Ever wondered why doctors are always telling us that eating fruits and vegetables is important for our health?
Researchers, physicians, and health organization agree that people should consume more fruits and vegetables. Health professionals have been advocating this loudly for a long time – and rightfully so!
In this post, we discuss how eating more fruits and vegetables prevents major health conditions. What is the evidence that higher intake actually results in lower risk for different health conditions?
Next, we focus on the issue of people not eating enough fruits and vegetables. What are the latest daily recommendations for eating fruits and vegetables? Why is it that so many people are not consuming necessary amounts for optimal health?
Last, we discuss selected healthy nutrients found in fruits and vegetables. What is the current state of knowledge regarding different nutrients found in these food groups?
I hope you enjoy discovering the links between fruits, vegetables, and optimal health.
Part 1: Healthy Amounts of Fruits & Vegetables
Fruits and vegetables are excellent sources of the types of nutrients that are commonly missing in people diets. You will likely recognize many of the household names of nutrients, including:
- vitamin A
- vitamin D
- vitamin E
- vitamin C
- potassium Source: [R1]
Despite numerous public awareness programs calling on people to focus on healthy nutrition, millions living in the United States are yet to start consuming fruits and vegetables at recommended amounts [R2].
This means that people are systematically missing-out on higher intakes of nutrients that are essential for health and performance.
1.1 Optimal Fruit & Vegetable Intake
How to use evidence-based recommendations to estimate whether you are consuming adequate amounts of fruits and vegetables?
To make it easy to understand healthy amounts of different types of foods in our diets, the US Healthy People 2020 Objectives now measure fruit and vegetable consumption in cup equivalents per 1000 calories [R3].
However, to date, the best way to explain recommendations is to think of your personal fruit and vegetable eating habits in terms of cup equivalents per day.
1.2 Understand Latest Fruit & Vegetable Recommendations
The key to understanding recommendations is to develop a sense for how much fruit or vegetable content exists in a single cup equivalent (1 cup) unit.
The answer is that 1 cup equivalent of fruits or vegetables is approximately equal to:
Considering these portion sizes, it is easier to estimate how many cup-equivalents of different fruits and vegetables you eat every day. Note that you do not have to be extremely precise, but it may take you two to three minutes in order to produce a rough estimate of your daily fruit and vegetable intake – in cup equivalents units.
TABLE – How Much Fruits & Vegetables Should You Eat?
Sex, Age Range
|Recommended Servings |
(cups equivalents / day)
|Recommended Servings |
(cups equivalents / day)
IMPORTANT NOTE: These values are suitable for adults who do not get more than ½ hour of moderate physical activity per day, beyond normal daily activities. If you are more physically active, then you may be able to consume more fruits and vegetables per day, while making sure you satisfy your calorie that increase because you exercise. | Sources: [R4] & [R5]
Part 2: Eating Fruits & Vegetables Prevents Health Conditions
How do researchers determine adequate levels of fruit and vegetable intake?
A great portion of the scientific research focuses on comparing different thresholds of fruit and vegetable consumption. In such studies, researchers examine whether higher fruit and vegetable consumption is associated with lower risk of developing specific health conditions.
These studies constitute very clear-cut examples of testing whether fruits and vegetables actually play important roles in keeping us healthy.
Next, we review the scientific evidence in support of eating more fruits and vegetables towards preventing major health conditions.
2.1 Overweight & Obesity Status (Lose Weight)
Researchers have reviewed the effects of different types of fruits and vegetables with regard to their ability to bute to weight loss in individuals. Not surprisingly, there is strong variation in how useful certain types of fruits and vegetables are towards losing weight in – the long run.
Most types of fruits and vegetables have been shown as beneficial for weight loss after 4 years of higher intake [R6]. The positive trend is definitely there – eating more fruits and vegetables helps us lose weight in the long run.
The following images present the average change in weight (in pounds) for every additional daily serving of different fruits and vegetables, measured over a course of 4 years in research participants.
IMPORTANT NOTE: Pay attention to Image 3 which shows how starchy (high-calorie vegetables) actually increase body weight over time!
This does not mean that you should completely avoid these vegetables in your diet if you are trying to lose weight. A much better strategy is to focus on nutrient variability – eating as many different types of the common fruits and vegetables while covering your calorie needs.
2.2 Cardiovascular Conditions
Results from one large study of more than 200,000 patients have shown that 3 to 5 daily servings of fruits and vegetables lower the risk for cardiovascular disease events [R7].
Atherosclerosis is a common condition in which harmful plagues build up in arteries. In turn, such plagues increase the likelihood of serious cardiovascular conditions including heart attacks.
Another research study followed more than 300,000 atherosclerosis patients for longer than 8 years. Researchers discovered that people who consumed 8 portions of fruits and vegetables per day had a 22% lower risk for atherosclerosis-related heart disease, compared to people to who consumed 3 portions or less per day [R8].
2.3 Type 2 Diabetes
Researchers have also shown that a diet that is moderately low in total carbohydrates, but contains high amounts of plant-based protein and fat, is associated with lower risk of diabetes [R9].
On the contrary, a diet low in carbohydrates but high in animal protein and fat is associated with higher diabetes risk [R9].
Higher intake of green leafy vegetables has been associated with lower
2.4 Different Types of Cancer
Different population-based studies have tracked the effects of eating fruits and vegetables on the risk for various cancer conditions.
Higher intake of fruits and vegetables is associated with
- breast cancer [R12]
- ovarian cancer [R13]
- colon cancer [R14]
- oral cavity cancer [R15]
- stomach cancer [R16]
- pancreas cancer [R17]
Overall, research suggests that eating more fruits and vegetables is an important strategy for lowering the risk for different types of cancer.
2.5 Mood Disorders
There is also strong evidence that higher fruit and vegetable intake is linked to preventing mental health complications.
Research conducted in three European countries has also concluded that increased fruit and vegetable consumption also lead to lower levels of perceived stress among students [R20].
The concept of optimal mental states has also been examined in relation to fruit and vegetable intake.
Higher intakes have been shown to increase the likelihood for experiencing greater:
all of which scientists consider to be optimal mental states in people.
Part 3: Healthy Nutrients in Fruits & Vegetables
You might be wondering – what is actually inside fruits and vegetables that cause positive health effects in people?
Fruits and vegetables contain large amounts of phytochemicals. These are the bioactive molecules that we consume from fruits and vegetables that are responsible for optimal health effects that go beyond basic nutrition .
Researchers have discovered more than 5,000 separate bioactive phytochemicals across the many groups of fruits and vegetables, including nuts, legumes and other plant-based foods [R26]. Yet a large percentage of phytochemicals remain unknown.
Scientists are currently focused on isolating and identifying single types of phytochemicals – towards improving our understanding of the health benefits of these compounds in whole foods [R26].
Vegetables and fruits are excellent sources of
Considering the 25 most commonly consumed fruits in the US, researchers have determined that wild blueberry and blackberry have the highest total phenolic contents, followed by pomegranate, cranberry, blueberry, plum, raspberry, strawberry, red grape, and apple [R27].
Considering the 27 most commonly consumed vegetables in the US, spinach contains the highest phenolic content, followed by red pepper, beets, broccoli, Brussels sprouts, eggplant, asparagus, and green pepper, in order of phenolic content [R28 & R29]
Commonly, carotenoids are the molecules that give fruits and vegetables their color, for example, the orange color in oranges. More than 600 specific carotenoids have been identified in fruits, vegetables, whole grains, and other plants.
There is a strong correlation between carotenoids levels in individuals and high fruit and vegetable intake [R30]. In turn, higher carotenoid concentrations are associated with lower risk for chronic diseases.
Carotenoids constitute another category of healthy phytochemicals. Important carotenoids for human health include b-carotene, zeaxanthin, and lycopene.
Here are overviews of the fruits and vegetables that are rich in these specific types of carotenoids:
Fruits and vegetables also consist
Potatoes are important sources of vitamin C, with vitamin C content in potatoes ranging from 22 to 69 mg per 100g of dry weight [R31]. This means that one medium-sized baked potato provides 16 mg of vitamin C – which is approximately 27 % of daily intake values for vitamin C [R31].
Vitamin C is also present in Guavas, kiwi, strawberries, oranges, broccoli, and tomato.
Folate (vitamin B9) is found in high amounts in oranges, spinach, green peas, beans and peas, and peanuts.
Hopefully, you gain some motivation to eat fruits and vegetables when it matters most – every single day 🙂
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