Studies suggest calorie restriction can also lengthen the lives of humans, too, but the extremely low level of food intake you’re allowed is not sustainable.
Fortunately, new research has unlocked an anti-aging secret of calorie restriction. And one day, this new discovery may give us another way to trigger the same life-lengthening benefits of calorie restriction without reducing food intake.
A diet that restricts calories also reduces the intake of proteins, fats and carbohydrates, since these “macronutrients” are what contain the calories. (Vitamins and minerals have few or none.) This led scientists to wonder if the key to life extension is something hidden within these macronutrients rather than depending on the number of calories consumed.
Scientists believed that the most promising macronutrient to investigate is protein and its building blocks, the amino acids, because of their important role in cellular health.
The Role of Protein in Aging
When a cell has a plentiful supply of amino acids, an enzyme called Target of Rapamycin (TOR) sends out a signal to ramp up the manufacture of protein. When amino acids are in short supply, TOR keeps the cells in a constant state of alert or readiness.The first situation, called protein translation, appears to be beneficial at first glance, while the latter, called 'mild stress response', seems detrimental.
In fact, the research reveals the opposite is true.
A cell that's busy making protein lowers its defenses and can't cope well with stress. On the other hand, an "on alert" cell copes better with internal and external stressors, a process which is intimately related to longevity.
Using Protein to Conserve Life-Sustaining Energy
When researchers compared the lifespan of different animals ranging from four to 200 years, the long-lived animals had a lower turnover of protein and reduced energy demands within their cells than the short-lived ones.What’s more, the enzyme TOR becomes increasingly active the more calories - and thus protein - a cell is supplied with. This requires protein translation and uses up energy. When calories and protein are restricted, TOR activity shrinks, translation is stopped and cellular energy needs are reduced.
This important research laid the groundwork for another discovery.
Earlier this year, scientists from the United Kingdom found a new anti-aging function of a protein called Gaf1.
Unique Protein Plays a Key Role in Life Extension
The scientists discovered that when TOR is inactivated by a low calorie diet, Gaf1 binds to genes within the cell's DNA that are needed to make proteins.This prevents production of proteins, as well as the production of energy required for that task. When amino acids become available again, protein and energy production resumes.
As a result, researchers found that cells lacking Gaf1 are short-lived because their growth cannot be curtailed.
"In other words," wrote lead researcher Charalampos Rallis, "we found a molecule that mediates some of the beneficial effects of dietary restriction."
Although this study examined yeast cells, proteins similar to Gaf1 exist in many species including humans and are known to be important to good health.
As Dr. Rallis explains, "TOR function, cell growth and protein production are important in our physiology and healthspan, but can also contribute to the development of certain diseases, such as cancer or Alzheimer’s.
"Our study has shown how dietary restriction is controlled even down to the cell’s genes. Knowing this can allow us to examine how specific drugs or diets can tweak the function of these factors for our benefit..."
My Takeaway
While the research is still very early, it underlies the importance of diet in aging. I’m not suggesting you embark on extreme caloric restriction, but it’s good to keep in mind that over-eating can harm your health and longevity, starting with your cells.I hope Dr. Rallis continues his research into the effects of specific diets on this protein process that appears to contribute to longevity.
