Women who eat crisps or chips every day may double their chances of ovarian or womb cancer, say scientists.
The fears surround acrylamides, chemicals produced when you fry, grill or roast a wide range of foods.
Dutch researchers quizzed 120,000 people on their eating habits, and found that women who ate more acrylamide appeared more at risk.
UK experts say other factors could be to blame, and urged women there was not need to panic.
General advice, resulting from this project, is to avoid overcooking when baking, frying or toasting carbohydrate-rich foods
Laboratory tests highlighted as a possible danger five years ago, but the University of Maastricht study, published in the journal Cancer Epidemiology, Biomarkers and Prevention, is the first to find a link between acrylamides in the diet and cancer risk.
Food which has been coloured or burned by cooking is far more likely to contain acrylamides.
Food experts say it is virtually impossible to eliminate them from our diets altogether.
The Dutch study followed the 120,000 volunteers - 62,000 of whom were women - for 11 years after their initial questionnaire, during which time 327 of them developed endometrial (womb) cancer, and 300 developed ovarian cancer.
Analysis of these findings suggested that those who ate 40 micrograms of acrylamide a day - equivalent to half a pack of biscuits, a portion of chips or a single packet of crisps - were twice as likely to fall prey to these cancers compared with those who ate much less acrylamide.
Despite the size of the study, the researchers said that the results needed to be confirmed by other research.
In the UK, there are approximately 6,400 cases of womb cancer, and 7,000 cases of ovarian cancer a year.
Women shouldn't be unduly worried by this news
Cancer Research UK
A spokesman for the Food Standards Agency urged people to try a balanced diet with plenty of fruit and vegetables.
"This new study supports our current advice, which already assumes that acrylamide has the potential to be a human carcinogen.
"Since acrylamide forms naturally in a wide variety of cooked foods, it is not possible to have a healthy, balanced diet that avoids it."
Experts at the EU said that food should not be overcooked.
An EU spokesman said: "General advice, resulting from this project, is to avoid overcooking when baking, frying or toasting carbohydrate-rich foods.
"French fries and roast potatoes should be cooked to a golden yellow rather than golden brown colour."
However, Dr Lesley Walker, from Cancer Research UK said that it was hard to be sure that the extra cancers were due to just acrylamides, rather than some other unhealthy component of the women's diets.
"Women shouldn't be unduly worried by this news. It's not easy to separate out one component of the diet from all the others when studying the complex diets of ordinary people."
The food industry says it has made efforts to reduce the acrylamides within processed foods in recent years.
A study published in 2005 found no evidence that acrylamide increased the risk of breast cancer.Technorati Profile