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The researchers of a recent study caution about the regular use of lavender and tea tree essential oils (e.g. in lotions or soaps) - that the oils may act as endocrine disruptors (chemicals that disrupt hormones and their actions in the body). Earlier research found a link between regular use of lavender essential oil and tea tree oil and abnormal breast growth in boys - called prepubertal gynecomastia. The condition went away after they stopped using the products.

Now researchers examined 8 common chemical components of lavender and tea tree oils for endocrine disrupting activity in lab tests - and yes, they found varying degrees of endocrine-disrupting activity in the chemicals. The researchers (from the National Institute of Environmental Health Sciences or NIEHS) warn that endocrine disrupting chemicals found in these 2 essential oils are also found in 65 other essential oils.

Note that essential oils are widely available, but they are not regulated by the FDA. Bottom line: No matter the age, avoid prolonged use of lavender and tea tree oil in personal care products, including "aromatherapy" -  especially important for children and pregnant women. The results were presented today at the 100th annual meeting of the Endocrine Society (ENDO) in Chicago. From Science Daily:

Chemicals in lavender and tea tree oil appear to be hormone disruptors

A new study lends further evidence to a suspected link between abnormal breast growth in young boys -- called prepubertal gynecomastia -- and regular exposure to lavender or tea tree oil, by finding that key chemicals in these common plant-derived oils act as endocrine-disrupting chemicalsLavender and tea tree oil are among the so-called essential oils that have become popular in the United States as alternatives for medical treatment, personal hygiene and cleaning products, and aromatherapy. Various consumer products contain lavender and tea tree oil, including some soaps, lotions, shampoos, hair-styling products, cologne and laundry detergents.   ...continue reading "Are Some Essential Oils Endocrine Disruptors?"

Once again a study found that a high fiber diet feeds beneficial gut microbes and causes changes in the gut microbe community (the microbiome). What's new in this study is that eating the high fiber diet had health benefits for people with type 2 diabetes - that it lowered their blood sugar levels (better blood glucose control), resulted in  greater weight loss, and better lipid levels. And that when these gut microbes were transplanted into mice - they had similar health effects (better regulation of blood sugar). Which showed it was the microbes that caused the beneficial effects.

What foods are high-fiber foods? Fruits, vegetables, whole grains, nuts, seeds, and legumes (beans). [See Feeding Your Gut Microbes] From The Scientist:

High-Fiber Diet Shifts Gut Microbes, Lowering Blood Sugar in Diabetics

A diet high in fiber can reshape the gut microbiome, helping people with type 2 diabetes stay healthy. A study published yesterday (March 8) in Science found that when patients with the condition ate a high-fiber diet, they had an abundance of microbial species that helped to reduce blood sugar and regulate weight compared with cohorts who ate a less fiber-rich diet ...continue reading "High Fiber Diet Is Beneficial For Those With Type 2 Diabetes"

People often wonder if there are any health benefits to buying organic milk versus conventional milk. And further, how about grass-fed organic milk? Now a recent study answers that question nicely with regards to beneficial fatty acids. Keep in mind that ideally (for health benefits) want fewer omega-6 fatty acids, and more omega-3 fatty acids, with a ratio close to 1. Guess which is the healthiest? The 100% grass-fed organic milk (ratio of .95 - just about 1) is best, then the organic milk, and in last place - conventional milk. Why is that? It's due to different food and grazing requirements (see below). From Beyond Pesticides:

Study Finds Grass-Fed and Organic Milk to be Healthier Than Conventional

Milk from 100% grass-fed cows has higher levels of beneficial fatty acids than conventional and even organic milk, according to a study published by an international team of scientists in the journal Food Science and Nutrition. The research follows up on data published in 2013, which compared only conventional and organic milk, finding organic milk contained 62 percent more omega-3 fatty acids and 25 percent fewer omega-6s

The study compared the composition of several fatty acids within the three types of milk tested (conventional, organic, and grass-fed). Of primary concern was the ratio of omega 6 to omega 3 fatty acids. Although omega 6s are not necessarily bad fats, high amounts or unbalanced ratios of omega-6 to omega-3s has been linked to a range of health problems, from cardiovascular disease, to cancer and other illnesses. High consumption of omega 3s, on the other hand, is linked to reduced risks of a number of diseases, including diabetes, high blood pressure, high cholesterol, cancer, and many other chronic disorders. The diet of early humans maintained a ratio of 1, but modern Western food production, with its focus on processed and hydrogenated fats, has raised that ratio to an average of 15.

Looking at over 1,600 milk samples over a 3-year span, results found ratios of omega-6 to omega-3 to be .95 for 100% grassfed milk, 2.28 for organic milk, and 5.77 in conventional milk ...continue reading "Differences Between Grass-Fed Organic, Organic, and Conventional Milk"

Just read about an international study that discussed how millions of bacteria and viruses circle the earth in the earth's atmosphere every day, and get deposited on land by rain and dust particles. Which could explain why similar viruses and bacteria are found in totally different environments in different parts of the world. The study measured what was deposited high in the mountains of the Sierra Nevada, but one would expect microbes to be deposited everywhere, not just in high mountains. We are surrounded by microbes! (Another post on this topic.) From Astrobiology:

Most Viruses And Bacteria Fall From The Sky

An international research project led by the University of Granada has revealed for the first time that almost one billion viruses and more than twenty million bacteria circulate in the Earth's atmosphere and are deposited in high-mountain places every day. The research findings, published recently in the ISME Journal: Multidisciplinary Journal of Microbial Ecology (part of the Nature group) help to explain why genetically identical viruses have been found in such distant locations and diverse environments of the planet. The University of British Columbia (Canada) and San Diego State University (United States) also participated in the project.  ...continue reading "Viruses and Bacteria Circle the Earth and Fall In Rain and Dust"

The results of a recent study in the United Kingdom are in line with what a number of researchers (here, here, and here) have been writing about for a while - that studies show that some cancer screening (e.g. for prostate cancer) of people with no symptoms does not save lives.

The UK study randomly assigned men (aged 50 to 69) to get a PSA test one time or to not get a PSA test (the controls). The PSA test measures prostate-specific antigen in the blood, and is typically used to screen for prostate cancer. It is not done routinely in the UK. They found that while more men were diagnosed with prostate cancer in the PSA group, after 10 years there was no statistical difference in death rates between the two groups. As the researchers themselves said, the PSA screening test resulted in "an increase in the detection of low-risk prostate cancer cases" (the ones that wouldn't cause a problem). But not in the aggressive killer cancers.  However, the researchers are now continuing the study to see if there are differences in the 2 groups after an even longer period of time. From Medical Xpress:

One-off PSA screening for prostate cancer does not save lives

Inviting men with no symptoms to a one-off PSA test for prostate cancer does not save lives according to results from the largest ever prostate cancer trial conducted over 10 years by Cancer Research UK-funded scientists and published today (Tuesday) in the Journal of the American Medical Association (JAMA). Researchers at the Universities of Bristol and Oxford found that testing asymptomatic men with PSA detects some disease that would be unlikely to cause any harm but also misses some aggressive and lethal prostate cancers.

The CAP Trial, which spanned almost 600 GP practices in the UK and included more than 400,000 men aged 50-69, is the largest trial ever to investigate prostate cancer screening. The trial compared 189,386 men who were invited to have a one-off PSA test with 219,439 men who were not invited for screening. After an average of 10 years follow up, there were 8,054 (4.3%) prostate cancers in the screened group and 7,853 (3.6%) cases in the control group. Crucially, both groups had the same percentage of men dying from prostate cancer (0.29%).

While some prostate cancers are aggressive and lethal, others are clinically insignificant and will never lead to any harm or death if left undetected. Ideally, aggressive prostate cancers need to be identified and treated as early as possible. But finding a cancer that would never have caused men harm during their lifetime can have a serious impact on quality of life, including the worry of a cancer diagnosis, the possibility of infection following a biopsy and impotence and incontinence following treatment. ... Dr Richard Roope, Cancer Research UK's GP expert, said: "The PSA test is a blunt tool missing the subtleties of the disease and causing men harm.

Are there foods that could prevent cancer? Well... studies show that a dietary pattern with lots of fiber, and perhaps along the lines of the Mediterranean diet, may be the most beneficial. In other words, it's not just one or a few "super-foods" that a person should eat, but an overall dietary pattern. But one specific food does appear beneficial for health - nuts, specifically tree nuts.

Researchers at the Yale Cancer Center followed a large group of stage 3 colon cancer patients after they had been treated for about 6.5 years, and looked at how frequently they consumed nuts. (Stage 3 colon cancer means it had spread to lymph nodes, but not to distant sites like the liver and lungs.) They found an association with frequent consumption (2 or more servings per week) of tree nuts (walnuts, hazelnuts, almonds, cashews, pecans, etc.) and a 42% lower incidence of the colon cancer recurring and 57% lower death rate. However, these findings did not apply to peanuts, which are legumes. [NOTE: One ounce or a handful of nuts is considered a serving.]

Why would nuts be beneficial? Generally speaking, nuts lower inflammation and insulin resistance. The lead researcher Dr. Charles Fuchs said that "behaviors that make you less insulin-resistant, including eating nuts, seem to improve outcomes in colon cancer". Parts of this research were discussed last year, but now it has been written up in the Journal of Clinical Oncology. ...continue reading "Nuts And Colon Cancer"

Recently I was asked about the human skin microbiome (skin microbial communities) and whether the things we do frequently (e.g. use soap and shampoo, go swimming in a pool) has an effect on our skin microbiome. As I've posted earlier, human skin microbes include bacteria, fungi, viruses, and  archaea. Most of these microbes are harmless or beneficial, but when the microbial communities are out of whack (dysbiosis), then there are diseases or skin disorders (such as acne, psoriasis, and eczema). The human skin acts as a physical barrier, a first line of defense, to pathogens (microbes that can cause disease). Studies have found that using soaps, lotions, make-up, our diet and lifestyle all have some effect on skin microbial communities. Even living with someone results in some microbial exchange. Spending more time outdoors, owning pets, and drinking less alcohol (or none) are all associated with higher levels of microbial skin diversity.

But then I came across a small study from 2016 (National Human Genome Research Institute, NIH, Bethesda, MD) in Cell - Temporal Stability of the Human Skin Microbiome. The researchers found that skin microbial communities are "surprisingly stable over time" (the study lasted 2 years), even though the humans were typically exposed to things daily that could disrupt their skin microbial communities (other people, clothing, the environments). But some individuals had more stable communities than others, and stability varied from site to site (the feet had the least stable microbial communities). Also, they found that bacterial, fungal, and viral communities not only show a strong preference for inhabiting specific skin sites, but also serve as "microbial fingerprints" that are highly unique to individuals. They did point out that "immunosuppression, illness, or the occurrence of disease have been shown to cause major shifts in skin communities".

Then there is a recent 2018 review article - but behind a paywall even though the researchers worked for NIH, thus paid for with our tax dollars (!!).They also discussed all the microbes living on the skin, and how when the microbial communities are out of whack (dysbiosis), then there is disease (whether acne, or eczema, etc.). Microbes that are beneficial in healthy people can become pathogenic, e.g. when the person has a disease. It also pointed out that only with modern genetic sequencing methods (rather than old style "cultures") can one really see what makes up the skin microbial communities. And that using these methods we can compare the skin microbes of healthy persons with those with a disease. And yes, there then is also the possibility of finding protective, beneficial microorganisms which are in healthy persons, but absent or under-represented in those with a disease. Sounds  like probiotics for the skin! ...continue reading "Microbes of the Skin"

Once again, a study found an association between a worrisome health problem (intestinal polyps) with a dietary supplement (calcium), but no problems with eating the foods (calcium rich foods). The large multi-center study specifically looked at serrated polyps (SPs) because they are considered precursor lesions for colorectal cancer - that is, that while they are not cancerous, some of them will develop into cancer. Persons invited to join the study had a recent colonoscopy with at least one adenomatous polyp detected and removed, and then were scheduled for another colonoscopy 3 to 5 years later. This was considered a "chemoprevention study" to see if certain supplements help prevent polyps (and thus cancer).

People in different parts of the US were randomly assigned to either receive calcium supplements (1200 mg/day of elemental calcium), vitamin D (1000 IU/day of vitamin D3),  both supplements (calcium supplement plus vitamin D), or neither. Supplement treatment continued for 3 to 5 years and then there was an observational period that was 6 to 10 years after the person first started supplementation. The higher incidence of serrated polyps was a "late effect" (6 to 10 years later) and not seen during the treatment time (the first 3 to 5 years). They found that women and current smokers had higher risks of serrated polyps when exposed to supplemental calcium. Vitamin D alone was not linked with polyps.

Other studies have also found an association between calcium supplements and increased risk of certain health problems, and a lower incidence of polyps with a higher intake of dietary calcium (real food). The researchers said: "Patients with a history of premalignant serrated polyps, especially women and smokers, may wish to avoid vitamin D and calcium supplementation." BOTTOM LINE: General guidelines should be to eat foods, not supplements, to get your nutrients, vitamins, and minerals. There are many studies also at this point that a high fiber diet with lots of fruits, vegetables, whole grains, legumes (beans), nuts, seeds are associated with better intestinal health and fewer polyps (here, here). Another way to view it is: feed your beneficial gut microbes with good, real food. And especially not highly processed junk. From Medical Xpress:

Calcium supplements may boost risk of abnormal bowel growths

Calcium supplements, taken with or without vitamin D, may increase the risk of small growths in the large bowel (colon) called polyps, suggest results from a large US trial published online in the journal Gut. Polyps are small growths in the lower part of the large bowel. They are non-cancerous, but some could eventually turn into cancer if they are not removed. Polyps come in different shapes and sizes, and this study specifically focused on the risk of serrated polyps, which are less common than conventional "adenomatous" polyps, but likely have the same risk of developing into cancer. 

...continue reading "Best to Eat Calcium Rich Foods, Not Calcium Supplements"

...continue reading "Can We Avoid the Endocrine Disruptors Around Us?"

Study after study has found negative health effects from frequent heavy drinking of alcohol, including a number of cancers. On the other hand, light to moderate drinking seems to have some health benefits (here and here). Recently a large study conducted in France found that chronic heavy drinking, which has resulted in alcohol use disorders (alcohol abuse, alcohol dependence, or alcoholism), is the biggest risk factor for developing dementia, especially early onset dementia. Only people with alcohol use disorders which resulted in them being hospitalized were included in the study.

But the surprising thing was that lower levels of "chronic heavy drinking" doesn't seem so much - it's daily consumption of more than 60 grams of pure alcohol  for men, and more than 40 grams of pure alcohol for women. In the United States, a standard drink contains about 14 grams of alcohol - which is a 12 ounce (350 ml) glass of beer, a 5 ounce (150 ml) glass of 12% wine, or a 1.5 ounce (44 ml) glass of spirits. In other words, drinking 3 glasses of wine daily (or more) is heavy drinking for a woman. (Note: The Centers for Disease Control (CDC) views moderate drinking as 1 glass of wine daily for women, and 2 glasses of wine daily for men).  ...continue reading "Heavy Drinking And Risk of Dementia"