Scientists have been aware that that animals with a reduced calorie intake had lengthened lifespans, but they were never able to understand the reasons why. A recent study by scientists from Harvard Medical School suggests that restricting calories to lose weight may also be the secret to extending life expectancy. Restriction of high calorie foods is believed to produce a molecular response that triggers a reaction within the energy core of cells, known as the mitochondria. Responsible for keeping cells alive and healthy, mitochondria can weaken and lead to cell deterioration and increased susceptibility to DNA stress, which eventually causes the cell to die.
By examining human enzymes in a lab, scientists determined that cutting down calories, but not nutrients, increased the activity of specific enzymes responsible for strengthening mitochondria.
Lead molecular biologist, David Sinclair says two specific genes called SIRT3 and SIRT4 produce proteins that go into the mitochondria. As we age we lose these proteins and as a result, our mitochondria become less efficient. However, by restricting calories, mitochondria are strengthened and the normal cell-suicide programs are mitigated.