Gut Health
Five a day of fruit and veg has been the mainstay of nutrition advice for many years. However, nutritionists are moving away from this advice to something else: 30 different plant based foods a week. Why?
Research carried out in the U.K. and USA have looked into gut health in great detail over the last 10-15 years. The American Gut Project was published in 2018. Using stool samples from 10,000 volunteers predominantly from UK, USA and Australia it found that people who ate 30 or more different plant based foods a week had a more diverse gut microbiome than those who ate 10 or less.
What is gut health and why is it important?
Our gut microbiome is the trillions of bacteria of thousands of different species which live in our gut. It has been estimated that there are actually more bacteria cells in the human body than there are human cells themselves. These bacteria weight over 2kg and are now thought of as effectively another organ in the body. These bacteria perform a critical role of producing chemicals in our body to break down food and produce other chemicals in the process. The fibre we eat in our diet is a source of food for the microbes. When digested it produces short-chain fatty acids which help nourish the cells lining the colon, reduce inflammation, and support overall gut health. The gut microbiome also controls how our immune system works and has an impact on the central nervous system which controls brain function by regulating neurotransmitter production, influencing mood, cognition, and stress responses, and potentially playing a role in conditions like anxiety and depression.
Recent studies have suggested that the microbiome plays an important role in affecting the risk of several chronic diseases, including inflammatory bowel disease, obesity, type 2 diabetes, cardiovascular disease, and cancer. Research has shown that imbalances in gut bacteria may trigger inflammation in diseases like inflammatory bowel disease, while certain bacterial strains have been linked to insulin sensitivity in type 2 diabetes. Studies on obesity suggest that a diverse microbiome supports better metabolism and weight management, and research in cardiovascular disease highlights how gut microbes may influence cholesterol levels and arterial health. Emerging evidence also points to a connection between gut bacteria and cancer development through the modulation of immune responses and inflammation.
What does 30 a week mean?
So what does 30 plant-based foods a week mean and how do you calculate it? A large number of foods qualify as plant-based.
Each different fruit and vegetable counts as one of your 30 plants. Different varieties count as a different plant – so if you ate lambs lettuce one day and then ate gem lettuce the next that would count as two plants.
All wholegrains count as one point. For example, oats, brown rice, buckwheat, quinoa, barley. Any white pasta or white rice doesn’t count towards the total.
Pulses and legumes count as one point too. So does any type of bean – cannellini, kidney beans etc. Also chickpeas and lentils are included. Again, a different variety will count as a separate point.
Nuts and seeds. There are a huge variety of different types of these – almonds, cashews, walnuts, peanuts and all the various different seeds – flaxseed, sesame, pumpkin etc. Each variety in your diet counts as one point.
Herbs and spices. Lastly herbs and spices also count towards your weekly total. This area is different because we would normally eat only a relatively small portion of these when we add them to our food. So each herb or spice adds a quarter point to your total.