Are Cashews Good for Arthritis and Inflammation?

Cashews contain a handful of compounds that work against inflammation in laboratory and animal studies, and limited human evidence suggests that nut-rich diets may modestly benefit people with arthritis. The strongest data come from research on oleic acid, anacardic acid, and cashew fiber, each of which appears to dampen inflammatory pathways relevant to joint disease. Still, no large clinical trial has tested cashews alone for arthritis outcomes, so the picture is promising but incomplete.

The Anti-Inflammatory Compounds in Cashews

Cashews are unusually rich in monounsaturated fat, with oleic acid making up roughly 60 percent of their total fat content. They also supply magnesium, copper, zinc, and a suite of plant compounds that function as antioxidants and anti-inflammatory agents.¹ Two of these compounds deserve particular attention when it comes to arthritis.

The first is oleic acid itself. In cartilage cell experiments exposed to the inflammatory signal TNF-alpha, oleic acid lowered the expression of a key enzyme that breaks down cartilage (MMP-1) and reduced the release of glycosaminoglycans, the structural molecules that keep cartilage springy and resilient.² Linoleic acid, the main omega-6 fat in many seed oils, did not produce the same protective effect. This distinction matters because it suggests that the type of fat in cashews, not just fat in general, may help shield cartilage during an inflammatory flare.

The second is anacardic acid, a compound derived from the cashew nut shell and present in trace amounts in the nut itself. Lab research found that anacardic acid suppresses NF-kappaB, a master switch that controls the expression of genes involved in inflammation, cell survival, and tissue invasion. By blocking this pathway, anacardic acid reduced levels of cyclooxygenase-2 (the same enzyme targeted by drugs like ibuprofen and celecoxib), along with several proteins that promote blood vessel growth and tissue breakdown.³ These are cell-culture findings, not human-diet findings, but they help explain why cashew-derived compounds keep turning up in inflammation research.

What the Osteoarthritis Evidence Looks Like

Osteoarthritis is the wear-and-tear form of the disease, where cartilage gradually erodes and the surrounding tissue becomes inflamed. An animal study using a pain-based model of degenerative joint disease found that oral cashew nut supplementation reduced pain-related behavior and restored several markers of antioxidant defense, including glutathione and catalase levels. Radiographic and tissue analysis showed less cartilage degradation, lower levels of pro-inflammatory cytokines and metalloproteinases, and fewer mast cells recruited to the joint.⁴

That is a single study in animals, so it would be premature to call cashews a treatment for osteoarthritis. But the results align with the cartilage-cell data on oleic acid. In both cases, the inflammatory cascade that chews through cartilage was measurably blunted. The animal study adds something the cell data cannot: evidence that eating cashews, rather than bathing cells in isolated compounds, still delivers enough of the active ingredients to reach the joint.

For people with osteoarthritis wondering whether to add cashews to their diet, the honest summary is that early signs are encouraging but the research is young. No human randomized controlled trial has yet isolated cashew consumption as a variable and measured joint outcomes. What exists is mechanistic evidence that points in a hopeful direction.

Nuts and Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a different beast from osteoarthritis. It is an autoimmune condition where the immune system attacks the joint lining, and its management relies heavily on suppressing that overactive immune response. Diet alone does not replace medication for RA, but certain foods appear to influence disease activity at the margins.

An Italian cross-sectional study of 365 RA patients examined whether olive oil and nut consumption was associated with disease activity scores. Higher nut intake showed a favorable trend, with the association becoming statistically significant in patients with more severe or long-standing disease. In those subgroups, average DAS28-CRP scores (a common measure of RA activity) dropped by roughly 0.55 points among higher nut consumers, and the odds of lower disease activity were meaningfully improved.⁵ Olive oil showed a somewhat stronger and more consistent effect than nuts did across the full sample, but both food groups appeared to help in the sicker patients.

A few caveats are important. This was an observational snapshot, not an experiment, so the direction of causation is not certain. People who eat more nuts and olive oil tend to follow a Mediterranean-style diet overall, and it is hard to separate the effect of one food from the entire dietary pattern. The study also grouped all nuts together rather than singling out cashews. Still, the fatty acid profile of cashews, dominated by oleic acid much like olive oil, positions them well within this category.

Cashew Fiber and the Gut-Joint Connection

One of the more interesting angles on cashews and inflammation involves the gut. Research over the past decade has increasingly connected gut bacteria composition with joint inflammation, particularly in RA. Certain bacterial populations produce short-chain fatty acids like butyrate, which help maintain the gut lining and regulate immune responses throughout the body.

In vitro fermentation experiments showed that cashew fiber produced more butyrate than fiber from several other tree nuts. Cashew fiber also promoted the growth of butyrate-producing bacteria, including Butyricimonas and Collinsella, at higher levels than other nut fibers tested. Researchers attributed this to cashew fiber’s unusually high ratio of soluble to total fiber and its distinctive sugar composition.⁶

A separate randomized trial in overweight women found that daily cashew and Brazil nut consumption during an energy-restricted diet modified gut health, with changes in intestinal permeability correlating with reductions in IL-8 (an inflammatory marker) and increases in beneficial Ruminococcus bacteria.⁷ Because the intervention combined two nut types and calorie restriction, it is hard to credit cashews alone. But the convergence with the fiber data suggests that cashews genuinely shift the gut microbial environment in a direction that favors lower systemic inflammation.

Why does this matter for your joints? A leaky gut lets bacterial fragments into the bloodstream, where they activate immune pathways that can worsen joint inflammation. If cashew fiber helps maintain gut barrier integrity and supports butyrate production, it could dampen the immune activation that feeds both RA and, potentially, inflammatory aspects of osteoarthritis.

What About Gout?

Gout is a form of inflammatory arthritis driven by uric acid crystals depositing in joints. Diet plays a well-known role: high-purine foods like organ meats and shellfish raise uric acid levels, while some plant foods seem to lower them. Where do cashews fit?

Cashews are low in purines compared to animal-based triggers, so they are unlikely to provoke a gout flare. A study of young adults found that higher pine nut intake was associated with a roughly 29 percent lower risk of elevated uric acid levels, and walnuts showed a marginally protective trend as well.⁸ Cashews were not individually highlighted in that analysis, so a direct claim about their uric-acid-lowering potential would go beyond the evidence. The broader pattern, though, is that tree nuts as a group appear either neutral or mildly protective for gout risk. If you have gout and are looking for protein-rich snacks that will not aggravate your condition, cashews are a reasonable choice.

How Roasting and Preparation Affect the Equation

Most cashews sold commercially are roasted, and the way a food is cooked changes its inflammatory profile. Dry heat promotes the formation of advanced glycation end products (AGEs), compounds that increase oxidative stress and inflammation in the body. Across food categories, dry-heat cooking can increase AGE levels by ten- to a hundred-fold compared with the uncooked state.⁹

For someone eating cashews specifically to manage inflammation, this creates a trade-off. Roasting improves flavor and digestibility, and it reduces certain anti-nutrient compounds like phytic acid and tannins. But it also generates AGEs that may work against the very anti-inflammatory benefits you are after. Raw or lightly roasted cashews will carry a lower AGE load than heavily dry-roasted or oil-roasted versions. Salted varieties add sodium, which in high amounts can exacerbate fluid retention and joint swelling. If inflammation management is the goal, choosing raw or minimally processed cashews and keeping salt low makes the most sense.

One practical note: truly raw cashews are uncommon because the nut shell contains urushiol, the same irritant found in poison ivy. Cashews labeled “raw” at the store have almost always been steamed to remove the shell safely, which is a gentler process than roasting and produces fewer AGEs. You can generally trust that store-bought raw cashews are safe, but homemade preparations from whole cashew fruits carry real risk. A case report documented severe dermatitis from cashew nut butter made at home, where shell oil contaminated the final product. The patient required three weeks of systemic steroid therapy.¹⁰

Practical Limits and Risks

Cashews are calorie-dense, at around 155 to 160 calories per ounce. For people with arthritis, maintaining a healthy weight is one of the most impactful things they can do, because excess body weight increases mechanical stress on joints and adipose tissue itself produces inflammatory signals. Overeating cashews in pursuit of their anti-inflammatory compounds could backfire if it leads to weight gain.

A reasonable portion is about one ounce per day, roughly a small handful. That delivers a meaningful dose of oleic acid, magnesium, and fiber without tipping the calorie balance. Spreading intake across the week rather than consuming large amounts in one sitting also avoids a less discussed risk: oxalate accumulation. Cashews are relatively high in oxalates, and excessive intake over a sustained period can overwhelm the kidneys’ ability to clear them. A case report described a 76-year-old man with pre-existing kidney disease who developed acute kidney injury after eating roughly 200 to 300 grams of cashews daily for several months. A kidney biopsy revealed extensive calcium oxalate crystal deposits.¹¹ That is an extreme case involving someone who already had compromised kidney function and who was eating several times a normal serving, but it illustrates that more is not better.

People with kidney stones, chronic kidney disease, or a history of oxalate-related problems should be especially cautious. For everyone else, normal snacking portions pose no documented oxalate risk.

Cashews Versus Other Nuts for Inflammation

If you are choosing among tree nuts for their anti-inflammatory potential, cashews hold up well but are not clearly superior across the board. Walnuts get the most attention in inflammation research because they are the richest tree nut source of alpha-linolenic acid, a plant-based omega-3 fat. Almonds are slightly higher in vitamin E and fiber. Brazil nuts supply extreme amounts of selenium, which plays its own role in immune regulation.

Where cashews distinguish themselves is in their oleic acid content (comparable to olive oil), their unusually butyrogenic fiber, and the presence of anacardic acid. No other common snacking nut contains a compound that directly inhibits NF-kappaB in the way anacardic acid does in cell studies.³ Whether the trace amounts of anacardic acid in a normal serving of cashews are enough to move the needle in a living human body remains an open question, but the mechanism is at least plausible.

For most people, the practical advice is not to agonize over which single nut is optimal but to eat a variety of tree nuts regularly. The Italian RA study grouped all nuts together and still found benefits in more severe disease.⁵ Cashews are a strong member of the lineup, and their flavor and versatility make them easy to incorporate. Pairing them with olive oil in cooking or salads gives you two oleic-acid-rich foods in one meal, which aligns with the Mediterranean dietary pattern most consistently linked to lower inflammation.

Why the Human Evidence Is Still Thin

Nutrition research on individual foods is notoriously difficult to do well. You cannot easily run a blinded trial on cashews because people know whether they are eating nuts. Long-term compliance is hard to maintain. And isolating the effect of one food from everything else a person eats requires sample sizes that most food studies cannot afford. The result is that most of the cashew-and-arthritis evidence sits in mechanistic and animal studies, with a few observational human studies filling in the gaps.

This does not mean the evidence is unreliable, but it does mean you should calibrate your expectations. Cashews are unlikely to replace anti-inflammatory medications for someone with active RA or severe osteoarthritis. They are better understood as a consistently anti-inflammatory dietary choice that, over months and years, contributes to an internal environment where inflammation has a harder time gaining ground. That is a modest but real benefit, especially when combined with other anti-inflammatory foods, regular movement, and appropriate medical care.

Researchers have called for more targeted clinical trials that test cashew supplementation against arthritis biomarkers in controlled settings. Until those studies materialize, the strongest honest advice is that cashews fit comfortably into an anti-inflammatory diet, their specific compounds have biologically plausible mechanisms for protecting joints, and a daily handful is a low-risk, potentially useful habit for anyone managing arthritis or looking to keep their joints healthier as they age.