Hormones: How much control do we have
There are a lot of supplements appearing on the market, along with dietary strategies to optimise your hormones or increase levels of certain hormones. Test boosters, adrenal fatigue, growth hormone boosters, to name a few. How evidence-based are these, and do any of them actually work? And what are the best ways to ensure our hormones are functioning the way they should?
Our hormonal milieu is a very tightly regulated, complex network of glands that secrete hormones in response to a stimulus. Hormones tell our body to do things, for example, insulin will lower our blood sugar, adrenaline will raise blood pressure and increase heart rate, and cortisol will raise blood glucose and help regulate blood pressure.
Insulin: Blood sugar optimisation
Insulin is secreted from beta cells in the pancreas and is elevated when high levels of carbohydrate and protein are consumed. Insulin does not just lower blood glucose, its role is to take things and put them into cells, whether that be skeletal muscle or fat cells.
A big worry people have about insulin is that it “blocks fat burning”and stimulates lipogenesis (the creation of new fat cells) which traps fat in fat cells. While it is true that insulin does transiently inhibit the release of free fatty acids from adipose, this is not the same as actually burning fat. Inhibiting the release of fatty acids from fat cells is not the same as them entering the mitochondria to actually be burned.
In short, just because you are burning more fat for fuel, does not equal greater losses in body fat.
If insulin has a negative effect on fat burning, we would expect to see lower rates of fatty acid oxidation in people who are obese and carrying more fat. This is not the case, and actually, in obese populations, we see a greater degree of fat oxidation (1). The key thing to remember is that insulin’s effects on lipolysis (the release of fatty acids) are very acute, and as long as calorie intake does not exceed expenditure, weight gain cannot occur.
However, there is data showing a benefit for many people from the abstinence of carbohydrate for certain periods of the day (2).
Let’s take a normal office worker. They wake up, eat a bowl of cereal, drive to work, sit all day, snack on a breakfast biscuit, eat a sandwich for lunch, sit some more, snack on a few biscuits, drive home, eat dinner, sit on the sofa. A large percentage of the population are extremely sedentary and do not have high energy requirements.
By constantly consuming carbohydrate, your body is constantly burning carbohydrate at rest. While this will not affect weight loss, but it can lead to poor metabolic health and flexibility, as the body does not know which fuel source is appropriate. When we are resting or being sedentary, fat is the optimal fuel source, so fasting from carbohydrate at appropriate times is one way in which we can select the best fuel for a given energy intensity.
Optimising insulin response
There are a few things we can do to improve our body’s response to insulin and reduce our risk of becoming insulin resistant.
1. Resistance training
This improves skeletal muscle insulin sensitivity, since muscle is responsible for 60-80% of the increase in glucose metabolism in response to insulin (3). If we have less muscle mass, we have more glucose entering the blood instead of the muscle, where it can then be stored as glycogen. There are still benefits to aerobic training, mainly in regards to creating an energy deficit. As aerobic training often uses fat as a primary fuel, it is not as effective at glucose utilisation, an important consideration in people with type 2 diabetes. HIIT may be more beneficial for aiding in reducing blood glucose levels.
2. Carbohydrate periodisation
Restricting carbohydrate for periods of the day may aid in improving insulin sensitivity. It is important to consider this is not a recommendation for a low carbohydrate diet, as by nature, these types of diet induce transient insulin resistance (not the bad kind) (4). This happens because the cell that wants to avoid burning glucose is precious to the body and is involved in numerous bodily functions. If you restrict fat, the body still oxidises the same amount of fat, but when you restrict carbs the body spares carbs and dips into fat stores (5).
Many studies link good metabolic flexibility to a reduced risk of type 2 diabetes, dementia, and metabolic syndrome. It is important to remember that weight loss itself improves insulin sensitivity, as does exercise (6). Fasting from carbohydrate or fasting, in general, is a tool in the toolkit, not magic.
3. Maintaining a healthy body weight
Excess body fat interferes with insulin signalling, increases chronic inflammation, mitochondrial dysfunction and hyperinsulinemia, all of which increase the risk of insulin resistance and all are more pronounced in obesity (7).
4. Diet and Supplements
Fibre and protein are two of the most important considerations to optimise blood sugar. Fibre will delay the rate at which food leaves our stomach, providing a smaller peak in blood glucose. Fibre also helps us feel fuller for longer so is a great way to reduce overall caloric intake if weight loss is an issue.
Protein, whilst very insulinemic, only has very modest effects on blood glucose (8). This is because when we eat protein, glucagon is also secreted, which opposes the effects of insulin. If it didn’t, we would all go hypoglycemic whenever we eat protein.
Protein therefore lowers the blood glucose in response to a meal, especially when ingested with carbohydrate. Protein is also the most satiating macronutrient, has the highest thermic effect and contributes to maintenance and building of skeletal muscle.
Cinnamon bark extrac t: Cinnamon acts as a mimetic of insulin and has good evidence in those with insulin resistance at reducing postprandial glycemia (9).
Chromium : Regulates how much insulin the body produces, and has been shown to be involved in carbohydrate and protein metabolism. There is evidence to suggest that chromium will curb sugar cravings, the only population it has been researched in it diabetics, and its effects are moderate (10).
Apple cider vinegar : Helps reduce the blood glucose rise after a meal in diabetics, has not been tested in healthy subjects.
Berberine : Perhaps the most well studied and effective supplement in regards to blood glucose, the evidence is almost overwhelming. Compared with metformin, berberine exhibits an identical effect in the regulation of glucose metabolism (11).
The myth of Adrenal Fatigue
Cortisol, Aldosterone, Adrenaline and Norepinephrine are the four main adrenal hormones, but the one that gets the most attention in the media is cortisol, which is the body’s main glucocorticoid.
Your body has two main nervous system states, sympathetic (fight or flight) and parasympathetic (rest and digest).
If you were being attacked by a bear, this would activate the hormones adrenaline and norepinephrine, and without these hormones, your body would not detect the threat and you would die. Cortisol acts more slowly than these hormones and works in the background. It modulates the metabolism of macronutrients and is involved in water and electrolyte homeostasis, through interaction with aldosterone, blood pressure, body temperature, mineralisation of the bones and immune system function.
Cortisol does not promote weight gain from a biochemical perspective. Cortisol is a catabolic hormone so it is permissive of fat loss (13) (14). The main issue people run into with cortisol is the behaviours that are associated with chronic stress. These could include comfort eating, reduced activity levels and poor sleep. A large 2011 meta-analysis concluded, “psychosocial stress is a risk factor for weight gain but effects are very small” (15) and the effects are very individual. Cortisol inhibits certain areas of the immune system, but also can strengthen others, so its overall effect on immunity is fairly uncertain. When we age, levels of cortisol to DHEA (dehydroepiandrosterone) become more skewed in favour of higher cortisol which leads to increased rates of immune system decay (16).
How can we manage our cortisol levels?
1. Exercise Low-intensity aerobic exercise is a great way to reduce cortisol, as the release of beta-endorphin suppresses adrenal output of cortisol (17). Contrary to popular belief, HIIT does not increase cortisol levels on an acute basis and “The present data indicate a HIIT reduced cortisol and increased total-testosterone/cortisol-ratio levels significantly in physically inactive adults” (18).
2. Sleep Cortisol should be naturally elevated in the morning, as this helps us to wake up. Lack of sleep raises cortisol levels in the evening, which is a more accurate marker of stress (19). Interestingly, research shows it is sleep quality, and not sleep quantity that affects how much cortisol your body produces, this is why sleep hygiene is so important. Avoiding caffeine, strenuous exercise and blue light exposure close to bedtime is important, as is setting the right bedroom temperature (20).
3. Stress and Supplements Managing your micro-stresses is key to cortisol management. Your working environment, relationships with family and friends and other stressors are very influential on how much cortisol your body will produce.
Ashwagandha : An anxiolytic supplement that can lower C reactive protein (inflammatory marker) and cortisol. KSM-66: 300 mg (root) of which 5% Withanolides: 15 mg 2x per day. Ashwagandha is possibly the most well-researched stress adaptogen herb.
Rhodiola Rosea: An anti-fatigue effect that increases mental performance, particularly the ability to concentrate, and decreases cortisol in subjects with extreme fatigue (21)(22). 3% Rosavins extract, 200-400 mg daily.
L-Theanine : Stimulates the activation of brain alpha waves to enhance relaxation without being sedative (23). Works well with caffeine. 150-400 mg daily.
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24. https ://www.sciencedirect.com/science/article/pii/S0091305706000645
25. https://scholar.google.co.uk/scholar?q=caffeine+and+cortisol&hl=en&as_sdt=0&as_vis=1&oi =scholart#d=gs_qabs&u=%23p%3DrBgM5f2g7QMJ