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Published on Leave a comment on Drinking Coffee May Improve Athletic Endurance and Performance

A University of Georgia review study of the research literature shows that drinking coffee (instead of a caffeine supplement) improves athletic endurance performance. Also, that caffeine from coffee has ergogenic benefits—that it enhances physical performance. More beneficial effects of coffee! From Medical Xpress:

Coffee may improve athletic endurance performance, review finds

The caffeine in a morning cup of coffee could help improve athletic endurance, according to a new University of Georgia review study....To research the issue, Higgins reviewed more than 600 scholarly articles and screened them for those that focused only on caffeinated-coffee conditions, measured the caffeine dose and measured an endurance performance. Of these, nine randomized control trials specifically used coffee to improve endurance."Previous research has focused on caffeine itself as an aid to improve endurance," Higgins said.

 Looking at the nine trials, Higgins found that between 3 and 7 milligrams per kilogram of body weight of caffeine from coffee increased endurance performance by an average of 24 percent. The amount of caffeine in a cup of coffee can vary from 75 mg to more than 150, depending on the variety and how it's roasted and brewed. 

In the nine trials, participants either cycled or ran after drinking coffee. They then exercised vigorously and the results were measured. In a majority of cases, endurance was noticeably improved after the use of coffee.When researching the effects of caffeine from coffee, Higgins found two important discoveries: that caffeine from coffee has ergogenic benefits—that it enhances physical performance—and that more research is needed on the use of caffeine from coffee versus pure caffeine use.

"While there is a lack of high-quality research on coffee as a source of caffeine, there is an abundance of research on pure caffeine," he said. "It's surprising how little we know about caffeine from coffee when its endurance effects could be just as beneficial as pure caffeine."

Higgins said that coffee shouldn't be dismissed as less beneficial for endurance. He found that coffee appears to be just as helpful as taking caffeine in the form of powder or tablets.... Higgins says that more research is needed before giving official recommendations to athletes, especially since the amount of caffeine in a cup of coffee can vary depending on how it's prepared.

Published on Leave a comment on Could Apigenin Be Considered a Brain Food?

The important thing learned from this study (though it was done in the laboratory and not directly on humans) is that it supports that apigenin (in the same chemical group as flavonoids) is important for neuron formation and for strengthening connections between brain cells. Flavonoids are known to positively affect memory and learning, and to preserve and enhance brain function. Apigenin is found in many fruits and vegetables, but common sources are parsley, celery, celeriac, thyme, chamomile, grapefruit, onions, oranges, red wine, and spices such as rosemary, oregano, thyme, basil, and coriander. Another good reason to eat a variety of fruits and vegetables. From Medical Xpress:

Plant compound found in spices and herbs increases brain connections

Brazilian researchers from D'Or Institute for Research and Education (IDOR), Federal University of Rio de Janeiro (UFRJ) and Federal University of Bahia (UFBA) have demonstrated in laboratory that apigenin, a substance found in parsley, thyme, chamomile and red pepper, improves neuron formation and strengthens the connections between brain cells.

Previous experiments with animals had already shown that substances from the same chemical group as the apigenin, known as flavonoids, positively affect memory and learning. Many studies highlight the potential of flavonoids to preserve and enhance brain function. While the effectiveness of flavonoids for brain health is not an entirely new concept, this research is the first to show the positive effects of apigegin directly on human cells and the first to unraveling its mechanism.

The scientists observed that just by applying apigenin to human stem cells in a dish they become neurons after 25 days - an effect they would not see without the substance. Moreover, the neurons that were formed made stronger and sophisticated connections among themselves after being treated with this natural compound."Strong connections between neurons are crucial for good brain function, memory consolidation and learning", says neuroscientist from IDOR and UFRJ Stevens Rehen, leader author of the paper published today atAdvances in Regenerative Biology.

The research team conducted by Rehen demonstrated that apigenin works by binding to estrogen receptors, which affect the development, maturation, function, and plasticity of the nervous system. This group of hormones is known to delay the onset of psychiatric and neurodegenerative disorders such as schizophrenia, depression, Alzheimer's and Parkinson's disease. However, the use of estrogen-based therapies is limited by the increased risk of estrogen-dependent tumors and cardiovascular problems.

Researchers believe apigenin can be used as an alternative approach on future treatments for neurodegenerative diseases as well as in neuronal differentiation strategies in laboratory. "We show a new path for new studies with this substance", points out Rehen. "Moreover, flavonoids are present at high amounts in some foods and we can speculate that a diet rich in flavonoids may influence the formation of neurons and the way they communicate within the brain."

Published on Leave a comment on Endocrine Disrupting Chemicals and Male Infertility

Recent research looked at environmental causes of male infertility, specifically endocrine-disrupting chemicals. Poor semen quality contributes to increases in infertility and the use of assisted reproductive technology.The researchers also discuss the higher incidence of testicular cancer worldwide, lower levels of testosterone in men, and poor semen quality among men aged 20 to 25 (with the average man having up to 90% abnormal sperm). From Science Daily:

Endocrine-disrupting chemicals may be threatening fertility in industrialized countries

The birth rate is declining in all industrialised countries, and socioeconomic factors and women's age are not solely to blame. Male reproductive health and environmental factors are also significant, as concluded in a new scientific review article. ...Behind the article are fertility researchers from Denmark, the US and Finland. The researchers studied a number of factors related to fertility, and one of the main conclusions of their study was that poor semen quality contributed to increases in infertility and the use of assisted reproductive technology.

The study also revealed higher incidence of testicular cancer worldwide, with the greatest frequency among Caucasian populations. Moreover, the researchers also observed lower levels of testosterone in average men. "I was surprised that we found such poor semen quality among young men aged 20 to 25. The average man had up to 90% of abnormal sperm. Normally, there would be so many sperms that a few abnormal ones would not affect fertility. However, it appears that we are at a tipping point in industrialised countries where poor semen quality is so widespread that we must suspect that it results in low pregnancy rates," said first author of the article, Professor Niels E. Skakkebaek from the Department of Growth and Reproduction (EDMaRC) at Rigshospitalet and the University of Copenhagen.

"The article also demonstrates the impact of the increasing number of male reproductive problems on low birth rates. There is no doubt that environmental factors are playing a role. These are the correlations we are researching at the new research centre EDMaRC at Rigshospitalet," added Professor Anders Juul, who is the last author of the article.

Many of the male reproductive problems could be due to damage to the testes during embryonic development. While the reproductive problems could arise from genetic changes, "recent evidence suggests that most often they are related to environmental exposures of the fetal testes," the researcher team wrote."Since the disorders in male genitals have increased over a relatively short period of time, genetics alone cannot explain this development. There is no doubt that environmental factors are playing a role and that endocrine-disrupting chemicals, which have the same effect on animals, are under great suspicion. The exposure that young people are subjected to today can determine not only their own, but also their children's, ability to procreate," explained Professor Skakkebaek.

Published on Leave a comment on Male Infertility Linked to Other Chronic Medical Conditions

A recent study found that men with infertility have a much higher risk for a variety of other chronic medical conditions, including diabetes, heart disease, renal disease, alcohol abuse, and drug abuse. Thus, it appears that male infertility may be a symptom or a clue that there may be other health problems. One example is that male infertility is linked to an 81% greater risk of diabetes, and the greatest risk for renal disease occurred among men with azoospermia (zero sperm counts, the most severe form of male infertility). From Medscape:

Infertility in Men Tied to Heart Disease, Chronic Conditions

Men with infertility have a higher risk for a variety of other chronic medical conditions, including diabetes, heart disease, alcohol abuse, and drug abuse, according to a retrospective cohort study published online December 7 in Fertility and Sterility."The results suggest that male factor infertility has more than just reproductive implications," write Michael Eisenberg, MD, assistant professor of urology and director of male reproductive medicine and surgery at Stanford University School of Medicine in California, and colleagues.

The researchers used insurance claims data from 2001 to 2008 from the Truven Health MarketScan to identify more than 115,000 patients for the study population. They compared outcomes among 13,027 men diagnosed with male factor infertility (average age, 33 years), with outcomes among 23,860 men (average age, 33 years) who received semen or infertility testing and with outcomes among 79,099 men who had received vasectomies.

The authors looked for 16 conditions: hypertension, diabetes, hyperlipidemia, renal disease, chronic pulmonary disease, liver disease, depression, peripheral vascular disease, cerebrovascular disease, ischemic heart disease, other heart disease, injury, alcohol abuse, drug abuse, anxiety disorders, and bipolar disorder.

The men with infertility had higher rates of obesity and smoking, but even after adjustment for these covariates and for age, follow-up time, and healthcare use, men with infertility had a higher risk for multiple conditions compared with vasectomized men or those receiving only fertility testing. Specifically, compared with the men who received fertility testing, men with infertility had a 30% increased risk for diabetes (hazard ratio [HR], 1.30; 95% confidence interval [CI], 1.10 - 1.53), a 48% increased risk for ischemic heart disease (HR, 1.48; 95% CI, 1.19 - 1.84) and for alcohol abuse (95% CI, 1.07 - 2.05), a 67% increased risk for drug abuse (HR, 1.67; 95% CI, 1.06 - 2.63), and a 19% increased risk for depression (HR, 1.19; 95% CI, 1.04 - 1.36).

Compared with men who received vasectomies, those with infertility had a 9% higher risk for hypertension (HR, 1.09; 95% CI, 1.02 - 1.17), a 14% greater risk for hyperlipidemia (HR, 1.14; 95% CI, 1.07 - 1.22), a 41% greater risk for ischemic heart disease (HR, 1.41; 95% CI, 1.19-1.67), and a 16% greater risk for other heart disease (HR, 1.16; 95% CI, 1.04 - 1.29). Further, men with infertility, compared with vasectomized men, had an 81% greater risk for diabetes (HR, 1.81; 95% CI, 1.57 - 2.08), a 60% greater risk for renal disease (HR, 1.60; 95% CI, 1.14 - 2.24), a 53% greater risk for liver disease (HR, 1.53; 95% CI, 1.31 - 1.80), and a 52% greater risk for peripheral vascular disorders (HR, 1.52; 95% CI, 1.12 - 2.07).

Published on Leave a comment on Beneficial Foods: Blackberries, Red Raspberries, and Black Raspberries

It seems that a lot has been written about the health benefits of some berries, such as blueberries, while other berries have been neglected. This study focused on red raspberries, black raspberries, and blackberries. While the study was done in Poland, it was pointed out that these berries are also commonly grown in the USA. Red raspberry, black raspberry, and blackberry fruits are abundant in dietary phytochemicals such as flavonols, phenolic acids, ellagitannins, vitamins C and E, folic acid, and β-sitosterol. Many of these bioactive compounds exhibit antioxidant activity. Anthocyanins and other phenolic compounds such as ellagitannins and ellagic acid, which distinguish raspberry from other berries, occur in high levels and are mainly responsible for their broad beneficial health properties (including anti-inflammatory, antimicrobial, and antiviral activities).

For these reasons, the researchers said that "raspberry and blackberry fruits can be regarded as natural functional foods". Another term for functional foods is nutraceutical, which is a food containing health-giving additives and having medicinal benefit. From Science Daily:

Looking for the best antioxidant fruit? Search no further than black raspberries

As far as healthy foods go, berries make the top of the list. They contain potent antioxidants, which decrease or reverse the effects of free radicals -- natural byproducts of energy production that can play havoc on the body and that are closely linked with heart disease, cancer, arthritis, stroke or respiratory diseases.

Unsurprisingly, the benefits of berries are extoled in one study after another....The research published now in Open Chemistry suggests that black raspberries grown in Central Europe show greater health benefits than their better known cousins -- raspberries or blackberries.

A group of researchers led by Anna Małgorzata Kostecka-Gugała measured the content of phenolics and anthocyanins in black raspberries, red raspberries and blackberries, assessing their antioxidant potential and health benefits. They were able to confirm that the antioxidant activity of natural products correlates directly with their health promoting properties.

It turns out that the amount of antioxidants in black raspberries was three times higher than the other fruits under investigation. Remarkably, the number was even higher for phenolics or the amount of anthocyanines -- with black raspberries topping their humble cousins by over 1000%. But most interestingly, black raspberries seem to be characterized by a higher content of secondary metabolites, which have been proved beneficial for human health.

Published on Leave a comment on Loneliness Is a Health Risk

Loneliness or social isolation is a health risk that can increase the risk of chronic illness and premature death. Why?  Loneliness leads to fight-or-flight stress signaling, which can ultimately affect the production of white blood cells. Essentially, lonely people had a less effective immune response and more inflammation than non-lonely people. The study was part of the Chicago Health, Aging, and Social Relations Study (CHASRS) and followed 144 people over 10 years. From Science Daily:

Loneliness triggers cellular changes that can cause illness, study shows

Loneliness is more than a feeling: For older adults, perceived social isolation is a major health risk that can increase the risk of premature death by 14 percent.

Now a team of researchers, including U Chicago psychologist and leading loneliness expert John Cacioppo, has released a study shedding new light on how loneliness triggers physiological responses that can ultimately make us sick. The paper.... shows that loneliness leads to fight-or-flight stress signaling, which can ultimately affect the production of white blood cells. The study examined loneliness in both humans and rhesus macaques, a highly social primate species.

Previous research from this group had identified a link between loneliness and a phenomenon they called "conserved transcriptional response to adversity" or CTRA. This response is characterized by an increased expression of genes involved in inflammation and a decreased expression of genes involved in antiviral responses. Essentially, lonely people had a less effective immune response and more inflammation than non-lonely people.

For the current study, the team examined gene expression in leukocytes, cells of the immune system that are involved in protecting the body against bacteria and viruses. As expected, the leukocytes of lonely humans and macaques showed the effects of CTRA--an increased expression of genes involved in inflammation and a decreased expression of genes involved in antiviral responses. But the study also revealed several important new pieces of information about loneliness' effect on the body.

Next, the team investigated the cellular processes linking social experience to CTRA gene expression in rhesus macaque monkeys at the California National Primate Research Center, which had been behaviorally classified as high in perceived social isolation. Like the lonely humans, the "lonely like" monkeys showed higher CTRA activity. They also showed higher levels of the fight-or-flight neurotransmitter, norepinephrine.

Previous research has found that norepinephrine can stimulate blood stem cells in bone marrow to make more of a particular kind of immune cell--an immature monocyte that shows high levels of inflammatory gene expression and low levels of antiviral gene expression. Both lonely humans and "lonely like" monkeys showed higher levels of monocytes in their blood.

Taken together, these findings support a mechanistic model in which loneliness results in fight-or-flight stress signaling, which increases the production of immature monocytes, leading to up-regulation of inflammatory genes and impaired anti-viral responses. The "danger signals" activated in the brain by loneliness ultimately affect the production of white blood cells. The resulting shift in monocyte output may both propagate loneliness and contribute to its associated health risks.

Published on Leave a comment on How a Sneeze Travels Through a Room

 Cold and flu season will soon be here, so it's time to review sneeze basics. Here's a nice little study looking at where our sneeze germs wind up - answer: basically all over the room within a "high propulsion sneeze cloud". From Medical Xpress;

Ah-choo! Sneeze 'cloud' quickly covers a room, study finds

Just in time for cold and flu season, a new study finds the average human sneeze expels a high-velocity cloud that can contaminate a room in minutes. Researchers at the Massachusetts Institute of Technology (MIT) came to that conclusion by analyzing videos of two healthy people sneezing about 50 times over several days.

It's well known that sneezes can spread infectious diseases such as measles or the flu, because viruses suspended in sneeze droplets can be inhaled by others or deposited on surfaces and later picked up as people touch them. But it wasn't clear how far sneeze droplets can spread, or why some people are more likely to spread illness through sneezes than others. In a prior study, the team led by MIT's Lydia Bourouiba found that within a few minutes, sneeze droplets can cover an area the size of a room and reach ventilation ducts at ceiling height.

In their latest new study, they discovered how sneeze droplets are formed within what they called a "high-propulsion sneeze cloud." The findings are slated for presentation Monday at the annual meeting of the American Physical Society in Mobile, Ala.

"Droplets are not all already formed and neatly distributed in size at the exit of the mouth, as previously assumed in the literature," Bourouiba said in a society news release. Rather, sneeze droplets "undergo a complex cascading breakup that continues after they leave the lungs, pass over the lips and churn through the air," said Bourouiba, who is head of MIT's Fluid Dynamics of Disease Transmission Laboratory.

Published on Leave a comment on Some Health Benefits of Eating Tree Nuts Daily

A newly published study reviewed 61 studies that looked at daily tree nut consumption on cardiovascular risk factors and found many health benefits. Tree nut (walnuts, almonds, pistachios, macadamia nuts, pecans, cashews, hazelnuts, and Brazil nuts) consumption lowers total cholesterol, LDL cholesterol, triglycerides, and ApoB, the primary protein in LDL cholesterol. It appeared that nut dose is more important than nut type in lowering cholesterol. The beneficial health effects are greater at about 60 grams (about 2 oz or 2 servings) or more nuts consumed per day, but positive health effects are also found at one serving per day. Five studies found that 100 g nuts per day lowered concentrations of LDL cholesterol by up to 35 mg/dL - an effect size comparable to some statin regimens.

Tree nuts are rich in unsaturated fats, soluble fiber, antioxidants, and phytosterols, which produce beneficial effects on serum lipids, blood pressure, and inflammation. Most studies have looked at walnut and almond consumption, but studies found positive benefits for all types of nuts consumed. From Medical Xpress:

Study finds tree nut consumption may lower risk of cardiovascular disease

A new study published in the American Journal of Clinical Nutrition found that consuming tree nuts, such as walnuts, may lower the risk of cardiovascular disease. After conducting a systematic review and meta-analysis of 61 controlled trials, one of the authors, Michael Falk, PhD, Life Sciences Research Organization, found that consuming tree nuts lowers total cholesterol, triglycerides, LDL cholesterol, and ApoB, the primary protein found in LDL cholesterol. These are key factors that are used to evaluate a person's risk of cardiovascular disease. Walnuts were investigated in 21 of the 61 trials, more than any other nut reviewed in this study.

"Our study results further support the growing body of research that tree nuts, such as walnuts, can reduce the risk of cardiovascular diseases," said Dr. Falk. "Tree nuts contain important nutrients such as unsaturated fats, protein, vitamins and minerals. Walnuts are the only nut that provide a significant amount (2.5 grams per one ounce serving) of alpha-linolenic acid (ALA), the plant-based form of omega-3s."

Beyond finding that tree nuts lower total cholesterol, triglycerides, LDL cholesterol and ApoB, researchers also found that consuming at least two servings (two ounces) per day of tree nuts, such as walnuts, has stronger effects on total cholesterol and LDL. Additionally, results showed that tree nut consumption may be particularly important for lowering the risk of heart disease in individuals with type 2 diabetes.

Of 1,301 articles surveyed, 61 trials met eligibility criteria for this systematic review and meta-analysis, totaling 2,582 unique participants. Trials directly provided nuts to the intervention group rather than relying solely on dietary advice to consume nuts. The dose of nuts varied from 5 to 100 g/day and most participants followed their typical diet.

Published on Leave a comment on Lifestyle Habits That May Protect Men From Lethal Prostate Cancer

Data from 2 huge studies was analyzed and found that vigorous exercise and other healthy habits seems to cut the chance of developing aggressive and lethal prostate cancer up to 68 percent in men over 60. The beneficial lifestyle habits are: weekly vigorous exercise or activity to the point of sweating, at least 7 servings of tomatoes a week, at least one serving of fatty fish per week, reduced intake of processed meat, and being a long-term non-smoker.

Interestingly, vigorous activity or exercise to sweating - ideally up to 3 hours a week - showed the biggest association with a 34 % reduced risk of aggressive prostate cancer.

From Science Daily: Working up a sweat may protect men from lethal prostate cancer

A study that tracked tens of thousands of midlife and older men for more than 20 years has found that vigorous exercise and other healthy lifestyle habits may cut their chances of developing a lethal type of prostate cancer by up to 68 percent.

While most prostate cancers are "clinically indolent," meaning they do not metastasize and are nonlife-threatening, a minority of patients are diagnosed with aggressive disease that invades the bone and other organs, and is ultimately fatal. Lead author Stacey Kenfield, ScD, of UCSF, and a team of researchers at UCSF and Harvard, focused on this variant of prostate cancer to determine if exercise, diet and smoke-free status might have life-saving benefits.

In the study, published in the Journal of the National Cancer Institute, the researchers analyzed data from two U.S. studies: the Health Professionals Follow-Up Study that tracked more than 42,000 males ages 40 to 75, from 1986 to 2010; and a second, the Physicians' Health Study that followed more than 20,000 males ages 40 to 84, from 1982 to 2010.

To gage the effects of lifestyle habits, the researchers developed a score based on the results of the health professionals survey, then applied it to the physicians' study. They assigned one point for each affirmative response to questions about regular intense exercise that induced sweating, body mass index (BMI) under 30, tobacco-free status for a minimum of 10 years, high intake of fatty fish, high intake of tomatoes and low intake of processed meat.

The researchers identified 576 cases of lethal prostate cancer in the health professionals' group and 337 cases in the physicians' group. Participants with 5 to 6 points in the health professionals' group had a 68 percent decreased risk of lethal prostate cancer and a 38 percent decreased risk was observed in the physicians' group for the same comparison.

"We estimated that 47 percent of lethal prostate cancer cases would be prevented in the United States if men over 60 had five or more of these healthy habits," said Kenfield, assistant professor in the Department of Urology at UCSF Medical Center, and formerly of the Department of Medicine at Harvard Medical School in Boston, where the study was initiated.

"It's interesting that vigorous activity had the highest potential impact on prevention of lethal prostate cancer. We calculated the population-attributable risk for American men over 60 and estimated that 34 percent of lethal prostate cancer would be reduced if all men exercised to the point of sweating for at least three hours a week," Kenfield said.

The researchers also calculated that lethal prostate cancer among American men over 60 would be cut by 15 percent if they consumed at least seven servings of tomatoes per week and that 17 percent would be spared this diagnosis if they consumed at least one serving of fatty fish per week. Reducing intake of processed meats would cut the risk by 12 percent, they reported. In contrast, the population-attributed risk for smoking was 3 percent, largely because the majority of older American men are long-term nonsmokers.

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Published on 1 Comment on Problems With Scented Candles

 Several people have recently asked me whether scented candles have any health effects. The answer is a big YES - they have many negative health effects, and so do other scented products such as air fresheners and dryer sheets (e,g, Bounce). All of them contain fragrances and other chemicals - all from petrochemicals (which means they are chemical products derived from petroleum). And yes - all 3 products are totally unnecessary, so ditch them for better health. View all of them as sources of indoor air pollution.

Most of the candles on the market are made with paraffin wax, derived from petroleum, and scented with synthetic fragrances, also derived from petroleum. Synthetic fragrances typically also contain phthalates that can interfere with your hormone system (endocrine disruptors).

In one study scientists at the South Carolina State University lit several brands of candles made of paraffin – the most common and inexpensive candle wax – as well as soy candles (thus vegetable based) and burned them for 5 to 6 hours in a chamber. All of the candles were unscented and undyed. They found that the paraffin candle smoke emits varying levels of pollutants, including benzene, toluene and ketones, as well as hydrocarbon chemicals called alkanes and alkenes, which are components of gasoline. They have been linked to cancer, asthma and birth defects. None of the vegetable-based soy candles produced toxic chemicals. From SC State University:  Frequent use of certain candles produces unwanted chemicals

Researchers point out that the emissions from burning an occasional paraffin candle will not likely cause health problems - it's the frequent lighting of scented paraffin candles in indoor rooms, and inhaling the pollutants in the air that may cause health problems, or as Dr. Massoudi of S. Carolina State University stated: "could contribute to the development of health risks like cancer, common allergies and even asthma."

Scented candles are known to release various volatile organic compounds (VOCs) including both pleasant aromas and toxic components both before lighting (unlit) and when lit. When lit, the "highest emission concentration" was of formaldehyde. By simply touching the candles, one absorbs chemicals through the skin.

Safe candle alternatives are beeswax candles and unscented soy candles. These do not emit toxic chemicals when burned. However, all burning candles emit soot, which is ultrafine, lung-damaging particulate matter that's capable of penetrating deep into the lungs.

From Huffington Post: The Big Problem With Scented Candles

Scented candles are one of the easiest and most effective ways to mask unpleasant odors in your home....But one of the main problems with scented candles is the scent itself. According to Anne Steinemann, an environmental pollutants expert who is a professor of civil engineering and the chair of sustainable cities at the University of Melbourne, certain candles may emit numerous types of potentially hazardous chemicals, such as benzene and toluene. They can cause damage to the brain, lung and central nervous system, as well as cause developmental difficulties.

"I have heard from numerous people who have asthma that they can’t even go into a store if the store sells scented candles, even if they aren’t being burned," Steinemann added. "They emit so much fragrance that they can trigger asthma attacks and even migraines."

Researchers at South Carolina State University tested both petroleum-based paraffin wax candles and vegetable-based candles that were non-scented, non-pigmented and free of dyes. Their 2009 report concluded that while the vegetable-based candles didn't produce any potentially harmful pollutants, the paraffin candles "released unwanted chemicals into the air," said chemistry professor Ruhullah Massoudi in a statement.

It may be shocking to think that your favorite candles could potentially be bad for you, and made worse by added fragrances. Steinemann said for some people, the effects are "immediate, acute and severe," while others may not realize they are being effected until they gradually develop health issues.

Though the risk to you may be small, there are alternatives. Steinemann suggests going the unscented route, avoiding "even those with essential oils, as they can potentially have hazardous chemicals," she said. "It's almost like air fresheners with the fragrance just sitting there ... permeating surfaces in the room."