DNA could be the key to your perfect diet

Life saver? Biologist John Hesketh calls personal nutrition the holy grail of healthcare.

Should we match our diet to our genes? A new multi-million-pound industry is promising people the perfect meal, all based on the results of a DNA test. Some scientists remain unconvinced.

At a kitchen table in the year 2030, a young boy is staring sullenly at a tower of brussel sprouts.

On his left, his sister’s plate is piled high with bread and jam. On his right, his father is feasting on steak and chips. Apologetically, the man turns to his son: “Sorry, but this is what the DNA test recommended”.

Last year, the world hit a grim milestone: bad diets killed more people globally than tobacco.

The figures are staggering: every year, 11 million people worldwide die due to unhealthy eating – and each death is entirely preventable.

Now, some are advocating a radical solution to the global diet crisis: nutrigenomics – the fusion of nutrition and genetics. The idea behind the emerging field is that because everybody has unique genes, everyone must also have a unique set of nutritional requirements.

Nutrigenomics itself first appeared in the early 2000s, but the theory that food affects people differently is far from new. As early as the first century BC, Roman poet Lucretius declared: “What is food to one, is to others bitter poison”.

It may sound futuristic today, but across the world, companies are racing to produce DNA tests that can provide health-conscious consumers with their perfect diet.

“We can personalise shoes and personalise clothing, but it wasn’t until recently that people realised, ‘We actually need to have personalised nutrition’,” says Sherry Zhang, CEO of GenoPalate, a DNA test kit company.

In the UK, a company called DNAfit markets itself to those who have noticed that “lucky people can rapidly process carbohydrates, allowing them to enjoy plates of pasta without putting on a pound while many of us bloat at the mere taste of a crisp”.

And across the Atlantic in California, nutrigenomic guru Habit promises customers personalised meal plans – but only if they send in a blood sample. Even celebrities are getting in on the action. Olympian Greg Rutherford, a DNAfit ambassador, swears that the company’s £175 personalised workout and shopping list has helped him perfect his exercise routine.

But despite the excitement, the science behind nutrigenomics remains hazy at best. Most scientists agree that genetic variation can affect how individuals’ bodies metabolise nutrients like fats.

And it is widely accepted that genes play a role in people developing conditions like Type 1 diabetes and lactose intolerance, which require sufferers to monitor their diet.

But critics argue that the extent to which “gene based” food choices actually influence concrete measures of health, such as blood pressure, are exaggerated.

“The idea that you could tell someone, not just ‘avoid carbs,’ but which type of specific foods to eat? I think we’re really far from that”, says cardiologist Venkatesh Murphy.

And even for Sherry Zhang, sticking to her DNA-recommended lactose-free diet is not always easy: “I sometimes still cheat a little bit because I love ice cream.”

So, should we match our diet to our genes?

Food for thought

Yes, say some. From education to clothing, we personalise almost every aspect of our lives today, so it makes sense to personalise our diets too. And the evidence is clear: unhealthy eating is destroying people’s lives and leads to millions of early deaths every year. We should embrace any scientific advancements that can help people improve their diet and live for longer.

No, say others. There is little evidence to say DNA-based diets work, and many of these companies rely on giving generic health advice that applies to everyone – cut down on salt, and exercise more. We often equate what is healthy with what is natural – and there is nothing natural about a family eating entirely different foods. Animals do not need unique diets to survive, and neither do humans.

You Decide

  1. Would you follow a new diet and exercise regime based on your genes?
  2. Is food about more than just nutrition?

Activities

  1. Devise a menu for your perfect meal. Compare your menu with your classmates.
  2. Imagine you are a chef in the year 2030. Write a diary entry describing your struggle to cook everyone unique gene-recommended food.

Some People Say...

“Animals feed; man eats; only a man of wit knows how to eat.”

Jean Anthelme Brillat-Savarin (1755-1826), French lawyer and politician

What do you think?

Q & A

What do we know?
It is generally agreed by anthropologists that people’s relationship to food is about more than just fuelling their body. For many, certain foods have a cultural significance. For example, several major religions prohibit pork, despite its nutritional qualities. And anthropologists believe that how people choose to eat can tell you a lot about their society – one study found that in Sweden, it is important that all members of the family eat the same food as a symbol of equality.
What do we not know?
One main area of debate surrounds whether or not a gene-based diet can actually help people become healthier. There is some evidence which suggests that a person’s genes can play a role in their response to certain types of diet, for example, high protein diets. But in 2015, a study exploring the role of 38 genes commonly analysed in nutrigenomics tests, using data from 500,000 people, found no significant relationship between the genes and health outcomes.

Word Watch

DNA
Deoxyribonucleic acid is the molecule that carries the genetic code of all organisms.
2000s
Nutrigenomics emerged after the completion of the Human Genome Project, an international research effort to map all of the genes of human beings.
Greg Rutherford
A British athlete who won a gold medal for long jump at the 2012 Olympics.
Type 1 diabetes
A serious condition stopping the body from producing insulin, causing blood sugar levels to rise dangerously. Roughly 400,000 people in the UK have Type 1 diabetes.
Lactose intolerance
A digestive disorder which means people are unable to digest lactose, a sugar found in dairy products. After infancy, approximately 65% of people have some level of lactose intolerance.
Cardiologist
A doctor who specialises in treating problems with the heart and blood vessels. Venkatesh Murphy works at the University of Michigan.
Metabolise
When the body uses chemical processes to turn food into new growth, energy and waste products.

Subjects

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