Diet to extend the health span

Innumerable scientific studies show that adherence to the Mediterranean Diet reduces deaths due to cardiovascular disease and therefore, increases the lifespan (see Insight 10).  As discussed below, several other diets, Okinawa, DASH, and Portfolio, reduce risk factors for cardiovascular disease. 

1.  Okinawa Diet

Background

Okinawa is a Japanese island where life expectancy since the end of WWII has been the highest in the world.  Although Okinawan life expectancy today is no longer higher than the Japanese national average, nevertheless, life expectancy in Japan relative to other countries remains exceptionally high.  As proof, Japan’s life expectancy ranks second among 191 countries  (average of both genders, 85 years in 2020  (www.worldometers.info/demographics/life-expectancy/). By comparison, life expectancy in the USA ranks 46 among 191 countries.

Okinawa Dietary Components

The Okinawa diet is the main factor contributing to the longevity of Okinawans and the plethora of centenarians.  The Okinawa diet is a plant-based diet that is high in consumption of vegetables and thus low in calories. Although low in calories, the diet is nutritionally dense with an abundance of vitamins and compounds with antioxidative effects.  Interestingly, the preferred vegetable, the sweet potato, is one with a low glycemic index, meaning it is metabolized slowly thus avoiding high surges in blood sugar that predisposes one to pre-diabetes and subsequent Type 2 Diabetes.  The diet includes moderate consumption of proteins and a selection of mono/polyunsaturated fatty acids in place of saturated fats.  Diet details are summarized below.  

Okinawa Diet Benefits

Clearly, the traditional Okinawa Diet as practiced by residents of Okinawa effectively forestalls the onset of age-associated diseases and increases the lifespan.  As discussed earlier (Insight 8), lifelong caloric restriction in many animal models from round worm to monkey, not only dramatically extends the maximal lifespan but reduces inflammation,  improves insulin sensitivity, and delays onset of diseases.  The Okinawa Diet is low in calories so it may provide benefits simply through reduction in calories. 

Additionally, the Okinawa diet is low in protein and high in low glycemic carbohydrates.  When mice are maintained on a diet comparable to the Okinawa Diet, their life span increases significantly.   Human dietary studies are difficult to perform but generally low protein consumption is not associated with a decrease in mortality.  On the contrary, diets high in protein and low in carbohydrates (opposite to the Okinawa Diet) are associated with increased mortality.  More data are needed to understand the role of protein in aging. 

2.  DASH Diet

Background

The DASH diet was developed more than 20 years ago to reduced the prevalence of hypertension.  DASH is an acronym for Dietary Approach to Stop Hypertension.  The prevalence of hypertension increases with age.  The prevalence in adults is ~ 30%, in those 65-80 years ~58% and as high as ~74% in those over 80 years of age.  Furthermore, elevated blood pressure predisposes one to cardiovascular diseases such as atherosclerosis, stroke and heart failure.

DASH Dietary Components

Previous science indicates that certain foods could possibly lower blood pressure better than other foods.  This became the basis of the DASH diet. This diet recommends consumption of fruits and vegetables, whole grains, low-fat dairy products, beans, nuts and seeds and some fish and poultry.  Also consumption of saturated and trans fatty acids and cholesterol is reduced.  This diet is rich in nutrients such as potassium, magnesium, calcium, and fiber and lower in sodium compared to a Western Diet.

The Mayo Clinic has put together 3 days of meals that follow the DASH dietary plan.  Also included is the nutritional analysis of the foods for the 3 days.  It is worth checking out.  https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/dash-diet/art-20047110

DASH Benefits

Numerous clinical trials show that the DASH Diet lowers both systolic (high number) and diastolic (lower number) blood pressure with greater reduction of blood pressure in those with higher baseline values.  Reducing sodium in the DASH Diet below the recommended amount produced an even greater reduction in blood pressure.

3.  Portfolio Diet

Background

This diet was developed to lower cholesterol and to prevent/reduce the onset of coronary artery disease. It was designed with scientific information that suggested certain foods (such as plant proteins and sterols, viscous fibers, nuts)  in various ways were helpful in reducing cholesterol.  High blood levels of LDL (bad cholesterol) is a serious risk factor for cardiovascular disease.

Portfolio Diet Components

The Portfolio Diet is basically a vegetarian diet.  It is rich in vegetables such as broccoli, eggplant, tomatoes, onions, okra, high in whole grains including oats and barley, and vegetable-based margarine, almonds, and soy protein. Soy products replace animal products and the accompanying saturated fat.  It is also low in sodium,  sweets, and refined carbohydrates.

WebMD has published a plan for what the typical Portfolio Diet would look like in daily life.  This is worth reading.  https://www.webmd.com/cholesterol-management/features/portfolio-diet-lower-cholesterol

Portfolio Diet Benefits

A systematic and meta-analysis in 2018 of the Portfolio diet in clinical trials longer than 3 weeks showed many benefits.  Benefits were reduction in LDL cholesterol, decrease in systolic/diastolic blood pressure, reduction in inflammatory factors and decreased risk of coronary heart disease.

Conclusions:

Whether you follow the diets discussed here or the Mediterranean Diet discussed earlier (Insight 10), there is ample evidence that inherence to these diets will result in longer healthier life.  Of the four diets, the scientific support for the Mediterranean Diet is the most extensive, but quality data also exists for the other three.

It is clear that all 4 diets differ radically from the typical Western diet.  The Western Diet is high in calories, saturated fats, meat and meat products, processed foods and sugar-laden foods. Consumption of fruits, vegetables and fiber is low.  Furthermore, the Western Diet is associated with development of obesity and cardiovascular disease.