Student number: 000706113-7
Title: “A calorie restricted diet has been shown to increase longevity” Critically appraise this statement in terms of current physiological evidence and Osteopathic relevance. Pay particular attention to the effect of diet on the musculoskeletal and immune systems and the Osteopathic concept of health.
“Calorie restriction” is the diminished intake of energy on a daily basis. Several laboratory experiments tested different animal species, discovering that reducing the intake of calories can decrease bodily fats and increase the life span of these species, therefore it has been also called “The Longevity diet” (Delaney and Walford, 2010). Diet is “the kinds of food that a person, animal, or community habitually eats or a special course of food to which a person restricts themselves, either to lose weight or for medical reasons” (Oxford Dictionaries, 2012). Several scientists in different experiments on animals also showed that “calorie restriction” could beneficially and non-beneficially affect other aspects of the animals health. “The Longevity Diet” is a diet that applies the “calorie restriction” method, claiming to be able to affect the anti-aging process in humans (Delaney and Walford, 2010). Experiments on humans started not many years ago, in order to understand if it is possible to recreate the same effects found in animals. Whether or not the process of ageing can be affected by low calorie restriction in humans is not yet known, due to a longer life span of humans, but it is known that to be slim decreases the the risk factors of developing “diseases such as cancer, heart disease, and diabetes” (Zamora, 2012). Several scientists, health organizations and complementary therapists are concerned as to whether a calorie restriction diet on humans could be beneficial, arguing quality of life, and possible physiological reactions of the body systems such as the musculoskeletal system and the immune system.
Scientist have been investigating for years the physiological benefits and side effects of calorie restricted diet on animals, sharing different findings. Mc Cay, et al. (1935), in an animal nutrition laboratory, providing the necessary nutrients in order to avoid malnutrition, confirmed that decreasing the daily calorie intake can extend length of life in mice. In the experiment it was also noticeable that in a selected group of mice, where growth was retarted by restricted daily intake of calories, the bones after death were thinner and more fragile. Findings of effects of calorie restriction has attracted the interest of many scientists for years. Nelson, et al. (1985) showed that limiting the food intake of female mice affected components of the reproductive system, “delaying the age-related loss of estrous cycling potential and retarding the rate of follicular depletion” (Nelson, et al., 1985). Further experiments on young mice on one hand showed that calorie restriction could possibly protect young mice from oxidative stress but on the other hand may affect the immune system delaying maturation of macrophage function, making “macrophages less responsive to lipopolysaccharide” increasing mice vulnerability to bacterial infection (Sun, et al., 2001). In order to understand more about calorie restriction diet and the potentials of it, scientists continued in the research adopting the same theory and methods on other animals. The experiment on the rhesus monkeys showed that it “improves glucoregulatory function, decreases blood pressure and blood lipids, and decreases body temperature”. It also showed that calorie restriction can affect body weight decreasing fatty tissues, but in particular the experiment showed that on young males monkeys the skeletal system and reproductive system were affected delaying the maturation of these (Mattison, et al., 2003). Furthermore Shelton, et al....