Is Genetically modified food harm to human?If so How it is harming?

Generally, we don't know.

We don't know how humanity will be effected by UV treated apples, etc. We just don't know.

Considering how many times Man has screwed up working things on this planet, people have good reason to fear.

However, virtually ALL of the food that we eat is genetically modified - in that we grow it from specific species that over the years have been "artificially" selected for certain quantities. When was the last time you drank milk that hadn't come from a cow that was bred for milking?

Most people consider "genetically engineered" to mean that we are actually, directly, microscopically, changing the genes to do what we want - and that assumes that we sufficiently understand the context in which that particular gene operates. For instance, a gene may be part of a cell's controlling mechanism to avoid infection, but it may also increase the incidents of cancer either within the host, or the human who eats the host. We might know one but not the other - and chaos may ensue because of this.

Ultimately, the only way to avoid this is incredibly thorough testing, just like with every new drug or drug used in a new way. Advocates maintain that sufficient testing has been done. Detractors maintain that it hasn't.

Extreme detractors don't believe that any amount of testing would be sufficient.

I wonder about the actual qualifications of the people on that programme.

There is no reason why genetically modified food should be harmful.

UV-treated apples stay fresh, but are often tasteless because they don't fully ripen.

The fish gene added to tomatoes (do you mean strawberries?) is to make natural antifreeze. It doesn't harm you when you eat fish, so why should it harm you when you eat fruit or vegetables?

If the chromium isn't harming the chicken, I don't think it's going to harm you either.

We started going against nature as soon as we invented agriculture. If we went back to nature, the earth could only support a tiny fraction of its present population.

Besides, natural isn't always good. Smallpox is natural.

Is Genetically modified food harm to human?

Not necessarily.

How it is harming?

If the bio-engineer makes a mistake or the inserted gene produces an effect that was not planned then there may be problems:

the new vegetable or animal may contain toxins that make people sick, or long term it may induce cancer.

But except for virus and bacteria -- the problem is before that: will the new plant be viable?