SIRT foods are the closest thing scientists have yet found to the fabled Fountain of Youth or Elixir of Life. What’s more they can also help you lose weight by boosting fat burning and mimicking the effects of fasting – without actually having to avoid eating. By selecting the right foods, which activate your SIRTs, you can burn fat faster and lose weight more easily.
What are SIRTs?
SIRTs, or sirtuins, are a family of enzymes which regulate key metabolic reactions involved in cell survival. Their discovery has generated great excitement due to their potential to boost fat burning, turbo charge your energy levels and, potentially, even extend your life.
The first SIRT was discovered in yeast cells and was given the rather unexciting name of SIR2 (Silent Information Regulator 2) protein. When similar proteins were later identified in human cells these were referred to as SIRTs or sirtuins. So far, seven human SIRT proteins, have been discovered, and are named SIRT1 through to SIRT7.
What do SIRTs do?
Sirtuin proteins are enzymes that play a central role in how cells respond to diet, exercise and other lifestyle factors. SIRTs work rather like Formula 1 racing car engineers for your cells, fine tuning their performance so that each cell functions more efficiently. They do this by tweaking the chemical structure of specific proteins and fatty acids found in the cell nucleus, cell fluid (cytoplasm) and energy-generating cell structures (mitochondria).
Within the nucleus, this selective modification (of which the most common is a chemical snip known as deacylation) triggers the activation or suppression of cell regulatory genes. Together, these gene tweaks help cells to:
- turbo-charge cellular energy production
- boost fat burning
- promote a healthy weight loss
- activate cell defense mechanisms to reduce inflammation
- repair damaged DNA
- regenerate worn-out cell structures (organelles)
- prolong cell survival during periods of stress caused by factors such as lack of oxygen, infection or a build-up of toxins
- lay down new neural connections within the brain to enable the formation, retention and retrieval of memories.
Each sirtuin protein is concentrated within specific parts of each cell depending on its function.
SIRT1, SIRT6, and SIRT7 are mainly found in the cell nucleus and are involved in regulating how genes are switched on and off in response to certain triggers – including the genes that code for the SIRT proteins themselves. Within the nucleus, SIRT7 is mostly concentrated in a region known as the nucleolus, where the cell’s protein-making machinery is regulated.
SIRT2 is mainly present in cell fluid (cytoplasm) where it regulates cell metabolism and also has anti-ageing tasks related to cell renewal and DNA repair.
SIRT3, SIRT4 and SIRT5 are mainly found within the mitochondria – the tiny ever-ready batteries that generate energy within each cell. SIRT3 is strongly related with the aging process and with longevity, while SIRT4 has specific actions related to insulin sensitivity.
SIRT1 and weight loss
SIRT1 acts as a master conductor that orchestrates metabolic reactions at both the cellular and whole body level. It ensures that energy production continues even when intakes of carbohydrate or the availability of glucose is reduced.
Normally, SIRT1 is activated by energy deprivation to help maintain glucose levels and energy production. Exercise, fasting and calorie restriction can all activate SIRT1 to stimulate the breakdown and burning (oxidation) of fat and cholesterol in liver cells, fat cells and skeletal muscles. What’s more, SIRT1 makes the fat burning process more efficient so that energy production continues even when oxygen and glucose levels are low. It ensures that fat is mobilised and burned rather than stored, and helps to prevent fat building up in liver cells (fatty liver) even when following a high-fat diet.
SIRT1 has been found to increase the size and number of energy burning units (mitochondria) in cells, to regulate the production of thyroid stimulating hormone, and to suppress appetite through a particular effect on special nerve cells (pro-opiomelanocortin neurons found in the hypothalamus of the brain) which respond to the appetite-suppressing hormone, leptin.
SIRT1 is now recognised as the metabolic key to healthy weight loss, and the good news is that you can activate SIRT1 just by eating more of the right types of foods, known as SIRTfoods, which have the same stimulatory effect on SIRT production as exercise, fasting and calorie restriction.
How to activate your SIRTs
Some foods contain SIRT activators that switch on the production of extra SIRT proteins in your cells, and stimulate the activity of those that are already present. These dietary SIRT activators have a rejuvenating effect on cells and eating more of them can significantly improve your fat burning, energy levels and your ability to lose weight. Interestingly, these foods are among those that have long been recognised as beneficial for health.
The most powerful SIRT activators are antioxidant polyphenols found in fruit and vegetables.
Resveratrol activates SIRTs
For a long time, resveratrol was the most potent natural SIRT1 activator known. The main dietary source of resveratrol is black grapes, which were associated with health-enhancing benefits long before resveratrol or sirtuins were known about. Black grapes are still commonly given to patients convalescing in hospital – you’ve probably given or received some yourself. Resveratrol is also found in high concentration in red wines.
Resveratrol activates SIRT1, whose metabolic effects mimic those of calorie restriction, as well as SIRT3 and SIRT5 which also stimulate fat burning in mitochondria.
Laboratory studies using human fat cells show that resveratrol can:
- suppress the formation of new fat cells
- reduce the accumulation of fat in white fat cells
- enhance fat burning.
By switching on genes which stimulate fat burning and increase the amount of energy lost as heat (thermogenesis), resveratrol allows white fat to act like brown fat, and provides a welcome weight loss boost. The sirtuin activating effects of resveratrol has extended the lifespan of many organisms, from yeast and worms to fruit flies, honeybees, fish and mice by 30% to 70%. Whether or not it has the same longevity effects for humans is currently the subject of intense debate.
Quercetin activates SIRTs
Quercetin is the most abundant SIRT activator in most people’s diet, and is found in a wide range of foods from capers and rocket/arugula leaves, to onions, berries, beans and buckwheat.
Quercetin switches off some genes needed for fat storage, and switches on other genes so that levels of SIRT1 increase by around 60%. The good news is that good dietary intakes of quercetin have been found to suppress the formation of triglycerides within fat cells by as much as 42%.
Rutin activates SIRTs
Rutin is closely related to quercetin and is found in asparagus, buckwheat, citrus fruits, oranges, lemons, limes, grapefruit, berries, peaches, apples, mulberries, cranberries, asparagus, buckwheat, parsley, tomatoes, apricots, rhubarb and, tea.
Scientists recently confirmed that rutin can active brown fat cells (BAT, brown adipose tissue) to increase metabolism and aid weight loss.
Other SIRT activators include quercetin, pterostilbene, piceatannol, luteolin, kaempferol, hesperidin, fisetin and butein. Catechins, found in green and black tea, and glucosinolates found in members of the cabbage and turnip family of cruciferous vegetables, also appear to stimulate SIRT1 which accounts for some of the effectiveness of green tea supplements, and the popularity of the cabbage soup diet.
Health benefits of SIRTfoods
Activating your SIRTs has beneficial effects on cell survival, especially during times of stress when DNA is damaged, oxygen levels are low, or the supply of nutrients is reduced. Their combined action protects against numerous healthy conditions, especially those associated with ageing such as middle-aged spread, obesity, type 2 diabetes, cancer, coronary heart disease, heart failure, dementia and cancer. In short, SIRTs are seen as playing a key role in staying slimmer, younger and living longer.
List of Sirtuin activating, fat burning SIRTfoods
SIRTfoods contain naturally occurring compounds that are known to activate sirtuin proteins. These sirtuin activators include powerful antioxidants called polyphenols.
|Almond||Apple cider vinegar||Apples|
|Bean sprouts||Bell peppers||Blackcurrants|
|Black garlic||Black grapes||Blueberries|
|Cherries||Chia seeds||Chickpeas (garbanzo beans)|
|Eggs||Elderberries||Fava (broad) beans|
|Garlic||Globe artichokes||Goji berries|
|Pak choi / bok choy||Papaya||Passion fruit|
|Physalis (Cape gooseberry)||Pine nuts||Pineapple|
|Purple Potato||Red Grapes||Red kidney beans|
|Red onions||Rocket (arugula)||Rye|
Herbs and spices
Most herbs and spices are powerful sirtuin activators, including black pepper, clove, cardamom, cinnamon, coriander, cumin, ginger, lemon verbena, mint, nutmeg, oregano, parsley, rosemary, sage, thyme, turmeric and edible flowers.
Fat burning drinks
Black tea, Green tea, Matcha, White tea, Rooibos, Chamomile tea and Red wine (one glass per day).
If you ate nothing but the above foods you would definitely lose weight!