Strawberries decrease circulating levels of tumor necrosis factor and lipid peroxides in obese adults with knee osteoarthritis

Abstract

Objective: Knee osteoarthritis (OA) is increasingly prevalent in obese people, who often have high cardio-metabolic risk factors. Among the few available non-surgical approaches, nutraceuticals have gained popularity, and dietary berries have mitigated arthritis symptoms in observational and animal studies. Clinical studies in OA are sparse, but recently we reported that strawberry supplementation can mitigate pain and reduce inflammatory markers in adults with knee OA. This study extends those observations. Methods: We conducted a randomized cross-over double-blind placebo-controlled trial on the effects of dietary freeze-dried strawberries on obesity-related hormones, biomarkers of inflammation and lipid peroxidation. Seventeen subjects (4 men, 13 women; age 57±3y) were randomized to strawberry supplements (50g/day for 12 weeks) vs. placebo (50g/day, matched for calories and fiber), for two 12-wk intervention periods, separated by 2-wk washout phase. Results: Among 24 biomarkers of inflammation examined (Bioplex-Pro human inflammation panel), 12 were detectable in all samples. Among these, high-sensitivity TNF-α (hs-TNF-α) and the soluble tumor necrosis factor receptor (sTNF-R2) were significantly decreased after strawberry consumption (p<0.05). There were no changes in other biomarkers of the TNF super family, such as APRIL and BAFF. Among serum biomarkers of oxidative stress, 4-hydroxy-2-nonenal (4-HNE) and conjugated dienes were also reduced (p<0.05). No changes were observed in body weight, serum obesity-related hormones, or osteocalcin. Conclusion: Strawberries lowered TNF-α, and lipid peroxidation products in obese adults with knee OA. Since, they also mitigate pain, these findings merit further investigation in larger trials.

The Implication of Reactive Oxygen Species and Antioxidants in Knee Osteoarthritis

“…Along with a protective role, a minimal reduction in pain intensity and improved joint function were associated with the consumption of strawberries, especially in obese patients with KOA [ 230 ]. Strawberries, similar to other berries [ 231 ], have antioxidant and anti-inflammatory properties due to their polyphenol content, and the effects have been supported by biochemical analysis of inflammatory markers, which exhibit lower concentrations when consuming strawberries for more extended periods of time [ 230 ]. In addition, the same effects accompanied by a reduction in edema and joint destruction are observed in the consumption of raspberries and blueberries [ 231 , 232 ] or of products containing resveratrol [ 233 ].…”

Dried Fruit Intake and Cancer: A Systematic Review of Observational Studies

“…What are the differences between dehydrated and raw fruits that would justify separation of the former into a distinct dietary category? A number of studies have demonstrated that fruits may undergo significant chemical changes upon their dehydration and storage ( 13 , 33 , 67 ), giving rise to chemical species that may also distinguish dried fruits from their raw counterparts for a variety of biological effects, ranging from immunomodulation ( 68 ) to insulin response ( 59 ) to changes in gut microbiota composition and activity ( 69 ). Analytical data on dehydration-specific products in dried fruits are scarce.…”

Yin-Yang Mechanisms Regulating Lipid Peroxidation of Docosahexaenoic Acid and Arachidonic Acid in the Central Nervous System

“…The reactivity of 4-HHE and 4-HNE to form adducts with biomolecules suggests the possibility to detect the adducts by antibody-based methods (73). An immunoblot assay was used to detect 4-HNE in human blood (104). In a study in which plasma proteins were separated by two dimension electrophoresis, increases in HNE-protein adducts were observed in autism subjects as compared to controls (105).…”