What’s the difference between physical and chemical sunscreens? And which one should you choose?
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Sun exposure can accelerate ageing, cause skin burns, erythema (a skin reaction), skin cancer, melasmas (or sun spots) and other forms of hyperpigmentation – all triggered by solar ultraviolet radiation.
Approximately 80% of skin cancer cases in people engaged in outdoor activities are preventable by decreasing sun exposure. This can be done in lots of ways including wearing protective clothing or sunscreens.
But not all sunscreens work in the same way. You might have heard of “physical” and “chemical” sunscreens. What’s the difference and which one is right for you?
How sunscreens are classified
Sunscreens are grouped by their use of active inorganic and organic ultraviolet (UV) filters. Chemical sunscreens use organic filters such as cinnamates (chemically related to cinnamon oil) and benzophenones. Physical sunscreens (sometimes called mineral sunscreens) use inorganic filters such as titanium and zinc oxide.
These filters prevent the effects of UV radiation on the skin.
Organic UV filters are known as chemical filters because the molecules in them change to stop UV radiation reaching the skin. Inorganic UV filters are known as physical filters, because they work through physical means, such as blocking, scattering and reflection of UV radiation to prevent skin damage.
Nano versus micro
The effectiveness of the filters in physical sunscreen depends on factors including the size of the particle, how it’s mixed into the cream or lotion, the amount used and the refraction index (the speed light travels through a substance) of each filter.
When the particle size in physical sunscreens is large, it causes the light to be scattered and reflected more. That means physical sunscreens can be more obvious on the skin, which can reduce their cosmetic appeal.
Nanoparticulate forms of physical sunscreens (with tiny particles smaller than 100 nanometers) can improve the cosmetic appearance of creams on the skin and UV protection, because the particles in this size range absorb more radiation than they reflect. These are sometimes labelled as “invisible” zinc or mineral formulations and are considered safe.
So how do chemical sunscreens work?
Chemical UV filters work by absorbing high-energy UV rays. This leads to the filter molecules interacting with sunlight and changing chemically.
When molecules return to their ground (or lower energy) state, they release energy as heat, distributed all over the skin. This may lead to uncomfortable reactions for people with skin sensitivity.
Generally, UV filters are meant to stay on the epidermis (the first skin layer) surface to protect it from UV radiation. When they enter into the dermis (the connective tissue layer) and bloodstream, this can lead to skin sensitivity and increase the risk of toxicity. The safety profile of chemical UV filters may depend on whether their small molecular size allows them to penetrate the skin.
Chemical sunscreens, compared to physical ones, cause more adverse reactions in the skin because of chemical changes in their molecules. In addition, some chemical filters, such as dibenzoylmethane tend to break down after UV exposure. These degraded products can no longer protect the skin against UV and, if they penetrate the skin, can cause cell damage.
Due to their stability – that is, how well they retain product integrity and effectiveness when exposed to sunlight – physical sunscreens may be more suitable for children and people with skin allergies.
Although sunscreen filter ingredients can rarely cause true allergic dermatitis, patients with photodermatoses (where the skin reacts to light) and eczema have higher risk and should take care and seek advice.
What to look for
The best way to check if you’ll have a reaction to a physical or chemical sunscreen is to patch test it on a small area of skin.
And the best sunscreen to choose is one that provides broad-spectrum protection, is water and sweat-resistant, has a high sun protection factor (SPF), is easy to apply and has a low allergy risk.
Health authorities recommend sunscreen to prevent sun damage and cancer. Chemical sunscreens have the potential to penetrate the skin and may cause irritation for some people. Physical sunscreens are considered safe and effective and nanoparticulate formulations can increase their appeal and ease of use.
Yousuf Mohammed, Dermatology researcher, The University of Queensland and Khanh Phan, Postdoctoral research associate, Frazer Institute, The University of Queensland
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Calm For Surgery – by Dr Chris Bonney
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As a general rule of thumb, nobody likes having surgery. We may like the results of the surgery, we may like having the surgery done and behind us, but surgery itself is not most people’s idea of fun, and honestly, the recovery period afterwards can be a pain in every sense of the word.
Dr. Chris Bonney, an anesthesiologist, gives us the industry-secrets low-down, and is the voice of experience when it comes to the things to know about and/or prepare in advance—the little things that make a world of difference to your in-hospital experience and afterwards.
Think of it like “frequent flyer traveller tips” but for surgeries, whereupon knowing a given tip can mean the difference between deeply traumatic suffering and merely not being at your usual best. We think that’s worth it.
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Longevity for the Lazy – by Dr. Richard Malish
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There are some people who devote all their resources to longevity, which can become a full-time occupation, not to mention a very expensive endeavor. This book’s for those who want to get the best possible “bang for buck” by doing the things that have the most favorable cost:worth ratio.
Dr. Malish covers what can be done easily for personal longevity, as well as what technological advances can be enjoyed that those before us didn’t have as options. He also discusses the diseases that are most likely to kill us, and how to avoid those.
He preaches a proactive approach, but one that is simple and consistent and based in good science, and good statistics. Indeed, while he’s served 20 years as an army doctor and a cardiologist, he now works as a healthcare policy consultant, so he is well-placed to advise.
The style of the book is halfway between regular pop-science and a textbook; you can either read it cover-to-cover, or skim first though the key points, highlight boxes, summaries, and the like. He also provides a time-phased task list, for those who like things to be laid out like that.
Bottom line: this is a very good, methodical guide to living longer without making it a full-time occupation.
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How community health screenings get more people of color vaccinated
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U.S. preventive health screening rates dropped drastically at the height of the COVID-19 pandemic. They have yet to go back to pre-pandemic levels, especially for Black and Latine communities.
Screenings, or routine medical checkups, are important ways to avoid and treat disease. They’re key to finding problems early on and can even help save people’s lives.
Community health workers say screenings are also a key to getting more people vaccinated. Screening fairs provide health workers the chance to build rapport and trust with the communities they serve, while giving their clients the chance to ask questions and get personalized recommendations according to their age, gender, and family history.
But systemic barriers to health care can often keep people from marginalized communities from accessing recommended screenings, exacerbating racial health disparities.
Public Good News spoke with Dr. Marie-Jose Francois, president and chief executive officer, and April Johnson, outreach coordinator, at the Center for Multicultural Wellness and Prevention (CMWP), in Central Florida, to learn how they promote the benefits of screening and leverage screenings for vaccination outreach among their diverse communities.
Here’s what they said.
[Editor’s note: This content has been edited for clarity and length.]
PGN: What is CMWP’s mission? How does vaccine outreach fit into the work you do in the communities you serve?
Dr. Marie-Jose Francois: Since 1995, our mission has been to enhance the health, wellness, and quality of life for diverse populations in Central Florida. At the beginning, our main focus was education, wellness, and screening for HIV/AIDS, and we continue to do case management for HIV screening and testing.
When the issue of COVID-19 came into the picture, we included COVID-19 information and education and stressed the importance of screening and receiving vaccinations during all of our outreach activities.
We try to meet the community where they are. Because there is so much misconception—and taboo—in regard to immunization.
April Johnson: So our job is to disperse accurate information. And how we do that is we go into rural communities. We build partnerships with local apartment complexes, hair salons, nail salons, laundromats, and provide a little community engagement, where people just hang out in different areas.
We build gatekeepers in those communities because you first have to get in there. You have to know that they trust you. Being in this field for about 30 years, I’ve [learned that] flexibility is key. Because sometimes you can’t get them from 9 to 5, or [from] Monday through Friday. So, you have to be very flexible in doing the outreach portion in order to get what you need.
I’ve built collaborations with senior citizen centers, community centers, schools, clinics, churches in Orlando and [in] different areas in Orange, Osceola, Seminole, and Lake counties. And we also partner with other community-based organizations to try to make it like a one-stop shop. So, partnership is a big thing.
PGN: How do you promote the importance of preventive screenings in the communities you serve?
M.F.: We try to make them view their health in a more comprehensive way, for them to understand the importance of screening. [That] self care is key, and for them to not be afraid.
We empower them to know what to ask when they go to the doctor. We ask them, ‘Do you know your status? Do you know your numbers?’
For example, if you go to the doctor, do you know your blood pressure? If you’re diabetic? Do you know your hemoglobin (A1C)? Do you know your cholesterol levels?
And now, [we also ask them]: ‘Have you received your flu shot for the year? Have you received all of your vaccine doses for COVID-19?’ We are even adding the mpox vaccine now, based on risk factors.
[We recommend they] ask their provider. For women, [we ask], ‘When do you need to have your mammogram?’ For the men, ‘You need to ask about your PSA and also about when and when to have your colonoscopy based on your age.’
We also try to explain to the community that the more they know their family history, the more they can engage in their own health. Because sometimes you have mom and dad who have a history of cancer. They have a history of diabetes or blood pressure—and they don’t talk to their children. So, we try to [recommend they] talk to their children. Your own family needs to know what’s going on so they can be proactive in their screenings.
PGN: What strategies or methods have you found most effective in getting people screened?
M.F.: Not everybody wants to be screened, not everybody wants to receive vaccines.
But with patience, just give them the facts. It goes right back to education, people have to be assured.
When you talk to them about COVID, or even HIV, you may hear them say, ‘Oh, I don’t see myself at risk for HIV.’ But we have to repeat to them that the more they get screened to make sure they’re OK, the better it is for them. ‘The more you use condoms, [the] safer it is for you.’
In Haitian culture, they listen to the radio. So we use the radio as a tool to educate and deliver information [to] get vaccinated, wash your hands. ‘If you’re coughing, cover your mouth. If you have a fever, wear your masks. Call your doctor.’
In our target population, we have people who have chronic conditions. We have people with HIV. So, we have to motivate them to receive the flu vaccine, to receive the COVID vaccine, to receive that RSV [vaccine], or to get the mpox vaccine. We have people with diabetes, high blood pressure, high cholesterol, depressed immune systems. We have people with lupus, we have people with sickle cell disease.
So, this is a way to [ensure that] whomever you’re talking to one-on-one understands the value of being safe.
This article first appeared on Public Good News and is republished here under a Creative Commons license.
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Muir Glen Organic vs First Field Original – Which is Healthier?
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Our Verdict
When comparing Muir Glen Organic Ketchup to First Field Original Ketchup, we picked the First Field.
Why?
This one was a little unfair to you, as you can’t turn them around to read the ingredients here. But the point we want to share the most today is: you have to turn them around and read the ingredients! You absolutely cannot rely on appearances!
While the Muir Glen Organic may have a very “greenwashed” aesthetic going on and the word “organic” is more eye-catching than any other word on the label, it contains 4x as much sugar and 4x as much sodium.
Side-by-side, they have, per tablespoon:
First Field Original: 1g sugar, 60mg sodium
Muir Glen Organic: 4g sugar, 240mg sodiumBut what about the importance of being organic?
Well, we have one more surprise for you: the First Field ketchup is organic too, non-GMO, and contains no added concentrates either.
This isn’t an ad for First Field (by all means enjoy their products or don’t; we’re not invested), but it is a heartfelt plea to always check the backs of products and read the labels, because fronts of products can’t be relied upon at all.
I’m sure we all get caught out sometimes, but the less often, the better!
PS: we write this, of course, before seeing the results of your voting. Maybe it won’t be a “Muir Glen Organic” sweep in the polls. But either way, it’s a call to vigilance, and a “very good, carry on” to everyone who does this already
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Cashew Nuts vs Coconut – Which is Healthier?
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Our Verdict
When comparing cashew nuts to coconut, we picked the cashews.
Why?
It can be argued this isn’t a fair comparison, as coconuts aren’t true nuts, but it’s at the very least a useful comparison, because they have very similar (often the same) culinary uses, so deciding between one or the other is something people will often do.
In terms of macros, cashews have 6x the protein and more than 2x the fiber, as well as slightly more fat (but the fats are healthy, as are those of coconut, by the way) and 2x the carbs. Depending on what you’re looking for, this head-to-head could come out differently, but we say it’s a win for cashews.
You may be wondering: if cashews have more of all those things, what are coconuts made of? And the answer is that coconuts have 8x the water (and yes, this is counting the coconut meat only, not including the milk inside). Of course, if you get dessicated coconut, then it won’t have that, but we’re comparing fresh to fresh.
In the category of vitamins, cashews have a lot more of vitamins B1, B2, B3, B5, B6, E, and K. Meanwhile, coconut has more vitamin C, but it’s not a lot. An easy win for cashews here.
When it comes to minerals, cashews have rather more calcium, copper, iron, magnesium, manganese, phosphorus, potassium, selenium, and zinc. On the other hand, coconut has more sodium. Another easy win for cashews.
Cashews also have the lower glycemic index.
All in all, cashews win the day.
Want to learn more?
You might like to read:
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Tasty Versatile Rice
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In the nearish future, we’re going to do some incredible rice dishes, but first we need to make sure we’re all on the same page about cooking rice, so here’s a simple recipe first, to get technique down and work in some essentials. We’ll be using wholegrain basmati rice, because it has a low glycemic index, lowest likelihood of heavy metal contamination (a problem for some kinds of rice), and it’s one of the easiest rices to cook well.
You will need
- 1 cup wholegrain basmati rice (it may also be called “brown basmati rice“; this is the same)
- 1 1/2 cups vegetable stock (ideally you have made this yourself from vegetable offcuts that you saved in the freezer, then it will be healthiest and lowest in sodium; failing that, low-sodium vegetable stock cubes can be purchased at most large supermarkets. and then made up at home with hot water)
- 1 tbsp extra virgin olive oil
- 1 tbsp chia seeds
- 1 tbsp black pepper, coarse ground
- 1 tsp turmeric powder (this small quantity will not change the flavor, but it has important health benefits, and also makes the rice a pleasant golden color)
- 1 tsp garlic powder
- 1 tsp yeast extract (this gently improves the savory flavor and also adds vitamin B12)
- Optional small quantity of green herbs for garnish. Cilantro is good (unless you have the soap gene); parsley never fails.
This is the ingredients list for a super-basic rice that will go with anything rice will go with; another day we can talk more extensive mixes of herbs and spice blends for different kinds of dishes (and different health benefits!), but for now, let’s get going!
Method
(we suggest you read everything at least once before doing anything)
1) Wash the rice thoroughly. We recommend using a made-for-purpose rice-washing bowl (like this one, for example), but failing that, simply rinse it thoroughly with cold water using a bowl and a sieve. You will probably need to rinse it 4–5 times, but with practice, it will only take a few seconds per rinse, and the water will be coming up clear.
2) Warm the pan. It doesn’t matter for the moment whether you’re using an electronic rice cooker, a stovetop pressure cooker, electronic pressure cooker, or just a sturdy pan with a heavy lid available, aside from that if it’s something non-stovetop, you now want it to be on low to warm up already.
3) Separately in a saucepan, bring your stock to a simmer
4) Put the tbsp of olive oil into the pan (even if you’re confident the rice won’t stick; this isn’t entirely about that) and turn up the heat (if it’s a very simple rice cooker, most at least have a warm/cook differentiation; if so, turn it to “cook”). You don’t want the oil to get to the point of smoking, so, to test the temperature as it heats, flick a single drop of water from your fingertip (you did wash your hands first, right? We haven’t been including that step, but please do wash your hands before doing kitchen things) into the pan. If it sizzles, the pan is hot enough now for the next step.
5) Put the rice into the pan. That’s right, with no extra liquid yet; we’re going to toast it for a moment. Stir it a little, for no more than a minute; keep it moving; don’t let it burn! If you try this several times and fail, it could be that you need a better pan. Treat yourself to one when you get the opportunity; until then, skip the toasting part if necessary.
6) Add the chia seeds and spices, followed by the stock, followed by the yeast extract. Why did we do the stock before the yeast extract? It’s because hot liquid will get all the yeast extract off the teaspoon 🙂
7) Put the lid on/down (per what kind of pan or rice cooker you are using), and turn up the heat (if it is a variable heat source) until a tiny bit of steam starts making its way out. When it does, turn it down to a simmer, and let the rice cook. Don’t stir it, don’t jiggle it; trust the process. If you stir or jiggle it, the rice will cook unevenly and, paradoxically, probably stick.
8) Do keep an eye on it, because when steam stops coming out, it is done, and needs taking off the heat immediately. If using an automatic rice cooker, you can be less attentive if you like, because it will monitor this for you.
Note: if you are using a simple pan with a non-fastening lid (any other kind of rice cooking setup is better), more steam will escape than the other methods, and it’s possible that it might run out of steam (literally) before the rice is finished. If the steam stops and you find the rice isn’t done, add a splash of water as necessary (the rice doesn’t need to be submerged, it just needs to have liquid; the steam is part of the cooking process), and make a note of how much you had to add (so that next time you can just add it at the start), and put it back on the heat until it is done.
9) Having taken it off the heat, let it sit for 5 minutes (with the lid still on) before doing any fluffing-up. Then you can fluff-up and serve, adding the garnish if you want one.
Enjoy!
Want to learn more?
For those interested in some of the science of what we have going on today:
- Should You Go Light Or Heavy On Carbs?
- Chia: The Tiniest Seeds With The Most Value
- Black Pepper’s Impressive Anti-Cancer Arsenal (And More)
- Why Curcumin (Turmeric) Is Worth Its Weight In Gold
- The Many Health Benefits Of Garlic
Take care!
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