Consider your usual diet for a moment. Think about what you routinely eat for breakfast, lunch, dinner and snacks.
Now, count the number of fruit and vegetable servings you typically eat in a day. A serving is equivalent to a medium-sized fruit, a half-cup of chopped fruit or berries, a quarter-cup of dried fruit, a half-cup of cooked or raw vegetables and one cup of salad greens.
How many? Less than five? Seven or more?
Ten is the optimal number you should be striving for, according to a review published last month in the International Journal of Epidemiology.
Five-a-day protective, 10 even better
For the review, a team of researchers from Norway, the United States and Britain combined and analyzed data from 95 independent studies looking at fruit and vegetable intake and the risk of coronary heart disease, stroke, total cancer and early death from any cause.
The studies were conducted in Europe, the United States, Asia and Australia and involved anywhere from 226,910 to 2.1 million participants.
The combined data showed that eating five daily servings of fruit and vegetables was protective on all counts. The greatest benefit, though, came from eating 10 servings each day.
Doing so was associated with a 24-per-cent lower risk of heart disease, 33-per-cent lower risk of stroke, 14-per-cent lower risk of cancer and a 31-per-cent reduced risk of early death.
Health Canada recommends that most adults eat seven servings for fruits and vegetables a day. (Men aged 19 to 50 are advised to get eight to 10 servings.) Guidelines for kids and teenagers range from four to eight daily servings depending on age and gender.
According to Statistics Canada six out of 10 Canadians, aged 12 and older, consume fruit and vegetables less than five times a day. A 2016 study from the University of Waterloo reported that only one in 10 Canadian children in Grades 6 through 12 met fruit and vegetable recommendations.
Some types more protective
The researchers also investigated which types of fruits and vegetables were most effective at reducing the risk of specific diseases.
To protect against heart disease, stroke and early death the findings suggest upping your intake of apples, pears, citrus fruit, salads, leafy greens (e.g., arugula, kale, Romaine lettuce, spinach, Swiss chard) and cruciferous vegetables (e.g., broccoli, Brussels sprouts, cabbage, cauliflower, kale).
Green vegetables (e.g., spinach, green beans), yellow-orange vegetables (e.g., carrots, bell peppers, squash) and cruciferous vegetables were most strongly tied to cancer prevention.
The fibre, vitamins, minerals and countless phytochemicals in fruit and vegetables act in many different ways to stave off chronic disease.
Fibre in produce has been shown to lower blood cholesterol, blood pressure, inflammation and improve blood vessel and immune function. Potassium, too, helps maintain healthy blood pressure.
Antioxidants such as vitamin C, beta-carotene and flavonoids may neutralize harmful free radicals and reduce DNA damage, injury that could lead to cancer. Folate, a B vitamin, plentiful in spinach, asparagus, broccoli and oranges, helps make and repair DNA in cells.
Once consumed, phytochemicals in cruciferous vegetables called glucosinolates are transformed into compounds that help the liver detoxify and dispose of carcinogens. Other phytochemicals are thought to have a beneficial effect on our gut microbiome.
Raw vs. cooked vs. supplements
If your go-to vegetable is salad, mix it up. Include a variety of raw and cooked vegetables in your diet to deliver the full spectrum of their nutritional and health benefits.
You'll get more minerals (e.g., iron, calcium, magnesium) and antioxidants (e.g., beta-carotene, lycopene, lutein) if you eat your vegetables cooked. Heating vegetables breaks down plant cell walls, making more of these nutrients available for your body to absorb.
Steaming, roasting, grilling and quickly sauteeing vegetables preserve more nutrients and antioxidants than boiling or pressure-cooking. If you microwave your vegetables, do so only until they're tender crisp.
To get more glucosinolates from cruciferous vegetables such as broccoli, cabbage, cauliflower and bok choy, eat them raw or lightly cooked.
That's because these vegetables contain a heat-sensitive enzyme that's needed to convert glucosinolates into anti-cancer phytochemicals. The longer you cook these vegetables, the more you destroy this enzyme.
You can't rely on a multivitamin, a vitamin C tablet or an antioxidant supplement to deliver the health benefits that come from eating fruit and vegetables. The array of beneficial compounds found in produce are thought to work synergistically and can't be replicated in a pill.
If your diet falls short on fruit and vegetables, put strategies in place to eat at least five servings each day (see sidebar). Once you've hit that target, build on your success to increase your daily intake to 10 servings.
Leslie Beck, a registered dietitian, is based at the Medisys clinic in Toronto.
Four ways to eat more fruit and vegetables
The following tips will help you get your 10 daily servings of fruit and vegetables. With a little planning and organization, I think you'll discover that it's not as difficult as you might think.
Map it out
To reach your daily target, you need to incorporate fruit and vegetables into all your meals and snacks. If you wait until dinnertime, it won't happen.
Include one or two servings at breakfast. Top hot or cold cereal with chopped fruit. Blend berries and leafy greens into smoothies and protein shakes. Add red pepper, baby spinach and mushrooms to omelettes.
Aim for three vegetable servings at lunch and dinner. Make a big salad with greens and other vegetables. Add grated carrot and beet or shredded cabbage to sandwiches and wraps.
At dinner, fill half your plate with vegetables. Fortify soups, pasta sauces and chili with chopped bell pepper and baby spinach or chopped kale.
Carry fruit for midday snacks. Clementines, apples, bananas, dried apricots and prunes and unsweetened fruit cups travel well.
Prep in advance
Clean and prep vegetables when you get them home from the grocery store. Wash and spin lettuce, chop broccoli and cauliflower, and grate carrots and raw beets so they're ready to quickly add to meals and snacks.
Grill or roast a batch of vegetables on the weekend for speedy weekday meals.
Eat in-season vegetables
This isn't the time of year for locally grown, farm-fresh vegetables but there is still plenty of seasonal nutrient- and antioxidant-rich produce to choose from.
Beets, Brussels sprouts, cabbage, carrots, parsnips, sweet potato, turnip and winter squash should be part of your regular diet right now.
Go for frozen
For out-of-season produce, don't discount frozen fruit and vegetables. They're super convenient and considerably less expensive than imported produce.
Plus, frozen fruit and vegetables may be higher in nutrient content than their imported counterparts since they're processed right after harvest, a time when they're most nutrient-packed.