Food provides an essential nutrient matrix for our skin, hair and nail health. Would supplementing with more nutrients improve your complexion and skin quality? There certainly are many promises of youthful glowing skin and hair diet supplements peddled on websites and in the popular press. But are they exaggerated and unproven?
Avoiding excessive sun exposure, smoking and too much alcohol, together with eating a well-balanced diet, taking regular exercise and getting adequate rest are all important for skincare in the long run. Rapid and frequent weight fluctuations don’t help.
If you are predisposed to acne you can’t really prevent it. Acne is not caused by sugary and fatty foods, although a well-balanced intake of nutrients may help the skin to heal and repair itself. Although largely driven by hormone fluctuations, acne can be somewhat controlled by cleansing with the right skincare products, avoiding cosmetics that clog pores and not picking at pimples.
For certain skin conditions, the primary focus is on what foods to avoid. Anecdotal reports implicate some common foods as triggers for rosacea, which can resemble acne. This is a chronic inflammatory disorder whereby central patches of the face become reddened. Spicy foods, thermally hot foods and drinks and alcohol have been identified as suspected triggers, although the advice is to keep a diary to track all dietary and environmental triggers leading to a flare up.
Only one small randomised trial provided some evidence for an improvement in rosacea symptoms after three months of supplementation with zinc sulfate three times daily according to Pen, the global source for nutrition practice.
The addition of zinc to the diet, but not in excess of the upper limit, may be worth considering in consultation with your doctor or dietician.
Eczema
Eczema, characterised by dry, reddened, itchy, cracked skin can be well controlled by keeping the skin moisturised and medicated. Current evidence does not suggest that supplementation of essential fatty acids from fish oil or evening primrose oil helps treat eczema.
Supplements containing single nutrients such as vitamin E, selenium or zinc do not seem to offer any benefit over adequate dietary intakes of these nutrients for the treatment of eczema. Health Canada recommends avoiding vitamin E supplements if you have risk factors for, or already have, heart disease, diabetes or cancer. The recommended intake for vitamin E, as with other vitamins and minerals, can easily be met with a balanced diet.
It has been suggested that avoiding foods high in arginine and selecting foods high in lysine might reduce the frequency or severity of recurrent cold sore infections.
Unfortunately, there is little or no clinical research to support this advice. While vitamin C and zinc are important for your immune system, there is no scientific evidence that supplementing the recommended intake for these nutrients helps prevent or treat coldsore infections.
Hair
Restrictive diets that are very low in calories may also fail to provide key nutrients for the hair. Detox, fad diets and eating disorders such as anorexia nervosa can significantly damage hair.
You may wonder whether nutritional supplements are worth the investment. The answer is probably not. In fact regularly surpassing the upper limit for certain vitamins and minerals such as vitamin A, selenium and boron can actually trigger hair loss.
There is little evidence that supplementing the diet with specific nutrients makes a difference, unless you are deficient in that nutrient.
While it is normal to shed more than 100 hairs a day, especially when washing, abnormal hair loss can be caused by iron deficiency. This can also result in low energy levels and both immune and cognitive impairment even before anaemia develops.
It’s important to visit your GP and have an iron deficiency diagnosed and treated. Taking iron supplements without your doctor’s knowledge could delay the diagnosis of a more serious problem such as a bleeding ulcer or cause an iron overload, known as haemochromatosis.
A zinc deficiency can also cause hair loss. Zinc is an important co-factor of many enzymes and protects the cell DNA, proteins and lipids from oxidative damage. It is essential for the immune system and helps maintain healthy skin and nails. Treating a deficiency is necessary to prevent symptoms, but again there is no evidence that supplementing with zinc will prevent hair loss if you don’t have a deficiency.
Nails
Like hair health, nail health is significantly affected only by having either a deficiency or a toxic overload of a nutrient.
For example correcting inadequate protein intakes and iron deficiency restores our general health, as well as our nail health. Similarly, there is no evidence that increasing your protein above the normal recommended intake will improve your nail health.
Spoon-shaped or concave nails may be a sign of an iron deficiency. Your doctor may ask you whether you are eating foods that are good sources of iron such as lean red meat, chicken, fish, fortified breakfast cereals, dried fruit, eggs, beans and green leafy vegetables. It’s a good idea to keep a food diary for the week before your visit.
A small number of studies have found that a change in the colour of the nail, in particular a blue hue, is associated with pernicious anaemia which is caused by a deficiency of vitamin B12. Treatment reverses the nail to its normal colour.
Untreated B12 deficiency can cause permanent nerve damage. More common symptoms of pernicious anaemia include numbness and tingling in the hands and feet, confusion, memory loss and depression.
There is inadequate evidence to support biotin or calcium supplementation for improved nail health, despite popular belief. The old myth is still circulating that a calcium deficiency manifests as white streaks and spots on nails. This is not true.
Too much vitamin A supplement results in brittle nails. The same is true for selenium toxicity. Getting your nutrients from fresh foods rather than supplements ensures an adequate nutrient intake for normal nail health.
Nail problems can have a wide range of causes including acute injury and trauma to the nail. Furthermore, aging affects the quality of nails: they tend to become thicker, more ridged, brittle and discoloured. Nothing that a good manicure or pedicure can’t improve, if time and circumstances allow.
To read Paula Mee’s guide to nutrients suitable for hair, skin and nail health, see irishtimes.com/health.
Paula Mee is a dietitian and a member of the Irish Nutrition and Dietetic Institute. Email: pmee@medfit.ie; @paula_mee
