Aging Biology / By

Most of us are familiar with signs of aging, but what causes it? We have seen family members gather wrinkles and mental changes ourselves, and many of us have experienced aging in ourselves. We now know there are nine biological processes that occur as part of aging.

 

1. Accumulation of senescent cells (Zombie cells)

Healthy cells are recycled after a certain period of time. But senescent or ‘zombie’ cells do not respond to normal signals, and do not die when they are supposed to. The accumulation of these cells accelerates aging and puts as at risk of:

  • Diabetes 

  • Accumulation of visceral fat, and obesity

  • Arthritis

Several nutritional supplements and medications have been shown to reduce numbers of senescent cells. These include:

  • Seaweed and strawberries: contain a compound called fisetin, that kills senescent cells. In one study, a high dosage of fisetin killed 50% of senescent cells.

  • Ashitaba: is a Japanese herb often consumed a tea form and contains a compound called DMC. It is thought that DMC slows the growth of zombie cells and in worms and fruit flies, DMC increases lifespan by 20 percent.

  • Pepper root extract: is commonly used in Ayurvedic medicine and contains a compound called PPL, which may reduce senescent cells.

  • Metformin: has been used since the 1950s to treat diabetes and is also believed to kill zombie cells. Metformin is currently being trialled as an anti-aging therapy in the TAME trial (2019).

2. Telomere attrition (shortening)

Telomeres are the caps at the end of our chromosomes, and protect our DNA . Telomeres shorten every time our cells divide and this is associated with aging, and this puts us at risk of:

  • Cancer

  • Heart failure

  • Diabetes

  • Early death

Luckily, there are a number of ways to reduce telomere shortening, such as:

  • Reducing stress: which speeds up telomere shortening. In one study, women with the highest rates of stress had shorter telomeres equivalent to one full decade. Yoga and meditation are two effective ways of reducing stress and anxiety.

  • Exercising: to help maintain tolmere length. One study showed middle-aged individuals who exercised had 40% shorter telomeres than those who were sedentary. 

3. Loss of proteostasis (the removal of waste products in cells)

Normally, certain enzymes in our cells remove waste products. But many foods contain compounds (aptly called advanced glycation end-products, or AGEs) that are not easily ‘digested’ by the cell. The accumulation of these waste products puts us at risk of:

  • Heart disease

  • Cancer

  • Alzheimer’s disease

To minimise this waste accumulation, try to avoid foods containing these ‘undigestable’ compounds , such as:

  • Animal-derived foods high in fat and protein

  • Meat products that have been cooked in oil

 Instead, choose foods low in these waste-products, including:

  • Vegetables, fruits, whole grains, and milk

4. Mitochondrial dysfunction

Mitochdonria have been dubbed the ‘power generators’ of our cells and are essential for normal functioning. Harmful changes to the mitochondria are associated with accelerated aging and elevate the risk of:

  • Diabetes

  • Dementia

  • Parkinson’s disease

  • Heart disease

  • Migraine headaches

  • Autism

 To keep healthy for longer, protect the mitochondria from damage by avoiding:

  • Consumption of heavy metals, found in swordfish, marlin and some varieties of fish

  • Pollutants

  • Alcohol

  • Antibiotics

  • Methanphetamine

  • Non-steroidal anti-inflammatories

5. Stem cell exhaustion

Stem cells are young and undifferentiated cells that can grow into many types of tissue. They are important for keeping us healthy. The number of stem cells in our body declines over time and this causes damage to our tissues, as well as muscle loss and frailty.

Stem cell counts can be increased naturally by:

  • Reducing sugar intake: as elevated glucose levels slow the growth of new stem cells.

  • Fasting: Studies show that periods of calorie restriction may trigger the growth of stem cells

  • Cutting back on alcohol and tobacco: which can negatively affect stem cell growth.

  • Sleeping well: Research has shown that sleep deprivation may reduce stem cell regeneration. Sleeping less than 4 hours has been shown to reduce stem cell counts by 50% https://stemcellthailand.org/6-ways-boost-stem-cells-naturally/

6. Genomic instability (DNA damage)

The DNA in our cells is essential for controlling many processes in our bodies. However, damage to the DNA leads to genomic instability and increases our risk of diseases such as cancer.

To keep the DNA as healthy as possible, try to avoid:

  • Sun exposure: Ultraviolet (UV) rays from the sun can pass into our cells and modify our DNA directly. It is recommended to use at least SPF 15+ sunscreen to protect the skin against cancer and aging.

  • Smoking: Avoid smoking or being around tobacco smoke. Cigarettes and tobacco are known carcinogens, since they mutate the DNA and cause cancer.

  • X-rays: are a form of high energy radiation that creates molecules that mutate the DNA. Limit the number of X-rays of teeth, bones and other body parts and try and for alternative imaging methods such as ultrasound.

7. Deregulated nutrient sensing (changes in metabolism)

Metabolism is the overall sum of chemical reactions that keep us alive. Some pathways of chemical reactions are associated with aging, such as the pathway that produces growth hormone. To keep healthy, it is best to avoid foods that accelerate these pathways, such as:

  • Processed red meats

  • Foods high in saturated and trans fats

  • Foods high in sugar

In addition, the following methods can reduce aging pathways:

  • Calorie restriction: this simply involves eating fewer calories in total. In model organisms such as yeast and mice, calorie restriction has been shown to prolong lifespan up to 30%.

  • Fasting: involves abstaining from food for several hours or days. Popular methods of fasting include intermittent fasting by eating in a small window (e.g. 8 hours) during the day, or a 5-day fast. Fasting improves insulin sensitivity and metabolic health.

8. Altered intercellular communication (e.g. inflammation)

Cells must be able to communicate with one another for good health. But cells reduce the ability to communicate following inflammation and other processes. Inflammation is thought to contribute to chronic diseases such as:

  • Obesity

  • Type 2 diabetes

  • Athelosclerosis

To reduce inflammation and ensure cells can communicate effectively with one another, ensure to:

  • Reduce inflammatory foods: such as red meat and foods containing trans fats, such as fried and processed foods, and margarine.

  • Eat anti-inflammatory foods: such as fruits and vegetables containing omega-3 fatty acids. These are found in tofu, tuna, flax seeds, walnuts and salmon.

  • Manage stress: through meditation, yoga, psychotherapy or hypnotherapy, as stress can increase inflammation.

  • Lose weight: by exercising and dietary control, as excessive fat tissue can contribute to inflammation.

9. Epigenetic alterations

The epigenome controls how the genes in your body are expressed. With age, the accumulation of epigenetic changes puts us at elevated risk of disease.

Several ways of reducing epigenetic changes include:

  • Calorie restriction: prevents epigenetic changes associated with aging.

  • Aspirin: is a widely used painkiller and mimics the effects calorie restriction. Aspirin supplementation has been shown to reverse aging effects.