June 21st, 2008 | Published in How to eat
This just in from the Department of Duh: fruits and vegetables are good for you. Also, sky is blue and water is wet.
OK, that part is easy. We know that we’re supposed to eat more fruits and veggies (henceforth referred to as F/V – interestingly also “future value” in accounting terms, which seems appropriate considering what F/V do for you).
Study after study has shown that F/V consumption is clearly correlated with good health, slow aging, a healthy body composition, and strong disease resistance. The more F/V you eat, the healthier you’re likely to be, and this holds true for a metric assload of possible health problems.
But why are F/V so dang good? And how can you get more into your daily diet?
antioxidants, polyphenols, and flavonoids, oh my!
It’s tempting to think that one can just pop a few vitamins and get the nutritional equivalent of F/V. Oranges have vitamin C, so if I eat vitamin C, that’s just like eating an orange, right? Nope.
First, the handful of vitamins that you get in a vitamin pill are only a tiny fraction of the hundreds of chemical compounds that occur naturally in F/V. The more colourful the F/V, the more likely they are to be chock-full of planty chemical goodness. There are many chemicals still waiting patiently to be discovered in our humble vegetal friends, and most of these chemicals are exceedingly good for you.
Flavonoids are chemical compounds in F/V that perform a variety of functions in the body. They help with healing and immune system, they may act as anti-inflammatories, they slow the aging process, and they may help prevent many types of disease.
Thus, the first thing to remember is that with a vitamin pill, you get the chemical equivalent of a single kazoo played by a drunk at 3 am; with F/V you get a full professional symphony orchestra plus some guy in the back row listening to an iPod.
There is emerging evidence that many diseases and symptoms of aging are caused and exacerbated by oxidative stress in the body. Similar to the oxidation process that causes rust in iron, the biochemical process of human metabolism and respiration results in byproducts known as free radicals.
Free radicals are like the mooching unemployed third cousin that nobody likes but everyone tolerates. He shows up, cleans out your refrigerator, sleeps on your couch, poaches your credit card for a few “necessities”, and over time turns your lovely house into a nest of old newspapers, smelly socks, and empty beer cans. Your cousin has a temper, too, and reacts badly with most family members. Now imagine a whole host of dirtball third cousins showing up on doorsteps everywhere with bottle opener firmly in hand just achin’ for a fight, and you have the equivalent of free radicals that rampage through the body causing family friction and sleeping on whatever couches they can find.
Free radicals react with other chemicals and cells in the body to cause damage, and over time, contribute to the cellular breakdown of the body. Oxidative stress has been implicated in a host of diseases such as cancer, cardiovascular disease (heart disease and stroke), Alzheimer’s disease, and rheumatoid arthritis. “Almost certainly,” writes William Clark in A Means to an End: The Biological Basis of Aging and Death, “oxidative damage to DNA is the major contributor to cellular senescence.”(1999: 159)
Antioxidants, as you can probably tell from the name, inhibit the oxidation that can lead to old Cuz Earl snoring and farting on the pullout. Antioxidants are tough love for deadbeat relatives! Antioxidants kick that no-good dog to the curb! And colourful F/V are bursting at the seams with antioxidants.
The other part of the puzzle is that antioxidants, isolated and put into supplement form, do not appear to work as well as antioxidants in food format — or sometimes even at all! (Nutrition and Heart Disease ed. Ronald Watson and Victor Preedy. Boca Raton, FL: CRC Press, 2004) Antioxidants and the other chemical compounds in F/V appear to need each other to do their job. No prima donnas in antioxidant world: the phytochemicals work synergistically, in teams.
And hey, guess where those teams like to hang out? In the many pretty colours of F/V. Antioxidant superfoods include citrus fruits, dark green leafy veggies such as spinach and kale, broccoli, berries, and red grapes.
a cherry a day?
Chemists have identified a group of naturally occurring chemicals, called anthocyanins, abundant in fresh cherries that could help lower blood sugar levels and increase insulin levels in people with diabetes (Nair, American Chemical Society’s Journal of Agricultural and Food Chemistry, Jan 5 2005).
Anthocyanins are a class of plant pigments responsible for the color of many fruits, including cherries. They are potent antioxidants, a group of chemicals that have been increasingly associated with a variety of health benefits, including protection against heart disease and cancer. The depletion of antioxidants has been linked to an increase in diabetes complications (Opara et al, Duke University Medical Center, 1998). Anthocyanins also have anti-inflammatory properties and may be useful in fighting arthritis and colon cancer. More…
fibre’s number two!
F/V are basically a delivery system for chemicals and water, held together by a matrix of soluble and insoluble fibre. Both types of fibre are part of a healthy diet. Both add bulk to material in the colon, increasing satiety (feeling of fullness), and helping food process through the system, reducing food’s transit time and preventing constipation.
Soluble fibre, as its name suggests, is like a sponge that mops up everything: sugar, water, and fat in the gut, and it eventually appears to lower LDL (bad) cholesterol in the blood (although research is somewhat equivocal on this point, soluble fibre in the form of psyllium is being explored as part of a multifaceted therapy for cardiovascular disease). Unlike insoluble fibre, soluble fibre often helps with inflammatory bowel conditions and diarrhea (counterintuitive, but true).
Insoluble fibre is your sticks and twigs: it’s usually cellulose or the hard coating of grains that also helps push the goods through.