3: Healthy/Prudent Diets and Health Benefits in Adults

Healthy/Prudent Diets and Health Benefits in Adults


Historically, nutrition research has focused on the relationship between specific nutrients, foods, and food groups with numerous health conditions. However, current research shows that various nutrients or foods have a cumulative effect in the context of a whole dietary pattern, which might differ from the effects of a single nutrient or food item in health (Hu, 2002). Due to the multiple combinations of nutrients that may correlate and interact with each other as we eat through food synergy (Jacobs & Tapsell, 2013), as well as the different food and food groups that can be consumed in a meal, dietary patterns have been examined in the literature in relation to chronic diseases and non‐communicable diseases (NCDs) (Jacobs, Tapsell, & Temple, 2011). Different approaches to assess adherence to several dietary patterns, including a priori and a posteriori scores, have been proposed.

Chapter 1 outlined the link between the Western dietary pattern and NCDs. This chapter will describe the health benefits associated with adherence to healthy/prudent dietary patterns.


Four principles were used to characterize and define a dietary pattern as a healthy or prudent: the avoidance of excess energy intake, increased dietary fiber intake, reduced total fat intake to approximately 30% of energy intake, and an increase in polyunsaturated fat consumption (Mann, 1979). More recently, according to a 2020 World Health Organization (WHO) report, a healthy diet should protect against all types of malnutrition (e.g., undernutrition, overnutrition, micronutrient abnormalities, sarcopenia, frailty, and re‐feeding syndrome (Cederholm et al., 2017)) and NCD development; limiting added/free sugars and salt are also included in the key facts that characterize healthy diets (WHO, 2020). Based on the 2020–2025 Dietary Guidelines for Americans, a healthy dietary pattern should represent all foods and beverages consumed, including foods and beverages across all food groups in nutrient‐dense forms, in the recommended amounts and within calorie limits, while individuals should have more than one way to achieve a healthy dietary pattern (US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025). Unfortunately, more than 80% of Americans follow dietary patterns that are low in vegetables, fruits, and dairy, while more than half of the population is meeting or exceeding total grain and total protein recommendations, but are not meeting the recommendations for the subgroups within each of these food groups (Figure 3.1) (US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025).

Schematic illustration of dietary intake compared to recommendations: Percent of the US population ages 1 and older who are below and at or above each dietary goal.

FIGURE 3.1 Dietary intake compared to recommendations: Percent of the US population ages 1 and older who are below and at or above each dietary goal.

Source: (US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025).

A healthy diet starts from infancy through breastfeeding. Healthy practices throughout childhood and adolescence helps to foster a healthy growth and cognitive development (WHO, 2020). However, it is important to understand that apart from some key elements, a healthy diet varies across populations as it depends on personal characteristics, age, gender, physical activity habits, dietary preferences, and cultural habits, but also on food availability and accessibility.

Nevertheless, to ensure good health, physical activity should also be considered among the essential components of everyday life. Physical activity may include planned exercise (e.g., sports), occupational (e.g., at work), domestic (e.g., household chores), transportation/utilitarian, and leisure time physical activities (e.g., physically active hobbies like bicycling) (Strath, Smith, & Swartz, 2013). Combining aerobic and muscle‐strengthening exercises seems to provide an additive health benefit (Walker, Tullar, Diamond, Kohl, & Amick, 2017). The basic concepts of physical activity and fitness as well as its implications and health benefits in adults will be discussed in Unit 2.

This chapter will focus on dietary patterns that are considered healthy based on long‐standing literature.


The Mediterranean‐type dietary pattern, the Dietary Approaches to Stop Hypertension (DASH) diet, the US‐style dietary patterns, and vegetarian eating patterns are all highlighted as healthy dietary patterns in the 2020–2025 Dietary Guidelines for Americans.


The healthy Mediterranean‐type dietary pattern (MD) is the result of several interactions between multiple civilizations, cultures, religions, and environments of populations living around the Mediterranean basin. Therefore, more than one version of this dietary pattern exists. Consequently, the MD reflects a way of living that incorporates an assortment of knowledge, expertise, customs, and rituals from different populations around the Mediterranean region that can be conveyed from previous generations to the next (Davis, Bryan, Hodgson, & Murphy, 2015).

A large body of evidence has led to the MD’s recognition as the gold standard dietary pattern of healthy nutrition and one of the best studied dietary patterns (Sepideh Soltani, Jayedi, Shab‐Bidar, Becerra‐Tomás, & Salas‐Salvadó, 2019). November 16, 2020, was the tenth anniversary since the MD was included on the UNESCO Representative List of the Intangible Cultural Heritage of Humanity. UNESCO acknowledged several characteristics (Bonaccio, Iacoviello, Donati, & de Gaetano, 2022) of the MD including:

  • The MD promotes social exchange and community events, as shared meals are the cornerstone of social customs in the context of traditional festivities.
  • Eating together is a fundamental aspect of the MD’s cultural identity.
  • Local markets play a key role in cultivating and transmitting the MD during the daily practice of exchanging traditional products.

The MD has evolved over the centuries. Despite the many versions and depending on local conditions, the MD essentials have remained the same. It is a diet with a semi‐vegetarian character high in olive oil (particularly cold‐pressed extra‐virgin olive oil) and it is based in the daily consumption of seasonal fruit and vegetables (including leafy green vegetables); whole‐grain cereals, nuts, and pulses/legumes; the moderate intake of fish and other meat, dairy products, and red wine; and a low intake of eggs and sweets (Davis et al., 2015; Hidalgo‐Mora et al., 2020). It is important to note that the MD is not a low fat dietary pattern as the main sources include olive oil and nuts (Table 3.1). Frugality is an important feature of MD due to the scarcity of food during winter or periods of financial constraints.

The recommended number of servings for the aforementioned food groups are usually depicted in a pyramid. A significant number of MD pyramids exist in the literature as each depends on the population and their national organizations’ policies (Davis et al., 2015). The latest MD pyramid was published in 2011 by the Mediterranean Diet Foundation (Figure 3.2) (Bach‐Faig et al., 2011). In this pyramid, sugary foods were moved to the vertex of the pyramid, shifting the consumption of red meat one place lower than in previous versions of the MD. Apart from the general principles of the MD that regard the frequency and approximate quantities of the MD food groups, other aspects of the Mediterranean lifestyle (MedLife), such as the healthy lifestyle and cultural elements were also added. Socialization, cooking, and sharing meals with friends and family as well as seasonality, biodiversity, and the eco‐friendly characteristics of the MD are included at the bottom of the pyramid to highlight aspects such as relaxation, community, and sustainability that constitute the MedLife.

Regular physical activity (such as walking, using the stairs instead of the lift, housework for at least 30 min throughout the day) is also represented in the pyramid for balancing energy intake, weight maintenance, and other health benefits (Bach‐Faig et al., 2011). Moreover, a reference to adequate water intake was added to highlight the essential role of water to human function and hydration, as regions around the Mediterranean Sea have climates that are hot and dry for several months of the year. Herbal infusions, such as herbal teas, low‐fat broths, and other non‐alcoholic beverages also contribute to adequate daily hydration.

Another significant aspect of the MedLife that is described in the 2011 MD pyramid is the conviviality of meals, i.e., the practice of eating a friendly, lively meal together in a pleasant environment. Indeed, people in Mediterranean countries seems to spend more time eating with others than people anywhere else in the world, which demonstrates the social character of meals in southern European countries. Moreover, although the culinary practices of human health have not been thoroughly studied, they are thought to contribute to individuals’ nutritional status, which is why they were incorporated into the 2011 MD pyramid. Many studies suggest that home cooking is positively correlated with better diet quality, while homemade meals are associated with increased consumption of fruits, vegetables, and whole grains. Improved cooking skills are linked to reduced fast‐food consumption, more shared meals, and cooking with low‐cost basic ingredients. Homemade meals are considered less energy‐dense, containing lower concentrations of total fat and saturated fatty acids, dietary cholesterol and sodium, but more nutrient‐dense, having greater fiber, calcium and iron content.

Sleep, an important aspect of the MedLife, is also highlighted in the latest version of the MD pyramid (Bach‐Faig et al., 2011). Indeed, adequate rest, both at night and during the day in the form of short naps or siestas is recommended. Siestas usually last 20 to 40 min. Mid‐day naps can be helpful for memory consolidation, subsequent learning, executive functioning enhancement, and emotional stability. As sleep deprivation narrows cognitive abilities, mid‐day naps can recover these abilities. However, more frequent and longer naps are linked to numerous negative outcomes such as hypertension and T2D, particularly in older adults.

The MD dietary pattern has many similarities and unique features with the US‐style and DASH dietary patterns, which will be described throughout this chapter (Figure 3.3) (Richter, Skulas‐Ray, & Kris‐Etherton, 2014).

Table 3.1 Healthy Mediterranean‐style dietary pattern for ages 2 and older, with daily or weekly amounts from food groups, subgroups, and components.

Source: (US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025).

Calorie level of pattern 1.000 1.200 1.400 1.600 1.800 2.000 2.200 2.400 2.600 2.800 3.000 3.200
Food group or subgroup Daily amount of food from each group
(Vegetable and protein foods subgroup amounts are per week.)
Vegetables (cup eq/day) 1 1 ½ 1 ½ 2 2 ½ 2 ½ 3 3 3 ½ 3 ½ 4 4

Vegetable subgroups in weekly amounts
Dark‐green vegetables (cup eq/wk) ½ 1 1 1 ½ 1 ½ 1 ½ 2 2 2 ½ 2 ½ 2 ½ 2 ½
Red and orange vegetables (cup eq/wk) 2 ½ 3 3 4 5 ½ 5 ½ 6 6 7 7 7 ½ 7 ½
Beans, peas, lentils (cup eq/wk) ½ ½ ½ 1 1 ½ 1 ½ 2 2 2 ½ 2 ½ 3 3
Starchy vegetables (cup eq/wk) 2 3 ½ 3 ½ 4 5 5 6 6 7 7 8 8
Other vegetables (cup eq/wk) 1 ½ 2 ½ 2 ½ 3 ½ 4 4 5 5 5 ½ 5 ½ 7 7
Fruits (cup eq/day) 1 1 1 ½ 2 2 2 ½ 2 ½ 2 ½ 2 ½ 3 3 3
Grains (ounce eq/day) 3 4 5 5 6 6 7 8 9 10 10 10
Whole grains (ounce eq/day) 1 ½ 2 2 ½ 3 3 3 3 ½ 4 4 ½ 5 5 5
Refined grains (ounce eq/day) 1 ½ 2 2 ½ 2 3 3 3 ½ 4 4 ½ 5 5 5
Dairy (cup eq/day) 2 2 ½ 2 ½ 2 2 2 2 2 ½ 2 ½ 2 ½ 2 ½ 2 ½
Protein foods (ounce eq/day) 2 3 4 5 ½ 6 6 ½ 7 7 ½ 7 ½ 8 8 8

Protein foods subgroups in weekly amounts
Meats, poultry, eggs (ounce eq/wk) 10 14 19 23 23 26 28 31 31 33 33 33
Seafood (ounce eq/wk) 3 4 6 11 15 15 16 16 17 17 17 17
Nuts, seeds, soy products (ounce eq/wk) 2 2 3 4 4 5 5 5 5 6 6 6
Oils (grams/day) 15 17 17 22 24 27 29 31 34 36 44 51
Limit on calories for other uses (kcal/day) 130 80 90 120 140 240 250 280 300 330 400 540
Limit on calories for other uses (%/day) 13% 7% 6% 8% 8% 12% 11% 12% 12% 12% 13% 17%

1 Amounts of dairy recommended for children and adolescents, regardless of the calorie level: for age 2 years, 2 cup‐eq per day; for ages 3 to 8 years, 2 ½ cup‐eq per day; for ages 9 to18 years, 3 cup‐eq per day.

2 The US Food and Drug Administration (FDA) and the US Environmental Protection Agency (EPA) provide joint advice regarding seafood consumption to limit methylmercury exposure for women who might become or are pregnant or lactating, and children. Depending on body weight, some women and children should choose seafood lowest in methylmercury or eat less seafood than the amounts in the healthy US‐style dietary pattern. Source: FDA.gov/fishadvice; EPA.gov/fishadvice.

3 Foods are assumed to be in nutrient‐dense forms; lean or low‐fat; and prepared with minimal added sugars, refined starches (a calorie source with few or no nutrients), saturated fat, or sodium. If all food choices to meet food group recommendations are in nutrient‐dense forms, a small number of calories remain within the overall limit (i.e., limit on calories for other uses). The amount of calories depends on the total calorie level of the pattern and the amounts of food from each food group required to meet nutritional goals. Calories up to the specified limit can be used for added sugars, saturated fat, and/or alcohol (for nonpregnant adults of legal drinking age only) or to eat more than the recommended amount of food in a food group.

NOTE: The total dietary pattern should not exceed dietary guideline limits for added sugars, saturated fat, and alcohol; be within the acceptable macronutrient distribution ranges for protein, carbohydrate, and total fats; and stay within calorie limits. Values are rounded.

Schematic illustration of the Mediterranean-diet pyramid by the Mediterranean Diet Foundation.

FIGURE 3.2 The Mediterranean‐diet pyramid by the Mediterranean Diet Foundation.

Source: (Bach‐Faig et al., 2011 / with permission of Cambridge University Press).


Numerous epidemiological and intervention studies have established the effectiveness of the MD in preventing and managing NCDs and other conditions. The beneficial effect of the MD on lifespan was first suggested in 1960s (Sepideh Soltani et al., 2019). In the following paragraphs, we will review the health benefits associated with all‐cause mortality, NCDs (namely cardiovascular diseases [CVD], dyslipidemia, metabolic syndrome, hypertension, T2D, and cancer), and healthy aging with the long‐term adherence to the MD.


Since the 1960s, several epidemiological studies have linked the MD to better survival and a protective association against all‐cause and disease‐specific mortality. In 2014, a meta‐analysis by Sofi et al. (Sofi, Macchi, Abbate, Gensini, & Casini, 2014) of 16 prospective cohort studies, including 4 172 412 subjects, revealed that a quite moderate 2‐point increase in the MD adherence score could lead to an 8% decrease in all‐cause mortality, a 10% decrease in CVD‐related mortality, and a 4% decrease in malignancies‐associated mortality. Another meta‐analysis (Sepideh Soltani et al., 2019) of 29 prospective studies with 1 676 901 participants and 221 603 cases of all‐cause mortality concluded similarly. The same meta‐analysis supported that the decrease in mortality risk was evident in both Mediterranean and non‐Mediterranean regions, although it was stronger in the former. A linear inverse association between adherence to the MD and risk of all‐cause mortality was also suggested.

The link between better adherence to MD and reduced all‐cause and disease‐specific mortality is attributed to the beneficial effects of some individual components. Meta‐analytic data support that those consuming more vegetables, fruits/nuts, legumes, cereals, and fish as well as less dairy and meat/poultry have a higher mono‐unsaturated to saturated fatty acids (MUFA:SFA) ratio, and those who consume moderate amounts of ethanol have better cardiovascular and cognitive health than those consuming less (Davis et al., 2015). However, the quantity used to define these associations varies across studies, one cutoff point may lead to loosing subtle improvements of specific food groups, e.g., nuts, in health. Nevertheless, the high fruit and vegetable content of the MD correlates with a 10% to 30% decrease in overall mortality among CVD patients (Grosso et al., 2017; D. D. Wang et al., 2021), especially when using a threshold of five servings of fruit and vegetables per day (X. Wang et al., 2014). With regard to olive oil, each 10‐g increment of olive oil has been associated with decreased CVD and mortality risk by 10% and 7%, respectively (Foscolou, Critselis, & Panagiotakos, 2018; Guasch‐Ferré et al., 2014), with the maximum benefit obtained consuming 20 to 30 g/day (Donat‐Vargas et al., 2022).

Schematic illustration of common and unique features of the USDA food patterns, DASH diet, and Mediterranean dietary patterns.

FIGURE 3.3 Common and unique features of the USDA food patterns, DASH diet, and Mediterranean dietary patterns. SFA: saturated fatty acid.

Source: (Richter et al., 2014 / with permission of Elsevier).


CVDs include coronary heart disease (CHD), stroke, heart failure, and other conditions that affect the heart and blood vessels (more on CVD in Unit 4).

The bulk of evidence comes mainly from prospective epidemiological studies that investigated the role of the MD on total CVD risk. All have found an inverse association between adherence to the MD and the risk of CVDs (Jordi Salas‐Salvadó, Becerra‐Tomás, García‐Gavilán, Bulló, & Barrubés, 2018). Overall, a 20% to 25% lower risk of total CVDs is suggested when compliance with the MD or Mediterranean‐like dietary patterns is high, compared to low (Rosato et al., 2019). The results align with meta‐analyses assessing the role of the MD on CVD incidence, comparing the highest versus the lowest categories of MD adherence showing a 25% to 47% lower risk of CVD incidence (Grosso et al., 2017; Rosato et al., 2019). The beneficial effect of the MD on strokes was also assessed by meta‐analyses of both observational and interventional studies, which show an approximately 30% lower risk and 35% favorable effect of the MD on stroke risk (Jordi Salas‐Salvadó et al., 2018) from high compared to low adherence, but not to moderate (Saulle, Lia, De Giusti, & La Torre, 2019). Furthermore, the beneficial effects of the MD were evaluated in lowering concentrations of inflammatory markers and improving endothelial dysfunction, atherosclerosis, and arterial stiffness, all well‐established factors for stroke (Saulle et al., 2019). Regarding heart failure, in a meta‐analysis of prospective cohort studies, a higher adherence to the MD, compared to a lower adherence, was associated with 8% lower risk (Liyanage et al., 2016). Moreover, the results from randomized controlled trials (RCTs) show a protective effect of the MD on the incidence of heart failure or worsening of cardiac function parameters for patients with previous cardiovascular disease (Sanches Machado d’Almeida, Ronchi Spillere, Zuchinali, & Corrêa Souza, 2018).

Mechanistically, based on population and RCT data, several components of the MD are associated with beneficial effects on total CVD prevention and risk (Widmer, Flammer, Lerman, & Lerman, 2015). With regard to foods and food groups, whole grains, fruit (especially citrus and deep yellow‐orange), and vegetables (especially dark green leafy, cruciferous, and deep yellow‐orange), fish, and olive oil, which are shown in Table 3.2 (Sala‐Vila, Estruch, & Ros, 2015; Widmer et al., 2015), as well as their bioactive components namely polyphenols, unsaturated fatty acids, all prevent CVD and ameliorate a host of CVD features.

Olive oil induces cardio‐protective effects due to the presence of a plethora of polyphenolic compounds. A number of mechanistic studies have demonstrated that olive‐oil polyphenols increase the high‐density lipoprotein level; prevent damage from oxidative stress; reduce thrombogenic, endothelial dysfunction, blood pressure (BP), and inflammation; and alter gene expression responsible for atherosclerosis (Mehmood, Usman, Patil, Zhao, & Wang, 2020).

Alcohol, and especially red wine, a typical component of the MD, is thought to play a significant role in CVD prevention due to its high concentration of polyphenols, which decrease oxidized LDL levels, prevent platelet aggregation, and improve endothelium function (Widmer et al., 2015).

Table 3.2 Effects of foods and food groups of the Mediterranean diet along with its bioactive components on the cardiovascular risk.

Sources: Sala‐Vila, Estruch, and Ros, 2015; Widmer et al., 2015.

Food group Population‐based data RCT data Bioactive components CVD effect Proposed mechanisms
MedDiet +++ +++
+++ Improves lipids, reduces ROS, endothelial Function, Platelet function
Fruits/ vegetables ++ + slow‐release carb and fiber + Improves lipid profiles, glucemic control and BP; reduces ROS
Unsaturated fats + +
+ Improves lipids, reduces ROS, endothelial function, Platelet function
Fish +/− ++ Long‐chain n‐3 fatty acids + Improves lipid profiles and BP (antiarrhythmic)
Whole grains ++ + Slow‐release carb and fiber + improves glucose metabolism, reduced inflammation, ROS, lipid profiles (eg cholesterol), and blood pressure

beta‐glucan (oats)

Eggs +/− +/− Lecithin; ACE inhibitory peptides NC controversial data; seems to imporve BP;
Nuts ++ ++ Unsaturated fatty acids + +/− ROS and lipid profiles (eg cholesterol); improves BP and endothelial function

Non‐sodium minerals

Alcohol ++ + Ethanol ++ Improves lipid profiles, BP, (+/−) ROS, and endothelial function


ACE: angiotensin converting enzyme; BP: blood pressure; Carb: carbohydrates; CVD: cardiovascular disease; NC: no change; RCT: randomized controlled trial; ROS: reactive oxygen species; +: positive effect; ‐ Negative effect.


High BP is a common and serious medical condition as it is a well‐documented risk factor of CVDs, brain, renal, and other diseases (Bakaloudi, Chrysoula, Leonida, et al., 2021) (more on hypertension in Unit 5). A healthful lifestyle is a fundamental strategy for decreasing hypertension, and the MD improves endothelial function by reducing reactive oxygen species (ROS), offering a considerable benefit against the risk of hypertension (De Pergola & D’Alessandro, 2018).

Although different versions of the MD exist, different populations or types of studies with high heterogeneity, multiple ways of monitoring BP (home or office), and/or patients with differing hypertension severity (De Pergola & D’Alessandro, 2018), pooled data from interventional studies (Bakaloudi, Chrysoula, Leonida, et al., 2021; Filippou et al., 2021; Nissensohn, Román‐Viñas, Sánchez‐Villegas, Piscopo, & Serra‐Majem, 2016), show a reduction in both systolic (SBP) and diastolic (DBP) in adults with normal BP or mild hypertension after adopting the MD. However, the magnitude of the effect is small, supporting a low clinical effect. Therefore, more convincing evidence is needed to support the beneficial effect of MD on BP.

Nevertheless, in a dose‐response meta‐analysis of 19 RCTs with 4137 participants and 16 observational studies on 59 001 participants, authors concluded that interventions based on the MD might reduce SBP and DBP by a mean 1.4 mmHg and 1.5 mmHg, respectively, versus control. In observational studies, the likelihood of developing hypertension was 13% lower with higher versus lower MD adherence (Cowell et al., 2021).


Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin production, insulin action, or both. Diet is considered a pillar for the prevention and progression of type 2 diabetes (T2D). Meta‐analytic evidence from observational studies have demonstrated an association between the adherence to the MD pattern and a decrease in T2D risk, showing an approximately 20% reduction of T2D incidence in individuals with the highest, versus the lowest, adherence to the MD (Koloverou, Esposito, Giugliano, & Panagiotakos, 2014; Martín‐Peláez, Fito, & Castaner, 2020; Lukas Schwingshackl, Missbach, König, & Hoffmann, 2015).

Concerning data from clinical trials, the large‐scale, multi‐center, controlled randomized PREDIMED trial (J. Salas‐Salvadó et al., 2011; Jordi Salas‐Salvadó et al., 2014) enrolled 418 non‐diabetic individuals with a high risk of CVD and randomly assigned them to a low‐fat diet (control group) or the MD supplemented either with extra‐virgin olive oil (1 L/week) or nuts (30 g/day). After approximately 4 years of follow‐up, the groups following the MD supplemented with olive oil or nuts exhibited a 50% lower risk of developing T2D, compared to controls. Approximately 5 years after the end of the study, non‐diabetic patients who had received the MD supplemented with olive oil had a 40% reduced risk of developing T2DM, whereas those received the nut‐enhanced MD had a 20% lower risk, compared with the control group. These beneficial effects were attributed to the overall composition of the dietary pattern, not caloric restriction, increased physical activity, or weight loss (Martín‐Peláez et al., 2020).

Some of the mechanisms that contribute to the impaired insulin secretion of β‐cells include insulin resistance, lipotoxicity, glucotoxicity, oxidative stress, activation of inflammatory pathways, endoplasmic reticulum stress, and cellular mitochondrial dysfunction. The MD seems to play a role in these T2D‐related mechanisms through actions and interactions by different nutrients including anti‐inflammatory/antioxidant actions, glucagon‐like peptide agonist compounds, and changes in gut microbiota (Martín‐Peláez et al., 2020).


The MD has been found to lower total, medium‐small, and very small atherogenic LDL particles, large very‐low density lipoprotein (VLDL) fractions and total cholesterol (TC) concentration. Indeed, results from the PREDIMED trial study show that the MD supplemented with olive oil or nuts effectively reduced plasma concentrations of LDL; the MD supplemented with nuts changed the lipoprotein subfractions to a less atherogenic pattern, suggesting a mechanism for the reduction of CVD events noticed in this group (Damasceno et al., 2013). Moreover, pooled data from observational studies support that HDL‐cholesterol levels are higher and triglycerides levels lower in individuals with a high adherence also to the MD compared to those with low adherence (Bakaloudi, Chrysoula, Kotzakioulafi, Theodoridis, & Chourdakis, 2021).

A possible mechanism explaining the alterations in lipid profiles of patients with high adherence to the MD is the high content of olive‐oil polyphenols and oleic acid as part of the MD, through the amelioration of the antioxidant and inflammatory status of the subjects (Tsartsou, Proutsos, Castanas, & Kampa, 2019). Moreover, phytosterol intakes of 0.6 to 3.3 g/day—including plant sterols and stanols, compounds in vegetable oils, nuts, seeds, grain products, fruits, and vegetables—can also reduce LDL‐cholesterol concentrations (Ras, Geleijnse, & Trautwein, 2014).


There is a long‐term (>12 months) effect of the MD on weight loss in individuals with overweight or obesity trying to lose weight (Mancini, Filion, Atallah, & Eisenberg, 2016). This seems to be mediated by decreased hepatic fat content (Gepner et al., 2019) and improvements in several cardio‐metabolic risk factors (Gepner et al., 2019; Mancini et al., 2016).

Considering the effects of the MD on metabolic syndrome (MetS), MD is a possible therapy for MetS, as it reduces the excess of adiposity and the obesity‐related inflammatory response. Moreover, pooled results from prospective and cross‐sectional data (Justyna Godos et al., 2017; Kastorini et al., 2011) support that a higher adherence to the MD is associated with a 19% lower risk of developing MetS, while its components (e.g., waist circumference, BP, hyperlipidemia, and hyperglycemia) can also be improved (Castro‐Barquero, Ruiz‐León, Sierra‐Pérez, Estruch, & Casas, 2020).


Cancer is a major public health problem worldwide, accounting for nearly 10 million deaths in 2020 (Sung et al., 2021). Based on 2014 data, an estimated proportion of 42% of all cancers in adults over the age of 30, were attributed to potentially modifiable risk factors (Figure 3.4) (Islami et al., 2018). Cigarette smoking had, by far, the highest proportion (19.0% of all cases), followed by excess body weight (7.8% of all cases), alcohol intake (5.6% of all cases), and physical inactivity (2.9% of all cases).

The MD is inversely associated with the development of several cancer types, such as colorectal, epithelial, breast, prostate, pancreas, endometrial, and cancers of the upper aerodigestive tract. Some of MD components, such as whole‐grain cereals, fruits, and vegetables, seem to lower the risk of cancers associated with the gastrointestinal, breast, and female genital tracts and epithelium.

In 2018, the World Cancer Research Fund along with the American Institute for Cancer Research (WCRF/AIRC) reported that the MD is “convincingly” associated with a reduced risk of weight gain, and overweight or obesity, suggesting that the MD might indirectly have a huge impact on cancer development. Moreover, the 2018 WCRF/AIRC recommendations suggest specific quantities of some foods and nutrients that are a part of the MD, including at least 30 g of fiber and 400 g of non‐starchy vegetables/fruits per day as well as limiting red meat consumption to no more than three portions (350 to 500 g) per week (Rock et al., 2020; WCRF/AICR, 2018).


Extended longevity is emerging globally and its impending effects on high‐income countries are based on whether individuals’ extended lifespans are accompanied by the adverse effects of aging. Indeed, aging is accompanied by a progressive loss of physical, mental, and cognitive functions, that if not treated, will ultimately lead to morbidity and mortality (Critselis & Panagiotakos, 2020). Although, specific hallmarks of aging exist (Shannon et al., 2021), there are some modifiable lifestyle factors, namely diet and physical activity, which, if altered via related interventions, can facilitate healthy aging (Critselis & Panagiotakos, 2020).

Schematic illustration of an estimated 42% of all cancers in adults aged 30 years and older in the United States in 2014 by sex were attributed to potentially modifiable risk factors, e.g., cigarette smoking, excess body weight, alcohol intake, and physical inactivity.

FIGURE 3.4 An estimated 42% of all cancers in adults aged 30 years and older in the United States in 2014 by sex were attributed to potentially modifiable risk factors, e.g., cigarette smoking, excess body weight, alcohol intake, and physical inactivity. PAF: the population‐attributable fraction.

Source: (Islami et al., 2018 / with permission of John Wiley & Sons).

Of all the dietary patterns linked to healthy aging (e.g. MD, Okinawan and DASH diets), most predominantly, the MD was associated with numerous health benefits and the prevention of a variety of age‐related disorders, such as all‐cause mortality, CVDs, T2D, MetS, and cancers as well as longevity (L. J. Dominguez, Di Bella, Veronese, & Barbagallo, 2021) and mental health (Ventriglio et al., 2020).

Of note, olive oil, and in particular virgin olive oil, which is rich in oleic acid and polyphenols (namely secoiridoids), a major component of the MD, impacts the biological pathways implicated in the hallmarks of aging (Critselis & Panagiotakos, 2020; Fernandez del Rio, Gutierrez‐Casado, Varela‐Lopez, & Villalba, 2016) (more on healthy aging in Unit 3).



The Dietary Approaches to Stop Hypertension (DASH) was first designed to prevent and treat hypertension. In the 1990s, the goals of DASH diet trials (Appel et al., 1997) were to create patterns similar to the BP lowering benefits of vegetarian diets, yet contain enough animal products to make them palatable to non‐vegetarians.

The initial trial, DASH (Appel et al., 1997), tested the effects on BP of (1) a diet rich in fruits, vegetables, low‐fat dairy foods, and low in total fat, saturated fat and dietary cholesterol (2) a diet high in fruits and vegatables and (3) a control diet similar to what many Americans consume. Daily sodium intake ranged from 2.5 to 4.0 g, depending on the energy level. Two years later, the DASH‐Sodium trial (Svetkey et al., 1999) compared the effects on BP of the DASH diet using three dietary sodium levels—low (40–80 mmol or 920–1840 mg), intermediate (80–160 mmol or 1840–3680 mg), and high (120–240 mmol or 2760–5520 mg)—in adults with above‐optimal BP or stage 1 hypertension over the typical American diet (control diet). In both trials, reductions in BP were significantly higher for participants eating the DASH dietary patterns either with or without sodium restriction compared to control diets.

Since then, several DASH diet alternatives have been tested including other lifestyle parameters or nutrients that seem to affect BP. The DEW‐IT trial (Diet, Exercise, and Weight Loss Intervention Trial) (Miller 3rd et al., 2002) and the PREMIER trial (a Trial of Lifestyle Interventions for Blood Pressure Control) (Funk et al., 2008), showed improvements in BP after implementing the DASH diet, along with weight loss, physical activity, sodium and alcohol restriction, compared to control diets; however, the effect of multiple lifestyle changes on BP were not be fully additive to that of the DASH diet alone on the aforementioned trials. With regard to nutrient content, a high‐fat DASH diet (HF‐DASH) compared to the original DASH diet had similar reductions in BP, although plasma triglyceride and VLDL levels decreased more in the HF‐DASH diet, without differences in LDL‐cholesterol levels (S. Chiu et al., 2016). Moreover, a DASH diet where the main protein source (55% of total proteins) was lean pork (DASH‐P) instead of chicken and fish (DASH‐CF), showed similar results in improving BP, suggesting an alternative DASH‐style diet for BP reduction (Sayer, Wright, Chen, & Campbell, 2015).


The DASH diet is a plant‐based dietary pattern characterized by a high intake of vegetables, fruits, whole grains, nuts; the addition of some fish, poultry, and low‐fat dairy products; and the minimization of processed/red meat, sugar, and processed foods. As a result, it provides low amounts of saturated fat (6% of energy), total fat (27% of daily calorie intake), dietary cholesterol (about 150 mg/day), and reduced sodium content (1500 to 2300 mg/day), while endorsing dietary fiber (>30 g/day), potassium (K), magnesium (Mg), and calcium (Ca) intake (Castro‐Barquero et al., 2020; Craddick et al., 2003).

A typical serving guide of the DASH diet (Figure 3.5) includes (Akhlaghi, 2020; Challa, Ameer, & Uppaluri, 2021) (University of Arcancas System):

  • Fruit: 4–5 servings/day (e.g., low glycemic index fruits)
  • Vegetables: 4–5 servings/day (e.g., kale, broccoli, spinach, collards)
  • Grain and grain products: 6–8 servings/day, whole grains are 3.8 servings/day (e.g., cracked wheat, millets, oats)
  • Low‐fat dairy foods: about 2–3 servings/day, with reduced total (25.6 % of energy) and saturated (7% of energy) fat
  • Legumes: 0.7 servings/day
  • Fish: 0.5 servings/day (e.g., rich in omega‐3 fatty acids)
  • Red meat: 0.5 servings/day
  • Lean meat products: about two or fewer servings/day
  • Sweets and sugar‐sweetened beverages: 0.7 servings/day, <5 servings/week
  • Nuts, seeds: 4–5 servings per week (e.g., avocados, hempseeds, flax seeds)


Over the last two decades, the DASH has emerged as a healthy‐eating guideline. Aside from its positive effects on hypertension, the DASH dietary pattern seems to positively affect the risk of several chronic diseases. It is inversely associated with the risk of CVD (Chiavaroli et al., 2019), MetS (Akhlaghi, 2020), chronic kidney disease (Raphael, 2019), and several types of cancer (Onvani, Haghighatdoost, & Azadbakht, 2015). There is also evidence that it improves lipid profile (Miller, Erlinger, & Appel, 2006), insulin sensitivity, inflammation, and oxidative stress in T2D (Fernandez & Murillo, 2022). Most importantly, even modest adherence to the DASH diet is associated with a lower risk of all‐cause mortality, while high versus low adherence seems to strengthen this risk‐reducing association (S. Soltani, Arablou, Jayedi, & Salehi‐Abargouei, 2020). Its high content in some bioactive compounds (such as fiber, vitamins, minerals, trace elements, and phytochemicals) found in whole grains, fruits, and vegetables, combined with its low content in harmful compounds found in processed meat and sugary beverages explain the above associations. (Akhlaghi, 2020). The DASH diet is also suggested to have antioxidant, anti‐atherogenic, anti‐inflammatory, antiproliferative, and anti‐tumor properties.

Schematic illustration of the DASH dietary pattern.

FIGURE 3.5 The DASH dietary pattern.

Source: University of Arkancas System, Department of Agriculture. Research & Extension Lowering Your Blood Pressure with the DASH Eating Plan.

The health effects of the DASH diet on the aforementioned chronic conditions will be discussed next.


The DASH diet has a significant, inverse dose‐response association with all‐cause, CVD, stroke, and cancer mortality. A meta‐analysis and systematic review (S. Soltani et al., 2020) of 17 prospective cohort studies revealed that for each 5‐point increment in adherence to the DASH diet, there was a lower of risk 5% for all‐causes, 4% for CVD, 3% for stroke, and 3% for cancer mortality. In the same meta‐analysis, the non‐linear dose‐response analysis showed that the DASH‐mortality association becomes stronger when the adherence score exceeds 20 points (medium to high adherence) (S. Soltani et al., 2020).


Adherence to the DASH diet seems to reduce the incidence of CVDs, stroke, CHD, and heart failure. A meta‐analysis of six prospective observational studies (Salehi‐Abargouei, Maghsoudi, Shirani, & Azadbakht, 2013) with follow‐ups from 7 to 24 years showed that a DASH‐like diet was protective against CVDs, CHD, stroke, and heart‐failure risk by 20%, 21%, 19%, and 29%, respectively.

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May 13, 2023 | Posted by in CARDIOLOGY | Comments Off on 3: Healthy/Prudent Diets and Health Benefits in Adults

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