Antioxidants, diet and degenerative diseasesPaul R EarlFacultad de Ciencias BiológicasUniversidad Autónoma de Nuevo LeónSan Nicolás, NL, Mexico
Do modern life styles reduce longevity ?Our plan is to lead a long and happy life, yet how this is to be done may not be clear for certain age groups, life styles and special problems like cultural disputes or lack of job skills. This plan includes desirable weight, regular excercise and abstinence from smoking, excessive alcohol and elicit drug use. Diet education can be one of the dominant themes. Especially beneficial foods are soya, unsaturated fatty acids, phytosterols and phytosterol esters, carotenoids, polyphenols, phytoestrogens and flavanoids, etc., dietary fiber, vitamins E, C and B, folic acid and selenium, potassium, zinc and magnesium.
Will you last longer if you eat less ?Obesity, diabetes mellitus, hypertension, hyperlipidemia, coronary artery disease and some cancers like breast cancer are sometimes considered life style diseases. The AIDS disaster, hunger and povery may not allow a clear vision of the present universal TRANSITION from focus from acute infectious diseases to chronic ones.
Antioxidants are protective agents that inactivate reactive oxygen ions and thus delay or prevent oxidative damage. Antioxidant enzymes like superoxide dismutase, catalase and glutathione peroxidase are naturally present within human cells. In addition, antioxidants such as vitamins E and C (ascorbic acid), polyphenols and carotenoids are available in food. Current dietary guidelines to combat chronic diseases, including cancer and coronary artery disease (CAD), recommend increased intake of plant foods. This includes fruits and vegetables, which are rich sources of antioxidants. The role of dietary antioxidants, including vitamin C, vitamin E, carotenoids and polyphenols in disease prevention is emphasized.
FlavanoidsFlavonols, flavones and isoflavones belong to the 3 subclasses of flavonoids. Flavonols and flavones have similar C-ring structure with a double bond at the 2-3 position. Flavones, as opposed to flavonols, lack a hydroxyl group at the 3-position. Major flavonols include quercetin (3,5,7,3’,4’-pentahydroxyflavone), kaempferol (3,5,7,4’-tetrahydroxyflav-one) and myricetin (3,5,7,3’,4’,5’-hexahydroxyflavone).
Another important dietary antioxidant is lycopene of tomatoes. The most widely found compounds are flavonols, flavones, flavan-3-ols, isoflavones, flavanones, flavanols, anthocyanidines and proantho-cyanidines. Flavonoids are almost ubiquitous in plant foods (vegetables, cereals, legumes, fruits, nuts, etc.) and beverages (wine, cider, beer, tea, cocoa, etc.). Treat potatoes as just starch !
Sources of antioxidants Allium sulphur leeks, onions and garlic. compounds: Anthocyanins: eggplant, grapes and berries.Beta-carotene: pumpkin, mangoes, apricots, carrots, spinach and parsley.Catechins: red wine and tea. Copper: seafood, lean meat, milk and nuts.Cryptoxanthins: red capsicum, pumpkin and mangoes. Flavonoids: tea, green tea, citrus fruits, red wine, onion and apples.
What is a serving ?One medium-sized fruit or vegetable is the simplest form of a serving. A serving can be 125 ml or 1/2 a cup of raw, cooked, frozen or canned vegetables or fruit. A perfect example is a small glass of orange, carrot or tomato juice. Drinking juice made from concentrate will not do. Instead, buy real juice with pulp which includes all the essential nutrients. The serving is a convenient yet vague term, perhaps of 237-250 ml. A slice of bread is a serving.
Diet1/ Choose a VARIETY of foods.2/ Balance the food you eat with physical activity. Maintain or improve your weight.3/ Choose a diet with plenty of grain products, vegetables and fruit.4/ Choose a diet low in fat, saturated fat and cholesterol.5/ Get a diet moderate in sugars, salt and sodium.
LowerModerateHigher1,600 2,200 2,800 calories Grain Group Servings 6 9 11 Vegetable Group Servings 3 4 5 Milk Group Servings 2-31 2-31 2-31 Meat Group2 (ounces) 5 6 7 Total Fat3 (grams) 53 73 93 Total Added Sugars4 (teaspoons) 6 12 18 Fruit Group Servings 2 3 4
Recommended Antioxidant Good Food Sources. Amount*Vitamin CWomen: 75 mg of citrus fruits, cruciferous vegetables such as broccoli, cauliflower and cabbage.Men: 90 mg. Smokers: extra 35 mg.Vitamin E15 mg of fortified cereals, vegetable oils, nuts, spinach and kale, mangoes and wheat germ. Selenium55 micrograms (mcg). Onions, garlic, mushrooms, wheat germ and rice bran. Vitamin A Women: 700 units as retinol: As beta-carotene: RAE** Eggs, liver, yellow-orange or dark-green leafy vegetables and fruits.Men: 900 REA vitamin such as kale, beet greens, spinach, carrots, sweet potatoes, A-fortified milk, pumpkin, papaya, apricots, parsley and basil.
Down with fat !Too much fat or cholesterol and inactivity can make you fat. Change from Whole or 2 % milk to 1 % skim milk.Regular cheese to low-fat cheese.Mayonnaise to mustard or low-fat mayonnaiseFried to baked chicken. Saturated fat to olive oil. corn oil or canola (rape seed extract). Bologna, salami or pastrami to sliced turkey or lean beef.
Some useful linksAntioxidant vitamin therapy Nutrition and health (in Russian) http://www.pitt.edu/~super1/lecture/lec10541/index.htmMediterranean diet and cardiovascular disease preventionhttp://www.pitt.edu/~super1/lecture/lec3261/index.htmLipids and cardiovascular disease prevention http://www.pitt.edu/~super1/lecture/lec5261/index.htm andhttp://www.pitt.edu/~super1/lecture/lec5271/index.htm
Body Mass Index & Basal Metabolic Rate Obesity is measured by the Body Mass Index (BMI). The BMI was invented by the Belgian mathematician Quetelet (1796-1874) who was fortunate enough to be a student of both La Place and Fourier. This universally applied index is weight in kg over height in m squared. BMI is one of the few factors (variables) that applies equally to men and women.Another measure is the Basal Metabolic Rate (BMR). The basal metabolic rate is calculated in kilocalories/day according to equations given by Harris & Benedict in 1919. But see Weir, J Physiol 1949;109:1–9. Also it can be given as kilojoules/min or kJ/day.
CholesterolWhen there is too much cholesterol in the blood, it builds up in the walls of the arteries to become atherosclerosis or hardening of the arteries. When blood cannot circulate normally, there may be chest pains and even a heart attack.These values are: Total cholesterol LDL (low density bad ! cholesterol) – the main source of cholesterol buildup and blockage in the arteries, HDL (high density good ! cholesterol) – helps stop cholesterol from building up in the arteries. Triglycerides are another form of fat in blood.
ObesityThe central issue might be lack of discipline to control overeating, but this conclusion may be wrong. Still, eating can be viewed as one more addiction, and next our society makes this a moral issue thus making it too easy to insult fat people. Nevertheless, the food addict lives in his own world and will have to break his own chains. Obesity has 30.0 or more BMI, whereas overweight is 25.0-29.5 BMI. The normal range is 18.5-24.9 BMI. Below 18.5 BMI is the condition anorexia nerviosa in young women who grievously undereat.
DiabetesInsulin is not produced in Type 1 and not properly used in Type 2 diabetes. High carbohydrate, high fiber diets can reduced insulin dosage by 40 %, fasting blood glucose by 6-27 % and serum cholesterol by 10-32 %. See also Jenkins et al, N Engl J Med 1993: 329: 21-26.Like obesity, diabetes is an extremely active field that is expected to take great strides now. Nonetheless, diabetes will kill those who do not follow their diet.
AtherosclerosisAtherosclerosis takes place in the major arteries and is the underlying cause of heart attacks, stroke and peripheral artery disease. The earliest detectable lesions, called fatty streaks, contain macrophage foam cells that are derived from recruited monocytes. More advanced lesions, called fibro-fatty plaques, are the result of continued monocyte recruitment and smooth muscle cell migration and proliferation.
Hypertension One central theme is enough oxygen for normal cardiac function.Angina pectoris has chest pain arising from the heart due to a lack of oxygen to the heart muscle. It can be brought on by exercise, emotional upset or heavy meals. Normally the arteries that supply blood to the heart can cope with an increased demand, but if coronary artery disease (CAD) is present or high blood pressure, the blood flow is restricted. CAD affects men over age 35 and postmenopausal women.
StrokeA stroke or "brain attack" occurs when a blood clot blocks an artery or a blood vessel breaks, interrupting blood flow to an area of the brain. Brain cells begin to die, and damage occurs. Abilities controlled by that area of the brain are lost. These abilities include speech, movement and memory. Some people recover completely from strokes, but more than 2/3 of survivors will have some type of disability.The risk of having a stroke is perhaps 1 % per year. Reduce cholesterol. Try an aspirin a day, but this is surely not for everyone.
Macular degeneration of the retinaMacular degeneration damages and destroys the central vision of up to one in 3 persons in their lifetime and has no known cause or cure. It can affect anyone, regardless of age or sex. See http://www.eyesight.org/
Cancer More fruit less meat and other advice for general dietary improvement are simply repeated for cancer prevention. Decisive facts seem illusive. More mutations thanks to exposure of DNA to more free radicals can lead to various cancers. Still, if “Just give us the facts” is applied, little might be forthcoming.
ConclusionsThe replacement of animal by plant proteins has been repeatedly suggested. It seems obvious that the heavily advertized foods are the high calorie ones. These tasty high-energy foods are the ones to avoid! More fruits, vegetables and fiber in the diet can combat the obesity epidemic. As the development of chronic lifestyle diseases are strongly influenced by diet, and as we CONTROL our diets, the timely dissemination of nutritional knowledge seems imperative. Up with soy and down with fried chicken! Otherwise, just blame the genes.