Growing or restoring hair with oral supplements; what is the evidence?

For me, hair is an accoutrement.Hair is jewellery. It’s an accessory. — Jill Scott, an American singer-songwriter, model, poet and actress.

Scott's saying indicates why so much care is given to hair, especially by the female gender.

Growth cycle of hair

Hair grows on human skin except in the palms and soles of feet. Growth starts underneath the skin and is nourished by blood. After a period of time, the hair shrinks away from the blood vessel and dies out. While this is ongoing, new strands of hair also begin to grow at the same spot and the cycle continues. Hair strands are lost and replaced at a faster rate; an average hair loss of 100-150 hair strands per day and hair loss greater than 150 hair strands per day are alarming.

Causes of hair loss

Hair can be lost via inherited genes, some illness (like anaemia), hormones, stress, medications, diet and hair hygiene.

Treatment

Individuals having one type of hair loss or another must be screened to determine the root cause through physical examination, medical and dietary history.

Dietary corrections could then be made for persons with nutritional deficiencies. Some oral supplements are also marketed as treatments for hair loss. These supplements are sold by some herbal practitioners, available online or sold in some health shops.
It is claimed that these oral supplements produce benefits such as healthy hair and sustained growth.

Some hair growth oral supplements

Some claims :

Methionine (an essential aminoacid): provides adequate amounts of sulphur to hair cells, aiding in growth and appearance, including delayed graying.

• Keratin (a protein that serves as a structural component of hair): contributes to healthy hair growth.

• Vitamin A: helps with hair growth by maintaining healthy follicles. Products high in vitamin A contribute to thicker and longer hair.

• Vitamin E: helps support cell membranes and is a powerful antioxidant that reduces the effect of free radicals on hair, especially when consumed with selenium

• Iron, selenium, zinc, cysteine, lysine: linked to hair loss

Hair growth and oral supplements: any evidence?

The underlying cause of hair loss will determine the effectiveness of oral supplements for hair growth. Majority of these supplements are the building block of proteins, vitamins and minerals. While these supplements contain a variety of nutrients, review of scientific literature finds limited evidence supporting their benefits for hair growth.Much of what is known about nutrient effect on hair loss is based on diseases that result in a deficiency.

There is some evidence that women with low ferritin (a protein that stores iron) need iron supplements since it is a vital cofactor for hair growth. A few studies among women in the United States also showed that some specific oral supplements promoted hair growth in women with thinning hair after 90 days of usage. It is worthy to note that health issues associated with prolonged use of these oral supplements are not known because many of the supplements on the market have not been tested in large studies. Again, many hair growth supplements are not regulated by the Food and Drugs Authority. There is currently limited scientific information regarding the effects of supplementation in individuals without nutrient deficiency. Frequent or continuous intake of these oral supplements in the absence of a nutrient deficiency may lead to toxicity of certain organs of the body (e.g. liver and kidney). For instance, high intakes of iron can be injurious to the liver.

Recommendations

Poor nutrition may be a major factor in hair loss. A diet which is not adequate in nutrients such as proteins, minerals, essential fatty acids and vitamins can lead to hair thinning, changes in hair colour or hair loss. Many of the nutrients required for hair growth will be provided if meals are varied. A simple way to achieve this is to eat regular meals, eat a variety of fruits and vegetables and consume adequate intakes of whole grains, legumes, oily fish and lean meat. Drinking enough water is also needed for the body to function properly since water helps to distribute nutrients throughout the body. This, coupled with a healthy lifestyle, may promote hair growth.

Conclusion

A review of scientific literature does not show strong evidence on the use of oral supplements for hair growth in the absence of an underlying diet-related nutrient deficiency. Consuming a balanced diet should prevent nutrient deficiencies associated with hair loss. In some illness and life stages, a supplement may be needed. Individuals taking oral supplements for hair growth should be cautious and be careful of its toxicity with prolonged use.

Written by:
Mawuli Wisdom Gunu, Eunice Nortey and Matilda Asante,
Department of Dietetics, University
of Ghana.
Email: [email protected]