There’s lots of buzz around plant-based diets at the moment. In the UK over 1.2 million people are vegetarians and over half a million are now vegan. A YouGov poll last year also showed that almost 20% of the population are eating less meat. People choose to eat plant-based meals or switch to plant-based diets for a variety of reasons. Here, I’m looking at the health considerations – what are the benefits and what are some of the things you need to take care with.
This is a really interesting area! Research published earlier this year suggested that the quality of your diet is linked to healthy cellular ageing in women, which may reduce chronic illness.1 Women eating a diet rich in fruit, vegetables and wholegrains (as well as low in added sugar, sodium and red and processed meats) showed significantly less cellular ageing compared with those on poorer quality diets. The researchers noted that the benefits of these plant-based diets may be related to their antioxidant and anti-inflammatory effects and could help us to avoid chronic diseases such as type 2 diabetes, heart disease and some cancers.
Eating plenty of fruit and vegetables also has great benefits for your heart health. As well as reducing your blood pressure, it’s also been shown that people eating more than 5 daily portions of fruit/ veg have a 17% lower risk of coronary heart disease than those eating 3 portions or less.2 Most beneficial are leafy greens such as spinach and lettuce, and also broccoli, cauliflower and cabbage and citrus fruit such as oranges and grapefruit.
Good for your gut
Upping plant-based meals will also boost your intake of fibre. This is an important element of the daily diet as it’s associated with a reduced risk of heart disease, stroke, type 2 diabetes and bowel cancer. It’s recommended that adults consume 30g of fibre per day, but most people only have around 18g. As the types and proportions of dietary fibre vary between plant-based foods, it’s good to go for as much variety as possible. So when thinking about including fibre in your diet, consider the whole range of grains, nuts, vegetables (celery, onions, potatoes each have a different type of fibre component), fruit, legumes (for example peas, beans, lentils), seeds and seaweed (such as nori).
The number one consideration, particularly for those on a vegan diet is vitamin B12. This vitamin has a number of functions, including supporting a healthy nervous system and metabolism of fats, carbohydrates and protein. All natural vitamin B12 is bound to animal protein and the richest source is liver, along with shellfish, fish, meat, eggs, milk, cheese and yoghurt.
As a vegetarian, you’re unlikely to be deficient if you eat dairy products and eggs. For vegans, the only reliable sources of vitamin B12 are supplements and fortified food, such as some non-dairy milks, some soya products such as tofu and some breakfast cereals.
Omega 3 fatty acids
Omega 3 fatty acids in whole food are important for heart health. The richest source of omega 3 fats is oily fish. If you don’t eat fish, then alternative sources are walnuts, pumpkin seeds, ground (not whole) linseeds/flaxseeds and soya products. For vegetarians, look out for foods fortified with omega 3, such as some eggs, milk and yoghurt.
Iron is essential for the transport of oxygen around the body, as well as supporting your immune system. The richest, most easily absorbed iron is found in red meat. Plant sources include pulses such as lentils and chickpeas, cashew nuts, tofu, green leafy vegetables such as kale, and dried fruit, including apricots and figs. These plant sources are less well absorbed. And so it’s worth considering a couple of extra factors: vitamin C (found in peppers, broccoli, kiwi and oranges, amongst others) helps to improve iron absorption; meanwhile, the tannins in tea and coffee inhibit iron absorption and so if you want to avoid this, it’s best not to drink these at mealtimes.
There’s less concern these days about the quality of plant-based protein versus animal protein. So for example, soya protein is considered to be of similar quality to that found in meat and dairy products. However, other plant-based sources of protein, including cereals, rice and legumes (peas, lentils and beans) are lacking in one of the essential amino acids (the building blocks of protein). Beans, for example, are very low in the amino acid methionine, but are a good source of another amino acid lysine. The opposite is true of cereals and rice, which are poor sources of lysine and good sources of methionine. It’s therefore a good idea to ensure your diet includes ‘complementary’ foods such as beans plus wholemeal toast, lentils with rice or kidney beans/ butter beans with pasta, so that you have ‘complete’ protein.
• Eating at least 5 portions of fruit and vegetables a day has lots of great benefits, including anti-ageing effects, lowering blood pressure, reducing your risk of heart disease and keeping your gut healthy.
• Make sure you’re getting sufficient nutrients, including vitamin B12, omega 3 and iron, and think about combining plant foods to ensure you’re getting all your essential amino acids.
1. Leung CW et al (2018) Diet Quality Indices and Leukocyte Telomere Length among Healthy US Adults: Data from the National Health and Nutrition Examination Surveys (NHANES) 1999-2002. American Journal of Epidemiology, June, doi: 10.1093/aje/kwy124. [Epub ahead of print].
2. He FJ et al (2007) Increased consumption of fruit and vegetables is related to a reduced risk of coronary heart disease: meta-analysis of cohort studies. Journal of Human Hypertension,21(9):717-728.