IN FOCUS6-8 min read

How the secret to wellbeing lies in our stomachs

Everyone can improve their gut health in just two weeks, Tim Spector, Professor of Genetic Epidemiology at King’s College London, told the audience at our latest Charity Investment Forum. Tim, told attendees how knowledge of the microorganisms within us could revolutionise our wellbeing and longevity, with a challenge to the received wisdom on familiar foods, and an explanation of what keeps identical twins from being exactly like each other.

Tim Spector 1000px


Victoria Beckett
Editor and Copywriter

Identical twins have long confounded doctors. Despite being genetic clones – usually growing up in the same environment – the age-related diseases they face can be vastly different. This flew in the face of genetic research, until Tim Spector, a Professor of genetic epidemiology at King’s College, London, tested their gut microbiomes – the community of microorganisms in our guts – 14 years ago as part of the Twin Registry, a long-term research programme on twins, at St Thomas’ Hospital, London. The results were startlingly different, with profound effects on long-term health.

“Most common western diseases have been linked to poor microbiome diversity and gut health – the mix of good to bad bugs,” said Tim. The gut produces chemicals that are key to our survival. This includes B vitamins and brain chemicals that prevent depression and relax you. They are key for maintaining a good immune system that not only fights infections but also repairs you, slows downaging and fights cancer. “Only now are we realising how important this is,” said Tim.

The good news is that anyone can change their gut health within two weeks through dietary adjustments. However, Tim argued that many of the public guidelines around healthy eating are misleading.

What are we getting wrong?

About ten years ago, Tim started to try to improve his own diet after having a minor stroke. He started by following the NHS guidelines. He ate muesli for breakfast, tuna sandwiches at lunch and snacked on fruit in the afternoon. When monitoring his own blood glucose levels, he was surprised to see them spike into the diabetic range on what he thought was a healthy diet. Prolonged high blood sugar creates inflammation in the body, which is responsible for a wide range of ailments. Tim also found blood sugar spikes dramatically impacted his concentration. While the connection between brain function and diet is well-known, much of the research has yet to filter into public health.

People are often recommended to limit foods such as chocolate, coffee and peanuts. However, these are all high in polyphenol which is associated with good health outcomes. And, while some bread can be healthy, most supermarket breads are classified as “ultraprocessed” foods which has been found to have negative health implications.

“The UK is the most overweight nation in Europe, with the worst diets. We are testament to how government guidelines have failed miserably,” said Tim. In a bid to correct this, he became the scientific co-Founder of Zoe – a tool for consumers to measure their gut health and the unique impact different food has on their blood sugar, to help them achieve long-term health and vitality.

What makes a healthy gut?

While we tend to divide the food we eat into fats, proteins and carbohydrates, Tim said: “The reality is far more complicated. There are over 800 different chemicals in a piece of garlic, for example.” A healthy gut has about as many microbes as there are cells in the human body, and there are just as many fungi and parasites that eat off those microbes.

About one in four people in the Western world have a parasite called blastocystis. While this may sound alarming, it can actually be a marker of good health as the parasite eats some microbes that are bad for you. “We all used to have it,” said Tim, “but bad diets and antibiotics have removed it. People with blastocystis tend to be slimmer with lower fat levels.”

Meat and the microbiome

Tim delved into a range of foods, sharing his views on their health benefits. He said: “I’ve changed my mind on meat a few times.” We should avoid very poor-quality meats as the evidence of them being bad for you is strong. They’re also terrible for the planet, particularly lamb and beef if it is farmed at the expense of rain forests, Tim says. “Health-wise a small bit of meat isn’t bad for you, but it does take up space on your plate from vegetables,” he commented.

Tim argued that fish is “overhyped” as a health food, as are omega 3 supplements. Epidemiologists suggest fish offers about an 11% benefit for longevity. However, there are plenty of cultures that don’t eat fish and they are perfectly healthy, he claimed. “Government guidelines on eating fish would make the oceans empty within months.” He also highlighted some ethical issues, with parts of the fishing industry being connected to slavery and the destruction of biodiversity. Tim suggested eating fish about once a week: “We should pick the small, ugly ones that aren’t commonly eaten to support marine diversity.”

Despite strong opinions from both sides in the public domain, milk is pretty neutral, according to Tim. “There is no evidence that menopausal women should drink milk for bone health,” he added.

Get your 30 a week

Rather than five fruits and vegetables a day, as per the NHS guidelines, everyone should eat 30 different types per week, Tim argued. “Iceberg lettuce is the most commonly eaten lettuce, but it is completely useless. Pick something with a bit of colour for a thousand times more nutrients,” he advised. He also recommended mushrooms: “We should all eat more. They’re not plants or animals – they’re something in between.”

Being derived from a bean, coffee is positive, and decaffeinated coffee has almost the same amount of benefit for heart health and longevity as caffeinated, according to Tim. Unfortunately, almost all alcohol is bad for your microbiome except for one to two glasses of red wine from time to time – as explored in the “French cheese diet.”

Probiotics and antibiotics

Probiotics in food are fantastic, according to Tim. They are most commonly in fermented foods. For example, in yogurt you get around two to three probiotic species. Kefir has around 12-20, kombucha 20-40, sauerkraut about ten and kimchi has at least 30.

Most probiotic tablets are unproven, but some do work. However, “knowing which ones work in which people is hard. Probiotic tablets will work very well when we start to personalise them,” said Tim. “A good kefir covers more bases than a tablet.”

Meanwhile, the harmful effects of antibiotics are well-documented. In children, they have been linked to food allergies and obesity. “Antibiotics are bad. We have too many of them, but we all respond very differently to them,” he summarised.

Tim did plenty of personal research into diets too. This ranged from the “French cheese diet”, in which he only ate cheese and drank wine for a week. “On day two I thought this was the best diet I’d ever tried, but by day four I wanted to quit,” he says. He also talked his son, Tom, into only eating McDonald’s for ten days. Despite, being a big fan of McDonald’s, Tom also wanted to stop after four days. After 10, tests showed that he had lost over 30% of his gut diversity. This level of loss makes an individual more likely to suffer from obesity and diabetes. Ten years later, it still hasn’t recovered. “Every time he wants money, he reminds me of that,” Tim laughed.

Why do identical twins have different microbiomes?

We all have completely unique microbiomes. There is no one-size-fits-all as foods will affect us differently. This is demonstrated by the blood glucose monitors that are sent to customers of Tim’s company, Zoe. Individuals are asked to trial different foods while they wear the blood glucose monitors that take a blood sugar reading every five minutes. The company can then recommend an individualised diet based on your body’s reactions to certain foods.

“We’re all born sterile,” explained Tim. “We have no microbes when we’re born. We acquire them during the birth process.” The birth process for all mammals is “a bit messy and a bit random”, Tim said. He described this as a clever evolutionary pathway to ensure that babies can pick up the microbes of their mothers. Babies who have had a natural birth or a caesarean section will therefore have different microbes.

In the first three years of a person’s life, their microbiome will continue to be constructed by their exposure to viruses, food and even which person picks them up first. For example, the nurse that first picks up a newborn will transfer some of his or her microbes to the baby. “It’s really fascinating. That’s why we’re all different,” said Tim.

This article is issued by Cazenove Capital which is part of the Schroders Group and a trading name of Schroder & Co. Limited, 1 London Wall Place, London EC2Y 5AU. Authorised by the Prudential Regulation Authority and regulated by the Financial Conduct Authority and the Prudential Regulation Authority. 

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All data contained within this document is sourced from Cazenove Capital unless otherwise stated.


Victoria Beckett
Editor and Copywriter


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