We hear from the lead scientist behind a study that promotes a new way of eating to rival the five-a-day approach
words TIM SPECTOR
Where has the idea of eating 30 different plant foods come from?
The suggestion that eating this number of plant foods every week can lead to improved health comes from a large study I worked on back in 2019. The British and American Gut Project looked at the diets of thousands of people, assessing how different dietary patterns were associated with different health outcomes.
One of the most interesting findings was around fibre. The recommended portion of fibre for an adult is 30-35g a day, but what the study was showing us was that the amount of fibre isn’t as important as the variety. Different plants have different fibres, so eating more plants diversifies the types of fibre you eat.
The study showed us that people who ate the largest variety of plant foods were found to have the healthiest microbiomes (the microbe environment that exists naturally in our guts) and were likely to report the best health outcomes. The study suggested that 30 was the optimum number of different plants for fibre diversity, as there wasn’t much improvement when you increased from 30 to 35 or 40.
What counts as a ‘plant food’?
Basically, everything that comes from a plant. Fruit and vegetables all count (even potatoes – particularly if you eat the skin), but so can wholegrains, pulses, seeds, nuts, mushrooms, beans, herbs and spices. The important factor is that you’re consuming plant fibre, so juice and oil wouldn’t count, but something like matcha (which is made from whole powdered leaves) would.
It’s hard to recommend exact portion sizes, but we do know that diversity is key. And, the beauty of this way of eating is that it’s not about restricting, it’s about adding more in. For instance, for a simple tomato sauce, fry onion, garlic, carrots and celery in extra virgin olive oil, then add the tomatoes, and finish with basil and oregano – that’s seven plants there already.
What are the health benefits?
1SUPPORTS A HEALTHIER GUT BIOME
The gut microbiome is the population of bacteria living in our large intestines. We think having a diverse gut microbiome with more helpful bugs leads to better health. Gut bugs are especially important for our health, as they are strongly connected to our immune system. Gut microbes process information from everything we ingest to figure out what’s happening to our bodies. This helps the function of o
