Thanks to studies that have mapped humans' genetic makeup - which can outline illnesses we are prone to - we could, in theory at least, change our diets to include foods that combat those ailments, a Canadian study shows.
"In the future, we may choose a breakfast cereal based on our genes," said Dr Peter Singer, director of the Joint Centre for Bioethics at the University of Toronto.
"It is hypothetical, but possible, that if you have a particular gene you eat honey nut cereal to reduce your chance of heart disease, or, if you have another gene, you take the raisin bran to cut your chance of prostate cancer."
But the benefits of dining your way to genetic health - the science of nutritional genomics - or nutrigenomics - also comes with a downside, the study cautions.
Scientists warn of the dangers of collecting and storing personal genetic information, adding that nutritional genomics is in its infancy, with no evidence yet that it will be
successful on a mass scale.
Since researchers mapped the human genome, or book of life, in 2001, they, along with business, have been intrigued by the idea of creating customized diet plans based on genetic roadmaps.
The Centre for Bioethics and the University of Guelph in Ontario led the study on the ethical questions surrounding genes and nutrition.
"It is hypothetical, but possible, that if you have a particular gene you eat honey nut cereal to reduce your chance of heart disease, or, if you have another gene, you take the raisin bran to cut your chance of prostate cancer"
Dr. Peter Singer, director of the Joint Centre for Bioethics at the University of Toronto
The report does not prescribe guidelines, but highlights concerns, such as privacy, confidentiality, misuse of information, discrimination based on genetic makeup and fears that employers and insurers could use genetic information to unfair advantage.
The study, which also included scientists from the United States and England, will be presented at the second annual International Nutrigenomics Conference in Amsterdam this week.
A few US, British and Canadian firms already offer tests to determine genetic risk profiles. Vancouver, British Columbia-based internet site onepersongenetics.com, for example, advertises a $379 test.
"There is a general question of how strong the science actually is and how reliable are the claims (that) can be made about whether genetic tests and modification of diet will improve health," said Dr David Castle, assistant professor of philosophy at the University of Guelph.
Nutrigenomics, unlike genetic engineering, does not involve altering foods, but changing diets based on genetic makeup.
Researchers have said that many government health agencies have advised citizens to eat right according to various food pyramids and charts since the mid-1900s and that these plans are still the best available.
But they added that nutrigenomics, if it can be applied on a mass scale, would be better because each person would have a customized plan.
Basing diets on genetic makeup can be beneficial, says Dr Abd Allah Daar, also with the University of Toronto's Joint Centre for Bioethics, because dietary patterns are linked to several of the top 10 causes of illness and death in North America, including heart disease, stroke and many types of cancer and adult-onset diabetes.
"There is a general question of how strong the science actually is and how reliable are the claims (that) can be made about whether genetic tests and modification of diet will improve health"
Dr David Castle
Daar, who is director of the programme in applied ethics and biotechnology at the centre, said the new science was complicated as more than one gene playsed a role the development of some diseases and one gene could be involved in causing many diseases.
Even though the mass application of nutrigenomics may still be decades away, Daar said its advance was "outstripping the public's ability to make informed choices about what kind of regulations should be introduced to address ethical and privacy concerns."