Healthy diet

Hippocrates, the father of medicine, once said:

“Consider food thy medicine and medicine thy food.”

Food is as important for our health as medicine.

A large number of diseases are associated with food. 

In some areas of the world the lack of food is the cause of malnutrition and its consequences, but  in other areas the problem is just the opposite, the excess of food.

In 1994 in the USA less than 14% had obesity (BMI >30). This number increased to 26% in 2014. In the same period, diabetes increased from <4.5% to more than 9% of the population (http://www.cdc.gov/diabetes/data).  The consequence was that in the USA cardiovascular disease increased to 41.5 % in 2015 (National Center for Statistics).

Unfortunately this trend is worldwide. Diabetes type 2 increased from 108 million people or 4.7% of the world population in 1980 to 422 million people or 8.5% in 2014 ( 1 ).

The change in eating habits and physical activity are causing an epidemic of obesity, diabetes, hypertension, cardiovascular disease, cancer, and premature death.

How can we keep a good health?

Two factors play a major role: food and physical activity.

Intake of calories and energy expended.

Most of the energy we need daily comes from carbohydrates, proteins and fats, what are called macronutrients.

Let’s consider each group

Carbohydrates should make up 45 to 65 percent of total caloric intake.

But both the quantity and type of carbohydrate are important.

Some carbohydrates are very quickly digested and release energy fast. But because insulin level increase, the sugar level also decrease fast and we feel hungry sooner and consequently we eat more. This is called carbohydrate with high glycemic index.

Some examples are maltose (beer), glucose,  baked potatoes, French fries, rice flour, mashed potatoes, potato chips, honey, corn flakes, popcorn, sugar, white bread, chocolate bars, cola, soda, cookies, white rice, noodles .

Several prospective studies have associated diets high in glycemic index with risk of developing type 2 diabetes mellitus, coronary heart disease, and some cancers.

The average American diet have 10% of their daily calories as sugar. But about 10% of Americans have 25% of their daily calories as sugar. This group that eat more sugar have the chance to die of a heart disease doubled (2).

The other type of carbohydrate is slowly digested, release energy slowly, and consequently we feel full longer and we eat less. This is the low glycemic index carbohydrates.

Examples are: whole wheat bread,   brown rice, sweat potatoes, spaghetti (al dente), oatmeal, 100% integral bread,   quinoa, dairy products, fresh fruits, dark chocolate (>70% cacao), soy, peanuts,  green vegetables, tomatoes.

Low glycemic index carbohydrates are associated with better weight, glycemic and lipids control and lower risk of heart disease.

So the first lesson is to avoid sugar and other carbohydrates of high glycemic index and substitute with low glycemic index carbohydrates.

What about proteins?

Protein should make up 10 to 35 percent of total caloric intake.

Common sources of dietary protein include meat, fish, egg, vegetables, milk, beans, nuts, whey, soybean.

Again the quantity and source of protein has a differential impact on health

Diet with high animal protein (>20%) is associated with 74% increase in mortality, 433% increase in cancer death and 393% increase in diabetes. In special, red meats are associated with increased mortality, compared with white meats.

This association is abolished with vegetable protein (3).

• Fish –A 2014 meta-analysis of 11 prospective cohort studies found that fish consumption ≥four times a week was associated with a decreased risk of acute coronary syndrome [4]. Long-term consumption of fish oil and n-3 fatty acids reduces the risk of cardiovascular disease.

Fat should make up 20 to 35 percent of total caloric intake.

The fat found in dairy and red meat is called saturated fat. Saturated fat increase LDL (bad cholesterol)  and  HDL (good cholesterol).

Another type of fat is the trans fats (also found in low levels in dairy and meat, but in high levels in industrial products of hydrogenation of polyunsaturated fat, such as in margarines, cookies, cake, deep fried food). The trans fat  increase LDL and reduce HDL cholesterol, so have a more deleterious effect than the saturated fats, increasing even more the risk of coronary heart disease.

In the other hand, fats from vegetables such safflower, sunflower and corn, called polyunsaturated fat and olive and canola oil (monounsaturated fat) are beneficial for our health.

Fiber is the portion of plants that cannot be digested by enzymes in the gastrointestinal tract. Fiber is available in fruits and vegetables. Increased fiber intake is associated with decreased risk in cardiovascular events [5-10],  cancer [11],  and all-cause mortality [12].  Patients should be advised to replace refined grains (eg, white rice, white bread) with whole grains (eg, brown rice, whole-wheat bread), which have higher fiber content.

Fruits consumption reduce blood pressure, glucose level, the risk of ischemic and hemorrhagic stroke, major coronary artery events and cardiovascular death (13)

• Nuts – A study found that the risk of myocardial infarction or stroke was reduced among participants who consumed nuts five or more times per week compared with participants who rarely ate nuts [14].

Second lesson is eat more vegetables, fruits and nuts daily and one to two servings of oily fish weekly.

MICRONUTRIENTS — Nutrients needed in very small amounts are called micronutrients and include several minerals (eg, sodium, calcium) and vitamins

Sodium — The recommended dietary sodium intake for the general population is less than 2300 mg per day. Avoid too much salt.

Calcium and vitamin D — Recommended calcium intake is 1200 mg for postmenopausal women and 1000 mg for other individuals; recommended vitamin D intake is 600 international units (IU) daily (or 800 IU daily if aged 70 years or older) [15].

Sweetened beverages — These beverages  are a key contributor to weight gain and obesity [16], increased risk of coronary heart disease (CHD), type 2 diabetes, hypertension, and metabolic syndrome [17-23].

The consumption of soft drinks and other sweetened beverages  should be discouraged. Drink plain water rather than sweetened beverages.

An example of a good diet is the mediterranean diet —  typically high in fruits, vegetables, whole grains, beans, nuts, and seeds; include olive oil as an important source of monounsaturated fat. There are typically low to moderate amounts of fish, poultry, and dairy products, with little red meat.

The Mediterranean diet is associated with several health benefits;  reductions in overall mortality, cardiovascular mortality, cancer, Parkinson and Alzheimer disease (24,29,30]. Studies have also found that a Mediterranean diet was associated with decreased risk for colorectal, prostate, digestive, pharyngeal, and breast cancer [16, 28, 31-33, 37].

A systematic review  showed good evidence that mediterranean diet  improved HbA1c and glucose level, decreased insulin resistance and mortality (35)

In conclusion, what would you say if a doctor offered a medicine that reduce the chance of colon cancer in 70%, stroke in 70%, in CAD 80% and Diabetes type 2 in 90%?

Well this medicine is available to all of us for free:

1. diet with less saturated and trans fats, and low glycemic index,
2. physical activity (walking 30 min a day),
3. not smoking
4. weight control ( BMI < 25 kg/m2).

If you follow these 4 healthy habits, you will have higher chance to avoid diabetes type 2, coronary heart disease, stroke and colon cancer.(36)

(1 )  http://www.who.int/mediacentre/factsheet/fs312/en/ updated Nov 2017

(2).  Jama Intern med 2014;174 (4) 516-524.

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(5) Pietinen P, Rimm EB, Korhonen P, et al. Intake of dietary fiber and risk of coronary heart disease in a cohort of Finnish men. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Circulation 1996; 94:2720.

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(7) Ascherio A, Rimm EB, Hernán MA, et al. Intake of potassium, magnesium, calcium, and fiber and risk of stroke among US men. Circulation 1998; 98:1198.

(8) Wolk A, Manson JE, Stampfer MJ, et al. Long-term intake of dietary fiber and decreased risk of coronary heart disease among women. JAMA 1999; 281:1998.

(9) Jensen MK, Koh-Banerjee P, Hu FB, et al. Intakes of whole grains, bran, and germ and the risk of coronary heart disease in men. Am J Clin Nutr 2004; 80:1492.

(10) Threapleton DE, Greenwood DC, Evans CE, et al. Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ 2013; 347:f6879.

(11) Pietinen P, Rimm EB, Korhonen P, et al. Intake of dietary fiber and risk of coronary heart disease in a cohort of Finnish men. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Circulation 1996; 94:2720.

(12) Key TJ, Thorogood M, Appleby PN, Burr ML. Dietary habits and mortality in 11,000 vegetarians and health conscious people: results of a 17 year follow up. BMJ 1996; 313:775.

(13) N Engl J Med 2016; 374:1332-1343

(14) Dagnelie PC, Schuurman AG, Goldbohm RA, Van den Brandt PA. Diet, anthropometric measures and prostate cancer risk: a review of prospective cohort and intervention studies. BJU Int 2004; 93:1139.

(15) Key TJ, Thorogood M, Appleby PN, Burr ML. Dietary habits and mortality in 11,000 vegetarians and health conscious people: results of a 17 year follow up. BMJ 1996; 313:775.

(16) Li S, Flint A, Pai JK, et al. Dietary fiber intake and mortality among survivors of myocardial infarction: prospective cohort study. BMJ 2014; 348:g2659.

(17) Pan A, Sun Q, Bernstein AM, et al. Red meat consumption and mortality: results from 2 prospective cohort studies. Arch Intern Med 2012; 172:555.

(18) Bellavia A, Larsson SC, Bottai M, et al. Differences in survival associated with processed and with nonprocessed red meat consumption. Am J Clin Nutr 2014; 100:924.

(19) Larsson SC, Orsini N. Red meat and processed meat consumption and all-cause mortality: a meta-analysis. Am J Epidemiol 2014; 179:282.

(20) Leung Yinko SS, Stark KD, Thanassoulis G, Pilote L. Fish consumption and acute coronary syndrome: a meta-analysis. Am J Med 2014; 127:848.

(21) Guasch-Ferré M, Liu X, Malik VS, et al. Nut Consumption and Risk of Cardiovascular Disease. J Am Coll Cardiol 2017; 70:2519.

(22) de Koning L, Malik VS, Kellogg MD, et al. Sweetened beverage consumption, incident coronary heart disease, and biomarkers of risk in men. Circulation 2012; 125:1735.

(23) Greenwood DC, Threapleton DE, Evans CE, et al. Association between sugar-sweetened and artificially sweetened soft drinks and type 2 diabetes: systematic review and dose-response meta-analysis of prospective studies. Br J Nutr 2014; 112:725.

(24) Fung TT, Chiuve SE, McCullough ML, et al. Adherence to a DASH-style diet and risk of coronary heart disease and stroke in women. Arch Intern Med 2008; 168:713.

(25) Schwingshackl L, Bogensberger B, Hoffmann G. Diet Quality as Assessed by the Healthy Eating Index, Alternate Healthy Eating Index, Dietary Approaches to Stop Hypertension Score, and Health Outcomes: An Updated Systematic Review and Meta-Analysis of Cohort Studies. J Acad Nutr Diet 2018; 118:74.

(26) Sofi F, Cesari F, Abbate R, et al. Adherence to Mediterranean diet and health status: meta-analysis. BMJ 2008; 337:a1344.

(27) Schwingshackl L, Hoffmann G. Adherence to Mediterranean diet and risk of cancer: a systematic review and meta-analysis of observational studies. Int J Cancer 2014; 135:1884.

(28) Widmer RJ, Flammer AJ, Lerman LO, Lerman A. The Mediterranean diet, its components, and cardiovascular disease. Am J Med 2015; 128:229.

(29) Fung TT, Hu FB, Wu K, et al. The Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets and colorectal cancer. Am J Clin Nutr 2010; 92:1429.

(30) Salehi-Abargouei A, Maghsoudi Z, Shirani F, Azadbakht L. Effects of Dietary Approaches to Stop Hypertension (DASH)-style diet on fatal or nonfatal cardiovascular diseases–incidence: a systematic review and meta-analysis on observational prospective studies. Nutrition 2013; 29:611.

(31) Pereira MA, O’Reilly E, Augustsson K, et al. Dietary fiber and risk of coronary heart disease: a pooled analysis of cohort studies. Arch Intern Med 2004; 164:370.

(32) Ludwig DS, Pereira MA, Kroenke CH, et al. Dietary fiber, weight gain, and cardiovascular disease risk factors in young adults. JAMA 1999; 282:1539.

(33) Hartley L, May MD, Loveman E, et al. Dietary fibre for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev 2016; :CD011472.

(34) Widmer RJ, Flammer AJ, Lerman LO, Lerman A. The Mediterranean diet, its components, and cardiovascular disease. Am J Med 2015; 128:229.

(35)  Sleiman, Front. Public Health, 28 April 2015 / https://doi.org/103389/fpubh.2015.00069

(36) Willett WC: Science 296:695-698, 2002. Spring B et al., Circulation, 2013 Nov 5; 128(19):2169-76.

(37) Graham A Colditz, David Seres, Jean E Mulder,  Healthy diet in adults. This topic last updated: Jul 16, 2018.