As an international team of researchers headed by Michael Ristow, a professor of energy metabolism, has now experimentally demonstrated, niacin and nicotinamide take effect by promoting formation of so-called free radicals.
"In roundworms, these reactive oxygen species prolong life," he said.
This might seem surprising as reactive oxygen species are generally considered to be unhealthy.
Ristow's view also contradicts the textbook opinion championed by many other scientists.
Reactive oxygen species are known to damage somatic cells, a condition referred to as oxidative stress.
Particular substances, so-called antioxidants, which are also found in fruit, vegetables and certain vegetable oils, are capable of neutralising these free radicals.
Many scientists believe that antioxidants are beneficial to health.
Based on the current and many previous findings he is convinced that small amounts of reactive oxygen species and the oxidative stress they trigger have a health-promoting impact.