Broccoli is loaded with health benefits. Photo / Getty Images
Dr Michael Greger is the leading voice for the healing power of diet and lifestyle newly releasing a recipe book packed with tasty meals to make it easier to eat a wholefood, plant-based diet.
Here he explains how a plant-based diet can protect you and your family against lung disease:
The worst death I ever witnessed was that of a man dying of lung disease. He was wide-eyed, gasping for air, his hands clawing at the bed. His lungs were filling with fluid and he was drowning.
Very sadly, there was nothing I could do. Our gaze remained locked as he suffocated in front of me. It felt like watching someone being tortured to death.
So go ahead and take a deep breath. Now imagine what it would feel like not to be able to breathe. We all need to take good care of our lungs.
In the UK 10,000 people are newly diagnosed with lung disease every week, and somebody dies from some sort of lung condition every five minutes — it represents 20 per cent of UK death from disease.
But a plant-based diet could help. Studies show a healthy diet may help mitigate the DNA-damaging effects of tobacco smoke, as well as perhaps help prevent lung cancer from spreading.
Unfortunately, there is no cure for COPD (chronic obstructive pulmonary disease), which, in addition to shortness of breath, causes severe coughing, excess mucus production, wheezing, and chest tightness. But there is some good news: a healthy diet may help to prevent it or keep it from getting worse. This could be very important news for the 1.2 million sufferers in the UK.
Studies show that the consumption of cured meat (bacon, ham, and sausages) may increase the risk of COPD. It's thought to be due to the nitrite preservatives in meat, which may mimic the lung-damaging properties of the nitrite by-products of cigarette smoke.
But data going back 50 years shows a high intake of fruit and vegetables is associated with good lung function. Just one extra serving of fruit each day may translate into a 24 per cent lower risk of dying from COPD. The more the better!
With each breath, we take in thousands of bacteria. Most microbes are harmless, but some cause potentially deadly diseases, such as influenza and pneumonia.
A plant-based diet may be able to boost your immunity and offer protection. In a 2012 study elderly volunteers given five or more servings of fruit and vegetables daily had an 82 per cent greater protective antibody response to a pneumonia vaccine compared to those who ate two or fewer servings a day.
ASTHMA
Asthma is an inflammatory disease characterised by recurring attacks of shortness of breath, wheezing, and coughing, which are caused by narrowed, swollen airways.
It affects 5.4 million people in the UK and claims three lives every single day. However, even asthma may be largely preventable with a healthier diet.
A study of more than 100,000 adults in India found that those who consumed meat daily, or even occasionally, were significantly more likely to suffer from asthma than those who excluded meat and eggs from their diets altogether.
Eggs (along with fizzy drinks) have also been associated with asthma attacks in children, along with respiratory symptoms. But removing eggs and dairy from the diet can improve an asthmatic's lung function in as few as eight weeks.
The explanation for why diet affects airway inflammation may lie with the thin coating of fluid that forms the interface between your respiratory-tract lining and the outside air.
The antioxidants in fruit and vegetables could help support the defensive action of this fluid, which acts as your first line of defence against the free radicals that contribute to asthmatic airway hypersensitivity, contraction, and mucus build-up.
Certainly, research suggests a few extra daily servings of fruit and vegetables can reduce both the number of cases of childhood asthma and the number of asthma attacks among people with the disease.
When researchers in Australia tried removing fruit and vegetables from asthma patients' diets to see what would happen, they found symptoms grew worse after just two weeks.
This occurred when they cut back to just one piece of fruit and two servings of vegetables per day — hardly a restriction by Western dietary standards. When they greatly increased fruit and vegetable consumption (as recommended by my Daily Dozen) to seven servings a day, asthma rates were cut in half.
SMOKING
If, despite all the evidence and warnings, you're currently a smoker, the most important step you can take is to stop. Now. Please.
The benefits of quitting are immediate because the human body possesses a miraculous ability to heal itself as long as we don't keep reinjuring it.
Just 20 minutes after quitting, your heart rate and blood pressure drop. Within weeks your blood circulation and lung function improve, and within months, the sweeper cells that help clean the lungs, remove mucus, and reduce the risk of infection start to regrow.
After a year without cigarettes, your smoking-related risk of coronary heart disease drops to half that of current smokers. Within about 15 years of stopping smoking, your lung cancer risk approaches that of a lifelong nonsmoker — your lungs can clear out all that tar buildup and, eventually, it's almost as if you never smoked at all.
But while you wait, be reassured that simple dietary changes may help to roll back damage wrought by the carcinogens in tobacco smoke.
Researchers rounded up a group of longtime smokers and asked them to consume 25 times more broccoli than average (just a single stalk a day). Compared to broccoli-avoiding smokers, the broccoli-eating smokers suffered 41 per cent fewer DNA mutations in their bloodstream over ten days.
It is clear broccoli boosts the activity of detoxifying enzymes in the liver, helping to clear carcinogens.
So, as well as quitting, keep a close eye on your Daily Dozen to effortlessly boost your intake of vegetables such as broccoli, cabbage, and cauliflower to help prevent further damage.
WHY BROCCOLI IS THE MOST MAGICAL VEGE OF ALL
Broccoli is truly incredible. Studies show it can help prevent DNA damage and the spread of metastatic cancer.
Research also suggests it can activate defences against pathogens and pollutants; help prevent lymphoma; boost the enzymes that detoxify your liver; target breast cancer stem cells; and reduce the risk of prostate cancer progression.
The key plant component responsible for all this is thought to be sulforaphane, a substance that is formed almost exclusively in cruciferous vegetables such as rocket, Brussels sprouts, cabbage, cauliflower, spring greens, horseradish, kale, mustard greens, radishes, turnip tops and watercress.
Sulforaphane may also help protect your brain and your eyesight, reduce nasal allergy inflammation and manage type 2 diabetes.
To get the full benefit of the sulforaphane, you should ideally eat cruciferous vegetables raw. Alternatively (and more deliciously), try adopting what I call the 'Hack and Hold' veg prep method.
There's a key enzyme that doesn't activate the sulforaphane until the vegetable is chopped or chewed, and that enzyme is destroyed by cooking — unless you're prepared to wait about 40 minutes before putting it in the pan or oven. What about frozen broccoli? Sadly, commercially produced frozen broccoli lacks the ability to form sulforaphane, as the vegetables are flash-cooked before they are frozen.
After that, it doesn't matter how much you chop or how long you wait — you won't get any sulforaphane.
But there is another way. The enzyme you need for the sulforaphane is also contained in mustard powder. You can therefore sprinkle mustard powder over cooked broccoli — even the frozen variety — and activate the sulforaphane.
Cruciferous vegetables such as broccoli have also been shown to boost the effectiveness of a special type of white blood cell that is the first line of gut defence against pathogens.
But it's not just broccoli that's loaded with health benefits — plenty of other fruits and vegetables are, too.
Blueberries have been shown almost to double our levels of natural killer cells, which are an essential part of the immune system's 'rapid response team' that fights against viruses and cancer cells.
Red cabbage, meanwhile, provides some of the highest levels of antioxidants very cheaply — three times as many as blueberries per pound. Tomatoes also appear to have special immunity-enhancing powers: drinking tomato juice can rescue the immune function of people who have not had any fruit or veg for two weeks, while carrot juice apparently can't.