We’ve written a lot about senescent cells lately. These are cells that have grown old and stopped functioning normally. We called them zombie cells in the past and they’re linked to a number of diseases of aging.
The thing is, senescent cells aren’t just found in seniors, babies also produce them.
The difference is that the young immune system clobbers them immediately, but as we get older, senescent cells hang around, clogging up tissues.
Numerous approaches to rid the body of these zombie cells are currently undergoing human trials, but you don’t have to wait. There’s much you can do right now to save your health from senescence just by eating the right foods and nutrients.
Senescent cells accumulate in all tissues and play a central role in multiple aging processes such as arthritis, osteoporosis, neurodegeneration, macular degeneration, cancer, kidney failure, vascular diseases, stroke, muscle wasting, and frailty.
These dysfunctional ‘down but not out’ cells inflict harm by secreting a slew of toxins that damage the surrounding environment, chew up collagen and promote chronic inflammation.
One reason they proliferate is because the aging immune system can’t cope with them, but the gene p53 might come to the rescue…
Genes are the trigger behind senescence
P53 is the tumor suppressor gene. During the cell cycle this ‘tumor suppressor’ gene oversees the process making sure cells grow and divide without errors, which can occur for multiple reasons.
If the gene finds any mistakes it repairs them before allowing the cycle to proceed. If this isn’t possible the cell is instructed to commit suicide. When cells come to the end of their natural life p53 should similarly instruct the cell to self-destruct. However, that doesn’t always happen. That’s because of a second gene, a gene called p21.
Researchers wanted to know why these genes work together, and they found a surprising answer…
Not all senescent cells are bad
Researchers were surprised to discover that senescent cells have positive attributes. They secrete growth factors that encourage tissue repair and regeneration. In animal research this is seen in skin cells, and it’s suspected this healing takes place in other organs too. Lab findings also show these cells are needed for normal amphibian and mouse embryo development.
So, senescent cells represent a double-edged sword. They’re necessary, but you don’t want them sticking around too long. To date two approaches have been devised to clear them.
Preventing senescent cell damage
The first approach is to get rid of senescent cells with drugs called senolytics. Studies in mice show after taking senolytics that calcified arteries were cleared or prevented, and improvements were seen in arthritic joints.
As we reported in 2018, a senolytic drug allowed very old mice to live 36 percent longer, an astonishing result.
Senolytics are seen as a major area of anti-aging research with many human clinical trials – mostly conducted by the prestigious Mayo Clinic – in progress to see if they’re effective in treating chronic kidney disease, Alzheimer’s, osteoarthritis, frailty and more, without negating the positive attributes of senescent cells.
Researchers already completed one trial already which included 14 patients with a progressive, fatal lung condition called idiopathic pulmonary fibrosis (IPF). The team found significant improvements in standing and walking ability.
The second approach aims to reverse senescence so cells function normally again. This can be done by using the drug rapamycin. Under normal use the drug has serious side effects but by manipulating the dosage and using it intermittently it proved safe in middle aged companion dogs with improvements seen in heart function. Human aging studies are the next step, and they’re being planned.
These cells can also be zapped back to life with ultrasound. We reported on this research in June and the initial findings are encouraging. Clearing senescent cells by either approach appears to be a promising way to slow aging and age-related conditions in the future. Fortunately, you don’t have to wait for brand-new, untested, expensive drugs and treatments, there are many natural ways to help defeat senescence right now.
Nature’s top three nutritional senolytics
- Quercetin: The current senolytic therapy of choice combines a drug with quercetin, an antioxidant and anti-inflammatory compound found in a wide variety of healthy foods. As a senolytic this combination targets the endothelial cells that line the arteries. Western diets contain 3mg to 40 mg per day, but a high intake of fruits and vegetables can provide a very healthy 250 mg. Increasing your quercetin intake through diet or supplementation is a wise idea with or without a senolytic drug, since this antioxidant has a positive effect on cells throughout the body.
- Fisetin: This antioxidant and anti-inflammatory compound is the most potent senolytic found in plants. It’s so powerful it’s currently being tested as the sole therapeutic agent in ten human trials. Amounts found in fruits and vegetables are way too small to act as a senolytic so it would have to be taken as a supplement.
- Grape seed extract: This supplement is rich in antioxidants and contains a senolytic compound called procyanidin C1 which extended the life of already elderly mice by 9.4 percent.
These are the most important compounds because their value has been demonstrated in animal and human studies. However, there are potentially many more.
In a recent review of cells studied in a petri dish the researchers wrote: “Naringenin, hesperetin, hesperidin, quercetin, fisetin, kaempferol, rutin, apigenin, luteolin, nobiletin, tangeretin, genistein, wogonin, epigallocatechin gallate (EGCG), theaflavin-3-gallate (TF2A), and procyanidin C1 possess potent antisenescence effects.”
These are all flavonoids and will be found in a diet containing plenty of fruits (including citrus), vegetables, herbs, spices, beans, and green or black tea.
The Aging Defeated Team
Armstrong, Sue, Borrowed Time – The Science of How and Why we Age (Bloomsbury Sigma, London, 2019)
Senolytics in idiopathic pulmonary fibrosis: Results from a first-in-human, open-label, pilot study. eBioMedicine (2019) https://pubmed.ncbi.nlm.nih.gov/30616998/
Potential Role of Polyphenolic Flavonoids as Senotherapeutic Agents in Degenerative Diseases and Geroprotection. Springer Nature (2022)