Background
Nutrition plays a significant role in the human lifecycle because it provides energy, helps prevent diseases and promotes growth. The first documented evidence associating dietary restriction and aging came in 1935 in a study conducted by McCay et al that found that reducing the amount of calories consumed by 20% without causing malnourishment increased the lifespan and resistance to age related diseases in a rodent model (Colman et al., 2009; Sinclair, 2005). Typically a reduction of 10-40% of calorie intake is suggested by several authors as being effective in lengthening life, although a recent study using 30% dietary restriction was found to be ineffective in doing so in rhesus monkeys (Mattison et al., 2012).
Several hypotheses exist to explain the mechanism behind life extension due to caloric restriction (CR). Some of the earliest theories that never gained much support include the following: McCay’s original hypothesis that CR reduced the rate of growth and development and thereby increased lifespan; CR reduced metabolic rate which resulted in slower aging; and that the control animals used in the experiments eat significantly more than normal, which makes them age quicker than CR animals (Sinclair, 2005). It has since then been found that CR at any stage of life extends lifespan, and animals on CR show similar or greater metabolic rates than control animals, and the extension of life by CR is significant even when the study controls are fed a normal (not ad libitum) diet (Sinclair, 2005).
Another study proposed that CR slowed aging process by increasing resistance to hyperoxidation. As aging progressed in yeast and other animals, the presence of free radicals increased in the cells. Usually, the levels of the...
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Molin, M., Yang, J., Hanzen, S., Toledano, M., Labarre, J. and Nystrom, T. (2011). Life span extension and H2O2 resistance elicited by caloric restriction require the peroxiredoxin Tsa1 in Saccharomyces cerevisiae. Mol Cell, 43 (5): 823-833. doi:10.1016/j.molcel.2011.07.027.
Ooka, H., Segall, P. & Timiras, P. (1988). Histology and survival in age-delayed low-tryptophan-fed rats. Mech Ageing Dev, 43 (1): 79-98. doi:10.1016/0047-6374(88)90099-1.
Sinclair, D. (2005). Toward a unified theory of caloric restriction and longevity regulation. Mech Ageing Dev, 126 (9): 987-1002. doi:10.1016/j.mad.2005.03.019.
Trepanowski, J., Canale, R., Marshall, K., Kabir, M., & Bloomer, R. (2011). Impact of caloric and dietary restriction regimens on markers of health and longevity in humans and animals: a summary of available findings. Nutr J, 10: 107. doi:10.1186/1475-2891-10-107.
Recently, researchers discovered an effect of dietary restriction on the average lifespan of many organisms, including yeast, worms, flies and rodents (Bishop, N., & Guarente, L., 2007). Since most heterotrophs have similar physiological mechanisms to utilize obtained nutrition, many are also affected by diets of different nutrition levels. Thus, future experiments on other animals with similar protocols can be conducted; these experiments can be based on other measurable parameters such as the average lifespan of
...nescence is result of a combination of the antagonist pleiotropy theory, mutation accumulation theory and disposable soma theory. The three evolutionary theories claim that natural selection is weak and ineffective in sustaining reproduction, growth, survival and somatic repair during the post-reproductive years causing genetic diseases in older individuals compared to younger individuals. As biological processes shut down, older individuals develop a weak immune system that can no longer fight the deleterious genes and mutations leading to death. Moreover, the evolutionary theories paved way for new research in gerontology that led to the development of new genetic theories of aging. The definite cause of genetic diseases in older individuals is yet to be determined, but all theories suggest that senescence is an inevitable process that all organisms experience.
Whitney, E., DeBruyne, L. K., Pinna, K., & Rolfes, S. R. (2007). Nutrition through the Life Span: Childhood and Adolescence . Nutrition for health and health care (3rd ed., pp. 301-329). Belmount: Thomson/Wadsworth.
Introduction In the 16th century, rumors of the Fountain of Youth had spread like wildfire. The thought of immortality, and everlasting youth has fascinated many old, and young adventurers. Most eukaryotic organism cells are affected by a biological process known as aging. The effects of aging may include the advent of illness, disease, and ultimately death.
Resting Metabolic Rate is the basal cost of the somatic maintenance for an individual and demonstrates the unavoidable costs of maintaining bodily functions (Okada, et. al., 2011).
...ensity and Energy Costs." The American Journal of Clinical Nutrition 79.1 (2004): 6-16. Web. 22 Oct. 2013.
Nutrition is a very controversial and confusing topic. One day coffee is bad for you, but the next day it is good. Alcohol is detrimental for our health one day, but the next day red wine is the elixir of life. There are dozens of diet plans and they promise a leaner and healthier body. There is the 3-Hour Diet that involves constantly eating small portions of anything we want to eat. The latest diet craze, the Paleo Diet, is based upon eating foods that our “hunter-gatherer ancestors” would have thrived on during the Paleolithic era. And there is the Blood Type Diet, the South Beach Diet, the Macrobiotic Diet, the Mediterranean Diet, and the list goes on. But who and what should we believe? Well, there is an optimal diet for humans and the answer might surprise many.
The population in the United States as of 2009 was 307,006,550 the younger population is projected to slightly increase and eventually plateau though the older population has been steadily increasing and projected to continue on an upward trend (Vincent & Velkoff, 2010). The lack of a healthier diet is something that has been highlighted in the media for the past decade and more often than not we are seeing the effects of overindulging and the consumption of highl...
A number of factors influence the nutritional status of the elderly. First, several physiological changes impact elderly nutritional requirements. Changes in taste and smell may decrease an individual's appetite or desire for food. Gastro-intestinal motility decreases with age and may lead to constipation, decreased nutrient absorption, and a decrease in fat and protein absorption. Metabolism also slows with age; this results in a decrease of lean body mass and an increase in body fat (8). Lastly, bone mass decreases, leaving the elderly vulnerable to bone fractures from falls and osteoporosis.
The weight loss industry is a multi-billion dollar machine, perpetually fueled by not only new information, but also data that have remained true for decades. Although it is unsurprising that the human body will lose weight when it expends more calories than it consumes, new findings lead to several alternative diets and weight loss methods that gain much more popularity than the basic concept of eating less and exercising more. For
In 1985, scholars S. Boyd Eaton and Melvin J. Konner published a paper in the New England Journal of Medicine entitled ‘Paleolithic Nutrition’ that provided insight to he evolution of human nutritional requirements. Although...
The antioxidant system plays an effective role in protecting testes and other biological tissues below a critical threshold of reactive oxygen species (ROS) thus preventing testicular dysfunction (Oschsendorf, 1999). ROS mediated oxidative stress is one of crucial reasons of infertility and decreased sperm viability and increased level of free radicals may cause degener...
Most of us strive to live long, happy, and healthy lives but unfortunately Dan Buettner stated that the “life expectancy in our country is only 78.” According to his research we have the capacity to live to about 90 years old, so how did we lose 12 years out of our life? Buettner attempts to answer this question with his presentation; but let us get one thing clear, our genetics only play a small role in this. The Danish Twin Study has already recognized that our genetics only have a 10 percent role in our longevity; the other 90 percent is something in our control, so the thought of someone having to win the “genetic lottery” to live long is somewhat of a myth. The Blue Zones that Buettner mentioned in his seminar shows correlation in the way their diet and lifestyle habits helps them live to 100 with vigor.
Human beings age and they have since the beginning of time, but it remains an unsolved mystery. This enigma has remained in the dark until the recent innovations technologies have shed some light on this elusive topic; cells are the key to figuring out why humans age. Aging seems to be a relatively simple process, but the more it is studied, it is evident that it is rather complex. There are a myriad of factors that contribute to aging, but none of them can single handedly answer the question of why humans age. This age long question is at the forefront of medical research. As a result, discoveries are frequently made, which contribute to the ever growing pool of knowledge. Perhaps in time, by researching this topic, the human lifespan will lengthen and the diseases that often plague the elderly can be prevented or subdued to a greater extent. Furthermore, human aging is proven to be closely linked with illnesses such as cancer, which is why so many world class scientists are pursuing this topic. Interestingly enough, there is no universal theory that is widely accepted by the scientific community; however, there are many theories that credibly explain the science behind aging. Aging is a subject that should be studied because it directly benefits many lives, and has tangible results.
Postlethwait, John H., and Janet L. Hopson. "Body Function and Nutrition." Modern Biology. Orlando: Holt, Rinehart and Winston, 2006. Print.