Do Fruits and Vegetables Really Help Prevent Disease?

How many times have you heard how important it is to eat fruits  and vegetables?  Now, is it five or nine servings a day?  Why are fruits and veggies always lumped together?  What does a watermelon have in common with spinach?

The author of a 2004 article in the Journal of Postgraduate Medicine answered some of these questions.  Here are a few quotes from from the summary:

The intake of 400-600 g/d of fruits and vegetables is associated with reduced incidence of many common forms of cancer, and diets rich in plant foods are also associated with a reduced risk of heart disease and many chronic diseases of ageing.

These foods contain phytochemicals that have anti-cancer and anti-inflammatory properties which confer many health benefits. Many phytochemicals are colourful, and recommending a wide array of colourful fruits and vegetables is an easy way to communicate increased diversity of intake to the consumer. For example, red foods contain lycopene, the pigment in tomatoes, which is localized in the prostate gland and may be involved in maintaining prostate health, and which has also been linked with a decreased risk of cardiovascular disease. Green foods, including broccoli, Brussels sprouts and kale, contain glucosinolates which have also been associated with a decreased risk of cancer. Garlic and other white-green foods in the onion family contain allyl sulphides which may inhibit cancer cell growth. Other bioactive substances in green tea and soybeans have health benefits as well.

Consumers are advised to ingest one serving of each of the seven colour groups daily, putting this recommendation within the United States National Cancer Institute and American Institute for Cancer Research guidelines of five to nine servings per day. Grouping plant foods by colour provides simplification, but it is also important as a method to help consumers make wise food choices and promote health.

Asking U.S. consumers to eat one serving from each of seven fruit and vegetable color groups daily is a bit much.  I don’t see that happening.  But the suggestion is a start.  Darya Pino (Summer Tomato blog) probably does it every day, but I don’t know any others.  My simplified message: Eat a variety of colorful fruits and veggies daily.

Note that the very low-carb Ketogenic Mediterranean Diet provides 400 grams of vegetables and fruits daily, and I count seven colors (assuming you allow me to include black olives).  On the KMD document I list avocado, cucumber, and tomato under “vegetables,” but they are indeed fruits.  Heck, I guess olives are fruit, too.

“So, what’s your point, Parker,” you might well ask.  I don’t expect anyone to follow the Ketogenic Mediterranean Diet for life.  When it’s time to move on to a “Diabetic Mediterranean Diet,” I’m considering adding more options: traditional fruits and some colorful vegetables like purple beets, yellow corn, and orange carrots and sweet potatoes.

I still don’t know why “fruits and vegetables” are joined at the hip.  Legumes, grains, and dairy products all rate their very own category.  It’s just not fair.

Steve Parker, M.D.

Reference:  Heber, D.  Vegetables, fruits and phytoestrogens in the prevention of diseases.  Journal of  Postgraduate Medicine, 50 (2004): 145-9.

4 Comments

Filed under Fruits, Health Benefits, Vegetables

4 responses to “Do Fruits and Vegetables Really Help Prevent Disease?

  1. I can’t imagine the color matters that much. Pretty much any diet high in fruits and vegetables is going to be beneficial over the long term.

  2. The nutrition literature is replete with references to colorful vegetables (other than green and white), with implications of different antioxidants, phytochemicals. Many of the orange ones, for example,have carotenoids (vitamin A).

    I’m not sure how much science is behind the color issue.

  3. Ha ha, I probably do. But I should add that I inspire envy in virtually everybody who sees what I’m eating–even those who don’t care about their health or weight. I’ve converted about half the floor where my lab is (and 3/4 of my officemates) to start bring their own lunches and making fresh, colorful salads at work. This happened just because my food always looks and smells so good (no preaching).

    Color is delicious 🙂

  4. I’m glad you took that the right way, Darya!

    Leading by example is a great way to change those around you, and to initiate change in the broader world. Much more effective than a nameless, faceless government agency making recommendations.

    -Steve