If you haven’t heard the term ‘sirt food’ or of the sirt diet, then you probably will over the next few weeks or months. It’s the latest new dietary idea to capture the imaginations of fad diet enthusiasts and those looking for a magic way to diet their way to better health and longevity.
There is no magic involved, unsurprisingly, but there is some science behind the sirt diet so it’s worth knowing about.
Related: Our diet expert weighs up the pros and cons of the Sirt Diet and other new diets
What are sirtuins?
Simply put, they are proteins. If you want the more complex answer, they are proteins that are used by the body via SIRT1 genes. (Sirtuin stands for silent mating type information regulation 2 homolog.) These proteins are used to regulate cell life and the genes themselves are believed to protect mammals against ageing.
Why are sirtuins in the news right now?
Researchers have only relatively recently identified how certain sirt proteins function and although quite a bit of research has been done on SIRT1 protein in the past decade, there are several others (from SIRT1 up to SIRT7) and scientists are still working on those to find out how they work in humans.
The findings that made everyone sit up and listen, however, related to how these proteins help to protect cells from dying and/or reacting to stressors. As cell death is associated with ageing as disease, this could potentially be an important finding.
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Sirtuins and longevity
Studies on mice, bees and flies, for example, have shown that SIRT1 can have a significant effect on health and longevity. And recently another study found that when study participants fasted regularly i.e. reducing their calorie intake to only 500 per day for two days each week, levels of SIRT3 increased. However, the study was tiny with only 24 study participants so more research is needed to confirm these results.
"The research in the area of how different foods can influence the way our genes express themselves is still in its infancy and this is only a fragment of the picture," says nutritionist Farah Cleret. "A good diet should never be limited to just how one gene is being affected as there are many other variables that will also be at play. Keeping the diet fresh and varied is always the key and avoid processed and junk foods where at all possible."
Where can I find these sirt foods?
In your local supermarket. Perhaps surprisingly, a sirt food isn’t some magical previously-unknown-to-man superfood. In fact if you’ve already been following a healthy diet and especially the Mediterranean diet, you’ll already be getting plenty of sirt foods.
So-called sirt foods are actually foods that activate sirt protein in your body. And some of the main activators of sirt protein are olive oil, green tea, dark chocolate, leafy or cruciferous green vegetables, blueberries, and citrus fruits. If you feel like you’ve read a list of foods just like that before, it’s no surprise - these are pretty much the same foods that are touted on any healthy diet.
Related: Low-carb or Mediterranean - which diet is best for losing weight?
So what’s the difference between this diet and the Mediterranean diet?
Some liken the sirt diet as being a mix between the Mediterranean diet (olive oil, lots of fresh vegetables and fruit, as well as fish) and the Asian diet, ie a vegetable-heavy diet with soy-based products such as tofu, green tea and oily fish too.
Some would also argue that a sirtfood diet must also entail some fasting, as some research has indicated that fasting raises levels of certain sirtuins.
The reality is that a so-called sirtfood diet can be any kind of dietary change that will improve sirtuin activity. And research shows that this means eating olive oil, dark chocolate, leafy green vegetables, blueberries, citrus fruits, tofu, oily fish and drinking green tea and the occasional glass of red wine.
Related: Tofu - find out how to get this superfood into your diet
This article was updated on 13/01/2016 to include a comment by nutritionist Farah Clerret.