Understanding the Blood Sugar and Hot Flush Connection
Studies investigating the impact of sugar consumption on human health have been ongoing since the mid-20th century. The stats about the increase in sugar intake are overwhelming, particularly in the USA, where the consumption of soft drinks per capita has increased by about 500% over the past 50 years.
Taking a life-course approach to menopause symptoms, means that we can also reflect on our own sugar intake over the past 50 years too.
Higher sugar intake over many years has long been recognized as a risk factor for increased incidence of many non-communicable diseases, including obesity, cardiovascular disease, metabolic syndrome, and type 2 diabetes (T2D) and post-menopausal women face a significantly higher likelihood of pre-diabetes and abnormal blood glucose compared to pre-menopausal women.
For midlife and older women, this is important to understand, because the role of sugar (glucose) in your hot flush intensity and frequency and your anxiety levels, during and after menopause, cannot be denied.
High glucose levels in your blood triggers insulin release. This directly stimulates sympathetic nerve activity and raises your heart rate and increases vascular resistance – the stiffening of blood vessels. Over time, this can contribute to worsening heart health as women age.
The connection between elevated glucose levels, higher body temperature and sweating are already known in Diabetes research, but for women in their menopause and post-menopause years, this is not only a diabetic issue.
In healthy people without diabetes, acute spikes in glucose, either by glucose infusion or excessive carbohydrate consumption, causes body temperature to climb. (Bikman, 2022).
I’m sure some of you, especially those of you who are overweight as you move through menopause, may have worked this blood sugar/body-heat connection out already.
But why does this happen? And why do our menopause hormonal changes generate more heat than we can tolerate?
The answer lies in our blood vessels, as well as in our changing insulin production as we age.
Hormonal changes during menopause can disrupt the production of insulin from our pancreas as can being overweight, not sleeping well and of course, being sedentary and eating foods higher in glucose, which may contribute to inflammatory changes around the body.
Excessive sugar intake (through any source) is now known to be an accomplice of inflammation [Ma, Nan et al., 2022].
When glucose intake is high, so too is insulin. High insulin levels can directly increase your core body temperature by signaling specific nerves in the hypothalamus region of your brain to generate heat. [Parry et al., 2021; Sanchez-Alavez et al., 2009].
But there is something else to consider too – your sweat glands are ageing and shrinking as your skin changes, as are your blood vessels changing with age. This means that as you move through menopause, it becomes harder for your blood vessels to carry this heat to your skin.
Furthermore, ageing itself, also ‘stiffens’ blood vessel walls, so a higher glucose intake, can exacerbate your already-ageing blood vessels.
Excess circulating glucose contributes to faster ageing of your blood vessels. The elastin fibres in the blood vessel wall become more rigid, contributing to their loss of elasticity. This is known to contribute to worsening cardiovascular health and higher blood pressure as women age.
Why High Blood Glucose Levels Increase your Body Heat
Glucose is a simple sugar and is also known as blood sugar.
Flowing through your bloodstream, it is the principal fuel of all of your body cells, especially your brain.
When glucose levels become too high in the blood-stream (e.g. with sweet treats; sugary drinks, alcohol and many processed foods with added sugar), there is a rapid release of insulin from the pancreas.
Insulin is the hormone made by the pancreas, and its role is to transport glucose from the blood into cells, where it is burned for energy.
Insulin carries sugar/glucose – it is your energy storage hormone.
When you eat something such as bread or white rice, or a cookie, or sweet treats, your blood glucose (sugar) rises. This signals the pancreas to release an amount of insulin necessary to carry the available glucose to the brain, the liver and muscles as well as other cells.
There is no energy storage in our muscles or liver cells without insulin.
Nor is there glucose which travels to the brain without insulin. It is a crucial hormone which holds the key to unlocking the door to glucose being stored in the liver, muscles and in fat cells.
During menopause as the liver, muscles and blood vessels adjust to declining reproductive hormones, there may also be changes in the ability of insulin to do its job.
This may arise from a number of factors, including:
- eating the wrong types of food, especially sugary foods
- eating too much or too little food,
- drinking alcohol
- having a sedentary lifestyle with very little activity
- having too much exercise/sports as with athletes training and competing, and blood sugar levels are crashing because food intake is inadequate
- carrying too much body-fat
- the ageing of the pancreas during menopause, which is the organ responsible for releasing insulin and glucagon (it’s opposing hormone).
- hormonal changes during menopause.
All of these factors can cause the pancreas and the liver to become inflamed and insulin production and function to get out of balance.
When insulin production and function is out of balance, this causes an increase in inflammatory changes in tissues. These inflammatory changes cause over-heating.
However, because our blood vessels are also losing some elasticity as mentioned earlier, then it becomes more difficult to move heat to the surface of the skin as efficiently. Hence, temperature regulation in the body is disrupted and this may become worse when metabolic function is disrupted and glucose levels are elevated. (Bikman, 2022)
That’s why changing your diet and learning how to reduce your sugar-cravings, is such an important part of hot flush management during and after our menopause transition. I talk about this in all of the MyMT™ programmes, especially for women already on HRT but who are putting on weight and their hot flushes have returned in post-menopause.
Understanding the Glycemic Index
I’m grateful to the scientists who have helped me pull together the menopause jigsaw so that I can use my knowledge to help others – and there are no borders to menopause symptoms and weight gain!
Over the years, women have joined me from over 50 countries either on my online Masterclass on Menopause or on the 12 week programmes. Each programme gives you your MyMT™ Food Guide and the charts and food lists which have the glycemic ratings of carbohydrates.
Throughout our lives we are influenced by others. One of the scientists who has helped me to help you, is Professor Jennifer Brand-Miller from the University of Sydney in Australia. Women on the MyMT™ programmes learn about her as well and why her research on carbohydrates is included in the MyMT™ Food Guide.
Over our lifetime, we need to eat differently depending on our age and stage. But food information has become so embedded in our psyche from the powerful influence of the modern food industry, the fitness and sporting industries and the dieting and media industries, that it’s no surprise that we all get a bit confused about food. I was confused too.
For over 25 years, Professor Brand-Miller has been a world-authority on carbohydrates and the Glycemic Index (GI).
Along with her team from the University of Sydney in Australia, she pioneered the concept that different carbohydrate foods have dramatically different effects on energy levels because of the effect that certain carbohydrates have on our blood-sugar levels.
With the rise in population obesity and Type 2 diabetes over the past three decades, understanding blood sugar control has important implications for weight management and appetite control. It’s also important for athletes and exercisers who need adequate energy levels for training and competing.
New studies have also confirmed that carbohydrate foods with a low GI rating, are associated with a lower risk of heart disease. And for women in menopause, low GI foods also help to keep hot flushes under control.
Not All Carbohydrates are Equal
The glycemic index (GI) is a physiologically based measure of carbohydrate quality. Professor Jennie Brand-Miller and her team have spent years analysing different types of carbohydrates to see the immediate effect on blood glucose levels. Each carbohydrate has then been given a rating.
Carbohydrates that break down quickly during digestion are rated with a high GI value – this is often processed carbohydrate foods such as snack bars.
This means that their blood glucose response is fast and high. Carbohydrates which break down slowly, releasing glucose gradually into the blood stream have a low GI value.
One of the greatest mistakes made in diets today, is that carbohydrates need to be avoided.
But the confusion results because the term ”carbs’ is used for processed foods and foods high in sugar, so yes, we have to try and remove these sources of carbohydrates, however, fruits and vegetables are carbohydrates too. So, are grains.
You must understand that carbohydrates are not created equal and they differ in type and amounts that you need. Herein lies the confusion – you must choose the right kind of carbohydrate for your lifestyle and your stage of life and for the amount of exercise or activity you are doing too.
For busy women with a lot going on in their lives (isn’t that most of us?) and who are going into peri-menopause or remain active in post-menopause, then it’s fruits, vegetables and grains that are important to our health.
These foods are far more important than supplements to help manage our weight, reduce hot flushes and give us energy. These are the ‘carbs’ that we need.
If we exercise, then carbohydrates are equally as important as protein.
Protein is for building and repair, carbohydrates and fats help our energy levels because they help to restore glucose back into muscles and our brain. With the emphasis on high protein and high fat diets these days, it’s important that you understand that healthy carbohydrates are equally important as we move through menopause.
If these carbohydrates are low glycemic index carbs, then this helps to promote weight control, reduce fatigue, increase satiety (fullness) and provide the body with a rich supply of micro-nutrients. When you are looking for Low GI foods, then you want to select carbs that have a rating value under 50. [Image Source: University of Sydney]
Foods to Choose with a low GI Rating
Instead of spending lots of money on endless supplements and diets as you move through menopause, I want you to visit your local fruit and vegetable shop instead.
If you buy these low GI foods, then you will also be helping to manage your weight, improve your energy and reduce your hot flushes.
- Apples – GI Rating 38. An apple a day really does keep the Doctor away and the hot flushes too .. they are rich in Vitamin C and fibre and have one of the lowest GI ratings for fruit because they are high in pectin which lowers their GI. [In comparison, a banana has a rating of 52 and kiwifruit has a rating of 58]. They also improve your gut microbiome – another important consideration in your hot flush management.
- Sweet Potato or Kumara – GI Rating 44 [this compares to a boiled potato which has GI rating of 88]. In New Zealand we call Sweet Potatoes, Kumara. Sweet potato belong to a different plant family to regular potato and come either as white, yellow or red in colour and are packed with antioxidants. Whilst the ‘sweetness’ comes from a high sucrose content, it is high in fibre which gives it a lower GI rating than regular potato varieties. When I researched women’s health as they age, especially cardiac health, I discovered that women in the Okinawa longevity studies have sweet potato as their main carbohydrate – in fact over 50% of their daily diet is carbohydrate from sweet potatoes. I have numerous Low GI sweet potato recipes in the MyMT™ Recipe Book, which women receive as part of all of the 12 week programmes [Circuit Breaker for thinner/ leaner women; Transform Me for menopause weight loss, Beyond Menopause for post-menopausal women or Rebuild My Fitness for those who want to get back into the right exercise for us as we age].
- Oats or Porridge – GI Rating 42. Compare this to Kellogs Rice Bubbles which has a rating of 87 and you know what breakfast cereal is going to give you lovely sustained energy throughout your busy morning don’t you? Add some stewed apples to porridge and you have a lovely Low GI start to your day.
- Carrots and Chickpeas – GI Rating of 28. Chickpeas are high in protein and carbohydrates and hummus is made from chickpeas. I try to have this fabulous low GI food every day. Dipping carrot sticks in hummus is a great afternoon snack. Protein-starch interactions contribute to their lower GI. Carrots are crunchy too which helps to stimulate saliva production and many women find that they get dry mouth in menopause, because saliva production is reduced as we lose oestrogen.
- Dark Chocolate – GI Rating of 44. You don’t need this every day, but for a sweet treat that doesn’t spike your blood sugar, then yes, the darker the chocolate, the lower the GI rating.
Learn to Take Back Control of your Menopause Symptoms with MyMT™
Controlling our blood sugar levels is just one dimension of learning to take back control of your hot flushes, and other symptoms, whether you are on HRT or not. For those of you overweight, then losing weight also matters for your hot flush management too.
Diabetes is a serious health risk currently affecting 15% of women aged 55 years and older. Its incidence is expected to more than double by 2050, so if you have uncontrollable hot flushes, then perhaps it’s time to get your blood glucose levels checked.
If your health has changed or you feel that your symptoms and weight are holding you back from living the life that you want to live, then I hope when you get time, you can join me for your menopause transformation.
Developed from scientific studies on women’s healthy ageing, there isn’t another programme like this around.
I know this, because when my own symptoms and weight was getting me down and menopause supplements and HRT weren’t working into the long-term, I looked too.
References:
Atkinson, S., Foster-Powell, K. & Brand-Miller, J. (2008). International Tables of Glycemic Index and Glycemic Load Values: 2008. Diabetes Care 31, 2281–2283.
Bikman, B. (2022). How do blood sugar levels affect body-temperature? Metabolic Insights, Online Publication.
Brand-Miller, J. Foster-Powell, K. & Colagiuri, S. (2002). The Glucose Revolution. University of Sydney: Hodder Print.
Dormire S, Howharn C. The effect of dietary intake on hot flashes in menopausal women. J Obstet Gynecol Neonatal Nurs. 2007 May-Jun;36(3):255-62. doi: 10.1111/j.1552-6909.2007.00142.
Ma X, Nan F, Liang H, Shu P, Fan X, Song X, Hou Y, Zhang D. Excessive intake of sugar: An accomplice of inflammation. Front Immunol. 2022 Aug 31;13:988481. doi: 10.3389/fimmu.2022.988481. PMID: 36119103; PMCID: PMC9471313.
Parry, J. (2021). Insulin Stimulates Production of Body Heat, New Study Finds. Yale School of Medicine Press Release.
Sanchez-Alavez M, Tabarean IV, Osborn O, Mitsukawa K, Schaefer J, Dubins J, Holmberg KH, Klein I, Klaus J, Gomez LF, Kolb H, Secrest J, Jochems J, Myashiro K, Buckley P, Hadcock JR, Eberwine J, Conti B, Bartfai T. Insulin causes hyperthermia by direct inhibition of warm-sensitive neurons. Diabetes. 2010 Jan;59(1):43-50. doi: 10.2337/db09-1128. Epub 2009 Oct 21. Erratum in: Diabetes. 2010 Mar;59(3):756. PMID: 19846801; PMCID: PMC2797943.
Yang R, Zhou Y, Li C, Tao M. Association between pulse wave velocity and hot flashes/sweats in middle-aged women. Sci Rep. 2017 Oct 23;7(1):13854.
