Lets start with some protein basics;

Protein is made up of smaller building blocks called amino acids.

There are 20 structural amino acids in the body of which:

9 are essential amino acids ( essential means our body can’t make them so we need to get it in the diet) - * these are totally indispensable
- Lysine * - think hormones, tissue repair and calcium
- Threonine *- recycles protein
- Histidine *- growth especially kids (found in seawed)
- Leucine- growth hormone + muscle repair (mTOR)
- Methionine- fat emulsifier, digestion, cardiac protective , heavy metal removal
- Phenylanine- dopamine+ memory+ mood
- Tryptophan- pain, sleep/wake regulation, serotonin
- Valine- muscle production, recovery, endurance
- Isoleucine- muscle production, recovery, endurance, haemoglobin (in blood)
  - Three called branched chain amino acids (branched chain chemical structure): Isoleucine, leucine, Valine.
11 are non-essential in the body (ie. we can make them) * well 6 are considered semi-essential
- Alanine
- Glycine *
- Serine
- Arginine *
- Proline*
- Cysteine*
- Aspartate/aspartic acid
- Glutamate
- Tyrosine*
- Asparagine
- Glutamine*

So now you are thinking there are so many how do i make sure i get them all?

We don’t need all types of protein at each meal- the aim should be to get a mix over the day or week. As we have an amino acid pool (skeletal muscle)in the body to draw on and that is stored. But for vegetarians and vegans they ned to be a lot more conscious of this than meat eaters.

Legumes: contain Isoleucine, Lysine
Grains; Methionine, Tryptophan
Soy: is a good protein for vegetarians and vegans as it is closet to animal sources + quinoa. But remember soy can worsen mensural symptoms in some women and may interfere with thyroid function.
Of note animal sources of protein are rich in leucine and are considered “complete”. Eating meat is the easiest way to get in protein.
Legumes also contain a lot of physic acid which is why they need to be soaked- can cause gastrointestinal inflammation and issues.
Egg: is a great source and 99% of the protein in eggs are absorbed they are considered the “benchmark” for protein food or a “1st class” protein source.

As a note for vegetarians/vegans its important to heck for deficiencies such as: protein, B12,B2, Vit D, Calcium, Zinc, Selenium, Iron. And supplement accordingly as it is difficult for you to obtain the correct amounts through plant sources.

Importance of muscle/protein

Proteins are required in literally every process in the body. From brain health, neurotransmitters, hormones, to being used in detoxification by the liver, transporting chemicals/nutrients in the body, repairing tissue the list literally goes on and on. The skeletal muscle tissue is essentially the biggest reservoir of this in the body. Not only that but skeletal muscle is what helps us to move and be functional and you can think of muscle as our body’s body armour. It maintains you in times of fasting, illness, injury, age and cancer. We know survivability in old age and cancer depends on the amount of muscle mass you have.

The body is designed for movement- the human machine was designed for hard physical labour. balance, strength, flexibility survivability. The body is made up of approximately 40% skeletal muscle.

Whilst it’s not easy to put muscle on: it takes time, attention and diet changes. As you get older you are not as primed for anabolic growth (much easier to put on muscle when you are younger). Skeletal muscle is one of the primary sites for insulin resistance. Insulin resistance begins in healthy 20 year olds that are sedentary before changes are seen in the blood, to insulin secretion , blood glucose levels, liver abnormalities, triglyceride levels etc. And insulin resistance is linked to so many conditions. This is more important to look at than adiposity (fat we are holding). 80% of glucose disposal is in skeletal muscle. If you destroy skeletal muscle where is the glucose going to go or be stored? Utilising glycogen, fatty acids- if skeletal muscle can’t do it where are these metabolites going to go?

While we are mentioning insulin resistance, the liver when it has become saturated with glucose and thus signalling from inulin to take it up (insulin resistance) becomes blunted. You can’t detect circulating blood glucose levels as well- so the liver pumps the glucose back out into the blood stream (this is what happens often in fatty liver). The P-PAR receptors regulate what energy to use and is what tells the liver not to release sugar. Glucose tolerance factor (GTF) makes insulin 3 times more effective. It is made up of guess what? 3 amino acids (glutamic acid, glycine, cysteine), chromium and B3. High insulin levels also cause IGF-1 (insulin like growth factor) to become resistant as well ( it is stimulated by calorie intake to increase muscle mass). Excess triglycerides, free fatty acids, glucose, coupled with physical inactivity, perturbs metabolism in skeletal and cardiac muscle.

We can’t make our kidneys bigger, our liver bigger, we can’t change a lot of other organs in the body but we can grow more muscle.

Muscle is an endocrine organ

Muscle is an endocrine organ that we can directly control. When muscles contract they release their own chemical messengers -the most well studied been IL-6 (interleukin 6), myokines, IL-10, in a low glycogen state.

Myokines are protein factors including cytokines and peptides secreted into the blood scream after muscle contraction. One of the myokines released from muscle contraction is BDNF (brain derived neurotrophic factor) often though of as the brain miracle grow molecule ( see post on BDNF) this is part of why working out makes you feel so good as well as endorphins.

Under optimal conditions skeletal muscle regulates energy balance in the body ( the more muscle mass you have the faster your metabolic rate). It's a major site for carbohydrate disposal, fat burning and is a reserve for amino acids. Obesity is a symptom of unhealthy muscle that is dysregulated.

Exercise interfaces with the immune system- it increases natural killer cells (NK cells) and reduces the risk of cancer, cardiovascular conditions, reduces inflammation in the body overall; in fact exercise helps with nearly all medical conditions. There is no such thing as healthy sedentary individuals. We are designed to move and exercise also bypasses insulin with glucose uptake (GLT-4) to take up glucose. Why is that important? Because especially if someone has insulin resistance we can get that excess glucose out of the circulating blood where it is doing damage to tissues.

Middle age is when we really need to be training and using the amount of muscle on our bodies to see ourselves into old age. As we age it becomes harder to put on muscle mass, as skeletal muscle ages it becomes less efficient at recognising protein to uptake it, skeletal muscles insulin resistance, decreased ability to use glucose.

Protein diet recommendations

RDA is set at 0.8g/kg -based on nitrogen studies on 19 year old men extrapolated from animal data. It has not changed in 40years! Higher protein diets always does better than baseline RDA- double the RDA is supported for most conditions for health. The RDA is currently 50% too low to maintain normal function. 1.6g/kg should be the recommendation at a minimum. Protein intake has been tested up to 3g/kg with no abnormalities being detected. For individual amino acids the range has been tested up to 250-300g or protein a day with no abnormalities.

What about my kidneys with all that protein?

There is a lot of old information that high protein diets will damage your kidneys. The only time we need to consider the protein strain on our kidneys is in chronic renal failure.

According to the journal of nutrition meta analysis and systemic review of more than two dozen studies (PMID: 30383278) invoking hundred of participants in processing large amounts (>=1.5G/KG) of protein DOES NOT I will repeat DOES NOT lead to a decline in kidney function.

mTOR

mTOR is in every tissue in the body, in skeletal muscle it is very sensitive to dietary protein. It requires a specific amino acids to stimulate it and that is Leucine. As we get older the tissue becomes less sensitive to dietary protein and we need double the amount of protein in order to stimulate mTOR and maintain healthy muscle mass. The minimum amount of dietary protein to stimulate the mechanistic target of Rapomysin based on Leucine is 2.5g Leucine which means the minimum amount of protein needed is 30g dietary protein to stimulate MTOR ( so we should aim to have this amount as a minimum at each meal). As you get older you need closer to 50g in order to stimulate MTOR and build muses in older years. You either stimulate mTOR or you don’t. There is not a little bit of stimulation (exercise/resistance training also stimulates mTOR).

The health benefits of resistance training and aerobic exercise

Resistance + aerobic training
- Glucose homeostasis
- Body composition
- Mobility
- Mitochondrial funciton
- Cognitive function
Resistance training
- Mitigating decline in muscle mass
- Muscle strength
- Aerobic exercise
- Cardiovascular funciton

Why you should build muscle

Improve your longevity
Decrease risk of cognitive decline
Correct your body composition
Maintain activities of a fulfilling life
Better blood sugar regulation
To be strong AF!

Benefits of higher protein intake for older adults

Higher bone density
Slower rate of bone loss
Slower rates of muscle loss
Increased resilience

One you are over 50years muscle mass decreases at an annual rate of 1-2%. The decline in muscle strength is even higher. The cause is likely a combination of disuse, inadequate nutrition, lower hormones, injury and inflammation. Often the loss of muscle is replaced by body fat, reducing muscle strength and mobility as well as disruption our metabolism- a condition called sarcopenia obesity.

Older people need more dietary protein than younger adults to support good health, promote recovery from illness and mating functionality.

Alzheimers study and exercise?

Recent research is showing that exercise is a great way to prevent and help treat alzheimers. The hormone irisin shows it has the ability to spur the cognitive benefits of exercise.

In a 2021 study using mouse models, the team showed that genetic deletion of irisin impairs cognitive function in exercise, aging, and Alzheimer’s disease, which was in part caused by alterations of newborn neurons in the hippocampus. The hippocampus is the compartment of the brain that stores memories and is the first to show signs of Alzheimer’s disease. At the same time, the study found that elevating irisin levels in the bloodstream improved cognitive function and neuroinflammation in mouse models of Alzheimer’s disease. Another important finding of the study is that irisin protects against neuroinflammation by acting directly on glial cells in the brain.

Exercise effects broader than weight loss

When we are active we are able to activate the parts of our human nature that brings us joy. We are designed to move! Movement is one of the few things that can actually changes the structure of your brain. Movement is also how we engage with life. Exercise is an anti-aging elixir, that spins the biological clock in reverse. When you look at the health of centenarians a commonality amongst all of them is that movement is a foundational part of their lives.

A big reason that movement is such a vital component of health and longevity is that it regulates the epigenome (our gene expression controls), including via DNA methylation. Positive, exercise-induced DNA methylation changes have been found in the following areas:

Obesity, diabetes, and fat storage (this particular study showed profound, beneficial changes in type 2 diabetics who started exercising in just six months!)
The inflammatory response and inflammation-associated diseases, when moderate exercise is practiced regularly over time
Learning, memory, and neuroplasticity (the ability of brain cells to form new connections)
Suppressing cancer – and this effect is more pronounced the older you are
Reverting global DNA methylation patterns to those of a younger person
Our exercise habits are heritable! You can hand down DNA methylation changes (favorably or not) to your offspring. Can you hand down those 6-pack abs? Probably not, but you can lower risk for diabetes and heart disease in offspring based on your habits.

It sensitises the brain to pleasure- it changes the function and structure of the rewards system. It teaches your brain to expect things to be pleasurable and enhances your capacity to enjoy everything from good food and a beautiful sunset to connection with friends, family etc anything you find pleasure. It makes your reward system more robust and responsive: endorphins work better and endocanibinoids work better in the brain. It makes you more resilient to stress and is a great antidepressant- and can enhance how antidepressant therapies work.

The “joy- gap” with exercise - people dramatically underestimate the pleasure they get from exercise- yes even for people who don’t like exercise. We think it’s going got be so hard, so uncomfortable and so awful. But when people actually exercise they self report afterwards - “I feel better, I feel more optimistic, I have more energy not less energy”.

Your muscles recreate hormones into the body that affect every part of the body as mentioned. It is an endocrine organ. They secrete hormones and proteins that are fight cancer cells and good for heart health and also for brain health. “Hope molecules” (aka Myokines- one of the main ones being BDNF) are excreted when you exercise (contract your muscles) that make you resilient to stress and act as a natural antidepressants.

Have you heard of the “runners high” that feel good sensation that goes from exercise and overriding the pain? Why do we get that? Well because in caveman days wee needed to hunt and to get food and to do this we needed to move and our body designed to make it pleasurable so we would engage with life and work hard. But not only that the endocannibinoid system helps us be more cooperative and compassionate. So once we killed the “woolly mammoth" for example instead of keeping it to ourselves it makes us more likely to share it with our tribe. It helps lower inhibitions, makes us more social, reduces anxiety , makes us feel good and helps us to connect with others. It gives us more pleasure from being cooperative and sharing with others. It helps make us willing to do the hard things and it feels good to do those hard things and be the person who contributes to community and it feels good too. You don’t have to run to get the runners hight- you just need to do something that is moderately physically challenging for you! Get your heart rate up, muscles contracting and moving!

When cultures want to strengthen ties traditionally or deal with grief- they use movement be that dance etc. It helps with all these feel good chemicals and also releases oxytocin. Moving is a form of social grooming- holding, touching etc. When you work doing labour together, walk in synchrony it helps bond you just like hugging.

If you block endocannibinoids you make people unable to have pleasure and bond with others. There was a drug developed that was a cannabinoid blocker “Remonabant” whose intention it was to be a weight loss drug. Block the endocannabinoid system and you won’t feel hungry . However unintended side effects where increased suicidal tendencies and depression. Because it reduced your ability to feel pleasure and bond with others. In mice studies it cause the mother mice to abandon their children and it makes them antisocial.

Those who exercise regularly is directly correlated with purpose and meaning in life. Those who move on days they move/exercise find more meaning in their life. When people are forced to be more sedentary their meaning in life decreases for those who are sedentary and when you increase that they gain more meaning.

Can you get addicted to exercise?

It is possible to get addicted to exercise- never say never. A small percentage of people will get hooked in an unhealthy way- but this is always linked with other addiction challenges. The majority of people experience a different kind of addiction ; they love it, they feel dependant, they know they need it, they feel withdrawl if they miss a workout.

The difference with this type of addiction to say drugs like cocaine etc. is with these drugs there is such a huge amount of neurotransmitters released it overwhelms the brain and your brain then decides this isn’t safe and it reduces receptors and kicks in the“ anti-rewards system’.

Exercise does the opposite it boosts the natural rewards system and increases receptors that will respond to neurotransmitters. It also helps repair brains that have been damaged from drug use. It helps to heal and rewire their rewards systems damaged from substance abuse.

So “exercise addiction” is more a recognition of the benefits of exercise rather than an addiction that affects regulation in a negative way.

The research coming out around protein intake, skeletal muscle and even exercise is becoming more and more compelling for why we need to move on a daily basis. I hope this encourages you to look at what movement you enjoy and how you can incorporate into your life. We want to be happy strong and healthy as we age. And even just so we look and feel good now! This is where the fitness industry meets science and the health industry- we need to stop looking at our bodies in isolation but the whole package of what can give us vitality and optimal health.