Study finds toxic levels of mercury in women

Penny Lancaster revealed she gave up fish when she was struggling to conceive

Dangerous levels of mercury have been found in women of reproductive age across the world, the largest study of its kind has found.

Excessive levels the neurotoxic metal can seriously harm unborn children and have been blamed on fish-rich diets. 

In some parts of the word gold mining and industrial pollution are also to blame, according to experts in Sweden.

Rod Stewart’s wife Penny Lancaster has previously revealed she cut fish out of her diet after two years of failed attempts to conceive her second child with her rocker husband. 

Now 46, she sought medical help and doctors discovered very high levels of mercury in her body due to her consumption of fish. After changing her diet, she then became pregnant following her third round of IVF in 2010.

Experts say fish-rich diets, gold mining and industrial pollution is causing excessive levels of mercury in women of child-bearing age worldwide (stock photo)

Experts say fish-rich diets, gold mining and industrial pollution is causing excessive levels of mercury in women of child-bearing age worldwide (stock photo)


Model Penny says within two months of not eating fish her mercury levels halved

Model Penny says within two months of not eating fish her mercury levels halved

Penny Lancaster was told the mercury levels in her body were a result of her love of fish. Her preference for a high-protein, low-fat seafood-based diet she believes was to blame. 

‘A homeopathic doctor told me my mercury levels were really high, off the scale,’ she told HELLO! Magazine.

‘I do love fish, and I thought it was healthy without understanding the high mercury levels that fish like tuna, swordfish and halibut can contain.

‘My doctor said it was unhealthy to have so much mercury in my body, and also for conceiving babies.’

The model revealed cutting out fish made a drastic difference to her mercury levels. 

‘After two months of not eating fish, my mercury levels dropped by half, which is scary – I had no idea what the fish had been doing to my body,’ she said. 

Recalling the moment she learned of her pregnancy, she said: ‘I couldn’t believe it. I burst into tears. I called Rod when I was still sobbing. 

‘Rod said, “I’m in the middle of a restaurant in Russia, crying”. ‘I kept pinching myself. Neither of us could believe it.’

The latest research, from Swedish safety group International POPs Elimination Network (Ipen), covered 25 of the countries with the highest risk and found worrying levels in women from Alaska to Chile and Indonesia to Kenya.

Babies exposed to mercury in the womb can have brain damage and hearing and vision problems.

‘Women have to be very careful, in any country, of what type of fish and how much they eat,’ Lee Bell who led the new study told The Guardian.

Key findings

Researchers coordinated hair sampling from 1044 women of reproductive age in 37 locations across 25 countries on six continents.

Analysis found that 36 per cent of women had average mercury levels over the US EPA health advisory level of 1ppm.

This is the level above which brain damage, IQ loss, and kidney and cardiovascular damage may occur.

Furthermore, the study found that 55 per cent of the global sample of women measured more than 0.58ppm of mercury, a level associated with the onset of foetal neurological damage.

The highest levels were found in women from sites in Indonesia where mercury is heavily used in small-scale gold mining and where fish is also commonly eaten.

Such gold mining leads to serious mercury pollution in sea levels and is also a source of harm to women in Kenya, Paraguay and Myanmar. 

Limit oily fish say experts 

Despite concerns about mercury, official advise from the NHS is that everyone should eat fish at least twice a week – including one portion of oily fish such as salmon or tuna.

This is because fish and shellfish are good sources of vitamins and minerals and are far lower in fat than any form of meat.

Oily fish is also particularly high in omega-3 fatty acids, which have huge benefits to the heart and brain, and in vitamin D, which strengthens the bones. 

Many studies suggest most of us are not eating enough oily fish. However, there is different advice for pregnant women. 

Experts recommend that women who are pregnant or trying to conceive limit themselves to two portions of oily fish a week. 

Furthermore, the UK’s Food Standards Agency recommends these women, and children, not to eat any shark, swordfish or marlin, as these top predators have the highest levels of mercury.

The FSA also suggests these groups limit their tuna consumption.


The Scientific Advisory Committee on Nutrition and the Committee on Toxicity provides the following advice about eating fish when trying to get pregnant, or when pregnant or breastfeeding:

  • Shark, swordfish and marlin: do not eat these if you are pregnant or trying to get pregnant. All other adults, including breastfeeding women, should eat no more than one portion per week. This is because these fish can contain more mercury than other types of fish, and can damage a developing baby’s nervous system.
  • Oily fish: if you are trying for a baby, or are pregnant or breastfeeding, you should have no more than two portions of oily fish a week. A portion is around 140g.
  • Canned tuna: if you are trying for a baby or are pregnant, you should have no more than four cans of tuna 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 canned tuna you can eat.

These figures are based on a medium-sized can of tuna with a drained weight of around 140g per can.

Remember, canned tuna doesn’t count as oily fish. So if you’ve had a portion of canned tuna during the week, you can still have up to two portions of oily fish.

Due to the higher levels of mercury in tuna, if you’re eating canned tuna, don’t pick fresh tuna as your oily fish.

Unless your GP advises otherwise, avoid taking fish liver oil supplements when you’re pregnant or trying for a baby. These are high in vitamin A (retinol), which can be harmful to your unborn baby. Pregnant women are advised to avoid taking supplements that contain vitamin A.

Source: NHS Choices