1. What Causes Symptoms of Aging?

2. Genetics? Defective mitochondria produce free radicals which cause other proteins to be inactive Caloric restriction seems to shut down these defective mitochondrial genes.

3. More Genetics? FOX03A gene – Regulates insulin pathway – Protects cells against free radicals – Involved in apoptosis (programmed cell death) important for ridding cancer cells

4. Hormonal system decline? Receptors on cells do not respond to hormones Ovaries and testes do not respond to FSH Cells do not respond to insulin

5. Immune System? Thymus gland becomes smaller and is replaced by fat and connective tissue Higher cancer rate in elderly; is immune system not destroying cancer cells anymore? Higher incidence of autoimmune disease in elderly; is immune system attacking self cells more often?

6. Collagen fibers? Become cross linked and flexibility in ligaments and tendons decreases Heart, lungs, blood vessels lose resiliency Less blood flow to liver, kidneys,

7. Extrinsic (outside) factors? Exercise Smoking Alcohol Nutrition

8. Alzheimer Disease Supporting protein (tau) around neurons becomes malformed Protein plaque around axons causes inflammation and neuron death Too little Ach neurotransmitter