How Fasting Can Improve Your Brain Health


If you have previously joined me for a webinar or listened to any of my talks over the years, you will know I have often talked about making sure your blood sugar is balanced by eating little and often as this is both beneficial for your body and also your brain. But are there benefits for your brain health if you fast or if you restrict your calories instead?

The Research Into Fasting

Animal studies have shown that mice live 30% longer when they eat half the number of calories – and dogs and fish live longer when their calories are cut. We humans would have to reduce our calories by 25-30% to achieve the same effect. And even though the research on animals has been around for 80 years, it is still not clear why calorie restriction as this effect.
Some researchers think that certain genes are turned on to help fight disease if the body perceives there is a famine, with the aim of making the body stronger. Other research suggest calorie restrictions decreases insulin levels and contributes to slowing down the ageing process as well as decrease risk of chronic disease.

Although the emphasis on this type of diet is reducing the calories, the aim is also to make the diet nutrient-rich, so that you are not malnourished.

The first study on humans in 2006 showed reduced signs of ageing in those who were restricting calorie intake. The men and women on the diet had reduced fasting insulin levels and lowered markers of inflammation. Furthermore, the rate at which their DNA decayed slowed down, reducing their risk of cancer. So, we know that restricting calories can increase your lifespan, but what about your brain health?


The Use Of Ketones For Brain Health

Ketones, which your brain can use as an alternative fuel if it can’t use glucose efficiently, has been shown to have positive effects on your brain health. There are two ways of increasing ketones. One way is to use coconut oil and the other is to change your diet so that your body produces ketones independently.
We know that if you eat a ketogenic diet, which is very high in fat and low in carbohydrates – or are fasting, your body produces more ketones and goes into what is called ketosis. During ketosis, the body compensates for the lack of carbohydrates and instead converts stored fat into ketones to use as fuel.

The theory sounds perfect – but despite the media hype about alternative day, intermittent and 5:2 dieting (which can all cause ketosis in the body), the evidence is just not there yet to show that fasting diets are helpful in terms of overall health. As one researcher says, ‘substantial further research in humans is needed before the use of fasting as a health intervention can be recommended,” because most of the research has been conducted on animals.

And, even if there are benefits, which of the very many variations of fasting diet is the one that has the best health effects?


5:2 Fasting Diet Or Alternative Day Fasting

On the 5:2 fasting diet, you fast on two days of the week and eat normally on the other five. But, should the fast be complete calorie restriction apart from water, or is it better to have a minimal calorie intake (usually about 600 for men and 500 for women)? Should fasting days be consecutive or are they better as any two days in the week?

If you follow the 5:2 fast with limited calories, is it better to have all the calories in one meal or spread them out throughout the day? Other regimes suggest alternative day fasting when you are fasting every other day of the week.

On non-fasting days, no matter what regime you are following, the suggestion is that you can eat as much as you like of whatever you fancy. As a nutritionist, this makes me extremely uncomfortable! It suggests you can eat your fill of junk food on the non-fasting days, but that cannot do you any good at all. Instead if you are looking to fast, on the non-fasting days I would recommend having your fill of nutrient-dense foods to help keep your nutrients levels higher on those days you are taking in restricted food levels. Generally, advocates for the fasting diets recommend that you drink water during the fast day. However, many people load up on black coffee and tea or diet drinks instead. If you use caffeine to get you though, then you are going to be living on adrenaline for the fasting days, putting your body into permanent state of stress.

Some people swear by fasting diets for weight loss – but they are not suitable for everyone. If you are diabetic, have a history of an eating disorder or have osteoporosis, then they are certainly not for you. Likewise, if you get blood sugar swings during which you feel weak, have headaches, or get dizzy and lightheaded when you don’t eat – I would not recommend fasting. I also don’t think it is good for anyone suffering from chronic fatigue or a lot of stress.

To your body, fasting is a stress, because it perceives there is a shortage of food, a threat to survival; it is a matter of life and death. So, if you are already stressed and fatigued, adding a further stress to your body is severely damaging to health. If you do a lot of exercise or are training for an event, then you are potentially doing more harm to your body by restricting your calories then any good.


Your Body’s Natural Fasting

There seems to be a much better way to get the beneficial effects of fasting without actually restricting your calorie intake. Your body has a process called autophagy. A sort of housekeeping system, autophagy is your system’s way to clear our dead cells and pathogens. This is good for your general health and also for your brain function. You can trigger the process of autophagy not by fasting during the day but by:

• Leaving 3 hours between your last meal and going to bed
• Not eating for 12 hours

This is a far easier to achieve than starving yourself for 2 or more days a week. It just means that if you go to bed at 11pm, then you have your evening meal at 8pm and then breakfast at 8am the next morning.

Alternatively, some researchers suggest that you can trigger autophagy by fasting for 16 hours each day and eating within an 8-hour time slot. To achieve this, you would eat only between 12pm – 8pm (as an example) every day. My feeling, though, is that a 12 hour overnight fast is enough.

As you can see, your body has natural ways to help fight disease, ageing and even help improve your health – especially when it comes to your brain health. These can be implemented easily within a busy lifestyle and can have noticeable effects on your day-to-day living. However, it’s always advised that if you are undertaking a big change in your diet or lifestyle it’s best to contact your GP or a nutritionist in order to help support you through the initial process.

If you wish to try fasting, you can find out more about my suggestions in my book ‘Natural Solutions To Dementia & Alzheimers’.

Or if you are interested in finding out more about your brain health and how you can help protect and prevent disease, memory loss and brain fog, book your place on my next webinar specifically designed to teach you my 7 Step Protection Plan For Brain Health.