Tuna-Related High Mercury Levels Cause Sudden Hair Loss in Women

Case studies involving two women's hair loss in New York, USA, have resulted in a potential connection between high mercury levels and sudden-onset shedding.

The source of the mercury was believed to be due to diets high in tuna as, once the women had eliminated tuna from their diet, their mercury levels dropped and normal hair regrowth resumed.

This has led to researchers calling for mercury testing women presenting with hairloss.

Both in early menopause

In the research, published in the North American Menopause Society journal by the team from across The Centre for Menopause, Hormonal Disorders & Women's Health, and Columbia University Medical Centre, Department of Medicine's Division of Endocrinology, two women's cases were outlined.

The first woman was 43 years old at the time she presented to the practice to be evaluated for early menopause though her symptoms also included sudden alopecia limited to the scalp.

The second woman was 39 years of age and was also initially seeking help for early menopause symptoms, including severe hot flashes, night sweats, and menstrual irregularity. As with the first woman, she also displayed scalp-only hair loss.

After low-testosterone treatment failed to address the symptoms, further investigation including blood tests of both women showed high mercury levels and diets which were high in tuna - a fish known to be rich in this potential toxic metal.

"Elimination of dietary tuna led to the reduction in the levels," the report states, "A reversal of alopecia, along with a decrease in blood Hg levels were noted following the recommendation to alter diet, including fish intake."

Although thinning hair in women can be a symptom of the menopause, this tends to be related to hormonal imbalances such as low oestrogen and higher testosterone levels, as well as age-related hair loss caused by declining collagen production. In each instance this appears gradually over time, not suddenly.

Moderate tuna consumption advised

A number of metals, often found in everyday diets, are known to be toxic to humans at certain levels, with abnormally high levels in the blood being associated with various adverse events, including diffusely thinning hair.

This particular hair loss condition is known as Telogen Effluvium when it lasts for up to six months, or Chronic Telogen Effluvium, if it lasts longer. It causes temporary shedding from all over the scalp and, although it may appear to have come on suddenly, it is generally triggered around three months prior to hair fall becoming noticeable.

Around 30 per cent of scalp hair tends to be affected simultaneously, giving the impression of intense hair loss. Whilst Telogen Effluvium treatment courses are available, in most cases normal hair regrowth will resume naturally within six months. It is worth noting that for those with an underlying or active genetic predisposition to Female Pattern Hair Loss, this may prematurely spark or exacerbate this permanent, hereditary condition.

However, when eaten in moderation as part of a balanced diet, these can have multiple health benefits. For example, tuna is known to be low-calorie, high in protein and vitamin B12 - deficiency of which can cause hair loss - omega 3s and selenium - an important mineral for the maintenance of healthy hair growth.

Ensuring you know which foods are high in mercury, what the official guidelines are for their consumption and how to stay within these is important.

The NHS advises that, for adults, a "healthy, balanced diet should include at least 2 portions of fish a week, including 1 of oily fish... fresh and canned tuna do not count as oily fish".

Furthermore, "if you are trying for a baby or are pregnant, you should have no more than 4 cans of tuna a week or no more than 2 tuna steaks a week. This is because tuna contains higher levels of mercury than other fish. If you are breastfeeding, there is no limit on how much tuna you can eat."

This advice bases portion size on a medium-sized can of tuna with a drained weight of around 140g per can and a 140g cooked tuna steak.

Anyone concerned about excessive hair fall, sudden shedding, or symptoms such as a drop in the volume of their hair or their parting becoming increasingly wider with more scalp visible, should consult a specialist at their earliest opportunity for a professional diagnosis and, where appropriate, treatment advice.