Cosmetics and toiletries
People sometimes worry about whether chemicals in common products such as cosmetics or toiletries could raise the risk of cancer. Cosmetics and toiletries covers a wide variety of products, including moisturisers, shampoos, deodorants and toothpastes. But there is no good scientific evidence to believe that any of these products could cause cancer.
How do regulations help protect us in the UK?
There are very tight regulations in the EU and the UK about cosmetics. Manufacturers must ensure that their cosmetic products are safe before they can be sold. The EU has produced a list of banned substances that are not allowed to be used. And other chemicals are only allowed in cosmetics subject to special restrictions. For example, they may only be present in limited amounts or may only be used in rinse-off products. This applies to both natural and synthetic chemicals.
You may have heard rumours that deodorants and antiperspirants could cause breast cancer. But these concerns were started by an e-mail hoax. There is no convincing evidence that antiperspirants and deodorants cause breast cancer.
Why are the claims about deodorants and breast cancer wrong?
The original e-mail claimed that antiperspirants stop your body from sweating out poisons. It suggested that these toxins build up in the lymph glands under the arm and cause breast cancer.
But the details of this are wrong. Breast cancers start in the breast and only later spread to lymph glands. Your body also has several ways of getting rid of toxins, and while sweating is one of them, it is a different system to the lymph glands.
Parabens and breast tumours
Parabens are chemicals found in some deodorants. They are similar to oestrogen, the human hormone that can increase the risk of breast cancer and some other cancers at high levels. But parabens are much weaker than oestrogen itself and any effects are likely to be overwhelmed by natural oestrogen produced in our body, or similar chemicals found in our diet.
A small study found traces of parabens in some breast tumours. Finding parabens in tumours is a far cry from saying that they cause breast cancer. To do that, scientists would need to compare levels in breast tumours to "safe" thresholds, to levels in healthy body cells, or to levels in healthy people without cancer.
In fact, breast tumours have large blood supplies and are likely to contain traces of anything that finds its way into our bloodstream. The study didn’t show that these parabens came from using deodorants rather than intake from food or any other source. And besides, most modern deodorants are parabens-free.
A recent review of the evidence surrounding parabens and breast cancer found that parabens can encourage human breast cells to behave like breast cancer cells, by moving about and invading tissue, avoiding cell death, and suppressing the work of a drug commonly used to treat breast cancer. But there are hundreds of other environmental chemicals that are found in human breast tissue, so it’s hard to be sure that parabens can cause cancer alone.
Aluminium in deodorants
There is no good evidence that aluminium in deodorants could increase the risk of cancer in animals or humans. This was confirmed by a review of all of the available evidence in 2014 that found no link.
A small study in 17 women with breast cancer was quite widely reported in the news in 2007. It found higher levels of aluminium in the part of the breast nearest the skin, and the authors speculated that aluminium in deodorants might cause breast cancer.
But the design of this study was not strong enough to draw that conclusion. For a start, it looked at a very small number of women. And the researchers did not compare levels of aluminium in these women’s breasts to levels in other parts of their bodies, or to levels in women who do not have breast cancer.
Furthermore, a larger study of 176 women in 2013 showed no significant differences in levels of aluminium in normal areas of the breast to the level in the tumour.
So, there is no strong evidence for a link. You can read more about aluminium, deodorants and breast cancer on our Science Update blog (although it’s worth noting that that blog post was written in 2007, so it doesn’t include details of the 2013 study mentioned above).
Some cancer units advise women not to use deodorants containing aluminium salts before going for breast screening. This is not because aluminium salts are dangerous, but because they can obscure the results of screening tests. This can make breast cancers harder to detect.
Links have been suggested between hair dyes and a variety of cancers including bladder cancer, breast cancer, leukaemias and lymphomas. But there is no clear evidence that hair dyes could cause any of these cancers.
In 2008, the International Agency for Research into Cancer (IARC) said that hairdressers “probably” have a slightly higher risk of cancer because they are regularly exposed to certain chemicals. They can reduce their exposure to these chemicals by wearing gloves.
There’s not enough evidence to say for sure whether people who use hair dyes themselves have a higher risk of cancer as a result. From the evidence that’s available at the moment, it seems there is no significant link between personal use of hair dyes and bladder cancer, even when using permanent dyes or using hair dyes frequently for a long time. And if hair dyes are linked to any other type of cancer, the increase in risk would only be very small in comparison to other risk factors.
Putting any risks in perspective
The biggest risk factor for bladder cancer is smoking, causing over a third of UK cases. If you smoke and want to reduce your risk of bladder cancer, as well as over a dozen other cancers, the best thing you can do is is stop smoking.
If you use hair dyes and are concerned, you could dye your hair less often, wear gloves and make sure the room is ventilated.
Improved safety over time
In the 1970s some hair dye ingredients were found to damage DNA and cause cancer in the lab. But since then, the use of these chemicals has been discontinued and modern dyes are thought to be much safer. Cancer can take many years to develop – so it could be that the link we are seeing now between working as a hairdresser and cancer is because of exposures to these older chemicals many decades ago.
In 2006, the EU Commission announced that it would ban 22 different hair dye substances which do not have adequate safety files. This is a reassuring move for consumers as it means that only dyes that are proven to be safe will be available.
Cosmetic body and talcum powders often contain a mineral compound called talc. Several studies have looked at talcum powder use and ovarian cancer. While on the whole studies have seen a modest increase in the risk of ovarian cancer in women who use talc on their genitals, the evidence isn’t completely clear.
Scientists are trying to see if there is a real link, but for now we can’t be sure whether or not talc itself could cause ovarian cancer. However, even if there is a risk it is likely to be fairly small.
Stronger studies don’t find a link
The majority of studies that have found a link between talc and ovarian cancer relied on people remembering things they did a long time ago. The most recent study of this type found using talc on the genitals increased the risk of ovarian cancer by 33%.
But these studies also have important weaknesses. People may not accurately remember how much talc they used in the past, and women with ovarian cancer may be more likely to remember using talc than women who don’t have cancer. This might skew the results.
Scientists can avoid these problems by using studies that start with a group of healthy women and follow them up over time, to see if those who use talc go on to develop ovarian cancer in the future. So far, there has only been one of these studies looking at talc and ovarian cancer – and it didn’t find a link with ovarian cancers overall.
The risk of ovarian cancer doesn’t increase when women use more talc
If something truly causes cancer, you would expect people who are exposed to more of that thing to have a higher risk. The evidence isn’t entirely clear, but the better quality, larger studies haven’t confirmed a similar relationship for talc use and ovarian cancer.
Using diaphragms (contraceptive caps) or condoms dusted with talc does not increase the risk of ovarian cancer
Talc from these contraceptives will be placed closer to a woman’s ovaries during sex than it would if simply applied to the genital area. So the ovaries would be exposed to a higher concentration of talc. But studies haven’t found an increased risk of ovarian cancer in women who used talc on diaphragms.
Direct application of talcum powder to the lungs does not cause cancer
Talc is used in a medical technique called pleurodesis that can help relieve symptoms of some lung problems. Doctors apply sterile talc directly to the lining of the lungs in this technique. And there is no evidence that this direct application of talc to the body causes cancer.
How could talcum powder cause cancer?
Before the 1970s, talcum powder was often contaminated with asbestos fibres which are known to cause cancer. But since then, all home products containing talcum powder are legally obliged to be asbestos-free.
Some scientists have suggested that talc particles could travel to the ovaries, irritate them and cause inflammation. Low-level, long-term inflammation may increase the risk of some types of cancer. But so far, it doesn’t look like using anti-inflammatory drugs can reduce the risk of ovarian cancer. And the evidence around whether talc could travel in this way is weak.
Putting any risk into perspective
The ovarian cancer charity Ovacome have produced an excellent factsheet. They make a really important point that puts any potential risks from talc into perspective:
The evidence for a link is weak, but even if talc does increase the risk of ovarian cancer studies suggest it would be by around a third. This is a modest increase in risk and ovarian cancer is a relatively rare disease. Increasing a small risk by a third still gives a small risk.
Ovarian cancer risk is affected by many things
As with most cancers, the risk of ovarian cancer increases with age. And women with a family history of breast or ovarian cancer may also be more likely to develop ovarian cancer. If you think you might have a family history of cancer, it’s a good idea to talk to your GP.
Childbearing and hormones are also believed to play a role in ovarian cancer. Risk of ovarian cancer is lower the more children a woman has. And taking hormonal medications, such as the contraceptive Pill or Hormone Replacement Therapy (HRT), can also affect the risk.
Smoking also affects the risk of ovarian cancer, and unlike age or family history, it is something we can control. A Cancer Research UK study has estimated that each year around 200 UK cases of ovarian cancer could be prevented by not smoking. For help to stop smoking, visit the NHS Smokefree website or speak to your doctor or pharmacist.
Another persistent hoax claims that lipsticks contain lead and therefore cause cancer. This is not true. In the EU, lead is banned from all cosmetics, apart from hair dyes. In the United States, the Food and Drug Administration (FDA) regulates the lead content in food and cosmetics. Their last survey of 400 lipsticks in 2011 found very low levels of lead. The FDA does not believe these levels are harmful.
Rumours that moisturisers could cause skin cancer also make the rounds occasionally. Most recently, such a claim was made based on a laboratory study which found that moisturizing creams could increase the risk of skin cancer in mice that were already exposed to high doses of ultraviolet (UV) radiation, mimicking the effect of heavy sun exposure.
But that is a long way from saying that this also applies to humans. Our Science Update blog took a thorough look at what the scientists actually found and what it means for humans.