A 90K-Person Study Linked This Common Fat Swap To Better Joint Health
When you think about protecting your joints, you probably think about strength training, staying active, or maintaining a healthy weight.
What you put on your plate might not be the first thing that comes to mind. But the fats you cook with and eat regularly could also play a role in how your joints age.
The results offer another reason to take a closer look at the fats in your diet.
About the study
The study combined data from three large population studies: the UK Biobank, the U.S. Health and Retirement Study, and the English Longitudinal Study of Ageing.
Together, they included more than 93,000 middle-aged and older adults who didn't have osteoarthritis when the research began.
Participants reported what they ate, including their intake of polyunsaturated fat (PUFA) and saturated fat (SFA). From there, the study tracked new osteoarthritis diagnoses over time.
The UK Biobank portion also included repeated dietary check-ins to get a better picture of participants' usual eating habits.
These two types of fat were the focus because they may affect inflammation differently.
Since ongoing, low-grade inflammation is thought to contribute to cartilage breakdown, the goal was to see whether the balance of fats in someone's diet might be connected to their long-term joint health.
More polyunsaturated fat was linked to lower OA risk
People who got a larger percentage of their daily calories from polyunsaturated fats had a lower rate of new osteoarthritis diagnoses.
For every one-percentage-point increase in calories from these fats, the rate of OA diagnoses dropped modestly.
The study also examined the ratio of polyunsaturated to saturated fat.
People with a higher ratio (meaning they ate relatively more PUFA than SFA) also had slightly lower rates of OA.
However, this association was weak and disappeared in one of the additional analyses, making it a less reliable finding.
Most of the evidence for the first finding came from the UK Biobank, which contributed the vast majority of the statistical weight. The other two studies were considerably smaller.
This research can't establish that eating more polyunsaturated fat directly prevents osteoarthritis, and the findings also aren't meant to set a specific dietary target for OA prevention.
Why the types of fat you eat may matter for your joints
One possible explanation comes down to inflammation.
Osteoarthritis isn't simply a matter of cartilage wearing down with age. Inflammation also contributes to changes in the cartilage and other tissues that help joints move comfortably.
Different fats can influence the body's inflammatory processes in different ways.
Polyunsaturated fats, particularly omega-3s found in fatty fish, help the body produce compounds involved in regulating inflammation. Some saturated-fat-rich diets, meanwhile, have been associated with more pro-inflammatory signaling.
That may be one reason people who ate more polyunsaturated fat had lower rates of OA, though the exact connection isn't fully clear yet.
RELATED READ: The 15 Best (And Expert-Vetted) Omega-3 Supplements
Simple ways to shift the balance of fats in your diet
You don't need to eliminate butter or avoid saturated fat altogether. A more realistic approach is to make room for more sources of unsaturated fats throughout the week.
A few easy places to start:
- Choose more plant oils: Use olive or sunflower oil in place of butter for some cooking and salad dressings.
- Eat fatty fish regularly: Add salmon, sardines, or mackerel to your meals a couple of times a week for omega-3 fats.
- Keep nuts handy: Walnuts are an easy source of polyunsaturated fats to add to snacks, oatmeal, or yogurt.
- Sprinkle on some seeds: Chia and flaxseeds can boost your intake of polyunsaturated fats with very little effort.
The takeaway
Your next grocery shop could be an opportunity to give your joints a little nutritional backup.
More polyunsaturated fat was associated with fewer new OA diagnoses in this study, so making fish, nuts, seeds, and plant oils regular staples is a smart move for overall health, even if the joint-specific benefits still need more research.
