Nitro-Boost Salad: a CardioKit recipe

Certain vegetables have the power to lower blood pressure and improve endurance

The combination of fennel, orange and oily fish is a classic. The aniseed fennel flavour perfectly complements fish and the sweet acidity of the orange perfectly balances the oily fish. Its also a visual and textural delight of fresh crunch, soft-sweet elements and rich fish— amazing!

But this salad is more than just a delicious meal — it’s designed to illustrate a point with a specific spot-light on nitrate containing vegetables. For some time we have known about the association of a vegetable-rich diet with lower blood pressure and reduced cardiovascular disease. Stroke is particularly linked with high blood pressure and studies observe an inverse relationship between strokes and vegetables — one analysis revealed a 5% cumulative reduced risk for every portion of vegetables eaten per day. Green leafy vegetables are also an essential element of the ‘Mediterranean diet’ which is consistently associated with better cardiovascular health (there is another interesting element to this story when these vegetables are combined with specific fats — more below).

The cardiovascular protective mechanisms of vegetables are likely to be complex but one clear association is the ability to lower blood pressure. There have been theories regarding the biochemical pathways leading to this effect including the potassium content and diuretic effects of vegetables. However, over the last few years there has been increased interest in vegetables that contain nitrates and this all started with beetroot. In fact, this interest was propelled into the public arena via the press in 2012 as a result of publicity resulting from the London Olympics and athletes use of beetroot juice to improve performance.

Beetroot is just one example of a group of vegetables that are high in nitrates.  Here are some others:

  • spinach
  • radish
  • rocket (Arugula in the US)
  • lettuce
  • Chinese leaf cabbage
  • fennel
  • celery
  • rhubarb

The reason beetroot became particularly popular is because it can be juiced to deliver the active nitrate ingredient in drink form (or concentrated shot). In fact, 250 mls of beetroot juice per day will consistently lower blood pressure by 5 mmHg — this translates to a significant reduction in cardiovascular risk and mortality, which is phenomenal (small consistent differences make a big overall difference). Some of these vegetables, such as fennel and celery, have mild diuretic effects as well which is also a strategy to lower blood pressure.

A full review of inorganic nitrates is a topic for another day and clearly we don’t want to dilute this beautiful salad in too much science. Here are the key facts you need to know:

  • It’s the bacteria in your mouth that help lead to the formation of the biologically active compound —Nitric Oxide. Therefore if you’ve brushed your teeth (or used mouth wash) within 3 hours of eating these foods they won’t have the same effect.
  • Nitric Oxide is fundamentally linked to cardiovascular health. It leads to dilation and relaxation of your arteries. This lowers blood pressure and improves the delivery of blood to organs, like muscles, therefore improving athletic performance.

The final concept to highlight is the current interest in ‘Nitro-fatty acids’ — in simple terms the combination of nitrates from vegetables and healthy fats (e.g. from olive oil) may have an even more pronounced biological health effect. This again has parallels with the Mediterranean diet.

Back to this delicious salad — this is super packed with nitrate containing vegetables (fennel, celery, radish, beetroot, rocket) and healthy fats (oily fish, olive oil) to give you a nitro-fatty boost. One more thing —vitamin C appears to help with the conversion of nitrates to Nitric Oxide and we have even got the oranges covered. Its amazing how nature works!

For 2 large main-meal servings (or 4 starters or side salads):

  • 1 fennel bulb
  • 1 celery heart
  • handful of radishes
  • 2 medium oranges
  • 1 small or medium red onion
  • handful of rocket
  • 2 large beetroot
  • 2 high-quality smoked mackerel fillets
  • pomegranate sprinkle (optional for colour and added zing)

For the dressing:

  • juice from the left over orange bits (or half an orange if they are not juicy)
  • asqueeze of lemon juice (if your oranges are very sweet)
  • extra-virgin olive oil
  • white wine vinegar
  • black pepper
  • honey
  1. A large flat serving plate or shallow bowl is ideal for scattering the ingredients.
  2. Remove the tough outer layer of the fennel bulb. Finely slice from the base towards the stem. If you have a mandolin then this is ideal. Save any fennel top as a garnish. Do the same with the radish and red onion.
  3. Remove the outer layers of your celery until you are left with the pale-green heart. Slice the heart from the base (discard the first thin tough base layer) to the top. Keep the young leaves as a garnish.
  4. Now for the beetroot. You can use ready cooked versions (without vinegar) but for a true sweet flavour its best to cook your own and very easy. Boiling or steaming is fine but can leach some of the flavour. The best results are from baking as this concentrates the natural sweet flavour — wrap each beetroot in tin foil and place on a baking tray. Bake in an oven at around 180 degree C for 1–1.5 hours depending on the size. They are cooked when a knife or skewer will easily pass through the beetroot. Allow to cool — the skin should easily slide of by hand. Cut into cubes. This can obviously be done before-hand and kept in the fridge ready.
  5. Now to segment the orange. With a sharp knife slice off the top and base. Place on a board or plate and cut strip of skin (and the pith) from the top to the base rotating as all the way around. Now you can directly cut out the pure orange segments (leaving behind the tough connecting membrane) over the salad so that you also catch any juice. Once all the segments have been removed, squeeze the remainder in your fist over a bowel to extract the remaining juice. Between the two oranges you should have around 3 tablespoons of juice. If your oranges aren’t juicy then squeeze half of an extra orange for the dressing.
  6. Scatter over the rocket, chopped fennel and celery tops to finish the salad.
  7. For the dressing mix the reserved orange juices (3 tablespoons) with an equal amount of extra-virgin olive oil. Add a splash (around 1/2 tablespoons of white wine vinegar), a small drizzle of honey and black pepper (the fish provides the saltiness). Taste (it needs to have an exaggerated zing) — if it needs more acidity you can add a squeeze of lemon juice or more vinegar.
  8. Serve with the fillets of smoked mackerel (skin removed) and drizzle over the dressing. Allow to stand for 5–10 minutes for the flavours to mix before eating.
  9. You obviously don’t need to add all of these nitrate containing vegetables — the basic combination of fennel, beetroot and orange works really well. Eat these foods regularly and combine with 20 minutes of regular cardiovascular exercise to see what happens to your blood pressure and fitness.
Back to top