WHY FINGERTIPS WRINKLE
Did you ever wonder why the tips of the fingers wrinkle like a prune when exposed to water for a long period of time? People often think that osmosis causes water to enter the outer layer of skin making the fingertips swell. But since the 1930's, scientists have known that fingertips don't swell or wrinkle when there is nerve damage to the fingers, even with prolonged submersion in water.
So if it's not osmosis, what causes this phenomenon? A recent study may give us an answer. Mark Changizi, an evolutionary neurobiologist at 2AI Labs in Boise, Idaho, and his colleagues, propose that wrinkling of the fingertips has an evolutionary function. That our nervous system, by causing vasoconstriction of blood vessels below the skin, is responsible for this involuntary reaction that offers an advantage in gripping wet objects.
The study demonstrated that wrinkled fingertips make it easier to grasp objects underwater. Participants in the study had to move dry and wet objects with both dry fingertips, and again, with wrinkled fingertips. The results showed that participants were able to move wet objects 12% faster with wrinkled fingertips than with dry ones. But wrinkled fingertips made no difference when it came to moving dry objects. Basically, when the pads of the fingers are wrinkled, they provide a better grip in wet conditions, like treads on a car tire that increase the surface area of tire on the road.
So why do our fingertips wrinkle when in water? Our brain causes this evolutionary trait to enhance the gripping ability of the fingers underwater! Perhaps this was beneficial to our ancestors who might have had to gather food from wetlands and streams.
And if it happens to you, don't worry, it goes away all on its own. Skin is truly an amazing organ!
"NATURAL" ISN'T BETTER
A growing number of consumers are opting for "natural" skincare products. The media loudly and aggressively sends the message the "natural skincare products are good and synthetic products are bad". They imply that standard facial moisturizers and cleansers are filled with poisonous cancer-causing chemicals. As a result, many people understandably opt for "natural" skincare items that seem "better". In truth, the term "natural" found on skincare product labels is simply an example of brilliant marketing.
The term "natural" on personal care products has no specific definition. The U.S. Food & Drug Administration (FDA) has not defined the term nor has it established any standards or regulatory guidelines for its use on skincare product labels. In addition, cosmetic companies are not required to prove these "natural" products live up to their claims. In fact, the FDA warns, "There is no basis in fact or scientific legitamcy to the notion that products containing natural ingredients are good for the skin."
"Natural" ingredients may imply where the ingredients come from but discloses nothing about the safety of the ingredient. A plant-based product is not necessarily healthy. While most consumers can apply personal care products that claim to be "all natural" without any ill effects, some plant-derived ingredients can cause severe reactions in those with allergies. Tea tree oil, lavender, chamomile and its related family plants, including daisies and ragweed, are commonly used in "natural" skincare products and may cause an allergic reaction in susceptible individuals. Additionally, exposure to natural oils like bergamot, lavender, musk, and citrus compounds from lemons and limes also frequently used in natural products may cause an increased sensitivity to the sun's harmful ultraviolet rays.
As for the claims that synthetic ingredients, those "bad" chemicals, cause cancer: poor scientific studies and the need to sell beauty magazines that rely on sensationalism consistently find cancer links that simply don't exist. Whether a chemical, "natural" or synthetic, causes cancer or any other toxic reaction depends on the dose of the chemical, not the chemical itself. Almost every chemical has a dose below which no adverse effect or harm can occur. (See DOSE VS TOXICITY)
Still, plant-based products remain popular. Whether just folklore, or the influence of the beauty industry and advertising media, many consumers definitely prefer to purchase "natural" skincare products formulated with plant-based ingredients. It's true, plants are a huge reservoir of potentially beneficial compounds. However, few studies, if any, demonstrate they are beneficial to humans. A plant-derived ingredient isn't necessarily good for you, nor is a synthetic ingredient necessarily toxic.
THE TYPICAL SKIN LOTION RECIPE
The majority of moisturizers on the market today, whether they be facial moisturizing lotions, eye creams, night creams, "anti-aging" creams or serums have the same basic formula. The basic moisturizer is a mixture of water and oils, the oils being used to make the skin feel soft and smooth and prevent water from evaporating from the skin's surface.
Moisturizers contain water-soluble ingredients and oil-soluble ingredients that are mixed together with emulsifiers, ingredients that keep the water and oil components from seperating.
Most moisturizing lotions are water based and contain up to 80% water. Moisturizing ingredients called occlusives create a barrier on the surface of the skin to prevent water from evaporating from the skin into the environment. Petrolatum and dimethicone are common examples of occlusive ingredients found in moisturizers. Other ingredients, that draw water from the deeper layers of skin into the most superficial layers, are called humectants. Glycerin is a commonly used, effective, humectant found in many over-the-counter (OTC) skincare products. Other ingredients that are added to the formulation to make the skin feel soft and smooth are called emollients. They commonly include essential oils and cetyl esters.
Emulsifiers that help combine the water component and oil component often include glyceryl stearate and stearic acid. In addition to these ingredients, silicates and thickeners are often added to give the product its appropriate consistancy and help keep the product stable. Preservatives are added to prevent overgrowth of bacteria and fungus, and fragrance, is often added to make the product more appealing.
There are a wide variety of skincare moisturizers on the market, from inexpensive products found at local pharmacies and retail shops to boutique products, packaged beautifully, found at department stores. All with the same basic formula. Shop wisely, and remember, there is NO correlation between the cost of a moisturizer and its ability to moisturize the skin.
SAME PRODUCT/DIFFERENT LABELS
Skincare manufacturers often sell the same exact product with different labels in order to target different customers. This means two products with the exact same formulation (or ingredient listing) are marketed differently and sometimes are sold for different prices!
Examples found in skincare aisles:
Neutrogena Rapid Tone Repair Night Moisturizer & Neutrogena Rapid Wrinkle Repair Night Moisturizer
Blue Lizard Australian Sunscreen Baby & Blue Lizard Australian Sunscreen Sensitive
Blue Lizard Australian Sunscreen Sport & Blue Lizard Australian Sunscreen Regular
Aquaphor Healing Ointment & Aquaphor Baby Healing Ointment
Aveeno Eczema Therapy Moisturizing Cream, Aveeno Baby Eczema Therapy Moisturizing Cream & Aveeno Eczema Therapy Hand Cream (often sold at a higher price point than the first two Aveeno products mentioned despite having the same ingredient listing)
Be an educated consumer!
Of the many marketing terms found on the front of skincare product labels, this is one of the most meaningless. 'Nourishing' the skin is medical absurdity. The use of the term is meant to lead the consumer to believe that the nourishig skincare product provides food or other substance necessary for skin growth. Marketing nonsense.
Skincare products are applied on the surface of the skin and are in contact with the outer 15-20 cell layers. These superficial layers of skin are comprised of non-living, yet functional, dead cells. It is not medically possible to 'nourish' dead tissue. Skin is 'nourished' from its blood supply in the much lower layers of skin.
As an organ, healthy skin parallels a healthy body. Healthy, nourished skin is a result of a nutritious diet, rich in fruits, vegetables, lean protein, and healthy carbs, adequate sleep, exercise, and the avoidance of the stressors that science has shown to be harmful to good skin health, like smoking and utraviolet light exposure. There is no scientific meaning to word 'nourishing' on a skincare product label.
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Hello, and welcome to FryFace!
I've been a New York based dermatologist for over 25 years. I love music. I love triathlons. I love chemistry. (I love petroleum jelly.) I study skincare ingredients and product formulation. I listen to skincare "advice" from self-proclaimed ......Read More