Anyone who buys this nonsense is just wasting his money. Unfortunately, many people are naive enough to waste their money on nonsense. There are no foods that can be used to treat an infection. There is no solid evidence that ginseng or gingko improves thinking, but for this discussion of functional foods, let's assume they do. Ginseng is a stimulant just like amphetamine.
Any reasonable person has to realize that it's the dose that makes a poison.
If a food causes a health benefit, you have to eat an exact dose. If you eat less, you don't receive the benefit. If you eat too much, you can die. But nobody measures exact doses of food. The same applies to New Morning GingkOs Cereal.