We are living through an epidemic of obesity and allergies, yet we are more obsessed than ever with our diet and lifestyle. Much of our confusion is due to the conflicting messages and poor science that has come from doctors, experts and governments over the past 30 years, regarding calories, exercise and how much fat, meat, sugar and fibre we should eat.
On top of that, fad diets are booming. Many people are cutting out gluten and wheat, meat and dairy, carbohydrates or refined sugars, while others are turning to juicing or fasting, or relying on vitamins and supplements. Amid the confusion and dogma we are living longer but conversely are becoming less healthy.
It turns out we have been ignoring what some scientists call the ‘forgotten organ’ of our bodies, one that has the power to restore our balance. It is called our gut microbiome and is an area within our lower gut weighing 4lb and containing 100 trillion microbes. We all possess a unique set of these microbes, which vastly outnumber our cells and genes, and their function is to digest our food and keep us alive and healthy.
Now cutting-edge research and technology are allowing scientists to discover how – by changing our diets – we can encourage microbes to keep us slim, avoid heart attacks and allergies, and even reduce a hangover. It’s time to stop believing the old myths and misconceptions about food and embrace what science is telling us.
Here are the ten facts about food and dieting that will change the way you eat for ever.
SO WHAT EXACTLY IS A MICROBE?
It is the scientific name for any small creature that you need a lens or microscope to see. Bacteria are the ones we know most about. They live inside us as well as on our skin, but we are also home to trillions of harmless viruses and billions of fungi that have evolved with us.
These microbes are mostly concentrated in our gut; we all carry thousands of species. We rapidly gain our gut microbes at birth and they enable us to develop a normal brain and immune system as well as to digest our food.
Microbes thrive on food that is high in fibre, which they break down, producing chemicals such as antioxidants that in turn keep us healthy. When we eat junk or processed foods low in fibre, our microbes suffer and can’t produce these beneficial chemicals.
1 Gut microbes, when disrupted, are a major factor in obesity. Studies show that overweight people have a smaller range of microbes. The diversity of microbes in our gut is now 30 per cent lower than 50 years ago and this has increased our susceptibility to gaining weight. Also, certain species of microbe can make you gain weight and make you resistant to diets. Antibiotics are routinely given to animals to make them fat and grow faster, and this alters the balance of their gut microbes.
The same may be true for humans and our overuse of antibiotics (especially in children) could be making us all fatter by killing off our protective microbes. The other big factors for this decrease in microbes are our over-hygienic lifestyles and increasing numbers of routine sterile caesarean births (during a natural birth infants come in contact with a rich dose of their mother’s bacteria as they are pressed through the birth canal).
2 Our ancestors’ diet was 20 times more varied than ours. We know this from archaeology and studying primitive tribes, who ate a much wider range of foods and nutrients with fasting periods and seasonal changes. This gave them a bigger range of microbes, better immunity and fewer allergies.
Now most of our modern diet comes from just five foods – corn, wheat, meat, sugar and soy – which are all found in processed foods. Most diet plans (eg, low GI, Atkins, paleo, gluten-free, low-fat, calorie-counting) advise cutting out even more foods, therefore reducing our gut microbe diversity even further with potentially significant long-term health consequences.
3 Traditional cheese is one of the richest sources of living healthy microbes and fungi. Unpasteurised cheeses and those with rinds contain even more species. Just a crumb of raw cheese contains over ten billion microbes containing bacteria and fungi. Studies show that people who eat cheese regularly have fewer heart problems despite the high fat content. As well as supplying new healthy microbes, eating cheese also encourages other microbe species to grow inside us.
4 Skipping breakfast may be good for you. Breakfast is a relatively new invention for humans and eating little and often (despite misconceptions) is actually not good for most people. Studies have shown that reducing the number of meal times can help people lose weight. The popular 5:2 (or Fast) diet whereby you semi-fast for two days a week also seems to be effective.
The reason intermittent fasting works well and constant grazing often fails is down to the effect on our microbes. Periods of fasting lengthen the time our microbes have to rest and interact with our gut lining which may increase our metabolism. Studies now show the more we extend our overnight fast, the more diverse our microbes, the more healthy chemicals are produced and the less weight we gain. Although not everyone can skip breakfast easily, they should find the pattern that best suits them.
5 Probiotic yoghurt makes you healthier – but only if you are a lab rat. Studies in humans have not been so conclusive except in the sick, elderly or babies. Studies of regular yoghurt eaters show long-term health benefits, but not if the yoghurt is low-fat and packed with sugar. This may be because the microbes in natural yoghurt are generally healthy, but the perfect mix of added microbes (probiotics) hasn’t been found yet. We each have such different resident microbes that we respond differently to the newcomers and need a more personalised approach with a wider variety of probiotics.
6 Whether you prefer to eat salads or chips is partly genetic. My research team’s studies of identical twins have shown that food preferences are not just down to upbringing, but are 50 per cent genetic. Some young children may hate greens for evolutionary reasons (as we may be programmed to avoid poisonous plants), not just to annoy their parents. So genes can point us towards the foods we like most and this in turn can alter our gut microbes for the better.
7 When two people are put on the same diet the results are very different. Studies including those in our twins have found that people react very differently to identical foods and weight-loss diets. This is partly genetic and partly because we all have different sets of gut microbes, which produce a range of different chemicals from food. These in turn can have very different health and weight effects. For instance, some people eating exactly the same bowl of potatoes or pasta will have a greater amount deposited as fat because of the effect of their genes on their microbes. So the same diet (whether it’s high or low in protein, fat or carbohydrates) will not suit everyone and much of this difference between us can be explained by our unique mix of gut microbes.
8 Eating red meat is safe for some people but risky for others. The overall risk of heart disease for people eating red meat regularly is on average 20 per cent more than for non-meat eaters. Some people are unlucky and develop thickening and blockage of the blood vessels. Microbes in our gut are responsible as they break down natural substances in meat (called carnitine), which produce toxins that damage the blood vessels. Other people can eat meat and never have problems because they have protective microbes that dispose of these chemicals safely.
9 The French drink more alcohol and have more fat in their diet than the British, yet are far healthier. They live longer and have less heart disease. This could be due to their more varied, drawn-out meals, including less ‘hygienic’ foods such as undercooked meats and unpasteurised cheeses. All of these factors have been shown to increase diversity of gut microbes, which in turn produce more healthy chemicals.
One reason that red wine, in moderation, is good for us is because it contains high amounts of naturally healthy chemicals called polyphenols. Microbes enjoy feeding off these antioxidants, which could provide much of the heart benefits.
10 Exercising is great for your heart but not for your waist. The advice to eat less and exercise more is outdated and nearly always fails. Exercise makes you put on weight, unless you are running daily marathons, as your body adapts and conserves the energy it is losing. The body is programmed to stop us losing weight via fat and we have to expend five times more energy to get rid of fat than muscle. It may convert some of the fat to muscle – but that doesn’t show up on the scales. Studies clearly show that you will live longer and be healthier if you are fat and fit than if you are lean and unfit.
HOW TO IMPROVE YOUR GUT MICROBES
The good news is that unlike your genes or personality it is possible to change or reboot your gut microbes. Think of your gut as a delicate garden that needs fertiliser, experimentation, nutrients, avoidance of toxins (junk food) and above all diversity and you can’t go wrong. You may wish to test your own gut microbes (at britishgut.org) and see how they change on different diets after only a few days.
- Experiment with different foods and diets to find the one that best suits you – everyone’s microbiome is different.
- Increase the fibre content and the quantity and variety of fruit and vegetables in your diet.
- Avoid foods with too much sugar and sweeteners, such as fruit juices and processed foods.
- Try a traditional Mediterranean diet which includes a wide variety of fresh foods plus lots of nuts, cheese, yoghurt and extra-virgin olive oil.
- Eat as wide a variety of foods as possible – try to eat at least 20 different foods per week including a few new ones.
- Eat more artichokes, leeks, celery, chicory, onions and garlic as microbes love them. Eat especially after illness, taking antibiotics or fasting.
- Drink coffee and eat dark chocolate in moderation – they are good for your health and microbes.
- Fast occasionally, even just for 16 hours, to give your microbes a holiday.
- Avoid vitamin supplements – unless you have a proven deficiency disease, vitamins don’t work and can be harmful to your microbes.
- Eat real food and your microbes will do the rest.