| Our children and grandchildren continually remind us | | | | DNA damage causes activation of specific |
| of our younger days, when we could perform | | | | enzymes, PARP (polyA ribose polymerase) and |
| physical and mental feats with seemingly no | | | | SIRT1. These cellular "machines" utilize large |
| effort or fatigue. So, why the age-related loss of | | | | amounts of the high-energy-containing NAD |
| energy? And can we do anything to stop or | | | | molecule to repair and protect the DNA. |
| attenuate its progression? Recent research | | | | Other stress-producing events occur to the |
| suggests the answer to the second question is | | | | nervous system with increased frequency as we |
| "yes." But first questions first. | | | | age. They are associated with elevated levels of |
| More Age, Less Energy | | | | toxic substances, such as free radicals and other |
| Those grandchildren are quick, physically and | | | | reactive oxygen species, in the cell. These |
| mentally, due to their cells' superb efficiency at | | | | substances have been shown to super-excite |
| converting food to energy and maintaining ample | | | | neurons by acting to cause the release of the |
| energy reserves. But, as part of the aging | | | | neurotransmitter, glutamate, in excess amounts. |
| process, the health of important cellular | | | | Although glutamate is important for the |
| constituents deteriorates. As a consequence, so | | | | transmission of nerve impulses, when produced in |
| does our cells' capacity to produce energy. | | | | excess, it can lead to an electrically over-excited |
| Perhaps the most important biochemical pathways | | | | neuron (commonly referred to as glutamate |
| to be affected by aging are those associated with | | | | excitotoxicity). This over-excited state results in |
| the cellular structures, the mitochondria. The | | | | the neuron's uptake of charged substances, ions |
| mitochondria provide virtually all the energy the | | | | such as calcium and sodium, in an attempt to |
| cells of our body need to stay healthy and active. | | | | restore normal ionic balance. Unfortunately for the |
| And having enough energy stored in the cell is like | | | | neuron, the process takes enormous energy and, |
| having enough fuel to heat your home during | | | | if the energy store is compromised – for |
| those bitter-cold winter days…youcan't survive | | | | example, by the low levels of NAD common in |
| without it! | | | | the elderly – the cell dies. |
| There are some steps we slower, older folks can | | | | Saving the Neurons |
| take to support energy production by our | | | | Vitamin B3 to the rescue? A series of articles has |
| mitochondria. (See Juvenon Health Journals | | | | reported on the effects of administering |
| Mitochondria: Regulators of Cell Death and | | | | nicotinamide to animals, or cells in culture, that |
| Longevity; Alpha Lipoic Acid: Less Cellular Stress, | | | | were under the type of NAD-depleting stress as |
| More Energy; The Carnitine Cousins.) This month's | | | | described above. |
| Journal presents information that suggests there | | | | Most recently, a mouse model for cerebral stroke |
| are also things we can do to help redirect limited | | | | demonstrated a decrease in NAD, coinciding with |
| cellular energy stores in aged tissues, making | | | | an increase in damage to brain tissue. The |
| them available to more vital cellular processes. | | | | damage was significantly less in those animals |
| | | | receiving vitamin B3. The vitamin, a precursor for |
| Highest Energy Consumer | | | | NAD, was shown to stimulate synthesis of this |
| The cells most affected by the age-related decline | | | | high-energy molecule, as well as inhibit the |
| in energy production are, naturally, those with the | | | | activation of the SIRT1 enzyme that consumes |
| highest energy requirements. The brain needs to | | | | NAD. The net effect? An increase in the energy |
| produce more energy than any organ in the body, | | | | molecule and the restoration of energy balance in |
| even during sleep. The nervous system requires | | | | those neurons affected by the stroke. (See this |
| the bulk of this energy to synthesize signaling | | | | month's "Research Update.") |
| molecules (neurotransmitters) and cellular pumps | | | | Additional research has shown the potential |
| to facilitate the transport of ions (salts) into and | | | | benefits of administering nicotinamide to animals |
| out of the cell (neuron) for the maintenance of | | | | engineered to develop symptoms of Alzheimer's |
| electrical charge. | | | | disease. Those fed this form of vitamin B3 had |
| Because of this high energy demand, the central | | | | significantly fewer symptoms of the |
| nervous system must have a consistent, as well | | | | neurodegenerative disease than those receiving a |
| as sufficient, supply of energy to maintain | | | | placebo. The mechanism, although not yet |
| optimum health. An energy deficit can result in the | | | | completely understood, appears to affect either |
| death of neurons, culminating in a dysfunctional | | | | the PARP enzyme, the SIRT1 enzyme, or both. |
| nervous system. | | | | Another interesting hypothesis proposes that |
| Deficit Defense | | | | over-excited neurons may cause specific types of |
| But what can we do, especially as we age, to | | | | migraine headache. There is some evidence, |
| support the nervous system's energy needs? | | | | although not yet compelling, that nicotinamide may |
| Studies seem to indicate a form of vitamin B3, | | | | be of help with this central nervous |
| nicotinamide, could help. | | | | system-related condition. |
| Nicotinamide is required for the synthesis of a | | | | Potential Health Benefits |
| molecule, nicotinamide adenine dinucleotide (NAD), | | | | The work described above is encouraging. Further |
| which is essential for the production of energy in | | | | results, from these and future studies, may |
| the mitochondria. NAD is not only important for | | | | provide information to help reduce age-associated |
| energy production, but is also necessary for the | | | | susceptibility to cerebral stroke. It may even be |
| synthesis of the building blocks of our genetic | | | | the key to preventing conditions that affect the |
| code, as well as the repair of damage done to | | | | nervous system, like Alzheimer and Parkinson's |
| the DNA comprising the code. | | | | diseases. |
| NAD-intensive Stress | | | | In the meantime, nicotinamide is a relatively safe |
| What causes this DNA damage? | | | | compound when taken in low doses (less than |
| Previous and recent work has shown what | | | | 500 mg per day), but can cause liver damage |
| happens during cerebral ischemic events (strokes). | | | | when taken in high doses by susceptible individuals. |
| At the biochemical level, an increase in the | | | | Consulting with your health professional is |
| production of oxidants leads to damage to cellular | | | | recommended. |
| structures, much of it to the genetic material. The | | | | |