Added Sugars Linked to High Blood Pressure
A review of studies on sugar-added foods shows that people who take in 10-25 percent of their calories from sugared beverages and foods suffer a 30 percent higher risk for heart attacks, compared with people who take less than ten percent of calories from added sugars (British Medical Journal: Open Heart, Dec. 11, 2014). The review also found that:
• higher added-sugar intake was associated with increases in systolic and diastolic blood pressure of 6.9 and 5.6 mm Hg.
• the more sugared foods you eat, the higher your bad LDL cholesterol.
• sugars occurring naturally in foods, such as fruit, did not appear to increase risk for high blood pressure or heart attacks.
Another review of twelve scientifically-dependable studies involving 409,707 participants showed that sugar-sweetened beverages are associated with increased risk for high blood pressure, a major risk factor for diabetes and heart attacks (The American Journal of Cardiology, February 2014).
What is High Blood Pressure?
You have high blood pressure if your systolic blood pressure is greater than 120 before you go to bed at night and just after you wake in the morning. That is when your blood pressure is at its lowest level. You may also have high blood pressure if your systolic pressure is greater than 140 after resting for 5 to 10 minutes during the day.
What Causes High Blood Pressure?
More than 90 percent of North Americans will develop high blood pressure. Kidney damage or an overactive adrenal gland can cause high blood pressure, but these causes occur so rarely that most doctors do not even order a renin level to look for kidney damage, or an aldosterone level to look for adrenal problems.
Many doctors believe that a high-salt diet is a major cause of high blood pressure, but low-salt diets reduce systolic blood pressure by less than 5 mm Hg in most adults with hypertension, and the average reduction in diastolic blood pressure associated with a low-salt diet among adults with high blood pressure is 2.5 mm Hg (JAMA Intern Med, 2014;174(4):516-524). Low-salt diets are associated with increased risk for death in people who also have diabetes.
The people who are most likely to get high blood pressure from taking in too much salt are those whose cells are insulin resistant. Their cells do not respond well to insulin (Hypertension, Jan 2013), so the pancreas keeps on releasing large amounts of insulin to try to lower high blood sugar levels. High levels of insulin constrict arteries to cause high blood pressure. People with high insulin levels are the ones who get high blood pressure when they take in too much salt (Am J Hypertens, 1998 (Apr);11(4 Pt 1):397-402). For them, a high salt intake increases blood pressure, insulin and blood sugar.
How Sugar-Added Foods Can Cause High Blood Pressure
More than 80 percent of people who have high blood pressure also have insulin resistance, an inability to respond normally to insulin. This means that when they eat or drink sugar-added foods, their blood sugar levels rise, causing their insulin levels to rise which constricts arteries to cause high blood pressure (British Medical Journal: Open Heart, Dec. 11, 2014).
How Can You Tell if You are Insulin Resistant?
People who are insulin insensitive usually have what is called metabolic syndrome. You probably have metabolic syndrome if you have any three of the following:
• storing fat primarily in your belly
• having small hips
• being overweight
• having blood triglycerides (>150)
• having blood HDL cholesterol (<40) • having high blood pressure • having a fatty liver • having a fasting blood sugar >100 (HbA1c> 5.7)
• having high insulin levels
Lifestyle Changes, Not Drugs, Can Cure High Blood Pressure
You cannot cure high blood pressure with drugs; you can only control it as long as you continue to take drugs (Hypertension, 2002;40(5):612-618). Most of the time, your blood pressure cannot be controlled with just one drug and most people end up with three or more drugs to treat their high blood pressure.
Lifestyle Changes to Lower Blood Pressure
• Restrict sugared drinks and sugar added to foods.
• Restrict refined carbohydrates. Whole grains are seeds with a fiber coating that forms a thick capsule which cannot be broken down efficiently in your intestines, so blood sugar and insulin levels barely rise after you eat them. However, when you grind whole grains into flour, you break the capsule so the starches can be absorbed quickly. Foods made from flour, such as bakery products or pasta, cause a high rise in blood sugar and insulin.
• Eat large amounts of fruits, vegetables and seeds. Unprocessed vegetables, whole grains, nuts, other seeds and most fruits contain complex carbohydrates and fats that are not released rapidly into the bloodstream. These nutrient-rich foods do not cause a high rise in blood sugar and insulin.
• Exercise. Resting muscles draw no sugar from the bloodstream. On the other hand, contracting muscles draw sugar rapidly from the bloodstream and don’t even need insulin to do so. The more intensely you exercise, the less insulin is needed by muscles to withdraw sugar from the blood and this effect lasts for up to 17 hours after you finish exercising.
• Avoid overweight. Your liver controls blood sugar levels. When blood sugar levels rise, insulin drives sugar from the bloodstream into the liver. However, the more fat you have stored in your liver the harder it is for sugar to enter liver cells in response to insulin. A fatty liver will raise blood sugar levels even higher by releasing stored sugar from its cells into the bloodstream.
• Avoid smoking. Smoking damages every cell in your body.
How Pre-Diabetes Increases Risk for Dementia
One of the definitions of pre-diabetes is a high rise in blood sugar after meals, and a recent study suggests that many cases of dementia are linked to these high rises in blood sugar (JAMA Netw Open, Jan 8, 2021;4(1):e2033012). This study of 3889 adults found that people who suffer from loss of mental function and dementia have much higher levels of Advanced Glycation Endproducts (AGEs) in their skin. AGEs form in your body when your blood sugar rises too high after you eat, causing the sugar to stick irreversibly to proteins, fats, or nucleic acids (Diabetologia, 2001;44(2):129-146). The AGEs turn on your immune system to cause inflammation that can damage all types of cells in your body and increase risk for dementia, heart attacks, strokes, and certain cancers (World J Cardiol, Apr 26, 2012;4(4):90-102).
This new study is the first to show that high levels of AGEs in the skin may be used to predict future loss of mental function and dementia. Many previous studies show that AGEs can accumulate in the brains of people who suffer from dementia (Biochem Biophys Res Commun, 1997;236(2):327-332), and researchers can measure the amount of AGEs in the skin to determine the amount of AGEs in the brain (Diabetologia, 2004;47(7):1324-1330). Measuring the amount of AGEs in the skin can also be used to demonstrate increased amounts of AGEs in arteries to predict risk for heart disease (Arterioscler Thromb Vasc Biol, 2014;34(12):2695-2699). Doctors use a blood test called APOE4 to check for genetic susceptibility for dementia. AGEs may well be the link to this dementia as people with this genetic susceptibility for dementia have higher levels of AGEs in their brains (J Gerontol A Biol Sci Med Sci, 2020;75(10):1899-1905).
Dementia Associated with a High Rise in Blood Sugar After Meals
Pre-diabetics have a high rise in blood sugar after meals and are at very high risk for episodic loss of memory, decreased executive function, and loss of verbal fluency, processing speed, cognitive flexibility, and cognitive control (Lancet, 2012;379:2291-2299). Blood sugar control can help to preserve brain function (J Gerontol A Biol Sci Med Sci, 2016;71(Suppl 1):S62-S71).
Everyone’s blood sugar rises after they eat. If your blood sugar rises too high, sugar sticks to cells to form AGEs. To prevent blood sugar from rising too high, your pancreas is supposed to release insulin, which lowers blood sugar by driving sugar from the blood into the liver and muscles. However, if your liver is full of fat, it does not accept the sugar and blood sugar levels rise even higher. This is called insulin resistance. You can also have high blood sugar from lack of, and failure to respond to, insulin.
Clues That You May Be Pre-Diabetic
Having a normal fasting blood sugar (less than 100 mg/dL) does not rule out diabetes. You are probably pre-diabetic and are at increased risk for Type II diabetes if:
• you can pinch more than two inches of fat under the skin near your belly button
• you have a big belly
• you have small buttocks compared to your belly
• you have an HBA1c blood test higher than 5.7
• your blood sugar one hour after a meal is greater than 145 mg/dL
• your triglycerides are greater than 150 mg/dL
• your HDL is less than 40 mg/dL
• you have small-particle lipids
See The Hidden Epidemic of Early Diabetes
Preventing and Curing Type II Diabetes
Many people are susceptible to develop diabetes because they genetically store fat primarily in their belly. Skinny people can be diabetic just because their liver is full of fat (“fatty liver“). A simple sonogram of your liver can show if you have a fatty liver. To reverse the progression toward diabetes, you need to lose enough weight to get the fat out of your liver.
• lose weight by whatever means works for you (I recommend intermittent fasting)
• try to exercise for at least 30 minutes every day
• eat plenty of vegetables, whole un-ground grains, beans, nuts, and whole fruits (not fruit juice)
• restrict or avoid meat from mammals, processed meats, sugar-added foods, fried foods, and all refined carbohydrates (found in foods made from flour and many processed foods)
• drink only water, coffee or tea with no calories or artificial sweeteners
At age 45, you have a 20 percent chance of developing dementia as you age (Dementia, 2015;11(3):310-20), and more than 35 percent of North Americans over the age of 85 have early or full-blown dementia. More and more studies are showing that a high rise in blood sugar is a major risk for dementia. If you have any of the risk factors for diabetes, you should immediately begin a program to lower the rise in blood sugar after you eat.
Exercise Treats Insulin Resistance
Up to 70 percent of North Americans adults will develop diabetes or pre-diabetes, usually from insulin resistance caused by excess fat in the liver and muscles. Exercise helps to empty fat from the liver and muscles, so exercise helps to prevent and treat diabetes.
Nearly 69,000 men and women with no diabetes or heart problems were tested for heart fitness by running on a treadmill (American J of Medicine, January 9, 2020). Insulin resistance was measured by a fasting blood sugar greater than 100 mg/dL and triglycerides greater than 150mg/dL. Compared to non-obese fit people, those who were:
• unfit women and men who were not overweight had more than double the risk of insulin resistance
• fit but obese women had 11 times the incidence of insulin resistance
• unfit and obese women had more than 20 times the incidence of insulin resistance
• fit but obese men had 7.4 times the incidence of insulin resistance
• unfit and obese men had 12.9 times the incidence of insulin resistance
Definition of Insulin Resistance
Insulin drives sugar, fat and protein into cells. Insulin resistance means that the cells do not respond to insulin, so sugar builds up in the bloodstream. Everyone’s blood sugar rises after they eat, but if blood sugar rises too high, sugar irreversibly sticks to cells and can destroy every kind of cell in your body. To prevent blood sugar from rising too high, your pancreas releases insulin into your bloodstream, which lowers blood sugar by driving sugar from the bloodstream into the liver. However, if the liver is full of fat, it does not accept the sugar and blood sugar levels rise even higher. Insulin resistance can be reversed by emptying fat from the liver and muscles.
Use Both Aerobic Exercise and Resistance Exercise to Combat Insulin Resistance
• The larger your muscles, the less likely you are to become insulin resistant. High blood sugar causes loss of muscle size (JCI Insight, February 21, 2019;4(4)).
• Six weeks of resistance exercise improves insulin sensitivity in young, overweight men (Experimental Physiology, Feb 1, 2019).
• A review of 105 studies shows that a regular exercise program lowers fasting blood sugar and HBA1c (which measures the amount of sugar stuck on cells) in both diabetics and non-diabetics, and that each additional 100 minutes per week of physical activity was associated with a mean average decrease of 2.75 mg/dL of fasting blood sugar (Acta Diabetol, (2017) 54:983).
• Strength training lowers high blood sugar levels and liver fat, even before weight loss occurs (Journal of Endocrinology, Apr 2019;241(1):59–70).
Intense Exercise Lowers HBA1c
• A review of eight studies on 235 participants who exercised from 12 weeks to six months found that the greater the intensity of exercise, the greater the lowering of HBA1c, a measure of cell damage from high blood sugar levels (Acta Diabetol, June 17, 2016).
• A review of 47 studies of 8,538 patients who exercised more than 12 weeks for more than 150 minutes per week, showed a significant reduction of HBA1c (JAMA, Nov 24, 2010;304(20):2253-62; JAMA, May 4, 2011;305(17):1790-9).
• A study of 262 sedentary middle-aged men and women, with type 2 diabetes and HBA1c levels of 6.5% or higher, found that a combination of aerobic and resistance training (three days a week for nine months) improved HBA1c levels, compared with a non-exercising control group. This was not achieved with aerobic or resistance training alone (JAMA, Mar 2, 2011;305(9):892).
• A review of 12 studies of 2-6 months of exercise in diabetics found that aerobic exercise reduced HBA1c more than resistance exercise, and the greater the weight loss, the greater the drop in HBA1c, peak oxygen consumption, and maximum heart rate. The authors felt that aerobic and resistance exercises were equal in helping to prevent heart attack risk factors (Sports Med, Apr 2014;44(4):487-99).
Most cases of diabetes are caused by insulin resistance which usually comes from excess fat in the liver and muscles. Both aerobic and resistance exercise help to prevent and treat diabetes by helping to empty the liver and muscles of excess sugar. Exercise helps to reduce excess weight, high blood pressure, high LDL cholesterol, and high triglycerides. Exercise also helps to increase healthy HDL cholesterol, strengthens muscles and bones, and combats depression
Recreational Runners and Cyclists Should Lift Weights
To preserve muscle and bone size and strength, recreational runners and cyclists should do upper body and core weight lifting and resistance training. Everybody will lose muscle and bone size and strength with aging. Your bones weaken progressively after age 30, and between ages 35 and 50, about 28 percent of North American men and women suffer from bone weakening called osteopenia (J Amer Osteo Assoc, June 2019;119:357-363). By age 65, 25 percent of women and six percent of men are at high risk for breaking their hips or spine with minor falls (CDC/National Center for Health Statistics, August 2015).
The people who lose the most muscle are usually the ones who are most at risk for falls and broken bones. Any prolonged period of inactivity, such as bed rest, injured nerves, wearing a cast or even living in a decreased force of gravity, will cause loss of muscle tissue (Med Hypotheses, 2007;69(2):310-21). If you inactivate a leg by putting it in a cast, you lose a significant amount of muscle size in just four days (Nutrition, Acta Physiol (Oxf), March 2014;210(3):628-41). Just one year of lifting weights can strengthen the bones enough to help protect people from fractures (Bone, Oct 2015;79:203-212).
The hard ground impact of fast running may slow bone loss (BMC Med, Dec 20, 2012;10:168), but cycling does not prevent age-associated osteoporosis. A review of 22 scientific studies shows that adding a resistance program such as lifting weights to endurance sports such as running or cycling can markedly slow this loss of muscle and bone, and actually increase muscle size and strength, with greater benefit from low volume, high-resistance weight lifting than high volume, lower-resistance exercise (Human Movement, July 23, 2020;21(4);18-29).
Strength Training May Not Help Competitive Cyclists or Runners Go Faster
Studies show mixed results on whether runners and bicycle racers can run and cycle faster with added strength training, but most studies show limited benefit of strength training for endurance athletes because strength training does not improve your ability to take in and use oxygen. The limiting factor for how fast an endurance athlete can run or cycle over distance is the time it takes to move oxygen into muscles, and that is improved only by training that involves creating an oxygen debt (becoming short of breath). Lifting weights and doing other resistance exercises do not increase VO2max, the maximal amount of oxygen that a person can take in and use (Med Sci Sports Exerc, 2002;34(8):1351–1359; Sports Med, Aug 2016;46(8):1029-39). Competitive runners and cyclists can do their leg strength training just by running or pedaling their intervals faster (Scand J Med Sci Sports, Oct 2010;20(Suppl 2):11-23 and Nov 2010;38(11):1965-70).
Leg Strength Training Can Cause Injuries in Runners and Cyclists
Most runners and cyclists should do resistance training only for their core and upper body, and use their legs only for running and cycling. A major problem with adding a weight lifting program for the legs to running or cycling is a marked increase in risk for leg injuries. Ideal training for endurance is to go more intensely on one day, damage your Z-lines in your muscle fibers, and feel delayed onset muscle soreness (DOMS) on the next day. (DOMS is necessary for gaining strength.) The day after you do weight training with your legs, your leg muscles will be weaker and this would interfere with any attempted intense endurance workout or resistance exercise (Sports Med, Nov 2017;47(11):2187-2200). You are supposed to exercise slowly and easily for as many days as it takes for the soreness to lessen before you do your next intense workout. Therefore you should not do resistance training for your legs on a day when your legs are recovering from the previous day’s intense workout.
For at least a day after lifting weights, an athlete is at high risk for tearing muscle fibers if he attempts an intense endurance workout. Thus you would need to do your intense endurance workouts and your resistance exercises on the same day, and this increases risk for injuring yourself. If you want to add leg resistance exercises to a leg endurance program, you must learn to recognize the signs of overtraining and back off when your muscles feel excessively fatigued or sore.
• Non-competitive runners and cyclists should alternate faster and more intense days with slower recovery days, do strength training only for their core and upper body, and not do resistance training on their legs. Combining endurance and strength training on the same muscle groups increases risk for injury. Most competitive athletes should also follow this program.
• Elite runners and cyclists may want to combine leg strength training with leg endurance training, but they should do the strength training not more than twice a week, only on hard days (after an intense endurance workout), and never on recovery days. They should skip the weight workouts when their muscles feel excessively sore or tight, stop the strength training workouts during their competitive season, and hope that they do not suffer injuries.
• If you are not already doing strength-training exercise, first check with your doctor to make sure you do not have any condition that may be harmed by exercise. I have always recommended joining a gym and using the weight training (Nautilus-type) machines there, but until COVID-19 is under control, you will want to find a way to do resistance exercises at home. Resistance exercise can increase muscle size and strength in older people, but with aging you need to work longer to gain the amount of strength that a younger person would get with the same program (Med Sci Sports Exerc, 2011;43 (2):249-58). Since lifting lighter weights many times is less likely to cause injuries, I recommend lifting lighter weights with more repetitions.
• Stop immediately if you feel severe pain or if you have pain that does not go away as soon as you stop lifting the weight. Pain in a muscle or tendon is often the first sign of an impending injury.
• Take the day off if your muscles feel sore or fatigued after a 5-10 minute pre-workout warmup.
• Just using and contracting your muscles in any activity offers health benefits, but you can gain additional benefits by adding intensity with some form of