But many blacks, elderly aren't getting enough, study suggests
HealthDay Reporter
(HealthDay News) -- Forget the fiber. You may be able to fend off colon, breast or ovarian cancer by simply getting enough vitamin D, a new analysis of previous research suggests.
But if you're overweight, black, older or live in the Northeast, there's a good chance you're not getting enough vitamin D in your diet, said study co-author Cedric F. Garland, a professor of medicine at the University of California, San Diego.
And that could put you at risk, he added.
Garland and his colleagues examined 63 previous studies that looked at possible links between several types of cancer and vitamin D deficiency. Their study appears in the current online edition of the American Journal of Public Health, and will appear in the February 2006 print edition.
According to the researchers, the studies -- from 1966 to 2004 -- suggest that vitamin D can reduce the risk of colon, breast and ovarian cancers, among others, by as much as 50 percent.
However, the debate over the value of vitamin D isn't over, said Lona Sandon, a spokeswoman for the American Dietetic Association.
The new research suggests a link between too little vitamin D and cancer, but doesn't confirm it, she said.
Why might vitamin D have a protective effect in the first place?
"Vitamin D's main role is to keep the balance of calcium and phosphorous in the blood, which helps keep bones strong," Sandon said. "However, a lesser-known role is how it regulates cell growth and determines what a cell becomes. A vitamin D deficiency may allow cells to become cancerous rather than becoming healthy cells."
The study authors found that several groups of people had low levels of vitamin D. Residents of the Northeast made up one group, perhaps because they miss out on vitamin D that's absorbed during exposure to the sun, Garland said. The obese had low levels, too, perhaps because they have trouble metabolizing vitamin D through their fatty tissues.
Other groups with low vitamin D levels include blacks -- they're five times more likely to be deficient than whites -- and the elderly, the researchers found.
"As we age, we lose the ability to convert vitamin D into its usable form, so elderly people are at greater risk," Sandon said.
And the increased skin pigmentation of blacks reduces their ability to synthesize vitamin D, the researchers said.
So what to do? The experts are divided on that answer.
Garland urges everyone to consume 1,000 International Units (IUs) a day of the active form of Vitamin D -- also known by its human form, Vitamin D3 -- which comes in yogurt, cheese, orange juice, fatty fish and milk.
By contrast, Sandon said adults aged 19 to 50 should get 200 IUs a day, equivalent to two glasses of fortified milk. People aged 50 to 70 should get 400 IUs, she said, while those 71 and older should get 700. But she acknowledged that "it is difficult to get this much vitamin D from food alone.
She recommends that people take brief walks during lunch to get exposure to vitamin D from the sun.
But what about seniors or those who refuse to change their diets or their habits? "A supplement of the active form of vitamin D would be the next option for those who just will not make even small changes, and likely to be a must in people over 50," Sandon said.
--By Randy Dotinga
More information
To learn more about vitamin D, visit the National Institutes of Health
Tuesday, January 10, 2006
Sunday, January 08, 2006
Antioxidant-Rich Foods Preserve Vision
Study found they cut risk of age-related macular degeneration
HealthDay Reporter
(HealthDay News) -- Mom was right, at least about carrots and eyesight.
Eating carrots, which are rich in the nutrient beta carotene, as well as foods containing the antioxidant vitamins C and E and zinc, results in a significantly reduced risk of age-related macular degeneration in elderly people, a new Dutch study has found.
"It's great news," said Dr. Robert Cykiert, a professor of ophthalmology at New York University School of Medicine. "It's an excellent way to prevent a condition that's difficult to treat."
The findings appear in the Dec. 28 issue of the Journal of the American Medical Association.
Macular degeneration, a progressive eye condition, attacks the macula, where your sharpest central vision occurs. The condition affects 15 million people in the United States alone, and is the most common cause of irreversible blindness in developed countries.
The disease rarely causes complete blindness, but it robs you of all but your outermost, peripheral vision, leaving just dim images or black holes at the center of your vision.
The incidence of age-related macular degeneration (AMD) increases sharply with age, and its prevalence is expected to rise.
"We're expecting to see more AMD because the Baby Boomer generation is approaching that age, and everyone is living longer," Cykiert said. "It potentially could be devastating."
Currently, age-related macular degeneration affects 11.5 percent of white people over the age of 80. The number of people severely disabled by late-stage AMD in the United States is expected to increase by more than 50 percent, to 3 million, in the next 20 years.
Previous studies evaluating antioxidants had shown conflicting results, with one major study showing that raising levels of beta carotene, vitamins C and E and zinc in people with early or single-eye late AMD resulted in a 25 percent reduction in the progression to late AMD over five years.
The new study sought to evaluate whether antioxidants as present in normal foods could play a role in preventing age-related macular degeneration.
At the beginning of the study, 5,836 people living in Rotterdam, the Netherlands, who were at risk of AMD were identified. Of these, 4,170 participated in the eight-year follow-up.
Participants were asked to fill out food questionnaires and were given periodic eye exams.
People who consumed higher levels of vitamin E and zinc had about a 10 percent lower risk of developing age-related macular degeneration. Those who had an above-average intake of all four nutrients (beta carotene, vitamin C, vitamin E and zinc) had a 35 percent reduced risk of AMD. Adding nutritional supplements to people who already had a high intake of these nutrients did not change the results.
People who consumed below-average amounts of these nutrients had a 20 percent increased risk of developing AMD, the study said.
Vitamin E is found in whole grains, vegetable oil, eggs and nuts; zinc in meat, poultry, fish, whole grains and dairy products; beta carotene in vegetables such as carrots, kale and spinach; and vitamin C in citrus fruits and juices, green peppers, broccoli and potatoes.
Although the study results still need to be confirmed, they do add valuable information, the researchers said.
"Up to now, we thought you needed to take heavy doses of supplements to achieve the benefits of these antioxidants," Cykiert said. "Now we know that if you eat a diet rich in these substances you achieve the same benefit, and possibly even more."
"If people start eating these things now, it may be a way to prevent problems 10, 15 or 20 years later," he added.
--By Amanda Gardner
More information
To learn more about age-related eye disease, visit the National Eye Institute
HealthDay Reporter
(HealthDay News) -- Mom was right, at least about carrots and eyesight.
Eating carrots, which are rich in the nutrient beta carotene, as well as foods containing the antioxidant vitamins C and E and zinc, results in a significantly reduced risk of age-related macular degeneration in elderly people, a new Dutch study has found.
"It's great news," said Dr. Robert Cykiert, a professor of ophthalmology at New York University School of Medicine. "It's an excellent way to prevent a condition that's difficult to treat."
The findings appear in the Dec. 28 issue of the Journal of the American Medical Association.
Macular degeneration, a progressive eye condition, attacks the macula, where your sharpest central vision occurs. The condition affects 15 million people in the United States alone, and is the most common cause of irreversible blindness in developed countries.
The disease rarely causes complete blindness, but it robs you of all but your outermost, peripheral vision, leaving just dim images or black holes at the center of your vision.
The incidence of age-related macular degeneration (AMD) increases sharply with age, and its prevalence is expected to rise.
"We're expecting to see more AMD because the Baby Boomer generation is approaching that age, and everyone is living longer," Cykiert said. "It potentially could be devastating."
Currently, age-related macular degeneration affects 11.5 percent of white people over the age of 80. The number of people severely disabled by late-stage AMD in the United States is expected to increase by more than 50 percent, to 3 million, in the next 20 years.
Previous studies evaluating antioxidants had shown conflicting results, with one major study showing that raising levels of beta carotene, vitamins C and E and zinc in people with early or single-eye late AMD resulted in a 25 percent reduction in the progression to late AMD over five years.
The new study sought to evaluate whether antioxidants as present in normal foods could play a role in preventing age-related macular degeneration.
At the beginning of the study, 5,836 people living in Rotterdam, the Netherlands, who were at risk of AMD were identified. Of these, 4,170 participated in the eight-year follow-up.
Participants were asked to fill out food questionnaires and were given periodic eye exams.
People who consumed higher levels of vitamin E and zinc had about a 10 percent lower risk of developing age-related macular degeneration. Those who had an above-average intake of all four nutrients (beta carotene, vitamin C, vitamin E and zinc) had a 35 percent reduced risk of AMD. Adding nutritional supplements to people who already had a high intake of these nutrients did not change the results.
People who consumed below-average amounts of these nutrients had a 20 percent increased risk of developing AMD, the study said.
Vitamin E is found in whole grains, vegetable oil, eggs and nuts; zinc in meat, poultry, fish, whole grains and dairy products; beta carotene in vegetables such as carrots, kale and spinach; and vitamin C in citrus fruits and juices, green peppers, broccoli and potatoes.
Although the study results still need to be confirmed, they do add valuable information, the researchers said.
"Up to now, we thought you needed to take heavy doses of supplements to achieve the benefits of these antioxidants," Cykiert said. "Now we know that if you eat a diet rich in these substances you achieve the same benefit, and possibly even more."
"If people start eating these things now, it may be a way to prevent problems 10, 15 or 20 years later," he added.
--By Amanda Gardner
More information
To learn more about age-related eye disease, visit the National Eye Institute
Saturday, January 07, 2006
Vitamin D Levels During Pregnancy Predict Kids' Bone Health
Moms who take extra supplements may protect offspring from osteoporosis, study suggests
(HealthDay News) -- Mothers who take extra vitamin D while pregnant could be protecting their children from osteoporosis later in life.
A study appearing in the Jan. 7 issue of The Lancet reports that children born to mothers with insufficient vitamin D during pregnancy had weaker bones when they were 9 years old.
"It's not the holy grail, but it's another piece of information that suggests that events beginning from gestation influence ultimate bone health and bone strength," said Dr. Stephen Honig, director of the Osteoporosis Center at the Hospital for Joint Diseases in New York City. "This is easily correctable, and seems to be something that comes at no particular cost, either economic or from an adverse-effect standpoint."
"It's very interesting and very suggestive," added Dr. Loren Wissner Greene, a clinical associate professor of medicine at New York University School of Medicine and co-director of the Bone Density Unit at New York University.
Many people show a vitamin D deficiency, and this includes otherwise healthy women during pregnancy.
Vitamin D is required for optimal calcium absorption, which is critical to bone growth. The main source of vitamin D is sunlight, and most people don't get enough of that.
"There has been a recognition that a lot of people in the United States are vitamin D-deficient in these days of sunscreen," Greene said.
At the same time, accumulating evidence suggests that environmental factors early in life can influence a person's chance of developing osteoporosis. For instance, birth weight can predict bone mass later on, while poor intrauterine and childhood growth are associated with double the risk of hip fracture 60 years later. A mother's build, nutrition, smoking and physical activity level during pregnancy can also influence bone mass of the baby at birth.
No one has yet looked at a relationship between the mother's vitamin D status during pregnancy and skeletal growth of their children. The authors of this study hypothesized that maternal vitamin D insufficiency during pregnancy had a long-lasting effect on childhood bone mass.
The researchers studied 198 children born in 1991 and 1992 at a hospital in Southampton, England. They assessed mothers' body build, nutrition and vitamin D status during pregnancy; children's body size and bone mass were measured nine years later.
Women who had reduced levels of vitamin D during the later part of their pregnancies had children with reduced bone-mineral content at 9 years of age.
Women who took vitamin D supplements and who were exposed to more sunshine were less likely to have a vitamin D deficiency. Reduced concentration of calcium in the umbilical cord blood was also associated with a reduced bone mass in the offspring.
"Their point is that there may be a programming effect that goes on in utero that effects calcium and bone accrual," Honig said. "Something happens in the last trimester that influences the transport of calcium across the placenta, and somehow that situation changes the developmental period over a prolonged timeframe."
The findings need to be confirmed, but they fit in well with other studies that have shown that issues early in life, such as low birth weight, can impact osteoporosis risk later in life.
"These are all things that are lending credibility to the need to think about bone growth and development as starting from gestation onward, rather than just thinking about this as diseases that occur after menopause," Honig said. "That's a significant thing."
The authors suggested that giving vitamin D supplements to pregnant women, especially if the third trimester occurs during the winter when there is less sunlight, could contribute to stronger bones in their children.
By Amanda Gardner
HealthDay Reporter
More information
The National Institutes of Health has more on vitamin D.
(HealthDay News) -- Mothers who take extra vitamin D while pregnant could be protecting their children from osteoporosis later in life.
A study appearing in the Jan. 7 issue of The Lancet reports that children born to mothers with insufficient vitamin D during pregnancy had weaker bones when they were 9 years old.
"It's not the holy grail, but it's another piece of information that suggests that events beginning from gestation influence ultimate bone health and bone strength," said Dr. Stephen Honig, director of the Osteoporosis Center at the Hospital for Joint Diseases in New York City. "This is easily correctable, and seems to be something that comes at no particular cost, either economic or from an adverse-effect standpoint."
"It's very interesting and very suggestive," added Dr. Loren Wissner Greene, a clinical associate professor of medicine at New York University School of Medicine and co-director of the Bone Density Unit at New York University.
Many people show a vitamin D deficiency, and this includes otherwise healthy women during pregnancy.
Vitamin D is required for optimal calcium absorption, which is critical to bone growth. The main source of vitamin D is sunlight, and most people don't get enough of that.
"There has been a recognition that a lot of people in the United States are vitamin D-deficient in these days of sunscreen," Greene said.
At the same time, accumulating evidence suggests that environmental factors early in life can influence a person's chance of developing osteoporosis. For instance, birth weight can predict bone mass later on, while poor intrauterine and childhood growth are associated with double the risk of hip fracture 60 years later. A mother's build, nutrition, smoking and physical activity level during pregnancy can also influence bone mass of the baby at birth.
No one has yet looked at a relationship between the mother's vitamin D status during pregnancy and skeletal growth of their children. The authors of this study hypothesized that maternal vitamin D insufficiency during pregnancy had a long-lasting effect on childhood bone mass.
The researchers studied 198 children born in 1991 and 1992 at a hospital in Southampton, England. They assessed mothers' body build, nutrition and vitamin D status during pregnancy; children's body size and bone mass were measured nine years later.
Women who had reduced levels of vitamin D during the later part of their pregnancies had children with reduced bone-mineral content at 9 years of age.
Women who took vitamin D supplements and who were exposed to more sunshine were less likely to have a vitamin D deficiency. Reduced concentration of calcium in the umbilical cord blood was also associated with a reduced bone mass in the offspring.
"Their point is that there may be a programming effect that goes on in utero that effects calcium and bone accrual," Honig said. "Something happens in the last trimester that influences the transport of calcium across the placenta, and somehow that situation changes the developmental period over a prolonged timeframe."
The findings need to be confirmed, but they fit in well with other studies that have shown that issues early in life, such as low birth weight, can impact osteoporosis risk later in life.
"These are all things that are lending credibility to the need to think about bone growth and development as starting from gestation onward, rather than just thinking about this as diseases that occur after menopause," Honig said. "That's a significant thing."
The authors suggested that giving vitamin D supplements to pregnant women, especially if the third trimester occurs during the winter when there is less sunlight, could contribute to stronger bones in their children.
By Amanda Gardner
HealthDay Reporter
More information
The National Institutes of Health has more on vitamin D.
Thursday, January 05, 2006
Tea Reduces Ovarian Cancer Risk
Women who drink tea can cut their risk by almost 50 percent
(HealthDay News) -- Women who drink at least two cups of tea a day can reduce their risk of developing ovarian cancer by almost 50 percent, Swedish researchers report.
There has been some experimental evidence that green and black tea might lower the risk of some cancers, but this is one of the few studies that has looked at the ability of tea to reduce the risk of ovarian cancer, the researchers noted.
The report appears in the Dec. 12/26 issue of the Archives of Internal Medicine.
In their study, Susanna C. Larsson and Alicja Wolk, of the National Institute of Environmental Medicine at the Karolinska Institute in Stockholm, looked at 61,057 women who were 40 to 76 years old.
The women all participated in a population-based study called the Swedish Mammography Cohort. At the beginning of the study, 68 percent of the participants said they drank tea (mainly black tea) at least once a month. During 15 years of follow-up, 301 women were diagnosed with ovarian cancer.
"We found a lower risk of ovarian cancer associated with greater tea consumption," Larsson said.
Larsson and Wolk found that women who drank at least two cups of tea a day reduced their risk of developing ovarian cancer by 46 percent.
"Each additional cup of tea per day was associated with an 18 percent lower risk of ovarian cancer," the authors reported.
In addition, women who drank one cup a day cut their risk by 24 percent, and those who even drank less than one cup of tea a day reduced their risk by 18 percent compared with non-tea drinkers.
"The advice to women is to increase the consumption of tea," Larsson said. "There are no harmful effects of tea."
One expert sees this study as reason to look for the components in tea that may be protecting women from ovarian cancer.
"This manuscript continues to increase our optimism that lifestyle interventions can be successful in cancer prevention," said Dr. Robert Morgan Jr., section head of medical gynecologic oncology at City of Hope Cancer Center in Duarte, Calif.
"These interventions are particularly important in ovarian cancer because, while ovarian cancer diagnosed in early stage disease is very curable, screening interventions have been only minimally effective in this disease due to the non-specificity of symptoms of early ovarian cancer, as well as the location of the ovaries deep in the pelvis, making them difficult to examine directly," Morgan said.
Because of this, prevention strategies are very important, Morgan added.
"Much data has recently been published suggesting that lifestyle changes, including exercise and statins, may lead to decreased incidences of new diagnoses of cancer or cancer recurrences. This manuscript suggests that there are other natural products which may be capable of the same phenomenon," he said.
Since the reasons tea may be protective are not known, Morgan thinks this study could lead researchers back to the lab to uncover the mechanisms at work.
More information
The National Cancer Institute can tell you more about ovarian cancer.
(HealthDay News) -- Women who drink at least two cups of tea a day can reduce their risk of developing ovarian cancer by almost 50 percent, Swedish researchers report.
There has been some experimental evidence that green and black tea might lower the risk of some cancers, but this is one of the few studies that has looked at the ability of tea to reduce the risk of ovarian cancer, the researchers noted.
The report appears in the Dec. 12/26 issue of the Archives of Internal Medicine.
In their study, Susanna C. Larsson and Alicja Wolk, of the National Institute of Environmental Medicine at the Karolinska Institute in Stockholm, looked at 61,057 women who were 40 to 76 years old.
The women all participated in a population-based study called the Swedish Mammography Cohort. At the beginning of the study, 68 percent of the participants said they drank tea (mainly black tea) at least once a month. During 15 years of follow-up, 301 women were diagnosed with ovarian cancer.
"We found a lower risk of ovarian cancer associated with greater tea consumption," Larsson said.
Larsson and Wolk found that women who drank at least two cups of tea a day reduced their risk of developing ovarian cancer by 46 percent.
"Each additional cup of tea per day was associated with an 18 percent lower risk of ovarian cancer," the authors reported.
In addition, women who drank one cup a day cut their risk by 24 percent, and those who even drank less than one cup of tea a day reduced their risk by 18 percent compared with non-tea drinkers.
"The advice to women is to increase the consumption of tea," Larsson said. "There are no harmful effects of tea."
One expert sees this study as reason to look for the components in tea that may be protecting women from ovarian cancer.
"This manuscript continues to increase our optimism that lifestyle interventions can be successful in cancer prevention," said Dr. Robert Morgan Jr., section head of medical gynecologic oncology at City of Hope Cancer Center in Duarte, Calif.
"These interventions are particularly important in ovarian cancer because, while ovarian cancer diagnosed in early stage disease is very curable, screening interventions have been only minimally effective in this disease due to the non-specificity of symptoms of early ovarian cancer, as well as the location of the ovaries deep in the pelvis, making them difficult to examine directly," Morgan said.
Because of this, prevention strategies are very important, Morgan added.
"Much data has recently been published suggesting that lifestyle changes, including exercise and statins, may lead to decreased incidences of new diagnoses of cancer or cancer recurrences. This manuscript suggests that there are other natural products which may be capable of the same phenomenon," he said.
Since the reasons tea may be protective are not known, Morgan thinks this study could lead researchers back to the lab to uncover the mechanisms at work.
More information
The National Cancer Institute can tell you more about ovarian cancer.
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