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:
- rocket (Arugula in the US)
- Chinese leaf cabbage
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!