The human body has about 60,000 different protein families. Sirtuins are a family of seven molecular proteins that are important for the health of the cells in the human body. For your reference, hemoglobin is another family which has two proteins. So what do sirtuins have to do with aging?
What Are Sirtuins?
Sirtuins coordinate with other enzymes in the body that exist in all living cells. These enzymes are responsible for a lot of biological processes in the body including cellular metabolism.
Two of these proteins are responsible for the functions of the mitochondria in the cells. Three others work in the cell’s nucleus and the last one deals with the cytoplasm. They all have different roles. Sirtuins are responsible for separating acetyl groups, which control certain reactions in the body, from the other proteins.
Now, we have been studying the functions of sirtuins only for about three decades since we learned about their main function in the 90s. As some of the enzymes that work with sirtuins decline with the passing of time, the efficiency with which sirtuins can function also gets affected adversely.
What Do Sirtuins Have To Do With Aging?
One of the functions that sirtuins perform is to make note of which proteins are available for the body to conduct specific functions. They have the ability to alter the pattern in which certain nutrients are available to ensure cellular metabolism.
This is how sirtuins have a role to play in the control they have over aging. That is because some of their functions involve responding to inflammation, the way mitochondria function, controlling the cell cycle, controlling the stability of the genome and repairing the DNA.
So, they can help control metabolism, regulate or control chronic inflammation and even prevent aging.
Sirtuins And Brain Aging
It has long been established that sirtuins have the ability to control certain physiological responses with respect to stress and metabolism. These are two factors that have a huge role to play in the aging process.
Since sirtuins have command over these two factors, they may be able to help us understand aging better, which in turn can help us figure out how to slow it down.
Now, the human brain degenerates steadily with age. This is because the neurons in our brains need a lot of energy to perform some of their key functions which include neurotransmission.
So, when your metabolism starts to go downhill as a result of aging, it can also cause cognitive decline. This can lead to age-related diseases that are classified as neurodegenerative disorders because the neurons in our brain have failed to adapt themselves to changes in metabolism caused by age.
The lack of adapting to the changes in metabolism also brings about a change in the way they perform tasks like neuromuscular coordination, awareness of the person’s environment and cognitive performance since these tasks require a lot of energy.
Now, sirtuins play an important role in modulating how the body responds to changes in metabolism. So, the way sirtuins function can tell us how a lot of diseases are caused. These diseases range from abnormalities in metabolism to those that are caused by neurodegeneration.
Calorie Restriction: How Sirtuins Can Extend Lifespan
It was discovered that, in yeast, sirtuins are one of the genes that promote longevity. So, further studies were conducted to see if they have the same impact in other organisms including mammals.
And since, we have found that they actually do manage the lifespan of other organisms of the lower order like fruit flies, nematodes, and yes, yeast. Some of this research is still heavily debated but a lot of them still state that SIRT1 is known to regulate how the metabolism responds when diet is controlled to restrict calories. Calorie restriction has been found to extend the lifespan of many species.
While SIRT1 did not do the same in mice, it does control many other pathologies like increased production of glucose, facilitating sensitivity to insulin, reduction of oxidative stress and more which are all connected to the aging process.
In mammals, when you restrict calorie intake by 30 to 40 percent, it is known to bring about a change in our metabolism. This, in turn, affects the way SIRT1 regulates the new rate of metabolism. And the end result seems to be an extension of lifespan and also a reduction in morbidity that comes with age.
In fact, this type of calorie restriction is said to be the only thing that has delayed the onset of many age-related diseases consistently. It has done so while extending the lifespan of short-lived species and some long-lived primates that are not human.
This is an indication that the same might be possible in human beings too. Even though it did not have the same effect on mice, some research claims that it does prevent some pathologies that are brought upon by aging.
Then there is SIRT3 which plays a role in preventing hearing loss that comes with age. SIRT3 has a strong connection to calorie restriction that affects the sirtuins in mammals that eventually cause aging. Reducing oxidative damage in tissues can be done by mediating calorie reduction. And SIRT3 is required for that process.
Foods That Stimulate Sirtuins
Obviously, we have a long way to go before we know how to manipulate any of this to find the key to anti-aging. But meanwhile, there are a lot of functional foods that can help us stay healthy and keep age-related diseases under control.
The key to this is to find foods that can increase the sirtuin protein levels in the human body. This can be made possible by eating foods that have some plant compounds which do the trick.
A lot of foods that are a big part of Japanese and Mediterranean diets contain these ingredients. They are:
- Dark chocolate
- Extra virgin olive oil
- Red wine
The study of sirtuins with respect to anti-aging is a vast subject. Some of the research findings are still hotly debated. But what we know so far is still a lot more than what we did about four decades back. So, it’s a promising field.