Wonderful waste! What nutritional treasures lie in the parts of vegetables we dispose of?

With rising fuel and food bills, the future looks financially tougher for all of us. This is going to make it harder and harder for us to nourish ourselves with adequate nutrition from natural, unprocessed and fresh foods, which tend to be more expensive. Therefore, it is time we looked at innovative, traditionally unthought-of plant-based sources of food. What superfoods do we unknowingly throw away simply because this is what we are used to doing? It is time we thought outside the box and saved food waste to help protect the environment (1/3 of carbon emissions come from unnecessary food waste) and in the process save money and gain physical and mental health. What is there to lose (except unwanted weight if overweight?)? It is time to reclaim this treasure.

Fantastic plant-based food we foolishly (it makes no logical sense) throw away…

1) Cauliflower stalks, stems and leaves

You often see fresh cauliflower in supermarket boxes or prepackaged without stems and stalks. Consumers are in the habit of and used to purchasing the white part of the plant and so food supply chains, shops, supermarkets and most people when cooking, dispose of the stalk, stems and leaves. I often go and pick these up and the supermarket gives them to me for free as no one wants this part of the vegetable. It is considered waste.

Yet why do we not eat the stems, leaves and stalks? I snack on the stems and stalks and eat them raw (or dip them in hummus or peanut butter) or cook them as the veg part of my meal, as they are an invaluable source of nutrition, energy and taste amazing. They are rich in iron, fibre, calcium, protein and most importantly, flavour. They are a positive addition to any meal, raw, boiled, roasted, steamed. The leaves are also great as a lettuce or spinach or kale alternative in salads.

A stem of cauliflower contains 7g protein. They are a great currently unnecessarily overseen, plant-based dietary protein source for any vegetarian or vegan and far cheaper than any whey, casein (both from milk) or collagen protein powder for anyone trying to gain muscle mass such as an athlete or bodybuilder.

Like all vegetables, it contains the complex carbohydrates Starch (alpha-glucose subunits join together to make starch which is the energy storage part of vegetables- why vegetables give you energy) and Cellulose which is the carbohydrate (made of beta glucose subunits) part of vegetables called fibre. The stem and stalk is a mid-range complex carbohydrate vegetable as 100g provides only 7g (100g potato contains 17g or a sweet potato 24 g) but is still rich in energy. It could be the carbohydrate part of your meal.

Carbohydrates are sugars and we have two types. Simple (sugars like caster sugar, honey, agave nectar and syrups which are quick energy supply) and complex Carbohydrates. Simple sugars effect is quick and short-lasting. This can cause energy lows which increases your appetite and make you hungry. Complex sugars effect is slower but more long-lasting. Therefore complex Carbohydrates keep you feeling fuller for longer, preventing unnecessary snacking which prevents the maintenance of a healthy weight. Cauliflower stalks and stems are rich in these complex carbohydrates. These help control your glycemic glucose levels, helping improve the symptoms of diabetes.

The starch (white bit) and cellulose (the long fibers you see in the picture- hence the name fibre) roughage in the stem of a cauliflower.

100g of cauliflower stems contain a whopping 2g of both soluble (dissolves in water) and insoluble fibre (cellulose fibers- called fibre- which do not dissolve in water and give the plant structure). Soluble fibre is the fibre that binds to sugars and slows their digestion- helping improve the glycaemic index of the food you have eaten. This keeps you full of energy and prevents the sugar-lows that make you hungry and which cause poor concentration, low “hungry-angry; hangry” angsty or depressed low moods and poor sleep. Soluble fibre is also found in pectin, oats, psyllium husk, barley and beans. Pectin is found in most fruits and vegetables because it’s found in the cell walls of all green plants. The richest sources of pectin are found in the peels of citrus fruits such as oranges, lemons, limes, grapefruit and passionfruit. Plants such as bananas, apples, peaches, raspberries, blackberries and apricots. Peas, green beans, sweet potatoes and tomatoes also offer a high amount but plant stems, stalks and peels are often overlooked.

Cauliflower stems and leaves are also rich in insoluble cellulose fibers fibre. This improves digestive health, acting as “roughage” to prevent constipation and help push food through the bowel. It is the insoluble fibre that helps improve digestive health. It is also very high in potato skins, carrot, parsnip and onion peels and the tops and ends of leeks and spring onions, which most people foolishly disregard and dispose of as waste.

Both types of fibre work as prebiotics to help boost the gut microbiota. The gut microbiota helps regulate the immune system (by regulating Treg production) to reduce inflammation and reduce allergy (helping reduce lactose and gluten intolerances which can cause so much gut upset). Fibre acts as food for the friendly bacteria living in your gut. When these bacteria feed on fibre, they produce SCFA (short-chain-fatty acids), which appear to further boost feelings of fullness. They also boost your mood by boosting Serotonin (the happiness brain chemical) production via the brain-gut-axis. They also help cardiovascular health via the brain-gut-heart access.

The stems and stalks are rich in Vitamin C. This helps improve your immunity and helps you absorb your iron. If you do not consume sufficient vitamin C, you cannot absorb iron and most Vitamin C lies in fresh plant-based food. This is why the elderly who live in care homes on pre-cooked, un-fresh, meals-on-wheels food, often suffer considerably worse from cognitive decline and memory loss, than those who consume a more fresh-plant based diet. The vitamins in fresh food are essential for iron absorption and iron for energy and energy for memory.

100g of cauliflower leaves and stem contain a fantastic 40mg of iron. This iron helps to give you energy and improves your vitality, memory and focus, helping to prevent dementia symptoms in the elderly and reduce brain fog. It makes you cognitively more alert and cleverer, helping improve exam results. It also helps prevent anaemia in young women who are menstruating and improves metabolic fitness (as iron is in haemoglobin which carries oxygen around the body and oxygen combines with glucose from our diet in respiration to give you energy) of athletes and those working out at the gym. Increased energy also makes you feel more positive and therefore improves your mental health.

Cauliflower leaves (as they are a green leafy vegetable and it is the green pigment chlorophyll in leaves which is made of Magnesium) also contain lots of Magnesium. Magnesium helps you convert your food to energy so you have more energy (and therefore is another positive mood food), it also helps you make proteins so helps improve your muscle mass, helps you convert fat to muscle and increases your basal metabolic rate. It is also very high in vitamin E and water, helping improve your skin, nails and hair, memory and concentration.

Cauliflower stems and leaves also contain Calcium mineral (626mg per 100g) which helps bone health. This is crucial for women to help prevent osteoporosis and osteopenia, brittle bone disease (when your bones fracture easily). Oestrogen supports bone formation and when women reduce or stop producing Oestrogen (due to causes such as athletes triad, PCOS, obesity, anorexia, menopause and in the elderly), their risk of osteoporosis increases. Increased dietary Calcium can help prevent this. Men also need Calcium to support their bone health and prevent osteopenia, especially as they age (though women are more at risk).

Cauliflower leaves are a cheap yet amazing source of nutrition. Do not waste this golden goose. Eat the leaves and stem, save money and the planet and improve your health.

Why do we waste the leaves and stems of broccoli and cauliflower? It makes no logical sense?

2) Brocolli leaf and stems- beautiful

Just like with Cauliflower, beautiful broccoli stems are a rich source of starch, soluble and insoluble fibre, iron and magnesium minerals and many essential vitamins. They help improve digestion and stop constipation, boost the benefits of the gut microbiota, maintain energy levels which helps boost mental health and mood and they reduce hunger and stop unnecessary snacking. They are rich in Iron, Magnesium, protein, fibre and B vitamins.

Broccoli stems can be cut into small circles and used in soups, cottage pies, fish pies, with roasts or as a snack raw. They are super high in Vitamin C with one cup of Brocolli stems containing more Vitamin C than an orange.

They are a low calorie, high fibre and complex carbohydrate that provides much energy. They can be the carbohydrate part of a meal instead of processed food like rice or bread or pasta or highly processed foods like chocolate and biscuits, but prevent the energy-lows that come with these simple sugars, keeping you energetic and full of vitality for longer.

Broccoli stems are also rich in Potassium, helping you to reduce your sodium levels (as these work against each other) and improve your blood pressure. There is a saying in biology, “wherever sodium goes, water flows.” More salt makes our body reabsorb more water, increasing our blood pressure and making us feel bloated. Increasing potassium reduces sodium levels. Highly processed foods tend to have more salt, and so broccoli stems can help reduce the negative effects of processed foods on our bodies.

3) Precious plant peels- why oh why do people peel off the precious plant peels? Are they insane?

Plant peels are incredibly high in insoluble fibre and full of nutrition and flavour, and yet so many of us peel them off or chuck them in the bin as “that's what our parents did” or “that's what the recipe says.” Well, chaps, it is time to think for yourselves and realise that you are throwing away a precious plant gift for your body, something that will make you slimmer, have a stronger immune system (so more able to fight off covid and colds), more full of energy and happier.

Peels are rich in fibre. Fibre feeds the gut microbiota and the gut microbiota increases Serotonin which is a neurotransmitter that makes you happier. Apple peels, carrot, squash and pumpkin (when roast or cooked till soft and delicious) are high in vitamin C and A which help boost energy and immunity. Vitamin A helps improve eyesight and helps your skin, reducing acne symptoms and spots.


Cucumber peels are full of vitamin C and water, helping hydrate you. They are also rich in Magnesium, helping improve your memory and sleep. Mushroom peels are full of protein and vitamin D which helps us build muscle and bone. Lemon, lime, passion fruit and Orange citrus fruit peels are high in soluble fibre pectin and can be grated as zest into cakes and recipes or eaten raw in salads. Why do so many people have a slice of lemon or lime in their drink and then throw it away with the ice? It is highly nutritious, and you are throwing away the best part of the drink!

4) Mushroom stems: magnificent

I have a secret habit. I sometimes go through the food waste recycle bin or bins of my friends and family and in office blocks, to see what people are chucking out. It always breaks my heart when I see the stems of white mushrooms in there. Why? People throw them away as that's what the recipe says, but it makes no sense. They taste exactly the same as the head of the mushroom and are equally high in vitamins and minerals. In fact, the stem contains a considerably high amount of vitamin D.

Why are people and the NHS paying drug companies huge amounts for Vitamin D supplements, when they can just get the vitamin from food? Why are people throwing away food containing the essential vitamin and then buying expensive supplements?

Vitamin D is needed to help bones absorb Calcium mineral, which is needed for bone strength, to prevent fracture and to prevent bone “rounding” that you see in people with a hunchbacked poor posture. This can be prevention of both small compression fractures such as shin splints that runners get, or large scale hip fractures that you see in the elderly. Including mushroom stems in food can help prevent this. Let's protect our bones and eat our vitamin D boosting mushroom stems.

5) Celery and fennel leaves

The wonderful leaves of fennel and celery taste amazing, are full of flavour, fibre and vitamin C. They are a fabulous addition to salads (you don’t need a sauce or dressing, just add fennel leaves to a dish and omgees the flavour pops in your mouth!) as they look pretty and also can be snacked on. Don’t waste what tastes so great.

6) The tops and ends of leeks and spring onion

This to me, is another illogical thing. Why are we wasting fibre? Why are we wasting vitamin D and C? The planet is under so much strain and burden from humans and yet we are arrogant enough to throw away treasured nutritional sources. Things need to change. Just try eating them. They won’t kill you and taste quite lovely. They also beef up a meal, making ingredients go further and saving you money on your food bills.

7) Melon rind- do not diss it till you have tried it.

Ok. This is unconventional but convention be dammed. Watermelon rind, once washed, is from the same nutritional subclass as a cucumber. It is high in fibre, vitamin C and is delicious thinly sliced and used in salads or tuna sandwiches raw like cucumber, or cooked and used in stews and casseroles instead of broccoli or Brussel sprouts. It is rich in vitamin A, vitamin C, potassium, magnesium and fibre. It feeds your eyes, immune system, heart, brain and gut microbiota.

8) Squash, pumpkin and watermelon seeds- protein and OMEGA 3 time!

Why do we dispose of the seeds of pumpkins at Halloween, melon seeds in the summer and squash seeds at Thanksgiving or Christmas? These babies are bursting with blooming marvellousity. They are high in Magnesium, protein (a great source for vegans and vegetarians), Zinc (needed for smell, immunity and digestion) and pumpkin seeds are rich in Omega 3. They are also free with your pumpkin at Halloween. Don’t buy Omega-3 supplements- eat your pumpkin seeds.

Omega-3’s help with weight loss, make you cleverer and like fibre boost the gut microbiota. They improve cognition and memory. 60% of your brain is made of fat and Omega-3’s help stimulate neurogenesis (the formation of new brain pathways), improving memory and intellectual and emotional intelligence (IQ and EQ) and preventing dementia.

We have three types of Omega-3, alpha-linolenic (ALA) which is converted to eicosapentaenoic acid (EPA), which is converted to docosahexaenoic acid (DHA). All three types lower your risk of cardiovascular disease by lowering the amount of “bad” LDL (low-density lipoprotein) cholesterol in your blood. Increasing Omega-3 also changes the Omega-3 to Omega-6 ratios. The more Omega-3 to Omega-6 (in processed foods and trans fats), we have, the more able we are to maintain a healthy weight.

9) Edamame bean shells- also rich in Omega-3

With the planet under so much strain, it is going to be harder and harder to get Omega-3’s from fish sources, and so we will need to rely on plant-based sources more and more. Let the pumpkin seed plant a seed of omega-3 in your brain and get cleverer whilst reducing food waste. Edamame bean pods which everyone chucks in the bin are high in fibre, Magnesium and Omega-3. They also taste great, especially when coated in Vitamin A rich paprika or salt and pepper. Please just try them (I feel like a mum coaxing her kids to try vegetables)!

There are many many more sources of fantastic food we throw away. So many nutritional, body and brain-boosting food feed bins, not humans. THINK before you act about what you are doing? Why buy a supplement when you can get the benefits from dietary sources you dispose of. Food is medicine. Food is a blessing. Don’t waste it!


  1. Faryadi, Q., 2012. The magnificent effect of magnesium to human health: a critical review. International Journal of Applied, 2(3), pp.118–126.
  2. Manchali, S., Murthy, K.N.C. and Patil, B.S., 2012. Crucial facts about health benefits of popular cruciferous vegetables. Journal of functional foods, 4(1), pp.94–106.
  3. Köksal, E. and Gülçin, İ., 2008. Antioxidant activity of cauliflower (Brassica oleracea L.). Turkish Journal of Agriculture and Forestry, 32(1), pp.65–78.
  4. Hathcock, J.N., 1997. Vitamins and minerals: efficacy and safety. The American journal of clinical nutrition, 66(2), pp.427–437.
  5. Huskisson, E., Maggini, S. and Ruf, M., 2007. The role of vitamins and minerals in energy metabolism and well-being. Journal of international medical research, 35(3), pp.277–289.
  6. Barber, T.M., Kabisch, S., Pfeiffer, A.F. and Weickert, M.O., 2020. The health benefits of dietary fibre. Nutrients, 12(10), p.3209.
  7. Swanson, D., Block, R. and Mousa, S.A., 2012. Omega-3 fatty acids EPA and DHA: health benefits throughout life. Advances in nutrition, 3(1), pp.1–7.
  8. Dyall, S.C. and Michael-Titus, A.T., 2008. Neurological benefits of omega-3 fatty acids. Neuromolecular medicine, 10(4), pp.219–235.



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Laurentia (Laura)Campbell

Laurentia (Laura)Campbell


Neuroscience, mental health and nutrition academic and writer. Life-experimenter, trying to add value with an insatiable appetite for actioning positive change.