Our Better Health

Diet, Health, Fitness, Lifestyle & Wellness


3 Comments

Garlic: Proven Health Benefits

Garlic (Allium sativum), is used widely as a flavoring in cooking, but it has also been used as a medicine throughout ancient and modern history; it has been taken to prevent and treat a wide range of conditions and diseases.

Garlic belongs to the genus Allium and is closely related to the onion, rakkyo (an onion found in Asia), scallion, chive, leek, and shallot. It has been used by humans for thousands of years and was used in Ancient Egypt for both culinary purposes and its health and therapeutic benefits.

This article will look at the potential health benefits of garlic and cover any research that supports the claims.

In this article:

  1. Garlic for food and medicine – a brief history
  2. Garlic is used widely today for its therapeutic properties
  3. Health benefits of garlic – scientific studies


Fast facts on garlic

  • In many countries, garlic has been used medicinally for centuries.
  • Garlic may have a range of health benefits, both raw and cooked.
  • It may have significant antibiotic properties.

 

Garlic for food and medicine – a brief history

Garlic has been used all over the world for thousands of years. Records indicate that garlic was in use when the Giza pyramids were built, about 5,000 years ago.

Richard S. Rivlin wrote in the Journal of Nutrition that the ancient Greek physician Hippocrates (circa. 460-370 BC), known today as “the father of Western medicine,” prescribed garlic for a wide range of conditions and illnesses. Hippocrates promoted the use of garlic for treating respiratory problems, parasites, poor digestion, and fatigue.

The original Olympic athletes in Ancient Greece were given garlic – possibly the earliest example of “performance enhancing” agents used in sports.

From Ancient Egypt, garlic spread to the advanced ancient civilizations of the Indus Valley (Pakistan and western India today). From there, it made its way to China.

According to experts at Kew Gardens, England’s royal botanical center of excellence, the people of ancient India valued the therapeutic properties of garlic and also thought it to be an aphrodisiac. The upper classes avoided garlic because they despised its strong odor, while monks, “…widows, adolescents, and those who had taken up a vow or were fasting, could not eat garlic because of its stimulant quality.”

Throughout history in the Middle East, East Asia, and Nepal, garlic has been used to treat bronchitis, hypertension (high blood pressure), TB (tuberculosis), liver disorders, dysentery, flatulence, colic, intestinal worms, rheumatism, diabetes, and fevers.

The French, Spanish, and Portuguese introduced garlic to the New World.

Garlic is used widely today for its therapeutic properties

Currently, garlic is widely used for several conditions linked to the blood system and heart, including atherosclerosis (hardening of the arteries), high cholesterol, heart attack, coronary heart disease, and hypertension.

Garlic is also used today by some people for the prevention of lung cancer, prostate cancer, breast cancer, stomach cancer, rectal cancer, and colon cancer.

It is important to add that only some of these uses are backed by research.

A study published in the journal Food and Chemical Toxicology warned that short-term heating reduces the anti-inflammatory effects of fresh raw garlic extracts. This may be a problem for some people who do not like or cannot tolerate the taste and/or odor of fresh garlic.

Health benefits of garlic – scientific studies

Below are examples of some scientific studies published in peer-reviewed academic journals about the therapeutic benefits (or not) of garlic.

Lung cancer risk

People who ate raw garlic at least twice a week during the 7 year study period had a 44 percent lower risk of developing lung cancer, according to a study conducted at the Jiangsu Provincial Center for Disease Control and Prevention in China.

The researchers, who published their study in the journal Cancer Prevention Research, carried out face-to-face interviews with 1,424 lung cancer patients and 4,543 healthy individuals. They were asked about their diet and lifestyle, including questions on smoking and how often they ate garlic.

The study authors wrote: “Protective association between intake of raw garlic and lung cancer has been observed with a dose-response pattern, suggesting that garlic may potentially serve as a chemo-preventive agent for lung cancer.”

Brain cancer

Organo-sulfur compounds found in garlic have been identified as effective in destroying the cells in glioblastomas, a type of deadly brain tumor.

Scientists at the Medical University of South Carolina reported in the journal Cancer that three pure organo-sulfur compounds from garlic – DAS, DADS, and DATS – “demonstrated efficacy in eradicating brain cancer cells, but DATS proved to be the most effective.”

Co-author, Ray Swapan, Ph.D., said “This research highlights the great promise of plant-originated compounds as natural medicine for controlling the malignant growth of human brain tumor cells. More studies are needed in animal models of brain tumors before application of this therapeutic strategy to brain tumor patients.”

Hip osteoarthritis

Women whose diets were rich in allium vegetables had lower levels of osteoarthritis, a team at King’s College London and the University of East Anglia, both in England, reported in the journal BMC Musculoskeletal Disorders. Examples of allium vegetables include garlic, leeks, shallots, onions, and rakkyo.

The study authors said their findings not only highlighted the possible impact of diet on osteoarthritis outcomes but also demonstrated the potential for using compounds that exist in garlic to develop treatments for the condition.

The long-term study, involving more than 1,000 healthy female twins, found that those whose dietary habits included plenty of fruit and vegetables, “particularly alliums such as garlic,” had fewer signs of early osteoarthritis in the hip joint.

Potentially a powerful antibiotic

Diallyl sulfide, a compound in garlic, was 100 times more effective than two popular antibiotics in fighting the Campylobacter bacterium, according to a study published in the Journal of Antimicrobial Chemotherapy.

The Campylobacter bacterium is one of the most common causes of intestinal infections.

Senior author, Dr. Xiaonan Lu, from Washington State University, said, “This work is very exciting to me because it shows that this compound has the potential to reduce disease-causing bacteria in the environment and in our food supply.”

Heart protection

Diallyl trisulfide, a component of garlic oil, helps protect the heart during cardiac surgery and after a heart attack, researchers at Emory University School of Medicine found. They also believe diallyl trisulfide could be used as a treatment for heart failure.

Hydrogen sulfide gas has been shown to protect the heart from damage.

However, it is a volatile compound and difficult to deliver as therapy.

Because of this, the scientists decided to focus on diallyl trisulfide, a garlic oil component, as a safer way to deliver the benefits of hydrogen sulfide to the heart.

In experiments using laboratory mice, the team found that, after a heart attack, the mice that had received diallyl sulfide had 61 percent less heart damage in the area at risk, compared with the untreated mice.

In another study, published in the Journal of Agricultural and Food Chemistry, scientists found that garlic oil may help protect diabetes patients from cardiomyopathy.

Cardiomyopathy is the leading cause of death among diabetes patients. It is a chronic disease of the myocardium (heart muscle), which is abnormally thickened, enlarged, and/or stiffened.

The team fed diabetic laboratory rats either garlic oil or corn oil. Those fed garlic oil experienced significantly more changes associated with protection against heart damage, compared with the animals that were fed corn oil.

The study authors wrote, “In conclusion, garlic oil possesses significant potential for protecting hearts from diabetes-induced cardiomyopathy.”

Human studies will need to be performed to confirm the results of this study.

High cholesterol and high blood pressure

Researchers at Ankara University investigated the effects of garlic extract supplementation on the blood lipid (fat) profile of patients with high blood cholesterol. Their study was published in the Journal of Nutritional Biochemistry.

The study involved 23 volunteers, all with high cholesterol; 13 of them also had high blood pressure. They were divided into two groups:

  • The high-cholesterol normotensive group (normal blood pressure).
  • The high-cholesterol hypertensive group (high blood pressure).

They took garlic extract supplements for 4 months and were regularly checked for blood lipid parameters, as well as kidney and liver function.

At the end of the 4 months, the researchers concluded “…garlic extract supplementation improves blood lipid profile, strengthens blood antioxidant potential, and causes significant reductions in systolic and diastolic blood pressures. It also leads to a decrease in the level of oxidation product (MDA) in the blood samples, which demonstrates reduced oxidation reactions in the body.”

In other words, the garlic extract supplements reduced high cholesterol levels, and also blood pressure in the patients with hypertension. The scientists added that theirs was a small study – more work needs to be carried out.

Prostate cancer

Doctors at the Department of Urology, China-Japan Friendship Hospital, Beijing, China, carried out a study evaluating the relationship between Allium vegetable consumption and prostate cancer risk.

They gathered and analyzed published studies up to May 2013 and reported their findings in the Asian Pacific Journal of Cancer Prevention.

The study authors concluded, “Allium vegetables, especially garlic intake, are related to a decreased risk of prostate cancer.”

The team also commented that because there are not many relevant studies, further well-designed prospective studies should be carried out to confirm their findings.

Alcohol-induced liver injury

Alcohol-induced liver injury is caused by the long-term over-consumption of alcoholic beverages.

Scientists at the Institute of Toxicology, School of Public Health, Shandong University, China, wanted to determine whether diallyl disulfide (DADS), a garlic-derived organosulfur compound, might have protective effects against ethanol-induced oxidative stress.

Their study was published in Biochimica et Biophysica Acta.

The researchers concluded that DADS might help protect against ethanol-induced liver injury.

Preterm (premature) delivery

Microbial infections during pregnancy raise a woman’s risk of preterm delivery. Scientists at the Division of Epidemiology, Norwegian Institute of Public Health, studied what impact foods might have on antimicrobial infections and preterm delivery risk.

The study and its findings were published in the Journal of Nutrition.

Ronny Myhre and colleagues concentrated on the effects of Alliums and dried fruits, because a literature search had identified these two foods as showing the greatest promise for reducing preterm delivery risk.

The team investigated the intake of dried fruit and Alliums among 18,888 women in the Norwegian Mother and Child Cohort, of whom 5 percent (950) underwent spontaneous PTD (preterm delivery).

The study authors concluded, “Intake of food with antimicrobial and prebiotic compounds may be of importance to reduce the risk of spontaneous PTD. In particular, garlic was associated with overall lower risk of spontaneous PTD.”

Garlic and the common cold

A team of researchers from St. Joseph Family Medicine Residency, Indiana, carried out a study titled “Treatment of the Common Cold in Children and Adults,” published in American Family Physician.

They reported that “Prophylactic use of garlic may decrease the frequency of colds in adults, but has no effect on duration of symptoms.” Prophylactic use means using it regularly to prevent disease.

Though there is some research to suggest that raw garlic has the most benefits, other studies have looked at overall allium intake, both raw and cooked, and have found benefits. Therefore, you can enjoy garlic in a variety of ways to reap its advantages.

 
Fri 18 August 2017    By Christian Nordqvist Reviewed by Natalie Butler, RD, LD
 


Leave a comment

Climate change is shifting areas of skin disease concern

Climate change is bringing certain skin diseases and other illnesses to regions where they were rarely seen before, according to a recent research review.

Dermatologists should keep these changing patterns of skin diseases in mind when making diagnoses, say the authors, who analyzed specific disease shifts in North America.

As the planet warms, many bacteria, viruses, fungi and parasites can survive in areas where they haven’t been found before, the review team writes.

In the U.S., for example, the incidence of the tick-borne Lyme disease increased from an estimated 10,000 cases in 1995 to 30,000 in 2013, and the area where it occurs keeps expanding from New England north into Canada as the ticks find their preferred habitat expanding.

“In places like Canada, now there are ticks that carry Lyme disease farther north than doctors would ever expect to see that,” Dr. Misha Rosenbach of the University of Pennsylvania in Philadelphia told Reuters Health said in a phone interview.

The range of Valley Fever in the southwest U.S. is spreading in a similar way, he said.

Viruses like dengue, chikungunya and Zika are transmitted by mosquitoes originally from Africa and Asia, which have now spread widely throughout North America as the mosquitoes can survive further and further north.

“We are seeing a much wider spread northward for some of these formerly tropical diseases that are now in Texas and Florida,” Rosenbach said.

Seventeen of the warmest years on record occurred within the last 18 years, largely due to combustion of fossil fuels and destruction of rainforests, the authors write in the Journal of the American Academy of Dermatology.

globe

Water warming and flooding can also give rise to skin threats not previously typical of certain areas, the authors note. Ocean warming increases jellyfish populations, and Portuguese man-of-war now swim along the southeast U.S. coastline where they once did not, for example.

Parts of North America, particularly the Great Lakes, should expect substantially greater rainfall and therefore more outbreaks of waterborne disease as well.

Increasing temperatures in the Gulf of Mexico contribute to the increased cases of illness from consuming raw oysters.

Another skin-related consequence of climate change is skin cancer: as ozone is depleted, the risk of skin cancer goes up. A two-degree temperature increase could raise skin cancer incidences by 10 percent each year, the authors write.

The dermatologic consequences of climate change may not all be negative – you could argue that if temperatures keep rising, some mosquito habitat will be dried out due to drought and some disease ranges may shrink, Rosenbach said.

When doctors see patients with a fever and a rash, he added, “what you suspect” as the diagnosis “depends on where you are.”
“It’s important to remember that what people learned 20 years ago or 10 years ago in medical school can be subject to rapid change,” he said. “The bottom line is it’s important to keep an open mind about possible diagnoses.”

By Kathryn Doyle      Fri Oct 21, 2016
 
SOURCE: bit.ly/2enGiMA   Journal of the American Academy of Dermatology, online October 11, 2016.       www.reuters.com


Leave a comment

Fun Fact Friday

Humans have a strong relationship with music

because of the way that music affects our feelings, our thinking, and our emotional state.

Kissing is healthier than shaking hands.

A study found that people born in May

have the lowest risk of illness and disease, while those born in October have the highest.

In Russia, it is illegal to tell kids that gay people exist.

The inability to pronounce the letter “r” is called rhotacism,

making it impossible for the sufferers to pronounce their own affliction.

Pluto is smaller than Russia.

President Lyndon B. Johnson owned an amphibious car

and would scare his guests by driving into a lake, screaming about brake failure.

When two people kiss, they exchange between 10 million and 1 billion bacteria.



Happy Friday  🙂
source:       factualfacts.com       https://twitter.com/Fact       @Fact


Leave a comment

The 4 Best Ways to Prevent a Cold

Follow these simple tips to avoid becoming a sniffly, snotty, glassy-eyed mess when cold season rolls around

BY ALEXA TUCKER    Friday, October 9, 2015

Getting a cold sucks, but it’s not inevitable. And while 33 million diagnoses each year—according to a CDC report—might suggest otherwise, we found four simple strategies that can help you escape cold season unscathed.

But you have to be diligent. And by diligent, we mean you can’t just read this and sort of follow the advice. You have to stick to it. Because the moment you let up is when colds take hold. (You’ll probably have to get a little lucky, too.)

1. Stop Touching Your Face

This tip may seem obvious, but it’ll be tough to follow through. That’s because people touch their faces an average of 3.6 times every hour, a 2012 study in Clinical Infectious Diseases found.

And that’s a problem, because bringing your hands to your face can spike your cold risk. Workers who report sometimes touching their nose or eyes with their fingers were 41 percent more likely to come down with an upper respiratory infection than those who keep their hands off, according to researchers in Japan.

While you can catch the common cold through germ droplets in the air, the most efficient form of transmission for that particular infection is actually hand contact with secretions that contain the virus, the researchers say. So if your hands touch a surface with the virus on it, and then you touch your face, you can easily introduce the bug into your body.

If you can’t help touching your face, just make sure your digits are clean. That means scrubbing your hands for at least 20 seconds (sing “Happy Birthday” in your head), making sure to hit the backs of your hands, between your fingers, and under the nails, the CDC says.

cold

 

2. Get Plenty of Sleep

Skimping on shut eye can leave you susceptible. People who sleep fewer than six hours a night are four times as likely to catch a cold as those who log seven hours or more, a study published in the journal Sleep found.

This may be because sleep loss messes with certain types of immune cells called B and T cells, which are critical in protecting us from viruses, says study coauthor Aric Prather, Ph.D., an assistant professor of psychiatry at University of California San Francisco.

“Additionally, sleep loss is related to an increase in inflammation, which is believed to play a role in cold symptom severity,” he adds.

3. Hit The Gym

You should keep up your workout routine when the temperature drops. The reason:  People who exercise five or more days a week take up to 46 percent fewer sick days than those who exercise one day or less a week, according to a study from Appalachian State University.

When you exercise, your blood flow and body temperature increase, and your muscles contract. These factors signal your body to recruit important disease-fighting cells that are stored in your lymphoid tissues.

These cells are then recirculated throughout your system, says lead researcher David Nieman, Dr.P.H. This allows your body to detect—and kill off—potential disease-causing intruders.

To jack up your immune system, Nieman says near-daily cardio of 30 to 60 minutes a session should do the trick. (He notes that resistance training can work, too, but says it should be total-body training, since it appears to be more effective in immune-cell recruitment than routines that target one or two body parts.)

4. Hug It Out

Preventing a cold may truly be in your own hands. Stressed-out people who were more likely to have hugged within the past day are better able to fight off the virus than those who are more hands-off, a study in the journal Psychological Science found.

“Hugging is a physical expression of social support, and when people feel they are supported, they also feel they are better able to handle stress,” says study co-author Denise Janicki-Deverts, Ph.D., a research psychologist at Carnegie Mellon University.

And that’s important, because stress itself has been connected to increased cold risk, possibly because it may spark the release of certain hormones that can wreak havoc on your immunity, says Janicki-Deverts.


Leave a comment

Acknowledge Your Anger to Help Prevent Disease

Erin Newman     August 11, 2015

The more we learn about disease, the more we start to realize that there is no separation of body from mind. Treating just the symptoms of a disease does us no good if we are not also changing our mental outlook. For instance, depressed patients with any type of disease, recover more slowly and have worse health outcomes than optimistic patients.

Scientists have also now seen enough cases of “broken heart syndrome,” often brought on by the death of a spouse, that we now have a medical term for it: stress-induced cardiomyopathy. All of this should give us cause for hope, though. It means that we can take charge of our own health, and that we can learn ways to prevent disease in our lives.

It is our mental and physical health, and not our genes, that carries the most weight in determining our health outcomes. To quote Craig Venter, a pioneer in genomic research,

“Everybody talks about the genes that they received from their mother and father, for this trait or the other. But in reality, those genes have very little impact on life outcomes. Our biology is way too complicated for that and deals with hundreds of thousands of independent factors. Genes are absolutely not our fate. They can give us useful information about the increased risk of a disease, but in most cases they will not determine the actual cause of the disease, or the actual incidence of somebody getting it. Most biology will come from the complex interaction of all the proteins and cells working with environmental factors, not driven directly by the genetic code.”

And as one recent study affirms, 90 to 95 percent of cancer is preventable with lifestyle changes, and one of the largest (and as yet least understood) is our mental disposition.

Releasing Anger: The key to prevention?

One study of over 160 women with breast cancer found a significant association between health and the suppression of emotions, most commonly anger. Another study concluded that suppression of anger may have a direct impact on mortality, including deaths from cancer. And yet another study determined that “Emotion-focused coping strategies were significantly associated with survival.”

All of which just means that if we want to live long and healthy lives, we’ve got to learn to express our anger and other emotions.

anger

Ways to tell that you may be suppressing anger or other emotions:

• People tell you that you are always smiling and happy.
• You often feel as if you can’t say no.
• You feel overwhelmed and tense.
• You no longer know what makes you happy, only what makes others happy.
• You worry often about the past or future
• Overeating, drinking, medicating, shopping, or other addictive behaviors

Women, especially, have been taught at an early age that it’s not okay to display anger. “Just who do you think you are, missy?” we might have heard, or later, we might have gotten the distinct message that we don’t want to be seen as a witch with a capital “B.” We may then mask this emotion with a happy face, or by eating, drinking, medications, or other ways to numb the emotion.

What’s behind the anger?

Often, we may not even know that we are angry about something. We might not hear the words that run through our minds about an incident or a person who’s angered us. And, while we may not want to admit it, or may not even recognize it on a conscious level, our anger is usually a mask for other, even less comfortable emotions. Sadness, shame, guilt or regret are often at the heart of our anger at another. These emotions may be even harder to recognize and discover, but when we get down to this level of emotions, then we can really clear them out and make way for love and joy.

Ways of handling anger:

Expressing or handling our anger doesn’t mean venting to others –either at the person that we are angry with or another. We must express the anger in a safe and loving way that allows us to acknowledge the anger and then work through it.

Journaling: Daily journaling is one of the most powerful ways to get in touch with your subconscious mind (which is where many of these suppressed thoughts and emotions may be lurking). This is not a “here’s what I did today” type of journal, but instead a “ this is what’s bothering me” type of journal. Clearly express everything on your mind, including just how you really and truly feel towards a person, whether that be your spouse, your child, a friend, or a parent. Many people worry that others might read their journal; if this is you, burn or shred the paper after writing. (Believe me, you won’t ever want to go back and read it!) I find (and many recommend) that journaling works best in the morning, when your mind hasn’t had time to fill itself up with thoughts of the day yet.

Loving our anger: Part of suppressing emotions is the idea that we should not be feeling a certain way at all, or that we would like for that feeling or thought to go away and leave us alone. If we can instead acknowledge that the feeling or thought is part of us, and allow it to be seen, then it will no longer have as much power to hurt us. Best yet, once we acknowledge the feeling or emotion, we can then direct love to that place in our bodies where we most feel the emotion. (This also seems to work best in the mornings, too, in a space that you can be quiet and still. But if that doesn’t work, then lunch breaks or evenings can be a good time, also.)

If these methods sound too tough or unrealistic, or just something that you can’t fit into your life, then it may help to speak to a professional who can help you to discover your inner emotions. We owe it to ourselves and to the people who love us to live the most emotionally rich and healthy lives as possible!


3 Comments

Three Ways To Fight Disease With Your Mind

Three psychological approaches which improve health at the cellular level.

Practising mindfulness meditation, yoga or being involved in a support group have positive impacts at the cellular level in breast cancer, a new study finds.

The study, conducted at Canadian cancer centres, found that breast cancer survivors who practised meditation and yoga or took part in support groups had longer telomeres, part of the chromosome thought to be important in physical health.

Dr. Linda E. Carlson, who led the study, said:

“We already know that psychosocial interventions like mindfulness meditation will help you feel better mentally, but now for the first time we have evidence that they can also influence key aspects of your biology.”

The role of telomores — protein complexes that book-end the chromosomes — is not fully understood, but shortened telomores have been linked to cell ageing and disease states.

Dr. Carlson continued:

“It was surprising that we could see any difference in telomere length at all over the three-month period studied.
Further research is needed to better quantify these potential health benefits, but this is an exciting discovery that provides encouraging news.”

The study divided 88 breast cancer survivors into three groups (Carlson et al., 2014).

One group took part in eight weekly mindfulness meditation classes that lasted 90 minutes, which also included some gentle Hatha yoga.

Participants continued their mindfulness practice at home for 45 minutes a day.

Happy Thoughts

Another group went to a ‘Supportive Expressive Therapy’ group in which they talked openly about their concerns for 90 minutes over 12 weeks.

The aim of the group was to help the women express both positive and negative emotions with each other along with building mutual support between group members.

A third group — the control — took a single 5-hour stress reduction class.

The results showed that while telomore length had shortened in the control group, it was maintained in the support and meditation groups combined.

One of the study’s participants, Allison McPherson, who was first diagnosed with breast cancer in 2008, said:

“I was skeptical at first and thought it was a bunch of hocus-pocus.
But I now practise mindfulness throughout the day and it’s reminded me to become less reactive and kinder toward myself and others.”

Another breast cancer survivor who took part, Deanne David, said:

“Being part of this made a huge difference to me.
I think people involved in their own cancer journey would benefit from learning more about mindfulness and connecting with others who are going through the same things.”


1 Comment

Study of Organic Crops Finds Fewer Pesticides and More Antioxidants

By KENNETH CHANG      JULY 11, 2014

Adding fuel to the debates over the merits of organic food, a comprehensive review of earlier studies found substantially higher levels of antioxidants and lower levels of pesticides in organic fruits, vegetables and grains compared with conventionally grown produce.

“It shows very clearly how you grow your food has an impact,” said Carlo Leifert, a professor of ecological agriculture at Newcastle University in England, who led the research. “If you buy organic fruits and vegetables, you can be sure you have, on average, a higher amount of antioxidants at the same calorie level.”

However, the full findings, to be published next week in the British Journal of Nutrition, stop short of claiming that eating organic produce will lead to better health.

“We are not making health claims based on this study, because we can’t,” Dr. Leifert said. The study, he said, is insufficient “to say organic food is definitely healthier for you, and it doesn’t tell you anything about how much of a health impact switching to organic food could have.”

Still, the authors note that other studies have suggested some of the antioxidants have been linked to a lower risk of cancer and other diseases.

The conclusions in the new report run counter to those of a similar analysis published two years ago by Stanford scientists, who found few differences in the nutritional content of organic and conventionally grown foods. Those scientists said the small differences that did exist were unlikely to influence the health of the people who chose to buy organic foods, which are usually more expensive.

The Stanford study, like the new study, did find pesticide residues were several times higher on conventionally grown fruits and vegetables, but played down the significance, because even the higher levels were largely below safety limits.

Organic farming, by and large, eliminates the use of conventional chemical fertilizers and pesticides. Those practices offer ecological benefits like healthier soils but produce less bountiful harvests. The Organic Trade Association, an industry organization, estimated organic food sales last year in the United States at $32.3 billion, or just over 4 percent of the total market.

What is disputed, vociferously, is whether organic fruits and vegetables provide a nutritional lift. Many naysayers regard organic as a marketing ploy to charge higher prices.

“The other argument would be, if you just eat a little bit more fruits and vegetables, you’re going to get more nutrients,” said Alan D. Dangour, a researcher at the London School of Hygiene and Tropical Medicine. Dr. Dangour led a review published in 2009 that found no significant nutritional differences between conventional and organic foods.

Such differences are difficult to discern, because other factors that can vary widely from place to place and year to year, like the weather, also influence the nutrients. Even if differences exist, it is unclear whether they would affect consumer health.

In the new study, an international team of scientists did not conduct any laboratory or field work of their own. Instead, they compiled a database from 343 previously published studies and performed a statistical procedure known as a meta-analysis, which attempts to ferret robust bits of information from studies of varying designs and quality.

Some of the studies reported many measurements, some only a few. Some included several crops grown over multiple years, while others looked at only a few samples. But if done properly, the results of a meta-analysis can be greater than the average of its parts.

Over all, organic crops contained 17 percent more antioxidants than conventionally grown crops, the new study found. For some classes of antioxidants, the difference was larger. A group of compounds known as flavanones, for example, were 69 percent higher in the organic produce. (At very high quantities, as in some supplements, some antioxidants have been shown to be harmful, but the levels in organic produce were not nearly that high.)

The researchers said they analyzed the data in several different ways, and each time the general results remained robust.

The study cost $429,000, which came from the European Union and the Sheepdrove Trust, a British charity that supports organic farming research. The scientists said the money came with no strings, and their research passed the rigor of scientific peer review for publication.

Charles M. Benbrook, a professor at Washington State University and another author of the paper, said this analysis improved on earlier reviews, in part because it incorporated recent new studies.

The findings fit with the expectation that without pesticides, plants would produce more antioxidants, many of which serve as defenses against pests and disease.

The study also found that organically produced foods, particularly grains, contain lower levels of cadmium, a toxic metal that sometimes contaminates conventional fertilizers. Dr. Benbrook said the researchers were surprised by that finding; there was no difference in other toxic metals like mercury and lead.

Even with the differences and the indications that some antioxidants are beneficial, nutrition experts said the “So what?” question had yet to be answered.

“After that, everything is speculative,” said Marion Nestle, a professor of nutrition, food studies and public health at New York University. “It’s a really hard question to answer.”

Dr. Nestle said she buys organic foods, because she believes they are better for the environment and wants to avoid pesticides. “If they are also more nutritious, that’s a bonus,” she said. “How significant a bonus? Hard to say.”

She continued: “There is no reason to think that organic foods would be less nutritious than conventional industrial crops. Some studies in the past have found them to have more of some nutrients. Other studies have not. This one looked at more studies and has better statistics.”

Dr. Dangour, however, remained entirely unconvinced. He said the researchers erred in not excluding the weaker studies from the analysis. “To my mind, there’s no convincing evidence that these foods are different in nutritional composition,” he said.