Short Answer: It is generally safe to eat apple and fish together or one after another. Because there is no scientific proof that they are harmful for health.
Apple and fish are both healthy foods.
Apple contains antioxidants, fiber, and vitamin C, while fish has omega-3 fatty acids, protein, and minerals.
According to Ayurveda, eating apples immediately after consuming fish, milk, yogurt, or curd is an unhealthy combination of foods or opposite foods (viruddhahara).
This can cause indigestion, bloating, gas, and other problems.
But according to science, there is no clear evidence that eating apples and fish together or one after another is harmful or beneficial for health.
Some studies suggest that apples and fish may have protective effects against asthma and allergies⁹, while others indicate that apples and fish may have different effects on the gut microbiome.
As a nutritionist, my advice is to try first.
If after eating apple and fish together you experience any discomfort or adverse reactions, then stop combining them. And if you can tolerate them, then continue.
However, you should be mindful of the quality and quantity of apple and fish you consume. Because eating too much of any food can have negative consequences, and choosing organic or wild-caught products can reduce your exposure to pesticides or antibiotics.
Whether you eat them together or not, you should always choose fresh and ripe apples and fish. Because they have more nutrients and flavor than unripe or spoiled ones.
You can store them in the refrigerator for up to a week, but do not store them in the same container or near each other. Because apples release ethylene gas that can spoil fish faster.
Finally, remember, apple is a fruit that can be enjoyed raw or cooked in various dishes. Fish is a source of lean protein that can be prepared in many ways.
Both are good for your health if eaten in moderation and with a balanced diet.