Even Reducing Calorie Intake Later in Life May Slow Aging
There’s quite a bit of research that suggests calorie restriction (CR), as long as essential nutrient needs are met, may help to significantly reduce disease risk and improve longevity. There are even organizations focused solely on the topic.
Researchers at the University of California and Children’s Hospital Oakland Research Institute note in a paper in the 2007 Annual Review of Nutrition that even reducing calorie intake later in life may lead to beneficial effects (e.g., preventing or slowing the growth of cancer).
The article mentioning the paper discusses some of the possible ways CR may work:
Physiological changes associated with aging include cell damage and the emergence of cancer cells. The most important effects of low calorie diets and longevity therapeutics given late in life may not be to prevent this damage, but instead to stimulate the body to eliminate damaged cells that may become cancerous, and to stimulate repair in damaged cells like neurons and heart cells. Low calorie diets drive the body to replace and repair damaged cells. This process usually slows down as we age, but low calorie diets make the body re-synthesize and turn over more cells - a situation associated with youth and good health. Dr. Spindler and his colleagues used their screening method to search for drugs which cause pre-cancerous and cancerous cells to commit suicide and to replace those cells with new, healthy cells. It is thought that the body does this because it normally kills some cells like damaged and rogue cancer cells to provide energy when it is starving. Then it replaces these cells when a meal is eaten.
A more detailed overview of the potential biochemical mechanisms behind CR’s beneficial health effects can be found in this March 2006 Scientific American article:
Unlocking the Secrets of Longevity Genes
There you’ll find a clear discussion of how CR and other stressors stimulate the activity of sirtuin enzymes via a couple of different pathways. The sirtuin enzymes, in turn, remove acetyl tags from histone proteins that package DNA, which results in more tightly wound DNA and longer-lived, more efficient cell replication.
Resveratrol: A Calorie Restriction Substitute?
In recent years, resveratrol, a polyphenol compound found in red wine, grapes, peanuts, and some berries, has received much attention as a sirtuin-activating compound. Unfortunately, to match the amounts used in promising recent animal studies (e.g., Nature), one would have to take very large (and expensive) supplement doses. Additionally, there is the question of resveratrol bioavailability. Resveratrol is well absorbed, but quickly breaks down in the body.
There are several companies, such as Sirtris Pharmaceuticals, that are trying to develop patentable resveratrol analogs that mimic the beneficial effects of CR at lower doses and with better bioavailability. Since “aging” is not a disease for which drugs can be approved, these companies target other conditions, such as improving blood glucose levels and insulin sensitivity in Type 2 diabetes.
Issues / Risks
Pursuing a calorie restriction diet is not without its downsides, including:
-
Hunger
-
Cold sensitivity
-
Hormone changes
-
Bone health (mineral intake, less weight/stress on the bones)
-
Difficulty fitting in socially around events involving food
-
Time & money spent preparing meals
Children and pregnant or nursing women should never pursue a calorie restricted diet.
Bottomline
It’s difficult to maintain a life-long diet that restricts calories to the extent that has resulted in the largest longevity gains observed in animals (30 to 40 percent calorie reductions). It’s just not very practical or enjoyable.
The work with resveratrol is interesting. Perhaps substances will be developed that allow for better bioavailability and higher doses that correspond with those used in recent, positive animal studies.
In the meantime:
- Eating nutrient-dense foods (e.g., vegetables/fruits, whole grains, lean protein sources, healthy fats)
- Putting together a sound, foundational supplement program
- Maintaining a normal body mass index (BMI)
- And avoiding toxins (e.g., heavy metals, pesticides, endocrine disruptors, etc.)
are your best bets for living a healthy, long life.
____________________________
Discover How Nutrition Can Make a Difference in Your Life …
