It’s crucial to eat your greens ... just not the ones you think
Veggies really are all they’re cracked up to be – but probably not the ones you’re eating every day, reveals Dr Mark Hyman
You’ve been told a thousand times to eat your veg. But here’s a good question: why should you eat your veg? After all, plants don’t contain all the vitamins and minerals that you need to be healthy. And, in some cases, they provide surprisingly little.
Beef liver has several times more vitamin A than any plant, including carrots, which, though noted for that particular nutrient, actually only contain beta-carotene, which has to be converted by the body into vitamin A. Oranges might come to mind when you think of vitamin C, but you can also get that from offal. Seafood is the best source of the essential omega-3 fatty acids that you need to survive and thrive; you can’t get them from vegetables, except purslane (a weedlike herb with a peppery lemon flavour) and algae.
We all know how crucial vitamin D is for health, yet plants deliver virtually none, except for certain mushrooms such as porcini. The same is true of the B vitamins, especially B12, which comes from animal foods like meat, eggs and wild salmon. Vegans must supplement with vitamin B12 to avoid becoming deficient.
Plants do contain some protein, and some, like kale and black beans, even have significant amounts. But plant protein is poor quality compared with animal protein. There’s nearly seven times as much protein in ground beef as in spinach, for example.
This is where my vegan and vegetarian friends run into trouble. Without eating meat or fish, they’re more likely to end up with nutritional deficiencies of iron, calcium, vitamin K, omega-3 fats, vitamin B12 and fatsoluble vitamins such as A and D – which is not to be ignored, particularly given the number of vegans in the UK has reportedly soared to 3.5million. However, vegetables do contain carbs, a source of energy. In fact, the majority of your diet should be carbs – not bread, potatoes, sugar, beans, or grains, but vegetables. They don’t spike blood sugar (except the starchy ones) and they are critical for health.
But it’s worth noting that carbs are not a nutritional necessity. While there are essential amino acids (protein) and essential fats (omega-3 and omega-6), most people don’t realise that there is no such thing as essential carbs. We do not need any carbs for our survival. None the less, we need vegetables because they contain many vitamins, minerals and powerful disease fighting, health-promoting compounds called phytonutrients. Indeed, veggies are our only source of phytonutrients (phyto meaning plants), a group of chemicals essential to vibrant health that protect us from cancer, inflammation, infection, heart disease, autoimmune disease and a long list of other chronic ailments.
Though they cannot deliver pristine health on their own, there are very compelling reasons to make vegetables the bulk of your diet. Plants are our only source of fibre, which is fertiliser for the good bacteria that make up the internal garden in your gut. Fibre keeps digested food moving smoothly through your system. It prevents cancer and heart disease. It helps you lose weight. And the average person doesn’t even come close to getting enough. Our hunter-gatherer ancestors ate 100 to 150 grams of fibre each day. Today? The typical Brit eats between 17 and 20g per day, falling far short of the British Nutrition Foundation’s recommendation that we consume 30g daily.
You can’t go wrong heeding the age-old “eat your vegetables” advice. It just doesn’t go far enough. The idea of dinner as a big slab of conventionally raised meat accompanied by two side dishes – one vegetable, usually overcooked,
and one potato – should be turned around completely. You shouldn’t just eat your veggies. You should aim to eat them at every meal. Nonstarchy vegetables like spinach, asparagus, broccoli and kale should make up 50 to 75 per cent of your plate, with a small portion of animal protein as “condi-meat”. Think of this as the 3-to-1 rule.
Yet while health experts have always insisted that we eat our veggies, they didn’t really specify which ones and why. Potatoes, often deemed a healthy accompaniment to a dish, are so full of fast-acting carbs that they’ll rapidly raise your blood sugar and insulin.
The number two vegetable in the Western diet is the tomato, which, as a nightshade (peppers and aubergines are also in this group), may be an inflammatory food for some. Most of them are tasteless, sold unripe and designed to fit stacked in a box. Sweetcorn, Britain’s second most popular vegetable, is not only a starchy carb, but another common allergen.
Meanwhile, the nutritional powerhouses, such as kale, radishes and artichokes, fail to make the UK’S top 10, yet we need to eat all the strange, weird and unpopular vegetables instead of the boring, all-too-common ones. This is where you’ll find the highest levels of healing
phytochemicals that Benefits: only now are we beginning to see the role of food as medicine pack the greatest nutritional punch. The sad reality is that for more than a hundred years we’ve deliberately bred our produce to be sweeter, less colourful, and less nutritious. The most potent phytonutrients are what give vegetables their bitter and astringent tastes and deep colours. We’ve taken our wild plants – vegetables and fruit – and stripped them of their best qualities.
So seek out wild or heirloom varieties. These are old-fashioned strains that have been grown and handed down through generations. They’re open-pollinated by wind or insects, meaning they have not been altered by human intervention or genetic modification.
We’re just beginning to understand the role of food as medicine, and how exactly the chemicals in plants interact with our own cells and those in our microbiome. We’ve all been told that our genes are our destiny. But that’s not entirely true. Studies show that your genes can be turned on or off by the foods you eat. This is referred to as the science of nutrigenomics, and means that there may come a time when you’ll know precisely which plants you need to eat to maximise your health and protect against disease.
Food: WTF Should I Eat? by Mark Hyman (£14.99, Hodder & Stoughton) is out now. To order for £12.99 plus p&p, call 0844 871 1514 or visit books.telegraph.co.uk