Chapter 148
Green Light for Mineral
Which sunscreen should you use? Creams are preferable to sprays because you’re more likely to be able to see where you applied them. Sunscreen spray should be rubbed in immediately after spraying so that it covers the skin well. I can’t recommend aerosols. They’re flammable and can even burst into flames on the skin after drying if you get too close to an open flame. In addition, it has still not been sufficiently studied whether it is harmless to inhale sunscreen aerosols; on the other hand, the same applies to the sunscreens you smear on your skin.
As I explain in see.nf/safestsunscreen, concerns about the systemic absorption of sunscreens were heightened in 2019 by the FDA’s surprising statement that none is generally recognized as safe. Only two active ingredients got the green light, namely the two non-chemical “mineral” sunscreens titanium dioxide and zinc oxide. This statement was based on increasing evidence that more sunscreen chemicals are absorbed through the skin than was thought, raising “unreviewed safety concerns.” Unreviewed because no one had thought that so much was entering the bloodstream.
Less Fat
How can we protect ourselves from skin cancer from the inside out, aside from nicotinamide? On the basis of studies showing that high-fat diets cause skin cancer to develop faster in mice, and population studies showing that high-fat diets are associated with higher cancer rates, the National Cancer Institute and a Veterans Affairs research team published impressive results in the New England Journal of Medicine, documenting that people with a history of skin cancer, when randomized to a low-fat diet, got ten times less skin cancer. Details are available at see.nf/lowfatskin.
Varicose Veins
Varicose veins are not just a cosmetic problem. They can be painful, cause a feeling of heavy legs, and itching. The traditional standard therapy for these symptoms was compression stockings, but this recommendation has been reconsidered over the last ten years because there is little evidence for the effectiveness of compression and minimally invasive endovenous ablation methods have been developed (details on this in see.nf/varicose). But none of that addresses the cause.
Topical application of vinegar
In see.nf/vein I present a randomized controlled trial on the effect of topically applied vinegar for varicose veins. Topically applied vinegar (not urine!) helps with jellyfish stings, but not with eczema. And for varicose veins? See the video for details, but undiluted vinegar could cause harm, and the benefit is questionable.
Anti-Varicose Vein Diet
In Uganda, in a survey of 5000 adults, only six cases of varicose veins were found. Perhaps people in rural Africa had more than 50 times fewer varicose veins for the same reason they had 50 times fewer heart diseases, up to 50 times fewer colon cancers, and up to 50 times fewer other “pressure diseases” such as diverticulosis, hiatal hernias, and hemorrhoids. Because their diet consisted of so many whole plant foods, they were among the few populations ever found to consume more than 100 grams of fiber a day—the amount that is normal for our species.
In the chapter on maintaining bowel and bladder function, I mention how straining hard during bowel movements can push blood back into the legs and cause the venous valves in the legs to break down, and in see.nf/varicose you can learn more about this. If you have to strain that hard, you have an unnaturally hard stool, but you can change that by eating enough high-fiber plant foods and producing a large, soft stool that you can pass effortlessly. Western vegetarians also suffer less often from pressure diseases such as diverticulosis, hemorrhoids, and varicose veins, which can also, but perhaps not only, be explained by the link with fiber. A study of older vegetarians found that they also had much less frequent varicose veins under the tongue, or the so-called caviar tongue, bleeding capillaries under the tongue. Because in scurvy the veins are dilated and the blood vessel walls are thinner, scientists suspect that the vegetarians’ higher vitamin C intake prevents varicose veins.
Healthy Nails
According to the American Academy of Dermatology, almost everyone is affected by a nail disorder at some point in their life. With age, nails grow more slowly, become more brittle, and can become pale, dull, or opaque. Starting at 25, nail growth slows by about half a percentage point per year, perhaps one reason why nail fungus, or onychomycosis, the most common nail disorder, becomes more frequent with increasing age. It is prevalent among adolescents at 2 percent, then rises to 20 percent among 60-year-olds and affects about half of 70-year-olds.
Treating toenail fungus
Nail fungus usually affects the toenails and causes the nails to become discolored, deformed, detached, thickened, crumbly, and ridged. The infection is stubborn, because the fungus can hide deep in the nail, shielded from the bloodstream on one side by the nail and from anything you apply topically on the other side. Even if you defeat it once, it often returns due to a residual infection.
Onychomycosis is usually treated with oral antifungals because they are much more effective than topical ones, but they have more side effects and interactions with other medications. Terbinafine, marketed as Lamisil, is usually the drug for older people. In the second month of treatment it can cause a metallic taste in the mouth; skin rashes are also common and sometimes severe. Other common side effects are headaches and gastrointestinal complaints; in rare cases liver, kidney, and heart failure. In older people, cure rates with oral antifungals are only about 64 percent, but that is still significantly more than with topical antifungals.
Oral antifungals for toenail fungus are typically taken for twelve weeks; with topical agents, treatment can take twelve months. (For fingernail fungus, it usually takes only half as long.) Given the long duration of treatment, it happens that patients adhere to the instructions only to a limited extent, especially those who want to conceal the infection with nail polish, but even if the agent is applied daily for a full year, the cure rate for most topical medications is only 9 percent, compared with 1 percent for placebo. There are new topical active ingredients that only need to be applied once or twice a week and that might work better, though not significantly better. Given the poor response rate, exclusively topical treatment is recommended only for mild cases or where oral medications are contraindicated. (For example, terbinafine is not recommended for people with liver disease.) To increase cure rates, oral and topical medications can be combined. Based on in vitro data on the antifungal effect of acidic pH values, some recommend an evening foot bath with a 50/50 mixture of water and vinegar before the antifungal agent is applied.
And other natural remedies? Diluted tea tree oil appears to help with a fungal infection of the scalp that causes dandruff, as well as athlete’s foot between the toes; couldn’t it then also be used topically for nail fungus? As I describe in detail in see.nf/teatree, the widely used antifungal clotrimazole, brand name Lotrimin, was directly compared with tea tree oil in a randomized controlled double-blind study and proved to be quite comparable in terms of healing effect, clinical assessment, subjective improvement, and even cost. Better yet, however, is to treat the causes.
Addressing ingrown toenails