Go With Your Intuition: Scientist Tim Spector on Why Food Isn’t Just Fuel | human biology

Tim Spector’s kitchen fridge is full of life: kefir grains, mother yeast, homemade kimchi, and kombucha. Then there are the vegetables: as varied and colorful as possible.

While many diets avoid certain food groups, Spector’s focuses on incorporating as much variety as possible: at least 30 different plants a week – including nuts, seeds, legumes, whole grains, fruits and vegetables – on top of starchy foods. , such as potatoes or rice . The reason? He believes diversity is key to preventing infections, fighting age-related illnesses and maintaining a healthy weight.

Diversity cultivates a healthy microbiome – the microorganisms that live in our gut – that play a vital role in digesting food, regulating our immune system and adjusting our brain chemistry through the chemicals they produce. “It’s this diversity of gut microbes that gives you a diversity of chemicals and, we believe, a healthier immune system and a better metabolism,” says Spector. “When people start to see that there is this link between the food we eat, our microbes and our immune system, I think it changes the way we think about food. It’s not just fuel. This is really changing the way our bodies work.”

Spector’s diet today is a far cry from what he used to eat: usually muesli, orange juice and tea for breakfast – sometimes with toast and jam – and a tuna mayonnaise sandwich, bag of chips and box of orange juice for lunch. “My breakfast now is a mix of kefir and full-fat yogurt with some fruit and nuts and seeds on top, plus a large cup or two of black coffee. For lunch, I could have a curry, or some other heavily vegetable-based meal. I’m practically a vegetarian and I eat a lot less starchy foods than I used to.”

The event that prompted this change was suffering a mini-stroke on top of a mountain at age 50, after an energetic day of skiing in the Alps. “I went from being a sporty, fitter than average middle-aged man to a depressed, depressed stroke victim with high blood pressure,” he recalls. It was a wake-up call that led him to reevaluate everything he thought he knew about healthy eating, including much of what he’d learned in medical school.

A professor of genetic epidemiology at King’s College London, Spector has spent much of his career researching how our choices and life events merge with our genes. In 1993, he founded the UK Twins Registry at St Thomas’ Hospital in London, one of the richest collections of data on identical and non-identical twins in the world.

For years, Spector believed that genetics would go a long way toward explaining why people are the way they are. And to some extent it does. For example, Spector’s group was one of the first to demonstrate that people’s weight distribution is largely influenced by their genes.

The problem is that while identical twins have many similarities, they can often be quite different – ​​despite sharing the same genes. “Trying to understand why one twin is sometimes overweight and the other is thin; one has diabetes or cancer and the other doesn’t has been a hot topic for the last 20 years,” says Spector.

The 2014 discovery that the composition of microbes in people’s guts could influence their body weight provided the first “Aha!” from Spector. time. But the blinders really fell off when he and his colleagues measured the responses of twins and non-twins to identical meals and found that they could vary enormously between individuals, influenced by both the microbiome and genetics.

“Up until that point, we didn’t have enough belief that you could customize nutrition or that you could link the uniqueness of the microbiome to the uniqueness of the food response — but suddenly you had those two elements together,” says Spector. “We are all very different in the way we respond to the same meal, and much of that is explained by the huge differences in our microbiomes.”

That doesn’t mean other factors are irrelevant to people’s health: “How much sleep you sleep at night, the quality of your diet, the exercise you get, all those things are also important,” says Spector. “All we are saying is that the microbiome is an important modifiable factor.”

Spector likens the bacteria, fungi and viruses in our intestines to a kind of internal chemical plant: they use the contents but produce many signaling compounds that send constant messages to our immune system,” he says. They also produce brain chemicals like serotonin, as well as additional molecules that control how our bodies turn food into energy.

“We don’t know exactly how, but the state of your gut microbes will influence your blood sugar spikes, as well as how you digest fats and how quickly those fats are eliminated from your body. Indirectly, both will lead to inflammation.”

This is important, explains Spector, because chronic inflammation can increase the risk of several diseases, including type 2 diabetes, heart disease and certain cancers. It can also guide people to accumulate more body fat, which in turn produces more inflammation.

Our microbiome can also shape our responses to infection. Spector is probably best known for his work studying ZOE Covid symptoms, which has seen millions of users log their daily symptoms through an app to help better understand how Sars-CoV-2 spreads and the nature of the disease. causes.

Tim Specter carrying giant asparagus
Photography: Alicia Canter/The Guardian

One insight from the study is that people who consumed a greater diversity of plant-based foods before the pandemic appeared to be less likely to catch Covid-19 or become seriously ill. While this doesn’t definitively prove that eating a diverse plant-based diet can ward off infections, Spector believes it can help: “Your immune system is compromised if you don’t have a good microbiome controlling it, and so — or overdo it.” [to pathogens],” he says. “I don’t think eating for our microbiomes would stop pandemics, but I think it could make everyone less sick if they got infected.”

So how do we eat for our microbiomes? In Spector’s view, this boils down to a diversified and predominantly plant-based diet, free of highly processed foods. “These are foods that you recognize and can make yourself with ingredients in your kitchen,” says Spector. “These are plants rich in defense chemicals called polyphenols – usually those with strong flavors and colors, light bitterness, thick skins – basically the opposite of iceberg lettuce. It’s those grapes we used to have as kids that were a little sour and bitter. It’s the purple carrot instead of the white carrot.”

To further boost the polyphenol content, Spector recommends green tea, extra virgin olive oil, colorful fruits and vegetables, herbs and spices – plus a layer of dark chocolate. And don’t forget the four Ks: kefir, kombucha, kimchi and sauerkraut (sauer) – as well as cheese and yogurt – which act as fertilizers for our resident gut bacteria.

What that means is very similar to a Mediterranean diet – rich in fruits, vegetables and whole grains and containing less meat and dairy than a typical Western diet. Spector says: “It doesn’t really matter if you have chunks of meat and fish on top of it – I don’t believe they are necessarily healthy, but as long as you have enough plants on your plate, that’s fine.”

In his latest book, Spoon Fed, Spector also discusses how microbes can affect people’s mental health. Among scientists, there is a growing consensus that depression may be linked to elevated levels of inflammation in at least a subset of patients; Spector argues that having the right gut microbes can combat this, because they secrete a number of chemicals that keep inflammation in check, as well as altering our mood more directly. For example, certain microbes help produce serotonin – the same chemical that is increased by some antidepressants. Studies have also suggested that people with depression have a less diverse set of microbes, on average, compared to healthy individuals. “A diverse Mediterranean-style diet with a variety of fermented foods to keep your microbes happy seems like the best gift you can give your brain,” writes Spector.

Spector describes the changes he made to his diet as “an evolving process”. He only eats meat about once a month, while concerns about sustainability mean that he only eats fish occasionally, in restaurants: “I wouldn’t say that I suddenly had the answer when I discovered the microbiome, but little by little I changed the habits I had when I was a smug doctor thinking I knew everything.” In addition to a desire to nurture his “inner garden”, his food choices are motivated by the insights he gained from monitoring his personal responses to different foods. That’s why he avoids large amounts of pasta, rice, and potatoes — not because they’re inherently unhealthy, but because using a continuous glucose monitor has revealed that they produce worryingly high spikes in his blood sugar levels.

He’s highly dismissive of one-size-fits-all diets and the notion that weight loss is all about calories in v calories: “It’s complete nonsense,” he says. “You and I can eat two identical muffins with the same calories, and you can have a slight sugar spike and no sugar dip, while I will have a big sugar spike and a sugar dip, and I will eat 200 calories in excess that day, and you will not. This simple experiment, which we’ve done on thousands of people, simply takes the idea that it’s all about calories out of the water.”

In April, ZOE, the personalized nutrition company that Spector co-founded, began inviting about 180,000 people on its waitlist to purchase an early access version of its “ZOE program,” an attempt to bring personalized nutrition to the masses of the Kingdom. United. It’s still a luxury lifestyle option at the moment – the £260 price tag puts it out of reach for the mass market – but Early Access members will start with an in-home test, the results of which provide personalized scores for thousands of foods. in the ZOE app. Members also access daily classes, recipes, live chat with ZOE trainers, and more. The program consists of two parts: testing and ongoing membership. A test kit consisting of three standardized muffin packs (to test your biological responses and challenge your metabolism with high doses of fat and sugar), a continuous glucose monitor, plus stool and blood sampling kits; the idea is to test how people respond to various foods over a two-week period and provide personalized scores for thousands of foods and nutritional guidance based on these results.

Spector’s ultimate goal is to change the way people think about food. “You’re eating hundreds of chemicals when you eat a carrot, it’s not just the orange color — there’s all these other things hidden away,” he says. “All those things are lost when you put food in a factory, ultra-process it, and put it in a vacuum package.”

Leave a Comment