Isoflavones are found in small amounts in a number of legumes, grains, and vegetables, but soybeans are by far the most concentrated source of isoflavones in the human diet (104, 105) .
Standing water under a house is usually the result of only two things; either a leaking water line, or from surface water drainage around the house. If it was from a leaking water line, the leak would have to be substantial, and you would hear running water in the house.
An undertow is a type of ocean current that is caused by waves breaking on the shore. Most are quite mild and not dangerous, as long as swimmers keep their heads, although some have been known to be powerful enough to sweep swimmers out to sea.