Incest is the act of having sex with a person who is genetically close to you. The only reason why this is taboo is because the offspring created sometimes doesn't come out right. The reason why this is, is because of the fact that because you and a family member share similar genes your offspring is more likely to express recessive alleles that both you and your family member have. The reason why receive alleles are dangerous is because they are rarely expressed and mostly stick around underneath the dominant allele, they are rarely expressed so they are not selected against in nature. If a species continual does incest for generations then each time more of the bad recessive genes are selected against and each generation becomes less "unhealthy". So yeah if you and your family do incest in a few generations you could expect to have healthy offspring.