A calorie-restricted diet has already been associated with a long list of health benefits, from increasing lifespan and reducing insulin resistance to helping to fight cancer. By cutting back on calories, you encourage your body to access stored fat to burn for energy. A calorie deficit will not only improve your body fat composition, but can also reduce organ damage, improve tolerance to metabolic stresses, and even lengthen lifespan. But the effects of calorie restriction on skin has been understudied.
However, researchers in Brazil have found changes to the skin and hair of calorie-restricted mice, stimulating fur growth, increasing blood flow, and altering cell metabolism to increase energy efficiency. The research, published in the Cell journal, indicates that calorie restriction may promote “extensive skin and fur remodeling” that may lead to better understanding of mechanisms that could be applied to help aging humans.
The scientists subjected mice to a calorie-restricted diet for six months. This time frame gave them enough time to observe some changes to their physiology, including a decrease in overall size and less body mass gain than the mice that ate however much they wanted.
The mice on a calorie-restricted diet for six months showed thicker, more even, and longer back fur than the control group mice.
The calorie-restricted mice had a significantly higher number of long, straight, smooth guard hairs than their counterparts. Also, the guard hairs were longer and thicker, and they trapped body heat more efficiently—keeping the animal warmer.
The skin also showed some interesting effects of the calorie restricted diet. The mice on the restricted diet had a higher number of interfollicular stem cells, as well as an increase in the stem cells in their hair follicles. The increase in both types of stem cells played a factor in the rapid hair growth. When the researchers trimmed the mice’s fur, the calorie-restricted group had nearly twice the re-growth rate, and their hair shaft loss was much lower.
The epidermis was also affected by the calorie restricted diet. Epidermal thickness was more than twice that of the well-fed mice, but there was only half the adipose, fat, tissue present. The stem cells responsible for transporting nutrients through the layers of skin to the hair follicles also increased in the calorie-restricted diet.
“These findings are especially significant since they unveil not only a striking effect of calorie restriction on the skin but also an adaptive mechanism to cope with reduced insulation derived from skin changes under conditions of reduced caloric intake,” says senior author Alicia Kowaltowski, a professor at the University of Sao Paulo’s Institute of Chemistry. “I think the research community will be interested in thinking about the skin and fur as integral players in metabolic responses and control.”
Her group now wants to focus on understanding the signals involved in promoting the changes in skin they observed with calorie restriction. Kowaltowski says that if we understand these pathways, we could uncover targets to keep the skin healthy during aging.
1. Forni, Maria Fernanda, Julia Peloggia, Tárcio T. Braga, Jesús Eduardo Ortega Chinchilla, Jorge Shinohara, Carlos Arturo Navas, Niels Olsen Saraiva Camara, and Alicia J. Kowaltowski. “Caloric Restriction Promotes Structural and Metabolic Changes in the Skin.” Cell Reports 20, no. 11 (September 12, 2017): 2678–92. doi:10.1016/j.celrep.2017.08.052.