Is health really determined by your genes? Discover why this argument is fading fast.
If you went to school before the millennium, it’s likely you grew up believing that your genes determined your destiny. Along with our hair colour and our eye colour, we were all taught that our risk of disease largely came from our parents too.
The Human Genome Project, launched in 1990, promised to find answers. From heart disease to cancer, scientists were confident that many of the most common diseases could be chalked up to soon-to-be-identified genes.
Except they weren’t.
When the project finished in 2003, scientists had discovered that the human genome comprised fewer genes than expected. What’s more, the human genome is 99.7% the same in all people.
So how could we explain the huge variation in characteristics and conditions between us?
Clearly, something else is going on. And believe it or not—the food we all eat is playing a part.
How your diet and genes interact
Enter nutrigenomics. This new scientific field sounds complex (and it can be) but its purpose is simple: it’s the study of how our food and genes interact.
There are two sides to this:
a) Your food influences your genes
All of our cells (apart from red blood cells) contain DNA. This DNA tells our cells what to do: make a protein; release a hormone; up-regulate an enzyme etc. This affects our bodily processes and, over time, has a dramatic impact on our risk of disease.
But here’s the important part: not all of this DNA is active all of the time. An easy way to understand this is to imagine a light switch. It’s always there, but it’s not until you turn it on that its function becomes clear.
This is what happens in your cells. All your DNA-containing genes are there, but some of them are switched off. And here’s the kicker: the vitamins, minerals and other compounds in the food you eat have the ability to switch certain genes ‘on’ and ‘off’.
Clearly, you want to eat in a way that turns health-promoting genes on and turns health-zapping genes off.
But that’s not all…
b) Your genes influence your response to food
As you’ve learnt, we’re all largely the same. But that 0.3% worth of differences between us is critical, and it’s a result of Single Nucleotide Polymorphisms (or SNPs, usually pronounced ‘snips’).
SNPs are random alterations to a DNA sequence. These little changes affect how your cells make proteins, which in turn affects everything from your metabolic rate to your ability to detoxify alcohol.
Ever wondered why your friend can have a huge night out and not feel anything—while you suffer after just two glasses of wine? Chances are your SNPs play a role.
Some of the SNPs can make your body less efficient, but some of them can make you more so. And the food you eat can help to compensate too.
If you know you have a SNP that means you’re not great at metabolising alcohol, for example, you have two options: 1) drink less. This is obviously preferable—but we all have nights when we have one too many. So, option 2) is to eat and supplement in a way that gives your alcohol-detoxifying enzymes a helping hand.
We know that one enzyme involved alcohol metabolism, ALDH2, needs vitamin B2, niacin, magnesium and zinc (amongst others) to carry out its task, so it’s biologically plausible that consuming enough of these nutrients can help this enzyme function at the best of its ability .
You can eat green vegetables, lean protein and seeds to get these nutrients, and you can take a supplement, such as sense* vitamin and superfood supplements that contain these and more too.
Which foods are good for your genes?
As you can see, your genes and your diet are intimately linked. And although it can seem a little bonkers, food telling your body what to do isn’t a new concept. After all, didn’t your mum tell you that carrots help you see in the dark?
What has changed is that new investigatory methods mean we can uncover how specific foods affect our genetic expression, and in turn our health. So far, researchers have discovered the following:
- Olive oil: Long heralded as a staple of the healthy Mediterranean diet, we now know that olive oil can switch off genes that code for inflammation. Lower inflammation means a lower risk of heart disease, along with many other chronic conditions .
- Soy: Studies suggest that genistein, a compound in soy, can affect the expression of genes that influence vascular tone . This may go some way to explaining the lower risk of cardiovascular disease in populations that consume a lot of natural soy.
- Green tea: A recent study found that green tea, one of the most popular drinks in the world, can affect genes involved in hormone metabolism in women. More research is required to know how this might impact the risk of breast cancer .
Why is nutrigenomics important?
We have a long way to go, but it’s clear that understanding how our genes and diet interact has huge implications for our health. Nutrigenomics is powerful because:
- It can reduce your risk of chronic disease. Diet and lifestyle-related diseases are predicted to be responsible for seven out of ten deaths . As you’ve learnt, food is not just fuel—it’s information. The more we discover, the more you’ll be able to choose foods that instruct your body to turn on health-promoting genes.
- It can help you personalise your diet. It’s likely that SNPs account for our differences in nutritional requirements. They can also influence which foods are best for us. In one illuminating study, people prescribed a diet based on their genetic information were found to maintain greater weight loss compared to a group on an ordinary diet . Yes, that means that even if you carry a ‘fat gene’, the way you eat can turn it off and enable you to maintain a healthy weight.
- It can empower you. As with the fat gene, there’s no doubt that we all have genetic susceptibilities. But they don’t seal our fate. If you know you have a greater risk of Alzheimer’s disease, for example, you can start making food, lifestyle and supplement choices now to minimise the likelihood of your developing the disease.
There’s still a lot we don’t know. The way food interacts with our body is deep and complex—it can affect lots of different things at once, which means it can be hard to determine cause and effect . What’s more, genetic testing comes with a lot of ethical considerations.
However, research is gathering pace. And what we do know is that nutrigenomics does away with genetic determinism and puts you in the driving seat. With every mouthful, you have the chance to feed your genes and redefine your health blueprint.
So, what’s for dinner?