The effects of a restricted calorie (CR) diet on skin has not been thoroughly researched, until now. In Brazil, researchers have concluded that mice live longer when their diets are calorie limited. The study also found that fat reserves in adipose tissue, which aids in insulating the body, was reduced.
To offset the effects of the diet, the mice skin stimulated fur growth and increased blood flow to warm the skin (an adaptive response). The authors also observed changes in cell metabolism while following the diet. “The changes in fur and skin were highly perceptible,” Kowaltowski said. “These changes are interesting because they appeared after only a few months when the animals were not yet old.” The study lasted six months and involved two groups of mice. One group (CR) was fed around 60% of the calories consumed by the other group (the control ), which was fed a pleasure diet (PD). The mice were free to eat as much food and as often as they chose. At the end of the study, the CR mice had 40% less body mass compared to the PD group, which became obese. The researchers speculated this was because the mice did not gain as much weight as the comparison group, not because of weight loss.
A thicker, longer, more uniform coat was also observed in the CR group, and it was suggested to be an adaptive response due to diminished fat. “Fur has properties that insulate animals to retain warmth,” Kowaltowski said. “We believe this is an adaptation present in mammals. Those that eat less have less fat, and they need more fur or body hair as thermal insulation.” Three times more blood vessels were seen in the CR mice, which increased blood flow to the skin. Differences in skin cell metabolism between groups were also noted, and in the obese mice, signs of premature aging arose. “The change in vasoconstriction helped the slimmer mice stay warm, and their skin also remained young,” Kowaltowski said.
To confirm that the extra fur was keeping the CR mice warm, the researchers shaved parts of the skin in both groups during the second stage of the study. “We shaved the mice and observed their evolution for one month,” Kowaltowski said. The researchers measured the loss of body heat and found that thicker fur did indeed help the mice retain warmth. “CR mice lost muscle mass and became lethargic,” Kowaltowski said. “This metabolic change directly resulted from the loss of body heat to the environment. The mice were unable to live well without fur.”
Additionally, both groups had their skin colored blue to examine if there was a difference in fur thickness, and the results showed that the PD mice had thinner fur compared to the CR mice. “They lost less fur, and their fur remained thick for longer. This could be an adaptation to avoid energy expenditure on growing fur,” Kowaltowski said. “These discoveries are particularly significant since they reveal not just a pronounced effect of the CR diet on the skin but also an adaptive mechanism to deal with the reduced insulation due to skin changes under conditions of lower caloric intake.”
Defending the Liver
Kowaltowski and colleagues also revealed that a restricted calorie diet might protect the liver from a heart attack (short-term ceasing of blood flow). “When we compared mice fed ad libitum with mice fed a CR diet, we found a huge difference,” Kowaltowski said. “Approximately 25% of the liver was damaged in the former group, and only 1% was damaged in the latter.” The research design suspended roughly 70% of blood flow to the liver, for 40 minutes to stimulate a heart attack. This event increased tissue calcium and created a collapse of mitochondria functioning and termination of individual liver cells.
“Calcium is important to regulate mitochondrial metabolism and increase ATP [adenosine triphosphate, the molecule that stores energy] production. However, an excessive amount of calcium causes the organelles to stop working properly. Therefore, our hypothesis was that the observed benefit of the diet was related to an increase in the capacity of the mitochondria to capture calcium from the intracellular medium without ceasing to produce energy,” said Sergio Menezes-Filho, a researcher at IQ-USP and first author of the article. To interpret the mechanisms involved and to explore the hypothesis, in vitro experiments were conducted by segregating mitochondria from both mice groups and locating it in an incubation medium with a fluorescent probe that radiated brighter as calcium levels increased. The CR mice were again fed 60% of the control mice’s intake while the control group was fed PD.
“We added a small amount of calcium to the medium, and the fluorescence intensified. As the mitochondria captured the calcium, the brightness diminished. We added a little more. When the mitochondria reached maximum calcium uptake capacity, calcium began returning to the incubation medium, and fluorescence increased even without the addition of more calcium,” Menezes-Filho explained. The researchers detected that, without functional impairment, the mitochondria in the PD mice absorbed nearly 70% less calcium and had few ATP molecules compared to the CR mice.
According to Kowaltowski, “We do not yet know why the mitochondria of the mice fed ad libitum have less ATP, but this difference is certainly associated with their calcium uptake capacity.” “When we artificially matched the ATP levels in both groups by adding ATP to control mitochondria or reducing it in CR mitochondria, calcium uptake also became equal.” The objective of the research is to explore the effects of a restricted calorie diet on different bodily tissues. “Simply telling people to eat less is not working. Obesity has become a global epidemic. We are trying to understand how CR acts in the organism and which molecules are involved to identify targets for preventing or treating diseases associated with weight gain and age,” Kowaltowski said.
**** I hesitated to post this research in the event someone may read it and use it as a reason to restrict calories. As one who has been in recovery from Anorexia Nervosa for 4 years (I struggled for almost 20 years), restricting calories for the reasons that you have will only make you more unhappy in the end. If you are struggling, please get help by clicking here or talk to a trusted friend or family member or contact me!
- Maria Fernanda Forni, Julia Peloggia, Tárcio T. Braga, Jesús Eduardo Ortega Chinchilla, Jorge Shinohara, Carlos Arturo Navas, Niels Olsen Saraiva Camara, Alicia J. Kowaltowski. Caloric Restriction Promotes Structural and Metabolic Changes in the Skin. Cell Reports, 2017; 20 (11): 2678 DOI: 10.1016/j.celrep.2017.08.052
- Sergio L. Menezes-Filho, Ignacio Amigo, Fernanda M. Prado, Natalie C. Ferreira, Marcia K. Koike, Isabella F.D. Pinto, Sayuri Miyamoto, Edna F.S. Montero, Marisa H.G. Medeiros, Alicia J. Kowaltowski. Caloric restriction protects livers from ischemia/reperfusion damage by preventing Ca 2 -induced mitochondrial permeability transition. Free Radical Biology and Medicine, 2017; 110: 219 DOI: 10.1016/j.freeradbiomed.2017.06.01
Spice up your meals (and your life)! Flavor foods by adding herbs and spices, rather than salt. You can buy fresh or dried herbs and spices. Better yet, grow your own!
Miscreant: A person who has done something wrong or unlawful
*Notice the “Mis?” It’s us women who have no limits!