An Overview of the Anti-Inflammatory Effects of Nuts

In a recent review published in nutrientsresearchers summarize the existing literature on the effects of nut consumption on biomarkers of inflammation and oxidative stress.

study: Effects of nuts on markers of inflammation and oxidative stress: a narrative review. Image Credit: Shebeko / Shutterstock.com

health benefits of nuts

Inflammation and oxidative stress mediate the pathophysiology of various noncommunicable diseases.

In particular, peanut and tree nut consumption have been shown to reduce the risk of developing certain cardiovascular and metabolic diseases such as atherosclerosis, hypertension and diabetes. Potentially, compounds within these foods may protect against inflammatory and oxidative processes.

In the current review, researchers elucidated the regulation of oxidative stress and inflammation by nut consumption, setting out the scope for future research.

oxidative and inflammatory processes

Tree nuts include brazil nuts, walnuts, almonds, cashews, macadamia nuts, hazelnuts, pine nuts, pistachios, and pecans.

Phytosterols found in peanuts and tree nuts, dietary fiber, monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs) such as linoleic and alpha-linolenic acids, and mineral-type antioxidants such as selenium, copper and magnesium. The molecule increases lipid metabolism and lowers low density lipoprotein (LDL) levels.

In addition, antioxidants such as tocopherols and polyphenols destroy free radicals, thereby inhibiting the oxidative modification of low-density lipoproteins (oxLDL). These processes prevent monocyte migration, macrophage differentiation and subsequent oxLDL endocytosis and foam cell formation by macrophage cells.

Elevated levels of free radicals in the subendothelial space alter the cellular phenotype of smooth muscle, thus promoting oxLDL uptake. This process is involved in inducing and maintaining low levels of inflammation, often in the presence of high levels of cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and other cytokines. It is important.

Walnut consumption is associated with decreased levels of TNF-α, E-selectin, interleukin-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-1β, and interferon-gamma (IFN-γ). increase. In comparison, hazelnuts have been reported to be able to reduce the levels of vascular cell adhesion protein-1 (VCAM-1) and C-reactive protein (CRP).

Antioxidants in nuts directly scavenge reactive oxygen species (ROS) generated in cells, reduce oxidative stress, and increase nuclear factor kappa B (NF-κβ) expression and release of proinflammatory cytokines. can also be decreased. Brazil nuts have also been shown to exert a positive effect on selenium-containing glutathione peroxidase (GPx) antioxidant enzyme activity.

Nut antioxidants also act as cofactors for various antioxidant enzymatic substances.Nuts can enhance antioxidant activity, increase nuclear factor erythroid-related factor-2 (Nrf-2) gene expression, and upregulate antioxidant response element (ARE) genes. Walnuts may also improve iron-reducing antioxidant properties (FRAP).

Room for further research

A cohort-type study has been conducted to evaluate the relationship between nut consumption and inflammation. However, these studies lacked assessment of oxidative stress biomarkers, nor did they assess the protection against disease outcomes posed by nuts.

Therefore, future studies should evaluate biomarkers of inflammatory and oxidative stress that mediate chronic disease exposure and outcome. Additional studies should also incorporate repeated dietary measurements at follow-up visits to eliminate biases associated with changes in lifestyle and behavior over time.

Well-designed randomized controlled trials (RCTs) with large sample sizes are needed to build scientific evidence for the immunological and cardiometabolic benefits of consuming nuts. These studies should also assess oxidative and inflammatory biomarkers as major research outcomes to clarify current discrepancies.

Future clinical trials should consider dosages, durations, and approaches that can be used to incorporate nuts into the diet, which are typically in the range of 40 g to 60 g per day. A nut-free control diet and adjustment for confounding factors such as age and gender are also essential to provide standardizable and generalizable data.

In addition, the individual’s medical history, including obesity, type 2 diabetes, and cardiovascular disease history, should be evaluated.

Future studies may also use genetic signatures of the metabolomics of inflammation rather than individual biomarkers. Underlying genetic and other mechanisms that contribute to the effect can be investigated.

Furthermore, potential future studies will incorporate diet-based approaches, including deoxyribonucleic acid (DNA) methylation assays, analysis of the relationship between the intestinal axis and the immune system, and the Dietary Inflammation Index (DII), to assess protection from nuts. Must be evaluated. Cardiometabolic disease.

Conclusion

Nuts such as walnuts and almonds may preferentially modulate inflammation, while other nuts such as Brazil nuts may selectively alter oxidative stress levels.

Peanuts and tree nuts, which are rich in potent bioactive nutrients such as PUFAs, MUFAs, α-tocopherol, copper and selenium, as well as non-nutrients such as fiber, polyphenols and phytosterols, can reduce cardiometabolic disorders induced by oxidative stressors. may be mitigated. and inflammatory substances.

Nevertheless, the quality of available evidence is moderate for some nuts, inconsistent for some, and has not been evaluated for many other types of nuts. Further research is essential to improve our current understanding of the protective role of nuts on processes.