Consumption of Green Tea May Help Prevent Obesity

Grove KA, Lambert JD. Laboratory, epidemiological, and human intervention studies show that tea (Camellia sinensis) may be useful in the prevention of obesity. J Nutr. 2010;140: 446-453.

Green tea (Camellia sinensis), a popular beverage worldwide, contains large amounts of polyphenols known as catechins: (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin-3-gallate (ECG), and (-)-epigallocatechin-3-gallate (EGCG). A cup of brewed green tea contains 240-320 mg of catechins, with EGCG accounting for 30% to 50% of that amount. Green tea also contains the xanthines: caffeine, theophylline, and theobromine. It has been studied for its potential health benefits and its effects on certain chronic diseases. Obesity, which affects about 20% of U.S. adults, is a risk factor for chronic diseases (e.g., diabetes, cardiovascular diseases, and cancer). These authors summarize the literature on the potential efficacy of tea to prevent obesity.

In their review of laboratory studies, the authors focus on mechanistic data from animal model studies that have examined the effects of tea on obesity and related pathologies, including diabetes, hypercholesterolemia, and fatty liver disease. Most studies have used green tea, green tea extract (GTE), or pure EGCG in both genetic and dietary models of obesity.

One cited study reported that treatment with 7.0 µmol/g dietary EGCG for 15 weeks reduced body weight gain in male mice fed a high-fat diet compared with control mice. The treated mice had significantly lower adipose tissue weight, fasting blood glucose, fasting plasma cholesterol, and plasma alanine aminotransferase levels. The same investigators reported that short-term dietary EGCG treatment of obese mice tended to reduce body weight gain compared with high-fat-fed controls. “This treatment regimen represents a more realistic obesity-related application of EGCG or green tea supplementation, because the most likely consumers of these products would have a preexisting weight problem,” state the authors. Other cited studies, as well as one including rats fed a normal-fat diet, support these findings.

Regarding tea and genetic animal models of obesity, the authors cite a study of the efficacy of GTE in obese, leptin-deficient mice, in which there was no significant effect on body weight. The study did, however, report higher plasma high-density lipoprotein cholesterol and lower hepatic triglyceride levels in the GTE-treated mice.

Few studies have examined the interaction between tea polyphenols and exercise; however, the animal studies cited by these authors support the benefits of tea polyphenols plus exercise in reducing body weight gain.

According to the authors, the “in vivo effects of EGCG may be explained by underlying mechanisms suggested by in vitro studies of de novo lipogenesis, lipid absorption, and carbohydrate absorption and utilization.” Several studies have begun to examine the effects of tea polyphenols on fatty acid synthase. Two studies have reported that EGCG can inhibit pancreatic lipase activity, but the effective concentrations in these studies varied.

The authors cite several studies in dietary models of obesity that have examined the role of green tea-mediated modulation of glucose uptake and disposition in obesity prevention. The findings from two studies indicate that treatment with green tea can increase carbohydrate catabolism. In vitro studies have suggested that EGCG and ECG play a role in inhibiting glucose uptake in the gut.

Most studies of animal models of obesity and tea have found no significant effect of tea or tea components on energy intake. The exceptions are two studies cited by these authors: one reported a significant decrease in food intake by mice treated with Oolong tea extract compared with untreated mice, and the other study reported that 0.5% tea catechins reduced energy intake by 5.6% (the trend was not significant, however).

Regarding human studies, the authors note that there are few epidemiological studies examining the impact of tea on body weight and other obesity-related markers. More interventional studies have been conducted. In one study of healthy Japanese men, the participants consuming high-catechin tea for 12 weeks had lower body weight, waist circumference, and body fat mass compared with baseline values. In a follow-up study by the same investigators, 240 obese subjects were treated with a catechin-enriched green tea beverage or a control green tea beverage for 12 weeks. Those in the high-catechin beverage group had a significant decrease in body weight, total fat area, and visceral fat compared with baseline values. These decreases were greater than those in the low-catechin control group. The authors note that the results of studies on tea and body weight and body fat have not been “universally positive,” citing some studies that reported no significant effects of green tea consumption on body weight.

The authors further cite a study that reported a beneficial effect on weight loss and weight maintenance following weight loss with green tea consumption and a study that showed a trend toward a greater decrease in body weight with green tea and exercise, compared with exercise only. “Further studies on the interaction between tea and exercise in humans are warranted,” say the authors.

U.S. sales of green tea-based dietary supplements are increasing, partly because of the number of reports describing the potential antiobesity and other beneficial effects of tea and tea polyphenols. Green tea-based dietary supplements can potentially deliver a much higher dose of catechins than do green tea beverages. Since 1999, say the authors, 34 case studies have linked the consumption of green tea-based supplements to hepatotoxicity. Laboratory studies in animals have generally supported the supplements’ potential toxicity at high doses. “These findings suggest that caution should be exercised in the use of green tea-based dietary supplements and that further studies are needed to determine the upper limit of safety for bolus dosing with tea polyphenols as well as the underlying mechanisms of toxicity.”

The authors conclude that “laboratory studies in animals, a limited number of epidemiological studies, and small-scale human intervention studies support the hypothesis that tea and tea polyphenols have beneficial effects on weight gain, weight loss, and prevention of obesity.”

—Shari Henson

DNA robots get sophisticated by Jef Akst

Scientists are one step closer to creating molecular robots that may eventually perform complex tasks, such as building nanomolecules or delivering drugs to target tissues.

They have constructed DNA-based robots that can walk along a specific path unaided or collect various nanoparticles along an assembly line, according to two studies published this week in Nature.

“This has the feel to me of the beginning of a technology revolution,” said Andrew Ellington, an evolutionary engineer at the University of Texas at Austin and the vice president of the International Society for Nanoscale Science, Computation and Engineering, who was not involved in the research. “This work will absolutely pave the way for how you build molecular robots.”

The robots built in one study are a type of DNA walker, called a molecular “spider.” They are minute, mobile molecules that move along a flat surface made out of folded DNA, known as DNA origami, binding to and unbinding from the surface as they go.

The movement of these spiders is largely random, however, said biochemist and study co-author Milan Stojanovic of Columbia University. But together with several other big players in the nanotechnology and DNA computing fields, including Nils Walter of the University of Michigan, Erik Winfree of the California Institute of Technology, and Hao Yan of Arizona State University, Stojanovic designed a DNA origami surface that directed the DNA spider down a specified path (see video).

“You just have to start it, and it walks the path,” said chemist Kurt Gothelf, director of Centre for DNA Nanotechnology at Aarhus University in Denmark, who was not involved in the research.

The spider is fueled by the chemical interactions its single-stranded DNA “legs” have with the origami surface. In order to take a “step,” the legs first cleave a DNA strand on the surface, weakening its interaction with that part of the origami surface. This encourages the spider to move forward, pulled towards the intact surface, where its interactions are stronger. When the spider binds to a part of the surface that it is unable to cleave, it stops.

In essence, the researchers created a DNA spider that can “sense the environment,” Stojanovic said — “molecules that respond [to environmental] cues and behave [in] certain programmable ways on their own.” The next step, he added, is to increase the complexity of movements performed by such autonomous robots by compiling “a collection of rules [of] interactions between molecules and between molecules and environment.”

A fluorescence video microscopy-generated animation of a DNA spider moving along the designated path from the green-labeled start site towards the red-labeled goal. Each colored dot represents its position at a given time over the 40-minute observation period (see legend).

Credit: Nils Walter, Anthony Manzo, Nicole Michelotti and Alexander Johnson-Buck, University of Michigan

Meanwhile, Nadrian Seeman of New York University and his colleagues have designed another type of DNA walker that can collect nano-sized “cargo” as it moves. Unlike the autonomous spider, the cargo-collecting walker is controlled by single strands of DNA added by the researchers to direct the robot. These strands instruct the robot to move past an “assembly line” of three small loading devices, also made out of DNA, each containing a gold nanoparticle. Each loading device can be programmed to either donate its cargo to the passing walker, or keep it, such that the walker can receive anywhere from zero to three particles along its short (less than 200 nanometers) journey.

It’s “like an automobile assembly line,” Seeman said. “We have the option to either add or not add various components to [the walker] depending on how the devices are programmed.”

One possibility for future experiments will be to combine the advances of each of the two papers into one complex, autonomous DNA robot, said Lloyd Smith of the University of Wisconsin, who wrote an accompanying review in Nature. “It’s going to take more work to take it to that next level, [but] bringing those two things together is going to be the next step towards” a fully autonomous, functional nano-sized robot.

Another future direction, the researchers agree, would be to scale up the length of the pathways and the complexity of the behaviors. But even once greater levels of complexity are achieved, what can actually be done with the little robots is still up for debate. “This whole field,” which is still in its early stages, Smith said, “hasn’t really found the application yet.” DNA robots have thus far proven to be capable of fairly sophisticated manipulation at the nanoscale, but the practical uses of this novel technology are still a little unclear.

One popular idea is to use cargo-collecting robots to construct nanomolecules that would be difficult to make using traditional methods, because of the control they offer researchers at such a tiny scale. “The ability to hold a molecule in a particular position and hold another molecule in a defined position could open up possibilities in organic synthesis,” said Smith. Another possibility is their use in drug delivery, said biochemist William Shih of Harvard University, who did not participate in the studies. “Having a very smart robotic delivery system could do a lot better job of killing the disease tissue and do far less damage to our otherwise healthy tissue,” he explained.

But most agree that these potential applications are yet to be realized; the current work merely shows “proof of principle” that such complex behavior might one day be achieved using this technology, Seeman said.

“I think these are both really, really significant papers, not because of what we can do with [these robots] now, but because of what we can do with them in the future,” said Ellington. They are “paving the way to a future where we can do practical DNA technology.”

H. Gu, et al., “A proximity-based programmable DNA nanoscale assembly line,” Nature, 465:202-5, 2010.

K. Lund, et al., “Molecular robots guided by prescriptive landscapes,” Nature, 465:206-10, 2010

Read more: DNA robots get sophisticated – The Scientist – Magazine of the Life Sciences http://www.the-scientist.com/blog/display/57400/#ixzz0oz3tm7it

Supplements Better Than Nothing By Sheah Rarback

srarback@hotmail.com

It would be a healthier world if everyone enjoyed fruits and vegetables, but unfortunately, that is not the case. Most Americans are not eating the recommended minimum of five servings a day, and for kids the most commonly consumed “vegetable” continues to be potatoes — as in French fried.

At least once a month someone sits down with me and starts our counseling conversation with, “I don’t like vegetables and I don’t want to be told to eat them.” It is challenging. Research demonstrates a reduced risk of chronic disease with a plentiful intake of produce, so sometimes an alternative is required for the vegetable-resistant.

One option is a powdered fruit and vegetable supplement. These supplements are made by juicing and then drying fruits and veggies at low temperatures, removing water, sugar and fiber.

The companies that produce the supplements fund academic research that is published in peer-reviewed journals. The most recent was in the April 2010 online edition of Molecular Nutrition and Food Research. This double-blind study of 117 healthy men and women measured changes in inflammatory blood markers after subjects consumed either placebo or two different powdered fruit and vegetable supplements. The goal is to have low levels of inflammatory markers, since inflammation increases risk for heart disease, diabetes and cancer.

After 60 days, the subjects receiving the fruit and vegetable supplements had lower levels of inflammatory markers, as well as higher blood levels of antioxidant vitamins, when compared to the group receiving placebo.

These findings are consistent with most previous research. Similar findings have been reported for people eating fruit and vegetables or enjoying a Mediterranean vegetable soup. These results show changes in blood levels — though not less disease — in people taking supplements. Long-term studies are needed to demonstrate disease changes.

For optimal nutrition, food is always the first choice.

Any whole food pill or powdered drink is meant to be a supplement to a varied food intake. But it’s good to know there are tested alternatives available if you are not getting your five servings a day.

Sheah Rarback is a registered dietitian and on the faculty of the University of Miami Leonard M. Miller School of Medicine. Her column runs every other week.

Read more: http://www.miamiherald.com/2010/05/18/1634231/supplements-better-than-nothing.html#ixzz0oZ02TFHA

The Chicago Blackhawks are the first vitamin D team in modern professional sports history.

According to my sources, the Chicago Blackhawk team physicians began diagnosing and treating vitamin D deficiency in all Blackhawk players about 18 months ago. Apparently, most players are on 5,000 IU per day.

After many losing seasons, last year the Blackhawks came out of nowhere to get to the Western conference finals. This year they are playing even better.

According to my sources, improved athletic performance is only one of the benefits for the Blackhawk players. The other is a reduction in the number and severity of colds and flu and a reduction in the number and severity of repetitive use injuries.

Six months ago, Runner’s World published a story on vitamin D and physical performance.

Asp K. Running on D: The “sun vitamin” may boost performance, but you probably aren’t getting enough. Runners World, December 2009.

A year ago, the flagship journal of the American College of Sports Medicine was the first journal to publish the theory that vitamin D would improve athletic performance.

Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ.  Athletic performance and vitamin D. Med Sci Sports Exerc. 2009 May;41(5):1102-10.

However, readers of this newsletter first learned about it in 2007:

Effects of Resveratrol on Cerebral Blood Flow Variables and Cognitive Performance in Humans

A double-blind, placebo-controlled, crossover investigation 1, 2, 3.

David O Kennedy, Emma L Wightman, Jonathon L Reay, Georg Lietz, Edward J Okello, Anthea Wilde and Crystal F Haskell

1 From the Brain PerformanceNutrition Research Centre Northumbria University Newcastle upon Tyne United Kingdom (DOK ELW JLR AWCFH)the School of Agriculture FoodRural Development Newcastle University Newcastle upon Tyne United Kingdom (GLEJO).

2. The research described herein was internally funded, and all materials were purchased on the open market.

3.Address reprint requests and correspondence to DO Kennedy, Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle, United Kingdom NE1 8ST. E-mail: david.kennedy@unn.ac.uk.

ABSTRACT

Background: The many putative beneficial effects of the polyphenol resveratrol include an ability to bolster endogenous antioxidant defenses, modulate nitric oxide synthesis, and promote vasodilation, which thereby improves blood flow. Resveratrol may therefore modulate aspects of brain function in humans.

Objective: The current study assessed the effects of oral resveratrol on cognitive performance and localized cerebral blood flow variables in healthy human adults.

Design: In this randomized, double-blind, placebo-controlled, crossover study, 22 healthy adults received placebo and 2 doses (250 and 500 mg) of trans-resveratrol in counterbalanced order on separate days. After a 45-min resting absorption period, the participants performed a selection of cognitive tasks that activate the frontal cortex for an additional 36 min. Cerebral blood flow and hemodynamics, as indexed by concentration changes in oxygenated and deoxygenated hemoglobin, were assessed in the frontal cortex throughout the posttreatment period with the use of near-infrared spectroscopy. The presence of resveratrol and its conjugates in plasma was confirmed by HPLC after the same doses in a separate cohort (n = 9).

Results: Resveratrol administration resulted in dose-dependent increases in cerebral blood flow during task performance, as indexed by total concentrations of hemoglobin. There was also an increase in deoxyhemoglobin after both doses of resveratrol, which suggested enhanced oxygen extraction, that became apparent toward the end of the 45-min absorption phase and was sustained throughout task performance. Cognitive function was not affected. Resveratrol metabolites were present in plasma throughout the cognitive task period.

Conclusion: These results showed that single doses of orally administered resveratrol can modulate cerebral blood flow variables.

Received for publication September 9, 2009. Accepted for publication March 3, 2010.

B Vitamins Reduce Stroke, Heart Disease Deaths

Benefits of Folate and B6 Apply to Men and Women, Researchers Say

By Bill Hendrick
WebMD Health News

Reviewed by Laura J. Martin, MD

April 15, 2010 — Foods rich in B vitamins such as folate and B-6 may reduce the risk of death from stroke and heart problems, Japanese researchers say.

Their study looked at the effects of B vitamins on men and women separately, but findings suggest that foods containing the B vitamins might benefit people of both sexes.

Their primary findings:

* Folate and B-6 may reduce the risk of heart failure in men.
* The same vitamins seem to reduce the risk of death from stroke and heart disease in women.

Sources of folate include vegetables, fruits, whole or enriched grains, fortified cereals, beans, and legumes. B-6 sources include fish, vegetables, liver, meats, whole grains, and fortified cereals.
Vitamin B6, Folate Fight Heart Disease

The researchers examined data from 23,119 men and 35,611 women between ages 40 and 79 who completed questionnaires about dietary habits as part of the Japan Collaborative Cohort Study.

They found that at a median of 14 years follow-up, 986 people had died from stroke, 424 from heart disease, and 2,087 from all diseases related to the cardiovascular system.

Patients were divided into five groups based on their intake of folate, vitamin B6, and vitamin B12. Researchers compared people with the diets lowest and highest for each nutrient and found that higher consumption of folate and B6 was associated with significantly fewer deaths from heart failure in men. In women, they detected significantly fewer deaths from stroke, heart disease, and total cardiovascular deaths.

Vitamin B12 was not found to be associated with a reduced risk of mortality.

The protective effects of folate and vitamin B6 did not change even when researchers made adjustments for the presence of cardiovascular factors or when people taking supplements were eliminated from the analysis.

The researchers say B6 and folate may fight cardiovascular disease by lowering levels of homocysteine, an amino acid in the blood that is affected by diet, but also heredity.

The researchers say the findings on the value of B vitamins were consistent with studies in North America and Europe. Homocysteine is believed to cause damage to the inner linings of arteries, promoting blood clots.
B Vitamins: More Research Needed

Hiroyasu Iso, MD, professor of public health at Osaka University and one of the study authors, says in a news release that people in Japan need to increase consumption of foods containing folate and vitamin B6.

The researchers say the correlation between intake of folate and B vitamins with cardiovascular disease is controversial and that evidence of benefits has been limited to Asian populations. Given their findings, the researchers say there is an urgent need for more research aimed at replicating the results of their study in different populations.

The study is published in the April issue of Stroke: Journal of the American Heart Association.

The Institute of Medicine (IOM), the health arm in the U.S. of the National Academy of Sciences, recommends 1.3 to 1.7 milligrams of vitamin B6 per day, depending on age and sex. The IOM says extremely high-dose folate supplements should be avoided and recommends adult intake of 400 micrograms daily.

D is for deficiency

Less exposure to sunlight leaves many Americans lacking key vitamin
By Gee Loeb Sharp McClatchy News Service
Posted: 03/28/2010 11:51:12 PM MDT

We have evolved into a society sorely lacking in vitamin D.

Countless research hours have been conducted to help spread the word on its benefits, debunk the myths associated with it and lay out a simple set of guidelines to follow for optimum usage.

According to Dr. Jay Mattingly, a full-time anesthesiologist working for University of Tennessee Medical Group who recently became certified by the American Board of Anti-Aging, more than 1 billion people worldwide are deficient in vitamin D.

Actually, vitamin D isn`t a vitamin at all, but a hormone with receptors in all organs of the body, including the brain, heart, breast, colon, prostate and pancreas.

According to the Vitamin D Council, vitamin D deficiency has been implicated as a major factor in the pathology of at least 17 varieties of cancer, as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis and more.

A major reason for our evolutionary decrease in vitamin D is our avoidance of the sun`s rays. Ask any vitamin D enthusiast about the sun`s ultraviolet rays and you`ll hear about its benefits, and how the skin produces about 10,000 units of vitamin D in response to 20 to 30 minutes of summer sun exposure.

Agnes Green, owner of The Healer Within wellness center in Portland, Ore., and a functional nutritionist, says we lack enough exposure to the sun to allow our bodies to produce sufficient amounts of vitamin D.

“We`re involved in more indoor activities,” Green says. “We are on our computers or watching TV, especially children and young adults who play video games. Our sun supply is cut down by diminished exposure, and what little time we do spend outdoors is rendered useless by the UV protection we lather over ourselves. … UV sunglasses also rob us of vitamin D production. … Unless you live directly under a hole in the ozone layer, you have no need for this militant sun protection. On the contrary, you`re doing yourself and your kids a disservice.”

How much vitamin D should you take? Though the U.S. government recently increased its daily recommendation to 400 IU daily, other doctors and health care professionals recommend a much higher dosage.

“The dose I recommend is 800 to 1,000 IU daily, though many of my patients with osteoporosis are still deficient at that dosage,” says Dr. Catherine Robilio Womack, internist and associate professor of medicine at the University of Tennessee Health Science Center. “Many osteoporosis patients need 1,000 to 2,000 IU daily or a bigger weekly dosage. It doesn`t matter so much what you take daily; it is the cumulative dose that is important.”

Vitamin D in pill form can be toxic when taken in excess, so it is always important to have your levels checked after increasing your intake.

According to Mattingly, everyone needs differing amounts of vitamin D, just like anything else, but the average person needs 5,000 IU daily.

“There are no adequate dietary sources of vitamin D,” Mattingly says. “The average multi-vitamin has only 400 IU and an 8 oz. glass of milk supplies only 100 IU. Even supplements like Caltrate have only 600 to 800 IU.”

Vitamin and calcium supplements may reduce breast cancer risk

Public release date: 18-Apr-2010
http://www.eurekalert.org/pub_releases/2010-04/aafc-vac041210.php

Contact: Jeremy Moore
jeremy.moore@aacr.org
267-646-0557
American Association for Cancer Research

Vitamin and calcium supplements may reduce breast cancer risk

WASHINGTON, D.C. — Vitamins and calcium supplements appear to reduce the risk of breast cancer, according to findings presented at the American Association for Cancer Research 101st Annual Meeting 2010.

“It is not an immediate effect. You don’t take a vitamin today and your breast cancer risk is reduced tomorrow,” said Jaime Matta, Ph.D., professor in the Ponce School of Medicine in Puerto Rico. “However, we did see a long-term effect in terms of breast cancer reduction.”

Matta said the findings suggest that the calcium supplements are acting to enhance DNA repair capacity, a complex biological process involving more than 200 proteins that, if disrupted, can lead to cancer.

“This process involves at least five separate pathways and is critical for maintaining genomic stability,” said Matta. “When the DNA is not repaired, it leads to mutation that leads to cancer.”

The study included 268 women with breast cancer and 457 healthy controls. Women were more likely to have breast cancer if they were older, had a family history of breast cancer, had no history of breastfeeding and had lower DNA repair capacity.

Vitamin supplements appeared to reduce the risk of breast cancer by about 30 percent. Calcium supplements reduced the risk of breast cancer by 40 percent. After controlling for the level of DNA repair capacity, calcium supplements were no longer as protective, but the link between vitamin supplements and breast cancer reduction remained.

“We’re not talking about mega doses of these vitamins and calcium supplements, so this is definitely one way to reduce risk,” said Matta.

Women who eat foods with high glycemic index may be at greater risk for heart disease

Public release date: 12-Apr-2010
http://www.eurekalert.org/pub_releases/2010-04/jaaj-wwe040810.php

Contact: Vittorio Krogh, M.D., M.S.
vittorio.krogh@istitutotumori.mi.it
JAMA and Archives Journals

Women who eat foods with high glycemic index may be at greater risk for heart disease

Consuming carbohydrates with high glycemic index—an indicator of how quickly a food affects blood glucose levels—appears to be associated with the risk of coronary heart disease in women but not men, according to a report in the April 12 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

High-carbohydrate diets increase the levels of blood glucose and of harmful blood fats known as triglycerides while reducing levels of protective HDL or “good” cholesterol, thereby increasing heart disease risk, according to background information in the article. However, not all carbohydrates have the same effect on blood glucose levels. The glycemic index is a measure of how much a food raises blood glucose levels compared with the same amount of glucose or white bread. A related measure, the glycemic load, is calculated based on the glycemic index of a given food and also on the total amount of carbohydrates it contains.

Sabina Sieri, Ph.D., of Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, and colleagues studied 47,749 Italian adults—15,171 men and 32,578 women—who completed dietary questionnaires. Based on their responses, the researchers calculated their overall carbohydrate intakes as well as the average glycemic index of the foods they consumed and the glycemic loads of their diets. During a median (midpoint) of 7.9 years of follow-up, 463 participants (158 women and 305 men) developed coronary heart disease.

The one-fourth of women who consumed the most carbohydrates overall had approximately twice the risk of heart disease as the one-fourth who consumed the least. When these carbohydrates were separated into high– and low–glycemic index categories, increased intake from high–glycemic index foods was significantly associated with greater risk of coronary heart disease, whereas low–glycemic index carbohydrates were not. “Thus, a high consumption of carbohydrates from high–glycemic index foods, rather than the overall quantity of carbohydrates consumed, appears to influence the risk of developing coronary heart disease,” the authors write.

The one-fourth of women whose diet had the highest glycemic load had 2.24 times the risk of heart disease compared with the one-fourth of women with the lowest glycemic load.

Overall carbohydrate intake, glycemic index and glycemic load were not associated with heart disease risk in men. This could be because the adverse changes associated with carbohydrate intake, including triglyceride levels, are stronger risk factors for heart disease in women than in men, the authors note.

“We tentatively suggest that the adverse effects of a high glycemic diet in women are mediated by sex-related differences in lipoprotein and glucose metabolism, but further prospective studies are required to verify a lack of association of a high dietary glycemic load with cardiovascular disease in men,” they conclude.

How Many Calories Per Day for the Elderly?

All foods contain calories that provide the body with energy necessary for human function. Reading, sitting quietly, the pumping action of the heart and normal breathing all require calories. Caloric needs are greatest for young adults. As we age and our activity levels and muscle mass decrease, so does the amount of calories we need to consume.

Elderly Energy Needs

1. After we reach 50, recommended nutrient intake drops by 5 percent for each decade we age due to a decrease in the body’s active cells and loss of muscle tissue.

But determining ideal caloric intake for the elderly is not much different than calculating it for younger adults. It does, however, require some basic arithmetic.

The Harris-Benedict equation is a formula that determines basal metabolic rate then factors in physical activity to derive at the recommended daily caloric intake. The basal metabolic rate is the amount of calories burned at rest.

The formula to determine metabolic rate varies for elderly men and women.

This is the formula for women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) — (4.7 x age in years).
And here’s the formula for men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) — (6.8 x age in years)

Once the basal metabolic rate has been determined, you need to factor in activity levels. To account for activity, you multiply the BMR by a figure representing the appropriate activity level. For the elderly individual who participates in little or no activity, multiply the BMR by 1.2. For the person who is lightly active or participates in sports one to three times per week, multiply the BMR by 1.375. The moderately active elderly individual who exercises or participates in sports three to five days per week should multiply his or her BMR by 1.55. The exerciser who works out hard six to seven days per week should multiply the BMR by 1.725.

An example might be useful. Here are the step-by-step calculations you would use to determine the ideal caloric intake for a 79-year-old female who is 66 inches tall, weighs 130 pounds and who exercises one to three times per week.

First, you would determine basal metabolic rate:

BMR = 655 + (4.35 x 130) + (4.7 x 66) — (4.7 x 79)
BMR = 655 + (565.5) + (310.2) — (371.3)
BMR = 655 + 504.4
BMR = 1,159.4 Calories
Then, you would you would account for her activity level. This elderly woman participates in activity one to three times per week; therefore, her BMR is multiplied by 1.375.
Activity level = 1,159.4 x 1.375
Activity level = 1,594.175 calories

Therefore, the women should ideally consume about 1,595 calories per day.

Food Pyramids as a Guide

2. The U.S. Department of Agriculture created an interactive tool, mypyramid.gov, to address individual dietary needs for the American population. At the mypyramid.gov site, individuals can enter personal information such as age, weight, height and activity level to determine caloric needs.

How the elderly get their calories also is important.

Researchers at Tufts University have revised the food guide pyramid for the elderly to focus on specific nutrient needs.
A healthy diet for the elderly consists of three or more daily servings of brightly colored vegetables, two or more servings of deeply colored fruits, six or more servings of whole and fortified grains, three or more servings of low-fat dairy and two or more servings of protein-rich foods such as lean meats, eggs and legumes.

Hydration

3. Hydration is also a concern for the elderly due to their decreased sense of thirst. An adequate consumption of water is eight 8-ounce glasses of water, fruit juice, tea or coffee per day.

Source: www.ehow.com/ livestrong.com

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