Bespoke dieting

Dieting is going bespoke and nutrition can now be tailored. Not just to you, but to your genes.

Nutritional Genomics is an emerging science that explains our bodies different reactions to diet.

"Some people are particularly susceptible to sugar or salt for instance," said Professor Lynnette Ferguson, of The University of Auckland. "For others, bringing down their salt content will do absolutely nothing."

The reasons are an interplay of genetics, environment and diet.

The doctor, who was just in Australia leading sessions on the subject at the International Conference of Dietitians, is enthusiastic about the potential of this new science."It helps us understand why certain people who have a healthy diet develop chronic disease."

"Genetics is one of the fastest growing areas of science," said Dr Graeme Smith, chief scientific officer at MyGene, a Melbourne-based biotechnology company. "With the advent of genetic testing… ‘personalised healthcare’ is the future of healthcare."

Take 52-year-old Paul Castran, for example. The otherwise fit and healthy father was suffering stiffness, fatigue and muscle aches. His doctor suggested genetically testing his body's response to statins (anti-cholesterol pills, which he was taking), caffeine and folate.

After a simple cheek swab, he received the results a week ago. It was found he has a gene which reacts negatively to coffee, "I like coffee - I've been having four a day for 30 years," he said. "But, the implications [with his particular gene response] are high blood pressure and a 287 per cent higher chance of a heart attack."

The tests also revealed that he is sensitive to statins, which may explain his aches and pains, and is 66 per cent less effective at processing folate, which may explain his fatigue.

"I think we might have found the problem and now, instead of a scattered shotgun approach, I can do something about it."

It is the potential to pinpoint what's going on that has doctors and dietitions excited.

"I think it's great," says Dr Erica Wils, Castran's GP. "The tests show susceptibility rather than diagnosis, but allow you to exclude things like coeliac disease or lactose intolerance."

This takes out much of the guesswork, allowing dietitians, like Linda Chemello, to custom-make programs targeting how a client absorbs, metabolises and eliminates certain nutrients.

Michelle Henry, 44 went to see Chemello in June after blood tests revealed low levels of folate.  Based on her diet, which was packed with folate-rich greens, Chemello couldn't see a problem.

But, genetic tests revealed the gene 'variation' associated with metabolising folate. It simply means Henry needs more folate than your average person for optimal health.

"We're all different, so building health based on my specific needs, makes sense," Henry says. The possibility that her children have the same susceptibility means Henry feels she can foster healthy habits specific to their needs too. Castran agrees and intends to have his children tested.

It's not about fear-mongering. Rather it's about being able to manipulate diet to sidestep hereditary issues and illnesses.

"There's good evidence you can overcome [gene] variants," Professor Ferguson said.

While nutrigenomics is so new in Australia doctors and dieticians in NSW are only just catching on, the US has been using the tests to customise diet for several years.

Concerns have been raised about direct-to-consumer marketing of the tests and especially the need to protect consumers from unreliable tests, false claims and unproven dietary supplements.

Direct to consumer testing is not permitted in Australia. Dr Smith believes this is important "as a healthcare professional is able to provide context." Also, some overseas companies offer genetic testing on genes before research has been completed.

In Australia, current genes/nutrients being tested include Folate metabolism, Coeliac disease, Caffeine metabolism, Lactose intolerance, Vitamin D metabolism and Inflammation. Costs for the test are upwards of $65.