Nails have practical value (such as picking up objects, and scratching), aesthetic value, and diagnostic value.

They act as a protective plate in contrast to the many sensitive nerves in your fingertips there to provide information when you touch something. Have you ever noticed how women shoppers are more likely than men to touch objects they are evaluating? Women’s bodies have more nerve receptors: for example 34 nerve fibres per square centimetre of facial skin compared to men’s 17.

Fingernails grow 2-3 millimetres each month, about 3 times faster than toenails. It will take 3-6 months to completely grow out a nail. Growth tends to slow with age, cold weather or poor circulation. Probably due to more movement, the nails on your dominant hand usually grow faster.

Nails can be excellent as a health status report. Science has long accredited them as indicators of mineral, protein and toxic heavy metal levels and of specific diseases. Nail clippings have proved more accurate than scans for diagnosing osteoporosis, and low levels of selenium associated with osteoarthritis (Journal of Women’s Health). Nails, joints and bones require sulphation – a building and detoxification process by the liver – which joins protein molecules to create bonds for structural integrity. (The pungent smell of burning hair is due to its sulphur compounds.)  A disordered process affects both keratin and collagen formation. Bony bumps on finger joints are also associated with arthritis, while fatty lumps on knuckles – that project when you make a fist – are made of dangerously excess circulating cholesterol: a fatty substance produced by the liver.

Your Dashboard Lights are Flashing: How to Interpret the Signs

Nails are mostly layers of a tough protein called keratin (as are animal hooves, horns, claws and 90% of your hair). This forms a translucent plate. The pink colour comes from the blood vessels beneath which feed the nail bed. Squeeze your nail at the base. It should immediately colour a deep pink. If this doesn’t happen or if your nails are generally pale, this could indicate low iron levels. If very pale this could be a sign of poor heart or liver function. Low protein levels cause nails and hair to be weak with slow growth.

Bluish nails or fingers can occur when blood is not being pumped efficiently such as with Raynaud’s Disease – associated with auto-immune conditions. Since more than 80% of the immune system lies along the gut wall, check for inflammatory particles as the over-activating trigger (contact this office for an allergy test). Nails blue from insufficient oxygen can be due to lung infection.

Red skin around the nail is common with poorly regulated blood sugar levels (BSL). If the skin is puffy as well as red then that indicates infection or a connective tissue auto-immune disorder such as lupus. The habit of nail biting can encourage infections in the nails, gums or teeth and is due to habit or anxiety. Chronic tension burns up your muscle and nerve-relaxing nutrients such as magnesium and potassium, critical for BSL, sleep, digestion, joints and bones. Anxiety can also increase inflammation and acidity – companions to most disease.

Practice the 4 Ds for breaking self-sabotaging habits: Delay; Deep Breathe; Drink Water; Do Something Else (try finger tapping instead of biting).

If  nails are deformed, yellow or crumbly the most common reason is a fungal infection. Some infectious fungi such as those causing athlete’s food and ringworm feed on keratin. Yellow colour alone can be due to pooling lymph fluid or lung fluid, or to poor BSL (see Carbohydrates below). Pitted nails often relate to psoriasis (another auto-immune disorder) which is associated with arthritis. With psoriasis there can also be white areas due to air bubbles beneath the nail, or complete nail detachment. A dark line below and following the white tip of your nail is linked with liver disease such as jaundice or hepatitis. Thin red-brown lines looking like splinters under the nails are hemorrhages and can be a sign of heart problems. Uninjured nails that are brown, black or purple should be investigated immediately as this can be caused by melanoma.

Nail Health from the Inside Out

Unlike harsh topical products, these natural food options can benefit the entire body your nails come attached to. The food sources listed are in order by weight but amounts are dependent on season, soil levels, variety and style of preparation. Minerals are less affected than vitamins by storage and cooking.

Water: the nail plate requires hydration to avoid brittleness. Enjoy 6-8 cups daily of water or herb tea.

Protein: comes in animal forms (egg, fish and seafood, dairy, meat) and plant forms (legumes, nuts and seeds, wholegrains, with a small amount in vegetables and fruit: all sources of carbohydrates and fibre). Most people will do best with more of one type than the other. See the questionnaire in The Shape Diet to work out which one of four metabolic body-types you are; which foods strengthen you or weaken you.

Fat: nail cells are constantly growing. Critical to cellular health is the membrane that surrounds and protects each cell. This is made of fat and requires nourishing forms of each: saturated fat (egg yolk, pasture-fed meat, coconut, cocoa, palm); monounsaturated fat (olive, peanut, avocado, almond, cashew, most nuts); and polyunsaturated fat which include the two Essential Fatty Acids (linseed, chia, sesame, most seeds, walnuts, soy, oily fish). Top quality fats help prevent weak thin nails (and hair).

Carbohydrate: yellow nails (not from nail polish use) can be due to diabetes or poor BSL. The colour shift from pink to yellow can be due to glucose attaching to the proteins in nails: a process which produces Advanced Glycation End Products (AGEs) attributed to ageing, diabetes and smoking. Glycation is when sugars in the blood attach themselves to fats and proteins, causing connective tissue to become stiff and malformed. The skin is the most prone. What’s in your sugar bowl is not necessarily the culprit, but the quality and breakdown rate of all your carbs. Each meal and snack needs the right ratio of high fibre carbs, protein and a little fat to regulate BSL. For specifics see The Shape Diet.

Antioxidants: help protect you against AGEs, other cell and tissue destroyers such as free radicals (highest from smoking, sun abuse and damaged fats: those over-heated or not cold-pressed). Antioxidants include vitamins A and D (oily fish, liver, egg yolk; carotenes in yellow, orange and green plants can be converted to vitamin A) and vitamin E (nuts, seeds) which all require dietary fat for best absorption; vitamin C (red pepper, parsley, kiwi fruit, berries, citrus); minerals zinc, selenium. Plus hundreds of specialised defenders high in herbs, spices, other plant foods and seafood. Also B vitamins: studies show increased nail firmness with biotin supplementation (peanuts, almonds, spinach, tomato, eggs).

Silica: helps with the utilisation of calcium; collagen production; healthy nails, skin, hair, joints, bones. Deficiency signs: lengthwise raised ridges on nails (sometimes beaded looking); thick, brittle, chipped pale nails; lengthways splits. Sources: alfalfa, whole grains, raisins, beetroot, leafy greens, seaweed.

Calcium: works with silica to strengthen tissue especially nails, skin, hair, collagen, joints, bones, teeth. Deficiency signs: cracked skin around nail bed; cracked or dry lips or heels; cracks or splits on tongue; white blotches or cloud-like shapes on nails. Sources: seaweed, sesame, sardine, carob, almond, salmon with bones, yeast flakes, parsley, tofu. Magnesium is essential for calcium absorption (rice bran, seaweed, pumpkin kernels, cocoa, sunflower seeds, almonds, parsley, fish, cashews, soy, yeast flakes).

Iron: carries oxygen to cells; forms red blood cells; helps immunity; lowers inflammation. Deficiency signs: flat nails; tips with weak curl or upturned (dish-like or with a dip in the middle; spoon-like nails can also indicate hypothyroidism). Sources: spirulina, cocoa, organ meat, sesame, parsley, linseed, dark dried fruit. Animal sources are absorbed more efficiently. Plant sources can be better absorbed when served with vitamin C rich foods. Black leaf tea within an hour of eating can lower iron absorption by 40%.

Zinc: critical to immunity, growth, wound healing; lowered by oral contraceptive. Deficiency signs: tiny white dots on nails; thin peeling nails; slow growth and wound healing; tendency to infections. Sources: oyster, liver, meat, pumpkin kernels, shellfish, mushrooms, legumes.

Sulphur: helps liver function, keratin production and immunity. Deficiency signs: thickened, distorted, yellow or humped nail; nail pitting. Sources: Brazil nuts, peanuts, almonds, egg, seafood, cabbage, garlic.

Nail Treatments

Take regularly holidays from all products not 100% natural. Avoid acetone-based polish removers. Remove polish no more than once monthly as it can weaken and dry out nails. Anything on your skin or breathed in can get into general circulation. Nails should be trimmed straight across and slightly rounded. Wear gloves to protect nails and hands from the drying effect of too much water exposure – especially if harsh cleaning, gardening or similar products are used. To prevent infection, clean nails and hands before touching food, eyes, mouth nose; and after contact with dirt, pets or toilet. After bathing, rub 100% natural moisturiser, or cold-pressed coconut, avocado, olive, almond or sesame oil over nails and hands.