Obesity is a major modifiable risk factor for knee osteoarthritis and is associated with chronic low-grade inflammation, pain, functional impairment, and cartilage degradation. Weight reduction is recommended as a core component of osteoarthritis management, while resveratrol has demonstrated anti-inflammatory and chondroprotective properties in experimental and clinical studies. However, the potential additional benefit of resveratrol supplementation when combined with dietary intervention remains uncertain.

This randomized controlled trial evaluated the effects of 150 mg/day trans-resveratrol supplementation as an adjunct to a low-calorie diet in postmenopausal women with obesity and knee osteoarthritis. Ninety-seven participants were randomized to receive either a low-calorie diet alone or the same diet combined with resveratrol for 10 days. Outcomes included pain intensity, functional status, urinary C-terminal telopeptide of type II collagen (CTX-II), anthropometric parameters, body composition, metabolic markers, lipid profile, and inflammatory biomarkers.

Obesity is a major modifiable risk factor for knee osteoarthritis and contributes not only to increased mechanical loading of the joints but also to chronic low-grade systemic inflammation, metabolic dysfunction, and cartilage degradation. Postmenopausal women represent a particularly vulnerable population because obesity and menopause-related hormonal changes may accelerate the development and progression of osteoarthritis. Current clinical guidelines recommend weight management as a core component of osteoarthritis treatment, particularly in patients with obesity.

Resveratrol is a naturally occurring polyphenolic compound found in grapes, berries, peanuts, and other plants. Experimental studies have demonstrated anti-inflammatory, antioxidant, and chondroprotective properties of resveratrol. Potential mechanisms include modulation of inflammatory signaling pathways, reduction of oxidative stress, inhibition of cartilage matrix degradation, and protection of chondrocyte viability. Although several clinical studies have investigated the effects of resveratrol in metabolic disorders and osteoarthritis, its efficacy as an adjunct to dietary intervention remains insufficiently characterized.

The purpose of this randomized controlled trial was to evaluate whether supplementation with trans-resveratrol provides additional clinical and metabolic benefits when combined with a low-calorie diet in postmenopausal women with obesity and knee osteoarthritis.

Eligible participants were postmenopausal women with obesity (body mass index ≥30 kg/m²) and radiographically confirmed knee osteoarthritis of Kellgren-Lawrence grade II or III. Participants were recruited during inpatient treatment at the Nutrition Clinic of the Federal Research Centre of Nutrition, Biotechnology and Food Safety. After baseline assessment, participants were randomized in a 1:1 ratio to receive either a low-calorie diet alone or the same low-calorie diet combined with trans-resveratrol supplementation.

All participants received a standardized low-calorie diet providing approximately 1700 kcal per day for 10 consecutive days. The diet was based on moderate energy restriction with reduced fat and carbohydrate intake and exclusion of added sugars. Participants assigned to the intervention group additionally received 150 mg/day of trans-resveratrol throughout the intervention period.

Assessments were performed at baseline and at the end of the intervention period. Clinical outcomes included pain intensity measured by the Visual Analog Scale (VAS), functional status assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Lequesne Algofunctional Index (LAI). Anthropometric measurements included body weight, body mass index, waist circumference, and hip circumference. Body composition was evaluated using multifrequency bioelectrical impedance analysis. Laboratory assessments included markers of carbohydrate metabolism, lipid metabolism, systemic inflammation, and routine biochemical parameters. Cartilage degradation was evaluated by measurement of urinary C-terminal telopeptide of type II collagen (CTX-II).

The primary objective of the study was to evaluate the effect of resveratrol supplementation on osteoarthritis-related outcomes and cartilage degradation markers when added to a low-calorie diet. Secondary objectives included assessment of changes in anthropometric parameters, body composition, metabolic indicators, lipid profile, and systemic inflammation.

Inclusion Criteria:

• Postmenopausal women aged 45-75 years.
• Diagnosed knee osteoarthritis.
• Obesity, defined as BMI ≥30 kg/m².
• Ability to comply with the study protocol and dietary recommendations.
• Written informed consent to participate in the study.

Exclusion Criteria:

• Allergy or intolerance to grapes, wine, peanuts, resveratrol, or supplement components.
• Acute infectious or inflammatory disease at screening.
• Unstable or exacerbated chronic disease requiring treatment changes or hospitalization.
• Malignancy within the past 5 years.
• Chronic liver disease, including hepatitis or cirrhosis.
• Major cardiovascular event within the past 6 months.
• Alcohol abuse or dependence.
• Severe psychiatric disorder or cognitive impairment limiting protocol adherence.
• Use of resveratrol-containing supplements or investigational products within the past 6 months.

The study included postmenopausal obese women.