The implications of nutrigenetics are far-reaching. Our individual genetic make-ups can dictate which foods we need to eat to delay, or even prevent, specific diseases to which we are genetically prone. As well as obvious conditions such as heart disease and diabetes, illnesses such as thyroid disease, rheumatoid arthritis, Alzheimer’s, breast cancer, coeliac disease, raised blood pressure, sickle-cell anaemia and osteoporosis may be pre-empted or combated via nutritional input.

For example, if you discovered through genetic testing that your 10-year-old daughter had a serious risk of osteoporosis later in life, you would be able to ensure that during her crucial bone-building teenage years, she had the right daily mix of nutrients, including calcium and vitamins D and K, to protect her from the disease.

The use of nutrigenetics may also signal an end to unnecessary dietary restrictions. Take the example of eggs. The general consensus is that we should limit our egg intake to one a day, for fear of raising cholesterol. Jose M Ordovas, director of the nutrition and genomics lab at Tufts University, in Boston, explains: “Most people’s blood cholesterol increases at least a little when they eat a lot of high-cholesterol items such as eggs. But about 15% of us have a gene mutation that makes us ‘resistant’ to dietary cholesterol. There have been cases of people eating 20, 30, eggs a day with totally normal cholesterol levels.”

The food industry is waiting impatiently in the wings as it anticipates the need for personalised diets and products aimed at those with a particular genetic make-up. In fact, individual testing and storage of the genetic codes necessary for such a scenario is on the horizon.

Ordovas predicts that the first wave of such data collection may be in place within the next decade in America and western Europe. “Of course, I don’t have a crystal ball, but I do think everyone will have their genome sequenced some day, and it will get to the point when it will be routine to have our sequences stored in a computer, say, at the doctor’s surgery.”

The cost for such genetic sequencing is currently about $1m for each person, and the blood-test results take a week to process. The goal, according to Ordovas, “is to make it cheaper — closer to $1,000. It will happen”.

Genetic-test kits have already appeared on the market, with most available over the internet for as little as £120. However, Dr Helen Wallace of GeneWatch UK, a campaign group that monitors developments in genetic technologies, urges caution. “An American government report has just branded such at-home test kits unreliable and misleading,” she warns. “At GeneWatch UK, we are hoping that all such testing kits will ultimately be banned from sale, and I really think that our government needs to get involved.”

This is a move Kathy Hudson, director of the Genetics and Public Policy Centre at Johns Hopkins University, in Baltimore, agrees with. “It’s not possible for consumers to determine whether the tests are bogus or based on real science. One of my concerns is that the effort to move genetics into clinical practice and to improve human health is going to be tainted by bad actors.”

Consumers have been left at a crossroads. The gold-standard technology is there for genes to be properly tested and for our diets to be altered according to the information revealed in our DNA — but at the moment, it is just too expensive for anyone other than the mega-rich to take advantage of.

There are other ways we can benefit, however, the most obvious being to build a family health tree (see below) — and to stick to what we know best by continuing to consume as many fresh fruit and vegetables as possible.

CREATE TYOUR FAMILY HEALTH TREE

First, contact as many members of your family as possible and start building a clear picture of your own family’s history of disease. Then take what you find to your GP for advice: this looking back can help predict your susceptibility to certain diseases. Given the short time we have in a consultation, the more information offered to create an idea of our health within the context of our wider family, the more able the doctor will be to factor in genetics and suggest the appropriate nutritional changes required.

You have an increased risk if, within your family:

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