Have you ever been so anxious that your stomach tightens up? Our mind and body are so integrated that we even use expressions like “heartache” and “gut-wrenching” to describe the connection between our emotions and physical state. Neglecting one part of the body can eventually bring down the entire system. Research shows that our chemistry (influenced by diet) can impact our mental, physical, and long-term health… and vice versa.
Dietary patterns are clearly linked to overall physical and mental health. For example, diets associated with poor health are low in fruits, vegetables, whole grains, nuts, and seeds, and high in refined carbohydrates, added sugars, sodium and saturated fats. Strong evidence and consensus among leading scientific bodies exist for increasing fruit and vegetable intake at or above 5 servings (about 5 cups) per day; unfortunately, about 90% of the population fails to meet this universal recommendation.
Produce for Better Health (PBH) commissioned an authoritative comprehensive review of the scientific literature, in which 13 globally recognized nutrition scientists concluded that fruits and vegetables provide benefits beyond helping to achieve basic nutrient requirements. In fact, a growing body of clinical evidence shows that consuming recommended amounts of fruits and vegetables has proven benefits for disease prevention and longevity. Data also support the assertion that certain types of fruits and vegetables, notably cruciferous vegetables, dark-green leafy vegetables, citrus fruits, and dark-colored berries have superior effects on health promotion and disease prevention.
Variety is key to optimizing the benefits of eating colorful fruits and vegetables. Each has a unique array of essential nutrients and dietary bioactive compounds that are important for many aspects of health. More than 5,000 bioactive compounds (chemicals found in foods that impact health above and beyond the basic nutrient composition of that food) have been identified in fruits and vegetables. The Academy of Nutrition and Dietetics recently led the development of the first North American guideline and intake recommendation for a group of bioactives known as the flavan-3-ols, recommending 400-600 mg per day from foods such as tea, berries, cocoa, apples, pears, and cinnamon. In a recent PBH webinar, expert scientists and registered dietitians reviewed the scientific data and the importance of flavan-3-ol- containing foods in the diet.
It has been estimated that there are 5.6 and 7.8 million premature deaths each year due to low fruit and vegetable intake, respectively. Looking more closely at the science behind fruits and vegetables, there’s a range of evidence-based benefits for both the mind and body:
Brain Health & Mood
Cognition represents a complex set of higher mental functions in the brain that includes attention, memory, thinking, learning, and perception. By 2030, one in five Americans will be over 65 years old, and age represents the single most important predictor of cognitive decline. Some studies have suggested a 13% reduced risk of developing cognitive impairment later in life for every serving (about 1-cup) of fruits and vegetables consumed daily. Large studies also show higher intake to be associated with a lower risk of depression.
Evidence is strongest on the benefits of fruits and vegetables in the prevention of cardiovascular disease, the leading cause of death worldwide. Fruits and vegetables have been reported to help increase elasticity of the arteries, decrease blood pressure, and improve blood lipid levels, which can all help reduce the risk of heart disease. A recent systematic review found an 8% reduced risk of cardiovascular disease for every 200 gram increase in fruit and vegetable intake up to 800 grams.
Energy & Weight Maintenance
Generally speaking, fruits and vegetables are low in energy (i.e., calories). They are also low or absent in saturated fats and free from added sugars. Soluble fibers present in fruits and vegetables have been shown to delay gastric (stomach) emptying by forming a gel-like environment in the small intestine that partially diminishes the activity of digestive enzymes essential for macronutrient absorption. This can lead to decreased insulin secretion and improvement in blood sugar control. Dietary fiber is known to have a satiating effect by slowing down the absorption of some nutrients, especially fat, in addition to delaying gastric emptying.
It is widely accepted by scientists that dietary bioactive compounds present in fruits and vegetables with high antioxidant potential (e.g., flavan-3-ols) play a role in how sensitive your body is to the effects of insulin. High insulin sensitivity allows cells in your body to use glucose more effectively, thus reducing blood sugar levels. Berries and dark-green leafy vegetables seem to show the best effects in current clinical and observational studies.
Infection & Immunity
The immune system is a highly integrated network of cells sensitive to nutrition. The immune response exerts a high metabolic and nutritional cost upon the body. Inflammation is the first biological action of the immune system. High fruit and vegetable intake can help combat both the nutritional loss and increased inflammatory state experienced during infection. I recently authored a commentary about how magnesium, a mineral commonly found in many fruits and vegetables, may have the potential to help combat COVID-19 infections and severity. Fruits and vegetables also contain many antioxidant dietary bioactive compounds that have the potential to decrease inflammation and support healthy immune functions.
There aren’t any downfalls to consuming many fruits and vegetables. Next time you’re in the grocery store check out the produce area. Your taste buds, mind, and long-term health will thank you!