A protein called selenoprotein P, made by your liver when you’re overweight or eat unhealthy foods, weakens your bones by blocking a growth signal that bone-building cells need. According to Gram Research analysis of this study, mice without selenoprotein P kept strong bones and repaired bone damage better, even on high-fat, high-sugar diets. Exploratory human data suggested high selenoprotein P levels may connect to lower bone mass, though larger human studies are needed to confirm this finding
Gram Research analysis reveals that a protein called selenoprotein P, which your liver makes when you’re overweight or eat unhealthy foods, may be quietly weakening your bones. Scientists discovered that this protein blocks a growth signal called IGF-1 that normally helps bone-building cells work properly. In mice, removing this protein protected their bones from becoming fragile, even when they ate a high-fat, high-sugar diet. While the human evidence is still early, this finding opens a new way to understand why people with metabolic problems often have weaker bones, and it could lead to new treatments to keep bones strong.
Key Statistics
In a 2026 research study published in the Journal of Bone and Mineral Research, mice lacking selenoprotein P preserved trabecular bone mass, bone formation, bone stiffness, and cortical bone defect repair when fed high-fat, high-sucrose diets that normally damage bones.
Purified human selenoprotein P inhibited IGF-1 receptor signaling in bone-building cells by blocking phosphorylation of IGF-1 receptor, IRS-1, PI3K, PDK1, and Akt, reducing alkaline phosphatase activity and matrix mineralization essential for bone formation.
In a 2026 cross-sectional analysis of a general population cohort, exploratory analyses in the highest quintile of circulating selenoprotein P suggested an inverse association between high selenoprotein P and bone mass, indicating higher levels may correlate with lower bone density.
The Quick Take
- What they studied: Whether a liver protein called selenoprotein P damages bone strength by interfering with how bone-building cells grow and work
- Who participated: Laboratory mice on high-fat, high-sugar diets, bone-building cells grown in dishes, and data from a human population study (specific sample size not provided in abstract)
- Key finding: Mice without selenoprotein P kept strong bones and better bone repair even when eating unhealthy diets, while the protein blocked a key growth signal that bone cells need to function properly
- What it means for you: This research suggests that people with metabolic problems may have weaker bones partly because their livers produce too much selenoprotein P. Future treatments targeting this protein might help protect bone health in people with weight problems or metabolic disease, though human studies are needed to confirm this
The Research Details
This research combined multiple approaches to understand how selenoprotein P affects bones. First, researchers studied mice with and without the gene for selenoprotein P, feeding them high-fat, high-sugar diets similar to unhealthy human eating patterns. They measured bone density, bone strength, and how well bones repaired themselves. Second, they grew bone-building cells in laboratory dishes and added purified selenoprotein P to see how it changed cell behavior. They tracked what happened to growth signals inside the cells and measured whether the cells could build bone properly. Third, they used mice with specific genetic changes to identify which receptor on bone cells catches selenoprotein P and causes the damage. Finally, they analyzed data from a large group of people to see if high levels of selenoprotein P in their blood connected to weaker bones.
This multi-level approach is powerful because it shows the same problem at different scales: in whole animals, in individual cells, and in human populations. This strengthens confidence that the findings reflect real biology rather than lab artifacts. By identifying the exact molecular pathway, the researchers created a potential target for future medicines
The study used rigorous genetic tools to prove cause-and-effect relationships, not just associations. The researchers blocked specific proteins and showed that doing so eliminated the protective effect, which is strong evidence. However, the human data came from exploratory analyses in a subset of people, meaning those findings need confirmation in larger, dedicated human studies before drawing firm conclusions
What the Results Show
Mice lacking selenoprotein P maintained healthy bone mass and bone formation even when eating a high-fat, high-sugar diet that normally damages bones. Their bones were stiffer and stronger, and they repaired bone damage better than mice with normal selenoprotein P levels. When researchers removed the gene for selenoprotein P only from liver cells, the protective effect on bones remained, proving the liver is the main source causing the problem. In bone-building cells grown in dishes, selenoprotein P blocked a critical growth signal called IGF-1 signaling. This signal normally tells bone cells to multiply, mature, and build new bone material. When selenoprotein P was present, it prevented IGF-1 from activating its receptor and downstream signals that drive bone formation. The protein specifically interfered with a chain of molecular events: IGF-1 receptor phosphorylation, IRS-1 activation, PI3K signaling, PDK1 activation, and Akt phosphorylation. All of these steps are essential for bone cells to function.
The research identified LRP1 as the main receptor on bone cells that catches selenoprotein P and causes the damage. When researchers removed LRP1 from bone-building cells, selenoprotein P could no longer block IGF-1 signaling or harm bone formation. This finding is crucial because it pinpoints a specific target for potential future treatments. The study also showed that selenoprotein P reduced alkaline phosphatase activity and matrix mineralization, two key markers of bone cell maturation and bone quality. Additionally, selenoprotein P blunted the production of reactive oxygen species (ROS) that normally help drive bone formation, suggesting the protein disrupts the delicate balance of oxidative stress that bone cells need to function properly
This research fills an important gap in understanding why metabolic disease damages bones. Previous studies showed that obesity and metabolic dysfunction increase bone fragility, but the exact mechanisms were unclear. This work identifies selenoprotein P as a new hepatokine, a hormone-like protein released from the liver that affects distant organs. It adds to growing evidence that the liver communicates with bones through multiple pathways, and that metabolic stress in the liver directly impairs bone formation. The finding that IGF-1 signaling is central to this pathway aligns with decades of research showing IGF-1 is critical for bone health
The human data came from exploratory analyses in only the highest group of selenoprotein P levels, not the full study population, so the human findings are preliminary and need confirmation. The study did not specify the exact number of human participants analyzed. Most evidence comes from mice, which don’t always behave identically to humans. The research focused on bone formation and didn’t deeply examine bone breakdown, so the full picture of how selenoprotein P affects overall bone health remains incomplete. The study was conducted in laboratory and animal settings, so it’s unclear how quickly or effectively blocking selenoprotein P would work in living people
The Bottom Line
Based on this research, there is currently no direct recommendation for patients to change behavior, as this is early-stage research. However, the findings suggest that maintaining a healthy weight and avoiding high-fat, high-sugar diets may reduce liver production of selenoprotein P and protect bone health. People with metabolic disease or obesity should discuss bone health screening with their doctors, as this research explains why they may be at higher risk for bone fragility. Future clinical trials may test whether medications targeting selenoprotein P or its receptor could strengthen bones in people with metabolic disease. Confidence level: This is preliminary research in animals and cells; human confirmation is needed before clinical recommendations
People with obesity, type 2 diabetes, or other metabolic diseases should pay attention to this research, as it explains a new reason why they face higher bone fracture risk. Older adults with metabolic problems may particularly benefit from future treatments based on these findings. Healthcare providers treating metabolic disease should consider bone health as part of comprehensive care. People with normal metabolism and healthy weight are less likely to have elevated selenoprotein P, so this research is less immediately relevant to them, though maintaining metabolic health protects bones for everyone
If a drug targeting selenoprotein P or LRP1 were developed, it would likely take 5 to 10 years of clinical testing before becoming available to patients. In the meantime, people can protect their bones by maintaining a healthy weight, eating balanced diets low in processed foods and added sugars, exercising regularly, and ensuring adequate calcium and vitamin D intake
Frequently Asked Questions
What is selenoprotein P and why does it hurt my bones?
Selenoprotein P is a protein your liver makes, especially when you’re overweight or eat unhealthy foods. It blocks a growth signal called IGF-1 that bone-building cells need to work properly. Without this signal, your bones become weaker and repair themselves more slowly
Can I lower my selenoprotein P levels to protect my bones?
While no direct treatment exists yet, maintaining a healthy weight, eating balanced diets low in processed foods and sugar, and exercising regularly may reduce liver production of selenoprotein P. These lifestyle changes also directly strengthen bones through multiple pathways
Does this research mean I will definitely get weak bones if I’m overweight?
Not necessarily. This research explains one pathway linking metabolic stress to bone weakness, but many factors affect bone health. People with metabolic disease can still maintain strong bones through exercise, adequate calcium and vitamin D, and healthy lifestyle choices
When will there be a treatment targeting selenoprotein P?
This is early-stage research in animals and cells. If pharmaceutical companies develop a drug targeting selenoprotein P or its receptor, human clinical trials would likely take 5 to 10 years before the treatment becomes available to patients
Should I get bone density screening if I have metabolic disease?
Yes. This research provides another reason why people with obesity, diabetes, or metabolic problems face higher bone fracture risk. Talk to your doctor about bone density screening, especially if you’re over 50 or have multiple metabolic risk factors
Want to Apply This Research?
- Track weekly average of high-fat, high-sugar food servings and correlate with bone health markers if available through medical records. Users can log specific foods and see trends over months to understand their metabolic stress load
- Set a goal to replace one high-sugar or high-fat meal per day with a balanced meal containing lean protein, vegetables, and whole grains. Log completed swaps in the app to build awareness of dietary patterns that may affect liver health and bone strength
- Monthly check-ins on weight, energy levels, and any bone or joint discomfort. Annual bone density screening for users over 50 or with metabolic risk factors. Track adherence to exercise goals, as physical activity reduces metabolic stress and strengthens bones directly
This research is preliminary and conducted primarily in mice and laboratory cells. While exploratory human data is included, larger human studies are needed to confirm these findings before clinical recommendations can be made. This article is for educational purposes and should not replace professional medical advice. People with metabolic disease, obesity, or concerns about bone health should consult their healthcare provider about appropriate screening and treatment options. Do not make changes to diet, supplements, or medical treatment based solely on this research without discussing with your doctor
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.