There is a legend from the 4th century BC, that there is a fountain called “The fountain of youth” in which, if you drink or bathe, it is capable of healing you and giving you back your youth.
Today, that source with such powers has not yet been discovered so we will have to find other methods to preserve our dear youth . And guess what? Nutrition is a great tool for this and I am going to explain how to achieve it.
First of all, to understand how to prevent it, we need to know what exactly this term means. According to the definition of the World Health Organization: aging is a normal physiological process that occurs over time and involves a series of changes such as functional losses and can even lead to the death of the individual 1 .
With this definition, we are clear about what our main objective is to prevent this aging: to avoid these functional losses . But … what does this mean?
What are functional losses?
Functional losses refer to the malfunction of tissues and organs , since a malfunction of these will create a situation of dependency in different aspects. A simple example would be diabetes. A malfunction of the ability of our cells to capture glucose will cause us to become dependent on substances that increase sensitivity to Insulin or increase absorption of glucose (Insulin) 2,3 .
Now, what is the nutrition tool to preserve the functionality of the organs? Now I will tell you.
Caloric restriction to prevent aging
Caloric restriction is defined as the reduction of caloric intake without deprivation of essential nutrients and without causing states of malnutrition . For it to truly have an anti-aging effect, it should be done after the growth stage and it would have to be sustained throughout life 4,5 .
I would like to emphasize that a reduction in caloric intake does not imply eating less or starving .
The Importance of Caloric Density During Caloric Restriction
There is a concept in nutrition called “caloric density” which is the amount of energy (calories) per gram of food . Low-energy-dense foods have fewer calories per gram of food. This means that with relatively large amounts, we will continue to consume a small amount of calories. This caloric density will be a very useful tool to apply the caloric restriction.
This anti-aging phenomenon has been previously confirmed in rodents in 1935 and in monkeys in 2009. From this last study, I would like to leave you a photograph to see the great phenotypic difference (in appearance) between the two monkeys 7 .
Image extracted from Colman, R (2009) 7 : in images A and B we can observe an individual who was not subjected to caloric restriction, while in photos C and D we can observe one who underwent a CR of the 10% per month until you maintain a 30% restriction for the rest of your life.
The scientific evidence in humans is scarce and limited . We know that the two longest-living populations in the world are the Mediterranean and the Japanese:
Regarding the first, there is a study called EPIC-Spain, which evaluated 40,622 participants over 13.4 years. They observed that the participants with a Mediterranean diet- type diet had a lower energy intake than those without (without specifying percentages). Furthermore, they had 21% less mortality from any cause . 8
Regarding the Japanese population, the oldest of all is one known as the Okinawa . On this population, it was observed that they also presented a caloric restriction (of 11%). They observed 6% and 20% more survival compared to the rest of the Japanese and the population of the United States, respectively. It is believed that this population has more survival due to the consumption of 3 specific foods: sweet potato, certain foods of marine origin and turmeric. 9 I could write another whole article on how they might help slow aging.
How does this calorie restriction act on the body?
Advantages of calorie restriction
Let’s start with the beautiful. Its advantages with the following:
- It has been seen that, in normal-weight patients subjected to a 25% restriction for 2 years, there was an improvement in total cholesterol, triglycerides, the HOMA-I R index (parameter related to type 2 diabetes), blood pressure and a r eduction of thyroid hormone T3 (hormone that increases the activity of metabolism) and of an inflammatory molecule called TNF-𝛼 (also associated with aging). These changes are indicative of longer life expectancy 4 .
- With a 15% restriction, the same biochemical changes were also observed, as well as a reduction in oxidative stress (a factor that accelerates aging) 10 .
- Finally, they also evaluated the safety of this type of dietary intervention against a free diet for 2 years. 11 Some complications that could appear as dysmenorrhea, tiredness, diarrhea, nasal congestion, constipation, muscle cramps, viral gastroenteritis, pain and urinary tract infections, among others, were evaluated, demonstrating good tolerance and safety . 11
Disadvantages of calorie restriction
On the other hand, the disadvantages are as follows:
- Weight loss not only at the expense of fat but also a small part of muscle mass r 4 .
- If there is not a good control by the health professional, in the case of athletes , a decrease in iron may appear , necessary to avoid pathologies such as anemia 12 .
- Restrictions of 25% or more for long periods of time can produce some bone resorption ( decrease in bone mass) in young adults and in important clinical positions of osteoporotic fractures . 13
How to perform this calorie reduction?
Now comes the part where I get wet as a professional. What do I recommend to carry out this feeding?
- First of all, it should be noted that very long-term human studies are observational. What does that mean? that despite seeing a good association and very positive effects, the scientific evidence is not strong . On the other hand, in periods of 2 years, it has been correctly evaluated with intervention studies showing interesting effects.
- Second: that you get advice correctly with a health professional who controls a lot the food issue. If preferred, you must be a Dietitian-Nutritionist. He or she will be able to control all the nutrients your body needs with this type of intervention and to keep a good track.
- Third and not least … That the caloric restriction is between 11-20% ! Why? As we have seen, there are also disadvantages to this treatment. however, these have been observed in reductions of 25% or more. With these high restrictions, despite obtaining benefits at the beginning, in the long run, the disadvantages would be greater . Better to make a small reduction as the longest-lived population, which reduces only 11%.
Finally, I hope you found this article interesting and different. Above all, to stop thinking a little about the current pandemic we are experiencing. A big hug to everyone, we will get out of this!