Is there risk of lead and PPD contamination of red and black henna?

The “average adult uses nine personal care products each day, with 126 unique chemical ingredients.” We used to think that anything applied to the skin would “always remain on the surface of the body,” and the only thing you had to worry about were problems like local skin irritation. But, over recent decades, “it was recognized that some topically applied substances can penetrate into or through human skin” and end up circulating throughout our bodies.

Take the toxic heavy metal lead (Pb), for example. As you can see in the graph below and at 0:38 in my video Is Henna Safe?, to see if lead could be absorbed through the skin into the body, researchers applied lead to a subject’s left arm and then measured the level of lead in the sweat coming off their right

What, if any, are the caveats for tea tree oil use and tips on safe storage?

Is tea tree oil toxic? That’s the topic of my video, Is Tea Tree Oil Safe?. “Anecdotal evidence…suggests that the topical use of the oil is relatively safe, and that adverse events are minor, self-limiting and occasional.” Published data, however, add some caveats: It can be “toxic if ingested in higher doses and can also cause skin irritation at higher concentrations.”

Normally, tea tree oil reduces skin inflammation. Researchers injected histamine into the skin of 27 volunteers, the equivalent of getting bitten by a fire ant. The application of tea tree oil significantly decreased the associated swelling and discoloration—the big, red, swollen mark. As you can see in the graph below and at 0:45 in my video, the swelling and discoloration continues to get worse after application of a placebo oil,

Do the estrogenic effects of tea tree oil get absorbed through the skin?

Concern has been raised about a “possible link between gynecomastia, topical lavender, and tea tree oil.” As I discuss in my video Does Tea Tree Oil Have Hormonal Side Effects?, gynecomastia is the abnormal development of breast tissue. (You can see a photo at 0:14 in my video.) You may recall that I’ve talked about lavender before, but what about tea tree oil?

It all started with a case series published in The New England Journal of Medicine. The researchers described three young boys in whom breast growth “coincided with the topical application of products that contained lavender and tea tree oils.” How do we know the products were to blame? “Gynecomastia resolved in each patient shortly after the use of products containing these oils was discontinued. Furthermore, studies in human cell lines indicated that

If there were such a thing as a “superfood,” cruciferous vegetables like broccoli would certainly be wearing the cape. Along with kale, collards, cabbage, bok choy, cauliflower, and many others in that vegetable family, crucifers contain a relatively unique class of phytonutrients that can potentially help prevent DNA damage, metastatic cancer spread, and lymphoma; activate defenses against pathogens and pollutants; boost your liver detox enzymes; target breast cancer stem cells; and reduce the risk of prostate cancer progression. That’s why I include cruciferous veggies in my Daily Dozen healthiest-of-healthy-foods checklist. For more information and all of my videos on broccoli, check out the topic page.

Recipe: Mexican-Inspired Bowl

If you’ve found yourself with a sudden hankering for broccoli, try this recipe from Ángela, our Spanish Social Media and Program Coordinator. With broccoli, beans, whole grains, and a homemade salsa, her recipe will check off several of your Daily Dozen

Add some green to your Black Friday with 20 percent off all merchandise on DrGreger.org. The sale is site-wide, so it includes all clothing, video downloads, outreach materials, and more. If you’re heading into winter, cozy up with our sweatpants (back by popular demand!), hoodies, or a crewneck sweatshirt. Sale ends November 28. All proceeds go to keeping NutritionFacts.org running! 

Key Takeaways: Walnuts

The Global Burden of Disease Study calculated that not eating enough nuts and seeds was the third-leading dietary risk factor for death and disability in the world. That is why I recommend a daily serving of at least ¼ cup nuts or seeds or 2 tablespoons of nut or seed butter in my Daily Dozen checklist. So, which nut is healthiest? Walnuts really seem to take the lead due to their high antioxidant and omega-3 levels, and they beat out other nuts in vitro in suppressing cancer