancers but can also injure the intestinal lining.

Foods Rich in Cysteine

Cysteine occurs naturally in many high-protein foods, including meat, dairy products, legumes, and nuts. The human body can also produce cysteine on its own by converting another amino acid called methionine in the liver.

However, researchers say dietary cysteine appears to have a stronger effect on the intestine because it reaches the gut directly before being distributed throughout the body.

“With our high-cysteine diet, the gut is the first place that sees a high amount of cysteine,” Chi says.

Cysteine has long been known for its antioxidant properties, but this is the first study showing that it can directly stimulate intestinal stem cell regeneration.

Future Research on Regeneration

The MIT team is now exploring whether cysteine may also support regeneration in other tissues. One ongoing project is examining whether the amino acid can stimulate hair follicle repair and regrowth.

Researchers are also continuing to investigate the effects of other amino acids that showed signs of influencing stem cell behavior.

“I think we’re going to uncover multiple new mechanisms for how these amino acids regulate cell fate decisions and gut health in the small intestine and colon,” Yilmaz says.

The research was supported in part by the National Institutes of Health, the V Foundation, the Kathy and Curt Marble Cancer Research Award, the Koch Institute-Dana-Farber/Harvard Cancer Center Bridge Project, the American Federation for Aging Research, the MIT Stem Cell Initiative, and the Koch Institute Support (core) Grant from the National Cancer Institute.