Monday, March 29, 2010

Variable High Blood Pressure More Likely to Cause Strokes

Four studies in the British medical journals, Lancet and Lancet Neurology (March 10, 2010), show that people whose high blood pressures go up and down are up to six times more likely to suffer strokes than those who have more stable high blood pressures. The greater the variability in blood pressure, the higher the risk. This is astounding because doctors usually reassure people with intermittent high blood pressure and often do not treat them.

• High blood pressure is a powerful risk factor for strokes and heart attacks.
• Lifestyle changes and drugs to lower high blood pressure markedly reduce these risks.
• Blood pressures that vary over time markedly increase risk for stroke.

Ninety-one percent of Americans will have high blood pressure. That doesn't mean that they all have to take drugs. More than 80 percent of people with high blood pressure can control their blood pressures with • a diet with lots of fruits, vegetables, whole grains, beans, seeds and nuts; some fish; and marked reduction in meat, whole milk dairy products, and refined carbohydrates; • exercise; • weight loss if overweight; • reduction of salt intake; • avoidance of tobacco smoke.

What you should do: Buy a blood pressure cuff and check your blood pressure each night before you go to bed. If your systolic blood pressure is above 120, you have high blood pressure and are at increased risk for heart attacks and strokes. If your systolic blood pressure varies from 120 to 135 or higher, you are at greater risk for a stroke, and the greater the variance, the greater the risk.

If your blood pressure cannot be controlled with lifestyle changes, you may have to take drugs. According to these studies, you probably should take a calcium channel blocker plus some other drug. A meta-analysis of 389 randomized trials involving different classes of antihypertensive medications found that calcium channel blockers were most likely to protect against blood pressure variability, whereas ACE inhibitors, beta blockers, and angiotensin receptor antagonists tended to cause wide swings in blood pressure. This explains why calcium channel blockers are better than beta blockers at reducing the risks of stroke when their effects on average blood pressure were the same. A problem is that calcium channel blockers are weak blood pressure lowerers so they almost always have to be given in combination with other drugs to be effective. If you are on blood pressure medication, check with your doctor about these important new studies.

• Calcium Channel Blockers: amlodipine (Norvasc), clevidipine (Cleviprex), diltiazem (Cardizem), felodipine (Plendil), isradipine (Dynacirc), nifedipine (Adalat, Procardia), nicardipine (Cardene), nimodipine (Nimotop), nisoldipine (Sular), and verapamil (Calan) Isoptin.

• ACE Inhibitors: benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril, (Monopril), lisinopril (Prinivil, Zestril), quinapril (Accupril), ramipril (Altace).

• Beta Blockers: Acebutolol (Sectral), Atenolol (Tenormin), Betaxolol (Kerlone), Bisoprolol (Zebeta, Ziac), Carteolol (Cartrol), Carvedilol (Coreg), Labetalol (Normodyne, Trandate), Metoprolol (Lopressor, Toprol), Nadolol (Corgard), Penbutolol (Levatol), Propranolol (Inderal, Inderal LA), Timolol (Blocadren).

• Angiotensin II Receptor Blockers: Candesartan (Atacand), Irbesartan (Avapro), Losartan (Cozaar), Telmisartan (Micardis), Valsartan (Diovan).

Diet to lower blood pressure

Friday, March 26, 2010

Saturated Fats Exonerated

A review of 21 studies covering 348,000 adults shows that eating large amounts of saturated fats does not increase risk for heart disease and strokes (American Journal of Clinical Nutrition, March 1, 2010). This is incredible because most doctors believe that the close association of heart attacks and strokes with eating meat or whole milk dairy products is explained by their high saturated fat content. Consider the following:

• Societies that eat lots of saturated fats in coconut, palm and palm kernel oils are not at increased risk for heart attacks, strokes and premature death (although these oils may raise the bad LDL cholesterol).

• Poultry is a rich source of saturated fats but has not been shown to increase risk for premature death, cancer or heart attacks.

• Replacing saturated fats with refined carbohydrates actually increases heart attack risk by increasing obesity, insulin resistance, triglycerides, and small LDL particles that cause heart attacks; and by lowering the good HDL cholesterol that helps to prevent heart attacks.

This questions the American Heart Association's recommendation that adults get no more than seven percent of their daily calories from saturated fat. For many years I have reported that inflammation is a more reliable predictor of future heart attacks than blood cholesterol. A recent ezine showed how mammal meat and dairy products can cause inflammation. This is more likely to explain the link between meat and heart attacks than the saturated fat theory.

Today, saturated fats from plant sources, poultry and seafood appear to be healthful as long as you do not take in more calories than you burn.

Monday, March 22, 2010

Atrial Fibrillation in Older Athletes

A study from Norway shows that 13 of 78 (16 percent) older competitive cross country skiers have atrial fibrillation, a condition in which the upper chambers of the heart flutter and collect blood (European Journal of Cardiovascular Prevention & Rehabilitation, February 2010). Blood that is not moving collects in the upper chambers of the heart where it can form clots that travel to the brain to block the flow of blood to cause a stroke. Almost all people who suffer from atrial fibrillation at any age are treated with drugs to prevent clotting, since they are at increased risk for strokes and heart attacks. However, the older endurance athletes are different from other people with atrial fibrillation.

• The incidence of atrial fibrillation in these great older endurance athletes is the same as for non-athletic Norwegian men over 75. However, the skiers developed their atrial fibrillation at the average age of 58, which is much younger than its occurrence in the general population.

• People who suffer from atrial fibrillation usually have a history of something damaging their hearts, such as high blood pressure, high cholesterol, heart disease, heavy drinking or chronic inflammation, but ten of the 13 skiers with atrial fibrillation had none of these risk factors. The older endurance athletes have the highest rate of fibrillation without any known cause in the entire world's literature.

• The vast majority of endurance athletes live significantly longer than average citizens.

Nobody has adequate data to show why athletes are at increased risk for atrial fibrillation or whether they are at increased risk for forming clots. My explanation is that life-long endurance athletes have large healthy hearts that contain much more heart muscle than nerves. This can interfere with the normal sequence of an electrical impulse starting each heart beat from a spot in the upper heart that causes the upper heart to contract. This electrical messages then travels along nerves down to the lower heart to cause it to beat. The large athletic healthy heart has such large muscles that they outgrow the nerves that carry each heart beat so that not all upper heart electrical impulses pass to the lower heart. Future studies will show whether this is harmful or a harmless condition in athletes.

Since doctors have no data to show that older endurance athletes with atrial fibrillation are not at increased risk for strokes, they usually put them on drugs to prevent clotting. The symptoms of atrial fibrillation include:
• a sensation of a rapid or irregular heartbeat
• a fluttering feeling in the chest
• sudden anxiety that the heart is beating irregularly
• sudden dizziness or faintness
• sudden shortness of breath
• sudden chest pain
• sudden loss of strength going up stairs or getting up from a chair
• sudden fatigue anytime

Saturday, March 20, 2010

Why You Should Exercise Every Day

Researchers at the University of Michigan show that exercise helps to control blood sugar only while you do it and for a few hours afterwards (Journal of Applied Physiology, February 2010). The authors also showed that restricting food after exercising does not clear blood sugar any better than eating a regular meal. The second point is very important because eating after exercising helps you to recover faster for your next exercise session, and you recover faster from exercise by eating a sugar- and protein-rich meal within one hour after you stop. Previous studies show that contracting muscles remove sugar rapidly from the bloodstream, without needing insulin, during and up to one hour after exercise. The effect tapers off to zero at about 17 hours after you finish exercising (American Journal of Clinical Nutrition, July 2008).

This study from the University of Michigan adds to the abundant evidence that exercise helps to prevent diabetes and its horrible side effects. Diabetes will affect one out of every three Americans. When your blood sugar rises too high, sugar sticks to cells. Once there, it can never get off. Eventually it is converted to sorbitol which destroys the cell to cause heart attacks, strokes, blindness, deafness, amputations, brain damage, impotence and so forth.

Doctors measure the amount of sugar stuck on cells with a blood test called HBA1C. A study from the University of Calgary shows that both aerobic and strength exercise lower HBA1C by 0.5 per cent in diabetics (Annals of Internal Medicine, September 18, 2007). Those who did both types of exercise lowered it by twice as much. A decrease of 1.0 percent in HBA1C value (from 7.0 to 6.0) is associated with a 20 percent decreased risk for heart attacks and strokes, and a 25 percent to 40 percent decrease in risk of diabetes-related eye disease or kidney disease.

Wednesday, March 10, 2010

Co-factors that Increase Cancer Risk

Many things you do increase your risk for cancer and the more risk factors you have, the greater your risk. Avoiding these risk factors after you are diagnosed with a cancer can increase your chance for a cure.

Smoking and being infected with the human wart virus (HPV) both cause fatal squamus cell cancers of the head and neck. A study from the University of Michigan shows that smokers who have an HPV-linked cancer are six times more likely to have a recurrence than those who have never smoked, and two- thirds of patients with HPV-linked tumors were current or former tobacco users (Clinical Cancer Research, February, 2010). Among those with HPV-linked tumors, six percent of those who never smoked had recurrences, compared to 19 percent of those who had smoked in the past and 35 percent of current smokers. Almost all cases of cervical cancers are caused by HPV, but only one woman of 250 infected with the HPV virus develops cervical cancer. If you are infected with HPV and smoke, you increase your chances of developing cervical cancer 15 times (Cancer Epidemiology, Biomarkers & Prevention, November 2006).

Lifestyle factors that are associated with increased cancer risk (as well as heart attack risk) include: smoking, taking more than two alcoholic drinks per day, being overweight, not exercising, not eating enough fruits and vegetables, eating too much saturated fat from mammals, eating burnt food (PAHs and HCAs), lack of vitamin D, lack of sunlight, and anything that increases risk for diabetes. Other risk factors include promiscuous behavior that exposes you to hepatitis B and C viruses, human papilloma virus (HPV), human immunodeficiency virus (HIV), Helicobacter pylori (H. pylori), Human T-cell leukemia/lymphoma virus (HTLV-1), Epstein-Barr virus (EBV), or Human herpesvirus 8 (HHV8); working in jobs that expose you to radiation, chemicals such as asbestos, benzene, benzidine, cadmium, nickel, or vinyl chloride, certain metals, pesticides or solvents; taking certain medications and hormones; repeated exposure of your skin to excess sunlight or getting too many X rays.

Wednesday, March 03, 2010

Replacements for Partially Hydrogenated Oils

Now that partially hydrogenated oils (trans fats) have been removed from many processed foods, which substitutes are acceptable and which should be avoided? Most of the foods previously made with trans fats now use saturated fats from palm, palm kernel and coconut oils. As far as I know, these tropical oils have not been shown to cause heart attacks or other health issues in any large population studies. However, they raise levels of the bad LDL cholesterol, while Canola oil (high in monounsaturated fat) and soybean oil (high in polyunsaturated fat) do not (American Journal of Clinical Nutrition, July 2006). I believe that they are more healtful than saturated fats from animal sources, and certainly better than the trans fats they have replaced.

Fats in nature are always a combination of saturated, polyunsaturated and monounsaturated fats. They are classified by their dominant fat. For example, most of the fat in meat and tropical oils is saturated, while the fats in most vegetables are primarily polyunsaturated. Here are my recommendations:

• Look for foods made with monounsaturated or polyunsaturated vegetable oils. Many food manufacturers now use trans fat-free oil from sunflower, soy, and cottonseed oils. (Wendy's switched to non-hydrogenated corn and soy oil in 2006. McDonald's now uses trans-fat free canola and soybean oils).
• Olive oil is high in healthful monounsaturated fats and is an excellent choice for salad dressings and low-temperature stir-frying.
• Saturated fats from plants (tropical oils) appear to be more healthful than animal saturated fats, as far as we know today.
• Avoid prepared foods that contain ANY partially hydrogenated or trans fats; always read the list of ingredients.
• Limit or avoid foods prepared with saturated animal fats such as lard and butter.
• French fries should be freshly sliced and cooked with a vegetable oil such as canola. (Many frozen french fries still contain partially hydrogenated oils).
• Make your own snacks using vegetable, nut or seed oils.

Always read the list of ingredients to make sure there are NO partially hydrogenated oils. Many products labeled "zero trans fats" contain up to a half gram of trans fats per serving because the FDA allows them to do this. Partially hydrogenated oils (trans fats) raise bad cholesterol and lower good cholesterol. Just five grams of trans fat a day can increase risk of heart disease by 25 percent. They are also associated with increased risk for breast (American Journal of Epidemiology, November 2008) and prostate cancers (Cancer Epidemiology Biomarkers & Prevention, January 2008).

Overall, snack foods and prepared foods should be a very small portion of your diet. Most of the food you eat should be vegetables, fruits, whole grains, beans and other seeds.

More on tropical oils
More on trans fats
Best diet