Two Calorie Restriction Studies
Two calorie restriction studies have recently been published--one showing benefits for humans, and the other showing benefits only for a strain of obese mice.
The first study is small, following 50 men and women over the age of 50 years for three months. People were divided into three dietary groups: 30% calorie restriction, changing 20% of fats to unsaturated while maintaining customary calories, and no change.
During memory tests, only the group reducing calories showed a memory improvement, with a 20% increase in memory (Witte AV, Caloric restriction improves memory in elderly humans, Proceedings of the National Academy of Sciences, January 2009).
The second antiaging health study tested two strains of mice, one that gets fat with an unrestricted diet and another that stays slim with an unrestricted diet.
By measuring oxygen consumption, the researchers found benefits only for the obese strain (Sohal RS, Life span extension in mice by food restriction depends on an energy imbalance, Journal of Nutrition, January 2009).
While these studies may offer hope for older or overweight people, they are too preliminary to suggest that calorie restriction has no benefits for others.
Calorie restriction has been studied for over 75 years with results showing a wide range of health benefits.
People interested in calorie restriction may want to try daily green tea at 0-2 calories per cup.
Antiaging Health: Anti-aging Benefits Seen In Blood Tests
Calorie restriction with optimal nutrition has proven to be the most powerful anti-aging diet for over 70 years.
Now a new study compares the blood samples of people participating in two forms of calorie-restricted diets: alternate day fasting, and 25% daily calorie restriction. The blood was tested by using it to culture human hepatoma or liver cancer cells, an easy way to see genetic changes.
For the alternate day fasting group, blood samples were collected at the beginning (baseline) and at the end of 21 days of a 12-hour fasting/12-hour eating routine.
For the calorie restricted group, blood samples were collected at baseline and after 3 months of 25% restricted dieting.
All test blood samples were collected after 12 hours of fasting.
Results showed that blood from alternate day fasting participants created a 20% increase in Sirt1 protein associated with anti-aging effects. It also showed decreased cellular proliferation and increased heat stress resistance.
Blood from calorie restricted participants showed a 17% increase in Sirt1 protein levels, as well as a significant 30% increase in PGC-1alpha mRNA levels, both indicators of anti-aging (Allard JS, In vitro cellular adaptations of indicators of longevity in response to treatment with serum collected from humans on calorie restricted diets, PLoS ONE, September 2008).
In other words, these two techniques of calorie restriction in humans both produce blood that can change the gene expression of other human cells and create anti-aging benefits.
Got any areas of your body that could use a little calorie restriction for your own antiaging health?
By the way, green tea has only 0-2 calories per cup!
Antiaging Health: Calorie Restriction Protects Aging Muscles
A serious problem during "normal" aging is muscle loss. Not only does loss of muscle tissue lead to less mobility and self-sufficiency, but cardiovascular and vascular systems also lose vigor, leading to heart disease or stroke.
Lifetime exercise can help prevent muscle loss, but now researchers have found that calorie restriction acts directly to protect muscle tissue over time.
A research team at the University of Florida studied a group of rats on a normal ad lib (eat at will) diet and a 60% calorie-restricted diet for over 3 years.
Animals on a normal ad lib diet showed twice as much iron accumulation in muscles in the last third of their lives compared to animals on calorie restriction.
This accumulated iron was concentrated in pockets of muscle mitochondria where it easily oxidized and damaged mitochondrial RNA, leading to increased muscle cell death.
Animals on calorie restricted diets were protected from abnormal iron-related muscle damage (Leeuwenburgh C, Iron accumulation with age, oxidative stress and functional decline, PLoS, August 2008).
Antiaging Health: Long Life, Exercise, And Calories
Regular exercise is necessary to maintain quality of life and can increase the average life span.
But only an anti-aging diet of calorie restriction with optimal nutrition increases the maximum life span.
Now, a new antiaging health study compares sedentary, treadmill exercised, and calorie restricted animals.
After 24 weeks, the sedentary mice who ate as much as they wanted were the fattest. Exercised mice had higher heat shock protein levels, but did not accumulate DNA damage from the oxidative stress.
The lowest levels of insulin and IGF-1 were only found in the 18% calorie restricted mice, leading the researchers to conclude that exercise may not be able to create the same hormonal and metabolic response that calorie restriction creates in the body (Huffman DM, Effect of exercise and calorie restriction on biomarkers of aging in mice, American Journal of Physiology, Regulatory, Integrative, and Comparative Physiology, May 2008).
Antiaging Health: Baby Boomer Burden?
In a couple of years, Baby Boomers will start to enter the over-65 age group.
And there aren't enough doctors to take care of them.
A new study evaluated the expected need for geriatric specialists over the next few decades.
Combining the number of Baby Boomers with an increased life expectancy for many of them, the actual number of over-65 geriatric people is expected to double. At the same time, the number of geriatric specialists is decreasing.
Since older people have more complex health problems than middle-aged patients, this study strongly recommended facilitating an increase in geriatric specialists (John Rowe, Gerontological Society of America and Institute of Medicine, April 2008).
Baby Boomers and healthy adults can help relieve this future burden by having an antiaging health program including maintaining a healthy weight, avoiding addictions, exercising regularly, using common sense disease prevention, and maintaining healthy habits like drinking green tea daily, if appropriate.
Learn more about anti-aging here
Antiaging Health: How Calorie Restriction Helps Adult Brains
A new study demonstrates one way that calorie restriction with optimal nutrition can help protect the brain from damage.
Researchers put adult rats on short-term calorie restricted diets for 7-10 weeks. During this time, there was no detrimental effect on neuronal function as measured by long-term potentiation.
Then they challenged the hippocampal areas of the rats' brains with kainic acid, a polyamine similar to glutamate that excites brain cells into toxic reactions.
Rats that had been on calorie restriction had almost twice the recovery to normal brain cell function as did a control group that had been eating freely (Youssef FF, Adult-onset calorie restriction attenuates kainic acid excitotoxicity in the rat hippocampal slice, Neuroscience Letters January 2008).
The hippocampus portion of the brain is important in antiaging health research because of its association with language, memory, nerve regeneration, and life support functions.
Antiaging Health: Managing Calorie Restriction
Many people are trying to adopt a lifestyle habit of calorie restriction without malnutrition for anti-aging benefits.
While understanding the concept is easy, putting it into daily practice is more difficult.
A new study shows that modified alternate day fasting may provide a portion of the antiaging health benefits that daily calorie restriction offers.
Researchers separated mice into five groups. One group received 25% fewer calories every day. Three groups received alternate day fasting--one day free eating, one day fasting at 75% fewer calories, 85% fewer calories, or 100% fewer calories (total fasting). The last group received free eating.
Results showed that skin cell, spleen cell, and mammary cell proliferation was decreased significantly for the 25% daily restricted group, and the 85% and 100% alternate day fasting groups. Insulin-like growth factor-1 was only reduced for the 25% daily restricted and the 100% alternate day fasting groups.
Body weight was only reduced for the 25% daily restricted group (Varady KA, Modified alternate-day fasting regimens reduce cell proliferation rates to a similar extent as daily calorie restriction in mice, FASEB J, Jan 2008)
Cell proliferation reduction and insulin-like growth factor-1 reduction are characteristic of lifetime calorie restriction without malnutrition and are involved in some of the anti-aging benefits.
If you're working on reducing unnecessary calories, here's some calorie counting tips.
And remember, green tea has only 0-2 calories per cup.
Antiaging Health: Theory Of Anti-Aging
In 1934, when Dr. McCay discovered that calorie restriction dramatically increased the maximum life span in rats, no existing theory could account for his results.
In the last 74 years, his results have been confirmed in many species, including single-celled organisms, yeast, spiders, fish, mice, hamsters, dogs, and now primates.
But theories of aging and anti-aging have still been unable to account for the successful life span increase with calorie restriction optimal nutrition.
The growth retardation/small size theory, biological clock hypothesis, low body fat theory, low metabolic rate theory, glucose-insulin hypothesis, and growth hormone hypothesis have so far proven inadequate to explain the anti-aging results of calorie restriction.
It is also unlikely that the oxidative damage/free radical theories will account for all the separate anti-aging effects of healthy calorie restriction.
It is possible that the concept of hormesis could encompass all the life-extending, anti-aging changes from calorie restriction.
Hormesis states that small amounts of stress can activate the body's natural defense systems. It is a concept used to explain the results of homeopathic remedies and exercise benefits from pulsed intensity workouts.
Basically, it says controlled stress is good for you.
Hormetic theory and other theories related to calorie restriction anti-aging are reviewed by Dr. Masoro, a pioneer researcher into calorie restriction, in Mechanisms of Ageing and Development, September, 2005, and Interdisciplinary Topics in Gerontology, 35, 2007.
Antiaging Health: Independent At 100 Years
How do they do it?
Are people who live longer than 100 years, those fabulous centenarians, just lucky from birth?
Now a new study of centenarians is helping those of us who are younger understand how centenarians achieve their longevity success.
Researchers in Boston, Massachusetts, examined 739 men and women over the age of 100. Approximately 30% of the centenarians had age-related diseases for over 15 years. These diseases included chronic obstructive pulmonary disease (COPD), dementia, diabetes, heart disease, stroke, hypertension, osteoporosis, and Parkinson's disease.
However, 72% of the men and 34% of the women were still independently active according to the Barthel Activities of Daily Living Index (Terry DF, Archives of Internal Medicine, 2008).
Researchers found that simply having a disease (morbidity) could be separated from disability, and that centenarians manage to postpone both disease and disability.
Important factors in lowering the risk of both disease and disability include early detection by regular consultations with a health care provider, daily exercise, stopping smoking, and a healthy diet (check out this research on anti-aging diets.
Adding healthy lifestyle choices that are safe and may reduce the risk of a wide variety of diseases, such as daily green tea, could also help if appropriate to the individual health condition.
Antiaging Health: Counting Calories Improves Muscles
Our bodies need daily exercise to keep our muscles strong and healthy. But people who are aging may experience an additional loss of muscle mass and strength called sarcopenia.
Now researchers have observed that an anti-aging diet using calorie restriction helps protect against muscle loss from age-related sarcopenia.
Two cellular factors that seem to have a primary association with sarcopenia are mitochondrial health and cellular signaling systems related to apoptosis or muscle cell death.
Both calorie restriction with optimal nutrition and a daily fitness program seem to help prevent malfunction with mitochondria and apoptotic cellular signaling. The result is greater preservation of muscle mass.
For aging humans, this could mean more mobility and self-sufficiency for a longer period of time.
These reviewed studies are considered preliminary (Marzetti E, Free Radical Biology Medicine, 2008).
Here's more fitness program benefits.
Antiaging Health: Primates Benefit From Calorie Restriction
One of the concerns about an anti-aging diet through calorie restriction with optimal nutrition, has been using research data from short-lived species.
After the calorie restriction lifespan extension discovery of Dr. McCay, researchers (Dr. Roy Walford) decided that using short-lived species would provide the greatest amount of information within the shortest amount of time. The results showed consistently prolonged youth and health across many species, with only a couple of exceptions (brown trout, housefly results were inconsistent).
But a legitimate question remains. Will these results prove true with species that live for a longer time?
To answer that question, researchers began studies with primates several decades ago. A recent review of primate calorie restriction research shows that results from primates are comparable to rodent studies so far.
Rhesus monkeys at 30% fewer calories are compared to ad lib monkeys (ad lib animals can eat all they want). The calorie-restricted monkeys show greater antiaging health by avoiding many diseases, show biomarkers (blood and other laboratory tests) that indicate protection against disease, and are aging more slowly (Ingram DK, Neuroscience, 2007).
Of course, it will be many more decades before primate research results are considered conclusive.
Don't want to wait that long?
People who are interested in exploring calorie restriction benefits for themselves can learn dietary strategies throughout Green Tea Health News.
For example, a cup of green tea tops out at 2 calories and five cups daily is less than 10 calories. Green tea offers delicious, soothing, gentle energy loaded with life-protecting antioxidants and almost no calories. Available world-wide, it's a great choice for a positive lifestyle change.
People who have health conditions should consult with their health care provider before making dietary changes.
Antiaging Health: It's A Longer Dog's Life
A recent review summarized over two decades of research testing calorie restriction diets for dogs.
The median lifespan of the calorie-restricted test animals was almost two years longer than for dogs that ate all they wanted.
Late life diseases like osteoporosis were postponed with the test animals. With all the dogs, once the muscle mass diminished and stored static fat increased, death within one year became strongly predictable.
Animals with larger fat masses also showed insulin resistance which was independently associated with chronic diseases and lowered lifespan.
The studies began when the dogs were eight weeks old and there were no negative effects on skeletal maturation.
The animals were matched pairs and received the same diet except for a 25% reduction in calories for the test groups (Lawler DF, British Journal Nutrition, 2007).
Most calorie restriction studies with rodents have used 30% to 50% calorie restriction with optimal nutrition diets.
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This page last updated by Sharon Jones.
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