Calorie restriction as a way for senior citizens to avoid gaining weight and live healthy has caught the interest of scientists.
Calorie restriction, involves the reducing of average daily caloric intake below previous daily levels without sacrificing essential nutrients. It can be accomplished in one of two ways. Either by not eating at all for a period of hours (known as “intermittent fasting”) or by eating less at some or all meals.
Several studies in animals and humans have shown that calorie restriction can lead to improvements in a variety of health conditions. Currently, the focus is on senior citizens, many of whom suffer from multiple chronic diseases, such as heart disease, diabetes, Parkinson’s and Alzheimer’s disease.
To date, researchers have studied eating patterns — what, when, and how much to eat— while keeping intact essential nutrients. The focus is not to gain weight. For seniors, this becomes increasingly difficult, since their metabolism slows down with age.
Calorie Restriction: How It’s Done The Standard Way
The standard protocol to date has been a diet that is balanced among the most important food groups that also provide essential nutrients. The key difference is the introduction of intermittent fasting. What this means is that instead of eating three meals a day at the standard times — breakfast, lunch, dinner; the patient will delay their meal for several additional hours. The thesis is that the body will burn more calories that are not totally restored by the delayed meal.
While this model does work in part for younger groups, it is less successful for senior citizens. This is because many seniors are also dealing with chronic illnesses such as diabetes, cardiovascular issues, and high blood pressure. This can make any type of scheduled eating more difficult to accomplish.
Calorie Restriction: Mimetics To The Rescue?
For those senior citizens and younger aged adults that have difficulty eating, researchers are now exploring whether calorie restriction mimetics will help them.
What is mimetics? The word ‘mimetics‘ means to copy, mimic, duplicate. In our context of trying to reduce calories to promote better health, mimetics refers to developing a drug that will reduce calories.
Biological pathways that work smoothly can promote good health. Those pathways that do not, may contribute to disease and aging. Calorie restriction mimetics is the search for drugs that target the same pathways affected by calorie restriction. The goal is to find finding ways to improve health and quality of life.
Based on current knowledge of key biological pathways, scientists are investigating if several drugs can lower caloric intake similar to that of calorie restriction.
Three of the most studied compounds are:
Resveratrol is a natural compound found in red wine and grapes, dark chocolate, blueberries, raspberries, and nuts. Animal studies with resveratrol show it having antioxidant, anti-inflammatory, and anti-cancer effects.
Rapamycin is a substance produced by bacteria found in soil. It extends the lifespan in mice. A recent study found that giving middle-aged rats rapamycin as they got older reversed memory loss and prevented reductions in blood flow to the brain.
Rapamycin protects against organ plant rejection in humans. It also is effective against certain cancers.
Metformin is widely used to treat type 2 diabetes, and protects against other age-related diseases, such as heart disease and cancer.