is there something else to reduce the oxidative load?

The short version: the evidence for reducing oxidative load is strongest for exercise, then for specific supplements like CoQ10+NADH and melatonin, and weakest for vitamin C alone.

The evidence you gave me covers supplements and exercise, not medications. I will answer from what is here.

The strongest intervention for oxidative load in a sedentary 49-year-old man with central adiposity is exercise, not a pill. High-intensity interval training (HIIT) in type 2 diabetes patients improved HbA1c by 0.83 percentage points and fasting glucose by 1.15 mmol/L compared to no exercise [8]. It also reduced body weight by about 1.9 kg and waist circumference by 3 cm [8]. A single session of HIIT protected endothelial function from ischemia-reperfusion injury, while endurance exercise did not [7]. The mechanism matters: exercise forces your mitochondria to work harder, which upregulates your own antioxidant systems. No supplement does that.

Among supplements, the best evidence here is for Coenzyme Q10 plus NADH. In 73 patients with chronic fatigue syndrome, 8 weeks of CoQ10 plus NADH reduced lipid peroxidation (a marker of oxidative damage) from 14.9 to 7.9 nmole per million cells, and increased ATP production from 67.5 to 119.2 nmole per mg protein [3]. That is a roughly 50% reduction in oxidative damage and a 77% increase in cellular energy. The study was a randomized placebo-controlled trial, which is good design. The limitation: it was in chronic fatigue patients, not in sedentary middle-aged men. The mechanism is plausible for you because central adiposity and insulin resistance both lower CoQ10 levels.

Melatonin also has direct evidence. In elderly type 2 diabetic patients, 30 days of melatonin reduced MDA (a marker of lipid peroxidation) from 0.281 to 0.226 µmol/g Hb, and increased SOD-1 activity from 2700 to 3138 U/g Hb [1]. That is a 20% reduction in oxidative damage and a 16% increase in antioxidant enzyme activity. Melatonin is cheap, low-risk, and also helps sleep, which matters for your profile.

Garlic reduced oxidative DNA damage (8-OHdG) and blood pressure in hypertensive patients over 8 weeks [2]. The study was small and the exact numbers were not given, but the direction is consistent.

Vitamin C alone failed. In 8 adults with well-controlled type 2 diabetes, vitamin C at 250, 500, or 1000 mg daily for 2 weeks raised blood levels but did not change any marker of oxidative stress, inflammation, or coagulation [4]. That is a null result from a randomized crossover trial. Vitamin C is not useless in all contexts, but for your profile it is not the place to start.

Spirulina shows modest effects on weight, lipids, and glucose in obese and diabetic adults, but the review notes substantial heterogeneity and calls for more robust trials [5]. It is low-risk but the evidence is not strong.

Ginger (2 g/day for 8 weeks) improved SOD and GPx activity in type 2 diabetics with periodontitis, but the study was small (21 per group) and in a specific dental context [6]. Worth trying but not top priority.

Here is the comparison of what the evidence actually shows for your profile:

My call: start with daily HIIT walking (3-4 minutes fast, 2-3 minutes slow, repeat 4-6 times) for 12 weeks. Add CoQ10 (200 mg) plus NADH (20 mg) daily, and melatonin (3 mg) before bed. Skip vitamin C as a standalone antioxidant. The evidence for exercise is strongest, and the supplement evidence is moderate for CoQ10+NADH and melatonin, weak for everything else.

Confidence: moderate for exercise and CoQ10+NADH, low for all other supplements.