Four Key Insights on Healthy Aging from Dr. Jerry Mixon

Dr Jerry Mixon describes himself as "tall, brilliant, incredibly handsome, and delusional as hell", and then, with a grin, adds that a little delusion gets him through the day. It is a fitting start to a conversation with a man whose career has taken some remarkable turns. He went from paratrooper to country doctor to one of the early pioneers of what used to be called anti-aging medicine, and he now teaches other physicians about longevity.

I sat down with Dr Mixon on the me&my health up podcast to ask what the fundamentals look like after three decades of clinical practice. His answer was refreshingly organised: four connected areas of life that push each other up or down.

From the army to longevity medicine

A roundabout path into medicine

Dr Mixon was raised on military bases and joined the army at 17 and volunteered for Vietnam. He was later medically discharged after multiple gunshot and shrapnel wounds. His first civilian job was scooping sewage out of a harbour from a leaky wooden rowboat. He says medicine was his response to what he had been through, because he wanted a life that was the opposite of combat. He studied at night, went on to earn his medical degree and spent 21 years as a country doctor, working 70-plus hour weeks.

The turning point at nearly 50

By his own account, he reached his late forties overweight, divorced, sedentary and stressed. That was when he came across the emerging field of anti-aging medicine. He was sceptical at first, but he went back to the basic science and opened his first clinic in 1997. Today he has three clinics and ten physicians working with him, and some patients have been with him for 25 to 30 years.

The four areas he says matter most

When I asked about fundamentals, Dr Mixon named four areas that are "tightly interrelated": excess body fat, muscle mass, hormones and senescent cells.

1. Body fat is not just cosmetic

Dr Mixon calls fat "a destructive gland". He explained that it releases more than 50 compounds called adipokines into the bloodstream, which he links with chronic inflammation, joint degeneration, cardiovascular disease, diabetes and chronic pain.

2. Muscle is a gland too

On the other side of the ledger, he describes muscle as a gland that produces over 600 peptides, enzymes and other compounds, which he calls myokines. His point was that the more muscle you have, and the more often you use it, the more of these helpful signals your body produces. He also noted that working muscle helps clear "zombie" cells.

3. Hormones drive whether you build muscle or store fat

Dr Mixon's clinical approach has long focused on the gradual decline of many hormones from our twenties onward. His reasoning is that when the anabolic (tissue-building) hormones fall, the body struggles to grow lean tissue, and "if you can't grow lean tissue, what do you think you grow instead? Fat."

4. Senescent cells: the zombies in the system

Senescent cells are cells that have stopped functioning normally. Dr Mixon uses a zombie analogy: they release signals, which he referred to as the SASP (senescence-associated secretory phenotype), that can push neighbouring cells towards the same fate. He explained that a build-up in glands such as the thyroid, pituitary and adrenals can contribute to falling hormone output, which then feeds back into the fat and muscle problem.

If you enjoy this big-picture view of the body, you may also like my earlier article on why purpose matters more than fitness for healthy ageing.

What can people do every day?

For listeners who are not ready for advanced clinical treatments, Dr Mixon pointed to two everyday levers.

• Plant polyphenols. He mentioned compounds such as quercetin, fisetin and EGCG from green tea, which are found in fruit, vegetables and tea, and which he says interfere with the SASP signalling.
• Working your muscles. In his words, "working muscle kills zombie cells", so regular, vigorous resistance training matters. He also stressed that starting early helps, since people who stay lean and fit from young adulthood tend to have longer, healthier lives.

If you are thinking about getting stronger, my article on how to build strength safely is a good starting point.

Why we are wired to gain weight

One of the most memorable parts of the conversation was Dr Mixon's evolutionary explanation. He argued that our ancestors were "intermittent eaters", not intermittent fasters, and that they evolved to put on as much weight as possible in summer and autumn to survive winter. In his words, "the chubbies inherited the earth." The catch is that winter never arrives in a modern supermarket, so the instinct that once helped us survive now works against us. His conclusion was that we have to make conscious decisions to eat what we need, and then stop.

He also gave a simple piece of arithmetic worth remembering: roughly 100 calories a day, about one slice of bread, adds up to around 10 pounds of fat in a year. The reverse also holds. Small, consistent adjustments beat dramatic ones.

Protein, fasting and peptides: his views

Protein

Dr Mixon said the standard figure in the literature is 0.8 grams of protein per kilogram of body weight, which suits a relatively sedentary younger person. That is enough to replace what you are losing, he said, but not enough to build new muscle. For someone who is exercising, he mentioned around 1.2 to 1.3 grams per kilogram. He also noted that stomach acid and digestive efficiency decline with age, so older adults may need more raw material to maintain muscle. At 79, he adds about 35 grams of protein a day as a drink on top of two meals a day.

Fasting

He said there is good data that 14 to 16 hours of fasting a day increases autophagy (the body's cellular clean-up) and helps with insulin resistance. His caution was that some patients simply made their two remaining meals enormous and lost no weight, so total intake still counts. If this topic interests you, see my article on why longer fasting isn't better.

Peptides

Dr Mixon was candid here. He said he cannot use many of them in his Washington State clinics because of regulations, and that there is a "paucity of human data". His warning was that people are part of a large uncontrolled experiment, and until good human data exists, "you paid your money, you take your chances."

His four rules of medicine

I loved how Dr Mixon wrapped things up, with four rules he teaches every doctor he trains:

1. Anything strong enough to help is strong enough to hurt.
2. The proper dose of anything is just enough to do the job.
3. If you don't measure, you don't know. (His clinics test an extensive panel every three months.)
4. You can do everything right and things can still go wrong.

Final thoughts

You do not need to agree with everything in this episode to take something useful from it. The common thread is that ageing is the result of several interacting systems, and that muscle, food choices and measurement matter more than quick fixes. If you would like personalised nutrition support to build your own foundations, you can explore my personal nutrition and wellness programs and book a free 15-minute clarity call with me&my wellness.

To follow Dr Mixon's work, visit lmclinic.com, where he hosts a Saturday call-in radio show. Listen to more episodes of the Health Up podcast on the me&my wellness podcasts page.

General information only. This article summarises one guest's views and is not medical advice. Speak with your doctor before changing medications, hormones, supplements or exercise.