Your grandmother may have told you to eat your vegetables. Ours certainly urged us to do so. If she did, she was right. Vegetables and fruits are good sources of flavanols, plant compounds that appear to have health benefits. A number of studies have explored some of these. One important link connects flavanol consumption and blood pressure. Another reader wonders whether you could get the same benefits from taking pills as from eating vegetables.
Can Pills Replace Vegetables?
Q. Are there any scientific studies on whether a person can get all their recommended allowance of fruits and vegetables from six pills a day? From what I understand, these pills are expensive.
A. We think it is unlikely that pills could actually replace fruits and vegetables. After all, produce contains a lot more than just vitamins and minerals. When you eat vegetables, you also get fiber and phytonutrients, including flavanols. Some of these have important health benefits.
We found one study on consuming fruit and vegetable in concentrate form (Journal of the International Society of Sports Nutrition, Oct. 12, 2011). The scientists wondered if these pills could counteract the acidity of a western style diet. They found no significant advantages.
Instead of pills, we suggest you find a range of vegetables and fruits that you like and try to eat at least five servings a day. If you cannot do that on a regular basis, you should definitely consider taking a multiple vitamin to help supplement your intake. But don’t count on taking pills instead of eating vegetables.
Vegetables and Lower Blood Pressure–an EPIC Story:
Previous epidemiological research has relied, for the most part, on people answering questionnaires about what they eat and how often. A large study has turned to a more objective way of determining flavanol consumption. The scientists collected urine specimens and measured flavan-3-ols (flavanol metabolites) in the urine (Scientific Reports, online, Oct. 21, 2020). These data have just confirmed that people who have higher levels of flavan-3-ols in their urine also have modestly lower blood pressure. These compounds are found in foods like berries, cocoa, tea, apples and nuts as well as vegetables.
The research included more than 25,000 participants. Men who had high levels of urinary flavan-3-ols had systolic blood pressure almost 2 points (mm Hg) lower, on average. For women, the difference was about 2.5 points. People who follow a Mediterranean-style diet lower their blood pressure by about this much. The investigators point out that even a small reduction in systolic blood pressure is associated with lower mortality rates.
They conclude:
“Flavanol intake could therefore have a role in the maintenance of cardiovascular health on a population scale.”
More Broccoli for Better Blood Vessels:
A study from Australia reinforces the benefits of eating lots of produce (Blekkenhorst et al, Journal of the American Heart Association, April 4, 2018). Researchers analyzed dietary surveys of 1,154 older women. These volunteers, who were at least 70 years old when the study began, also underwent carotid artery ultrasound to assess the thickness of these blood vessels.
The results were striking. The women who reported eating at least three servings of veggies a day had thinner carotid arteries. The thinner the better, as that indicates less arterial plaque and greater flexibility. Cruciferous vegetables such as cabbage, cauliflower, broccoli and Brussels sprouts were especially beneficial. For each additional 10 g of broccoli or cabbage the women ate each day, the thickness of their carotid artery walls dropped by a measurable 0.007 mm. (This is a very small measurement, but it is statistically significant.)
Now for the Bad News:
Less than 10 percent of the Australians who participated in this study consumed five or more daily servings of vegetables. This suggests that there is a lot of room for improvement in Australia, just as there is in the US. According to the CDC, only about 9 percent of Americans get two to three cups of vegetables a day (MMWR, Nov. 17, 2017).
Previous Research on Vegetables and Blood Vessels:
Previous studies also indicated that people who eat vegetables have healthier blood vessels. In one, scientists published the results of dietary data from more than 3.5 million older Americans (Heffron et al, Arteriosclerosis, Thrombosis and Vascular Biology, May 18, 2017 ). The participants averaged 65 years of age.
Fewer than one-third of the participants ate three servings or more of vegetables and fruits daily. However, the researchers found that people who ate the most produce had the lowest risk of peripheral artery disease.
What Is Peripheral Artery Disease?
In peripheral artery disease (PAD), the large blood vessels that carry blood to the limbs become narrow due to atherosclerosis. As a result, they carry less oxygenated blood to hard-working muscles. Consequently, this condition causes pain and interferes with a person’s ability to function.
Since the legs are affected most often, a person with PAD often suffers pain or muscle cramps while walking or climbing stairs. The muscles may become overtired without much exertion. The pain usually disappears with rest, but it may crop back up again as soon as the person starts moving.
Avoiding PAD will greatly improve your quality of life. You’ll get a head start on that if you eat your vegetables.
How About a Mediterranean Diet?
Even earlier, researchers in Spain reported that the Mediterranean diet rich in vegetables and fruit reduced the risk of peripheral artery disease. A Mediterranean-type diet has previously been linked to a reduced risk of heart disease, stroke, diabetes and dementia.
Benefits of the Mediterranean Diet:
A study published as a Research Letter in the Journal of the American Medical Association shows that Spaniards randomly assigned to a Mediterranean diet with extra olive oil or nuts instead of to a low-fat control diet were less likely to develop peripheral artery disease (JAMA, Jan. 22/29, 2014).
When PAD reduces blood flow to the extremities, especially the legs, circulation may become compromised. People may find it difficult and painful to walk. Other symptoms may include cold feet, numbness, weakness, leg cramping and sores that don’t heal.
Those who got extra olive oil in addition to a standard Mediterranean diet were 66% less likely to develop symptoms of PAD during the roughly five years of follow-up. Vegetables are a hallmark of the Mediterranean diet, whether we look at Spain, France, Italy, Greece or another country.
Learn More:
Enjoying delicious Mediterranean-style meals with friends and family and staying active sound like a great prescription for artery health, with no unpleasant side effects. If you would like guidance on what constitutes a Mediterranean diet, we offer our book, The People’s Pharmacy Quick & Handy Home Remedies, as a resource. In it, we describe the DASH Diet (Dietary Approaches to Stop Hypertension), the low-carb diet and the Mediterranean diet.
You can also learn more about recipes that will help you learn how to cook veggies and incorporate them into your diet from our 2010 book, Recipes & Remedies From The People’s Pharmacy.
