Broccoli is incredible. It can prevent DNA damage and metastatic cancer spread; activate defences against pathogens and pollutants; help to prevent lymphoma; boost the enzymes that detox your liver; target breast cancer stem cells; and reduce the risk of prostate cancer progression.
The component responsible for all this is thought to be sulforaphane, which is formed almost exclusively in cruciferous vegetables — including 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.
It was even recently found to help treat autism. A placebo-controlled, double-blind, randomised trial of boys with autism found that two to three servings of cruciferous vegetables a day improves social interaction, abnormal behaviour and verbal communication — within a matter of weeks.
But here’s something you need to know. To get the full benefit of the sulforaphane, you need to eat your cruciferous vegetables raw or adopt what I call the Hack and Hold method.
That’s because there’s an enzyme that doesn’t activate the sulforaphane until raw broccoli, say, is chopped or chewed. And that enzyme is destroyed by cooking — unless you wait.
So first, chop the broccoli (or other cruciferous vegetable) and then wait 40 minutes. At that point you can cook it.
What about frozen broccoli? Sadly, commercially produced frozen broccoli lacks the ability to form sulforaphane because 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’s another way. The enzyme you need for the sulforaphane is also contained in mustard powder.
This means that instead of waiting 40 minutes, you can sprinkle mustard powder over cooked broccoli — even the frozen variety — and activate the sulforaphane.
Popeye was right about spinach: dark green, leafy vegetables are the healthiest food on the planet. As whole foods go, they offer the most nutrition per calorie.
You should aim to get a dozen servings a week of greens — including rocket, spring greens, kale, young salad greens, mustard greens, sorrel, spinach and swiss chard.
Of all the food groups analysed by a team of Harvard University researchers, greens turned out to be associated with the strongest protection against major chronic diseases.
That meant about a 20 per cent reduction in risk for heart attacks and strokes for every additional daily serving. Yet today, only about one in every 25 people even eat a dozen servings in a month, let alone a week.
All greens contain a plant pigment called chlorophyll. In the name of science, volunteers drank a radioactive carcinogen. Those who also had chlorophyll — 360g of spinach — appeared to be able to block about 40 per cent of the carcinogen.
Amazing! But that’s not all chlorophyll can do. It may also help regenerate a critical molecule called coenzyme Q10 — an important antioxidant in the fight against disease. Eating a chlorophyll-rich diet may be especially important for those on cholesterol-lowering statin drugs, as these medications can interfere with CoQ10 production.
Which greens are best? The ones you’ll eat most of. For many of us, that means a big daily mixed salad.
Try mixing greens with a healthy source of fat: nuts, seeds, nut or seed butters or avocados. For instance, you can make a creamy dressing based on tahini (a paste made from sesame seeds, available in most supermarkets), put walnuts in your pesto or sprinkle some toasted sesame seeds on your sauteed kale.
Indeed, you should include fats in each meal because they boost absorption of nutrients. Just 3g of fat — a single walnut or a spoonful of avocado — in a meal will make your greens more effective.
Important warning: In 1984, a 35-year-old woman on the blood-thinning drug warfarin failed to tell her doctor she’d gone on a diet composed almost entirely of salad, broccoli, turnip tops and mustard greens.
Five weeks later, she suffered a blood clot and died. So, if you’re on warfarin, talk to your doctor before increasing your greens intake. The drug works (as a rat poison and a human blood- thinner) by crippling the enzyme that recycles vitamin K, which is involved in clotting your blood.
If your system gets an influx of fresh vitamin K, which is concentrated in greens, you can thereby undermine the effectiveness of the drug.
You should still be able to eat greens, but your doctor will have to adjust the dose of the drug to match your dietary intake.
Studies have shown mushrooms can boost the immune system and may prevent cancer.
The yellow fluid surrounding tomato seeds helps stop the production of blood clots that cause heart attacks. So, if you consume only tomato sauce, juice or ketchup, you may be missing out because the seeds are removed during processing.
So choose whole, crushed or chopped tomatoes instead of tomato sauce, puree or paste.
Garlic, onions, leeks and other vegetables in the allium family appear to have anti-cancer properties. In one trial, a dose of garlic blocked nearly 80 per cent of cancer cell growth.
But make sure you eat a variety of vegetables and fruit. The addition of just two different types per week, for instance, has been associated with an 8 per cent reduction in the incidence of type 2 diabetes.
Vegetables can even make you more attractive. One study got college students to eat nine servings of fruit and vegetables a day for six weeks. Another group ate only three servings.
The ones who ate the most fruit and vegetables were deemed more attractive-looking to strangers.
In Japan, researchers measured the extent of crow’s feet wrinkles around the eyes of more than 700 women.
The result? They found that ‘a higher intake of green and yellow vegetables was associated with decreased facial wrinkling’.