Saturday, September 3, 2005

Apple #104: Fingernails

(photo from A Sizable Apple blog of health tips)

I was filing down a rough spot in my fingernail and I thought, "I bet there are a few things about fingernails that I don't know." So I checked it out, and I was right. Here are a few fingernail facts:
  • Fingernails grow from the white, half-moon shape often visible at the base of the nail. This is called the "growth plate" or "lunula".
  • As more cells form in the growth plate, the older cells are pushed forward. During this growth process, the cells die and become filled with a hard protein called keratin. It is keratin that makes the nails hard.
  • A fingernail grows about 1/10th of an inch per month. It takes 6 to 9 months to grow a nail from cuticle to fingertip.
  • Fingernails also have a high sulfur content. This is why, if you accidentally burn your fingernail, say, in the flame of a candle, it stinks something awful.
  • Nails are ten times more porous than skin and can become chapped. Chapped nails are more likely to break in response to environmental damage -- that is, when you use your nails to pry something open, or when you catch them on things, or when you do a lot of gardening.
  • Infants' fingernails are very thin. Their nails tend to get torn rather than cut.
  • As people age, their fingernails get thin. Their toenails, however, get thick.
  • Changes in your fingernails may reflect changes in nutrient levels. There are some pretty creepy pictures of fingernails and in some cases, yeah, it's obvious, these people have something really wrong.
      • If the pink skin under the nail is spoon-shaped, rather than rounding upwards, or if it is pale rather than pink, you may have low iron levels.
      • Yellow or green nails may signal a respiratory condition, or swelling. The discoloration occurs because the growth of new cells has slowed.
      • Pitting, or what looks like tiny holes or scratches in the nail surface, is common in people who have psoriasis, a condition that makes scaly patches in the skin.
      • When the tips of your fingers enlarge and the nails curve around the tips, almost like claws, this is called clubbing. This signals low oxygen levels in the blood and can be a sign of lung disease. Come to think of it, I've noticed nails like this on older women who are hard-core smokers.
      • If the nails have ridges that run side to side, you may have recently had a fever or inflammation. In people who have recently had a heart attack, these depressions can be very deep, so that it looks like they slammed their fingers very hard in a door.
      • If your nails have ridges that run lengthwise, this is a signal of age and not any particular problem.
  • White spots on the nail are commonly said to be because of a zinc deficiency or a lack of calcium. Many doctors & dermatologists say that's a myth. Actually, the white spots are usually the result of some injury, like dropping something heavy on your hand so that it hits the nail just wrong, or catching your hand in the door. It may take several days before the white spot shows up, so most people don't remember the injury and attribute the white spot to that event.

White marks on the nail are called leukonychia. Despite the important-sounding name, most of the time, they're caused by some mild injury and are nothing to worry about.
(Photo from the Gemini Geek)

  • Another, less common, possible cause is an allergic reaction to nail polish, polish remover, or nail hardener. If you get lots of manicures and lots of white spots, hold off on the manicures for a while and see if that takes care of the white spots.
  • It is also possible that the white spots could be signs of an infection. This is unusual, however. If they get bigger, then it might be time to look into treatment. But probably they'll get smaller and fade away on their own.
  • For those of you who want to take extra care of your fingernails:
      • Don't have the cuticle removed. This makes your skin susceptible to bacteria, and it can also weaken the nail. Plus, it hurts like hell.
      • Do rub hand lotion into your nails.
      • Some nail polish and polish removers can irritate the skin or dry the nails and actually make them weaker, instead of stronger, which is what people think nail polish can do. Avoid polishes and removers that contain sulfonamide, formaldehyde, or acetone.
      • Drinking Jell-O or other gelatin products will have no effect on the strength of your nails. While gelatin contains protein, and protein is an essential part of fingernail cells, protein is essential to lots of other cells in your body, too, and the protein you eat gets all mixed into the protein pool, so to speak, and gets used in all kinds of part of your body. Extra protein from gelatin would not "go to" your nails but would get stored as fat.
MadSci Network, "Are our fingernails made up of stiff hair?"
Ask the Dietician, Fingernails, Hair & Skin
Mayo Clinic, What your fingernails can tell you about your health, sourced from Mayo, Fingernails: keep them healthy and strong
Health Guidance, What Causes White Spots on Fingernails?
Dr. Weil, Worried about White Spots on Fingernails?
WiseGeek, What Causes White Spots on Fingernails?


  1. Gelatin is a very useful ingredient in aiding in the strength of nails. Gelatin contains Amino Acids which are found in Keratin. The more amino acids, the thicker the keratin and the thicker the nails. Amino acids, protein and keratin are the make up of nails. So, gelatin is very important in the strength of nails.

  2. Um, I'm afraid somebody sold you a bill of goods when it comes to gelatin. What you wrote sounds exactly like an advertisement for gelatin, and not necessarily an informed statement of fact.

    As I noted in the above entry, it's true that gelatin contains proteins (amino acids combine to create proteins). It's also true that improved proteins in your diet will improve the strength of your nails.

    However, you can get protein from lots of different sources -- meat, beans, yogurt, cheese, milk, etc. Any one of these sources of protein will also help strengthen your nails, and other parts of your body that use a lot of protein, such as your hair and your bones.

    Any protein you eat will be used for lots of different purposes. It is incorrect to think that if you eat X protein it will "go to" Y part of your body and no place else.

    If you eat more protein than your body needs, your body will store it as fat.

    And finally, gelatin is made from ground-up cow and horse bones, hooves, and connective tissues. (see

    If you really want to eat lots of gelatin (ground-up horse and cow bones) and stare at your fingernails and think they're getting stronger, I suppose that's your choice. But I, for one, will be content to eat other types of proteins and use hand lotion to keep my fingernails strong and pliable.

  3. I have suffered from white spots on my nails (and occasionally, when rundown, on my teeth) all my life. Recently I found out this might be a zinc deficiency. But, more interestingly, the only time in my life when I had strong nails was during a time when I was eating gelatine daily. This happened by accident when I was on a no sugar diet and couldn't eat fruit. I was eating sugar-free fruit jellies as a replacemnt and I noticed a month or so into it that I suddenly had strong smooth nails that were growing to a decent length instead of breaking off or splitting as normal.

    I think this may be something to do with some research I saw recently by Russian scientists who discovered gelatine was having a good effect on stomach ulcers. It wasn't the protein in it, but the particular amino acids (I think - don'tquote me). I have a theory that the same thing that protects the stomach wall is also stopping'leaky gut' which often leads to zinc deficiency which causes the nail problems.

    I have also had gut problems all my life (constant antibiotics as a child) including an ulcer and candida overgrowth.

    I believe therefore that, for me,the gelatine helped repair the gut which stopped the zinc loss which improved the nails.

    I'll just say in closing that I would have put no store in gelatine if I hadn't had the accidental proof of it - something I had not been seeking to do.

  4. I seem to have little pits all over my nails but no current skin problems other then really dry skin on my 2 big toes only??? Weird? What could it be?

  5. Er, better consult your doctor about that one. I'm not a doctor, I just quote them online.

  6. very helpful info, thanks so much, receive warm greetings from Tijuana Mexico

  7. Thanks for the warm greetings from Tijuana!

  8. i have white marks on my nails. what causes them?

    1. Read the dam article/blog your asking plainly explains the caws.....Wow don't people read any more?

  9. Thanks for the question about white marks. I've updated the entry with the answer to your question.

  10. Hello apple lady,
    my nails grow upwards and are very soft they feel almost like flexible plastic material for as long as I can you know why??Is there anything that I can do about that??

  11. Hi Denisa,

    No, I don't have any idea why your fingernails grow like that. Sometimes soft fingernails are caused by other health conditions, but I'm not going to speculate about that because I'm not a doctor. But a doctor might be able to help you. Next time you've got an appointment for a check-up, ask your regular doctor about it.

  12. If you have white spots on you nails, check out the list of symptoms for pyroluria, pyrroluria, or kryptopyrrolurria. (google it) It is easily treated with supplements, so doctors want no part of it, and will tell you it doesn't exist. It is devastating when neglected, and can ruin your life. It has mine.


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