Are dairy products healthy?

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Many books and articles contain health recommendations based on little or no scientific evidence. So when making personal decisions about how to maintain and improve one’s health, it is important to look for books and articles based on solid studies, especially large, well-controlled ones. A good example of science-based health information can be found in the July/August 2011 issue of the Nutrition Action Health Letter, published by the Center for Science in the Public Interest. It evaluates the pros and cons of consuming dairy products, Some of its key points:

Bones
We all know that milk is a major source of dietary calcium, which is needed to maintain bone density. Recently however, some health writers have contended that eating animal protein lowers bone density. Because protein contains amino acids, the alleged mechanism is increased acidity of the blood, prompting the body to respond by leaching calcium from the bones to neutralize the acid. Since milk is a protein source, it is implicated in bone loss. However, scientific study has refuted this contention. In actuality, bone mineral density is higher among people who eat more protein and lower among people who eat less protein. Radio isotope studies that tracked actual deposition and depletion of calcium have verified that consumption of dairy foods does not increase bone loss as we age.

Colon Cancer
A major analysis by the Harvard School of Public Health of 10 studies conducted in 5 countries, involving over 500,000 people concluded that people who drank at least one cup of milk per day had a 15% lower risk of colon cancer than those who drank less than 2 cups per week. Similarly, people treated for colon cancer who took 1200 mg of calcium per day and who had an above-average Vitamin D level had 15% less chance of recurrent colon cancer than those who didn’t take the calcium. Twenty-five percent of experimental animals fed a high-fat diet low in fiber, calcium, Vitamin D, and folic acid, developed colon tumors, but those supplemented with calcium and Vitamin D got none.

Prostate Cancer
There is some inconsistent evidence that high calcium consumption (in excess of 1500 mg/day) may increase the risk of prostate cancer. Milk increases the body’s level of insulin-like growth factor-1 (IGF-1), a hormone that stimulates the growth of both muscle and bone, but may also stimulate prostate-cancer growth. Even though a study of men receiving a 1200 mg calcium supplement daily showed no prostate cancer increase, the article recommended that men limit their calcium intake from food and supplements combined to 1000 mg/day if under 70 years of age and 1200 mg/day if over 70.

Blood Pressure
Adding 2 servings per day of low-fat dairy foods to a diet rich in fruits and vegetables, lowered blood pressure even further. In addition, a study of 28,000 women over 10 years showed that those consuming at least 2 cups/day of low-fat dairy foods reduced their risk of high blood pressure by 10%.

Weight Loss
When restricted to the same number of calories per day, women consuming more dairy products showed no difference in weight loss than those who consumed less dairy. However, when allowed to eat all they wanted at the end of the study, the dairy group consumed fewer calories. The implication is that dairy may help control appetite. While the weight-loss results were equivocal, the women in the low-dairy group lost bone density in their hips, while the high-dairy group did not. This is an important finding, considering that dangerous loss in bone density is common among both women and men as they age.

Lactose Intolerance
Lactose is the sugar found in milk. The following is the lactose content of some dairy products:

• 8 oz cup of milk: 12 grams
• 6 oz cup of yogurt - 10 grams
• 1 oz hard cheese or cream cheese - 1 gram or less
• ½ cup cottage cheese - 4-5 grams
• ½ cup ice cream - 4-5 grams

Many people think they are lactose-intolerant, However, the article cites evidence that between one-third and three-quarters of people who think they are lactose-intolerant are actually not so. Many of them show none of the typical symptoms of gas or diarrhea when lactose is put in their non-dairy drinks without their knowledge. Many people’s digestive systems can adjust to lactose by building up intestinal bacteria over a period of time. So the authors recommend that people who think they are lactose intolerant try to adjust to lactose by:

• Limiting lactose to 12 grams at a time (the amount in one 8 oz glass of milk).
• Consuming lactose along with other foods to give it more time to be digested
• Eating dairy foods regularly to maintain lactose-digesting bacteria
• Other Health Issues Related to Dairy Products

Diabetes
A study of 200,000 people over 20 years showed that those consuming 3-5 servings per day of dairy products had a 14% lower risk of Type II diabetes than those consuming less than 1.5 servings per day. However, it is not known whether that is an effect of the dairy products or another factor common to people who consume more dairy products.

Breast and Ovarian Cancer
Eight studies of 350,000 women in several countries did not find any link between milk consumption and breast cancer. However, research on 500,000 women in the U.S. and Europe did show a weak and marginally significant increased risk of ovarian cancer for women who consumed more than 30 grams of lactose per day. However, two major cancer research organizations did not feel the evidence was conclusive.

Bottom Line
Dairy products made from skim or one-percent milk can be considered health-promoting foods. They contain large quantities of calcium necessary for maintaining bone-density as we age. Also, most are excellent sources of protein (except products made primarily from milk fat, such as cream cheese and butter). Milk appears to help control blood pressure and avoid colon cancer, and may also help control appetite. However, high milk consumption may increase the risk of prostate cancer among men and ovarian cancer among women. Therefore, men should limit calcium consumption from food and supplements combined to 1000 mg/day below age 70 and 1200 mg/day above age 70. Adequate Vitamin D intake is essential for healthy bone mineralization, even if calcium intake is adequate. Many people are deficient in Vitamin D because of low sun exposure. Current recommendations for daily Vitamin D supplementation are in the neighborhood of 1,000-2,000 IU.

Additional Note
The main type of saturated fat found in milk (myristic acid) is particularly potent in raising blood cholesterol, specifically the harmful low-density variety (LDL). Because of that, consumption of milk fat should be very limited. High proportions of milk fat are found in cream, butter, ice cream, cheese (especially cream cheese and soft cheeses like Brie), whole milk, and 2% milk. That is why non-fat and 1% fat milk products are preferable. Unfortunately, many dishes popular in the U.S., such as cheese burgers cheese ravioli, macaroni and cheese, and pizza, contain large amounts of cheese. The evidence indicates that the cardiovascular health of Americans would benefit from a reduction in cheese consumption.

Omega-3 Fats from Fish Oil Raise Risk of High-Grade Prostate Cancer

It has been increasingly evident that there are trade-offs in the quest to get and stay healthy. In other words, there are actions we can take that will reduce the risk of one health problem, but increase the risk of another. One example is playing high-impact sports such as basketball, which is great for improving and maintaining physical fitness while having fun, but also increases the risk of sprains, strains and other musculoskeletal problems. Now, an article by Brasky et al. in the American Journal of epidemiology (published online April 24, 2011)  points up a trade-off involved in taking fish-oil supplements, which have been widely recommended for reducing the risk of cardiovascular diseases and other health problems.

The researchers analyzed blood samples of 3,461 men to measure levels of omega-3 fats (DHA and EPA from fish consumption), omega-6 fats (from common vegetable oils), and trans-fats (from hydrogenated oils in margarine, shortening, and processed foods). The men were then followed over a 7-year period in order to see the association of the different fat types to the incidence of prostate cancer. The hypotheses were that:

• Because of the anti-inflammatory effect of the omega-3 fats, men with the highest blood levels of them would have a lower incidence of prostate cancer
• Because of the inflammatory effect of the trans- fats, men with the highest blood levels of them would have a higher incidence of prostate cancer

Results
The statistical analysis produced the following surprising results:

   > There were no effects of any of the fat types on overall incidence of prostate cancer.
   > When looking at the high-grade form of prostate cancer that progresses rapidly and is the most lethal:

• Those men with the highest blood levels of DHA from fish oil had more than twice the risk of contracting high-grade prostate cancer as men with the lowest blood levels of DHA.
• EPA from fish oil had no effect on the incidence of high-grade prostate cancer.
• Those men with the highest blood levels of trans-fats had about half the risk of contracting high-grade prostate cancer as men with the lowest blood levels of trans-fats
• Blood levels of the type of omega-3 fat from vegetable sources (e.g. flax seeds, walnuts) had no effect on the incidence of high-grade prostate cancer.

Bottom Line
The results of highly surprising, given the widespread view of fish oil as all-good and trans-fats as all-bad. Here is a clear case of trade-off. There is considerable evidence that fish-oil is good for the heart and cardiovascular system and reduces the incidence of heart attacks. Yet, here we see that it increases the risk of high-grade prostate cancer. Eating omega-3 fats from flax-seeds or other vegetable sources is not a solution because that type of omega-3 fat has not been proven to reduce the risk of cardiovascular disease. The good news is that most prostate cancer is of the low-grade variety. Given that heart disease remains the number one killer of both men and women, it doesn’t appear that fish and fish-oil be abandoned as a health-promoting dietary elements. Yet men must be aware of the trade-off in risk of eating fatty fish or taking fish-oil supplements in order to make an informed decision about how best to promote their health.

Update (May 8, 2011):
Consumerlab.com, a company that tests the quality of supplements from various companies, contacted Dr. Theodore Brasky, the lead author of the study described herein. He stated that the blood levels of DHA and EPA measured in the study were largely based on fish consumption rather than fish-oil supplements. However, a recent study of his, soon to be published, shows no link between fish oil supplementation and risk of prostate cancer. He also noted another study (Szymanski, Am J Clin Nutr 2010) that found fish consumption associated with a large reduction in late state or fatal prostate cancer.

As We Age, Cholesterol Level Loses Its Value as a Risk Factor

Because both a high total cholesterol level and a high LDL-cholesterol level are risk factors for heart disease, statin drugs, which lower both levels, are widely prescribed. In the U.S., more prescriptions are written for Lipitor, the most popular statin, than for any other drug. Estimates for the number of people who take statins range between 11 million and 30 million. But should so many people be taking statins? A recent analysis, in which scientists reviewed 14 studies that included data from over 34,000 patients, showed little evidence that statins prevent heart trouble in patients with no history of cardiovascular disease. And because there is some evidence linking low cholesterol levels with increased risk of death from other causes, the study authors feel that doctors should be more cautious about prescribing statins.

An important factor to consider when deciding whether or not to prescribe statins is the patient’s age. A study by Kronmal et al., entitled, “Total Serum Cholesterol levels and mortality risk as a function of age” in the Archives of Internal Medicine (vol. 153, pp. 1065-1073, 1993) examined how age affected the ability of cholesterol level to predict the risk of dying, and it showed that the predictive value declined with age.
The most important consideration when judging mortality risk is the overall likelihood of dying from any cause. In that regard, at age 40, those people with higher total serum cholesterol levels had a significantly higher all-cause mortality risk. However, the relationship declined with age, and by age 60, the relationship between total cholesterol level and all-cause mortality had vanished. By age 80, the relationship actually reversed, so that those with higher cholesterol levels were at significantly lower risk of dying.

Looking specifically at the risk of death from coronary heart disease, the death risk at ages 40, 50, and 60 years was greater for those with higher cholesterol levels, although the effect got smaller with age. By age 70, the relationship was still positive but weak, but by age 80 the relationship reversed, and those with higher cholesterol levels actually had less chance of dying.

Looking at death due to causes other than heart disease, (e.g. cancer), from age 50 on, there was a lower risk of dying as cholesterol levels rose. This apparent protective effect of cholesterol against non-heart-disease death increased with age. Seventy-three percent of 80 year-old men with cholesterol levels above 240 survived for 5 years, while only 49% of those with levels below 240 did. The effect was in the same direction but weaker for women, with a 74% and 70% 5-year survival rates for women with cholesterol levels respectively above and below 240 mg/dl. In regard to cancer alone, higher cholesterol level was associated with lower death risk.

Bottom Line
The current practice of the medical establishment of prescribing statins to anyone with a total cholesterol level above 200 appears to be unjustified. For patients with elevated cholesterol levels and a history of heart disease, statins provide a proven reduction in risk. However, for patients with mildly elevated levels and no history or heart disease, the evidence in favor of prescribing statins is weak or nonexistent. And for men above age 70, even those with cholesterol levels above 240, statins could very well increase the risk of death.

Heart Attack Deaths in the U.S. Have Dropped Sharply

In the Harvard Health Letter, vol 35, no. 10, August 2010, and article appeared entitled, "Is the heart attack going out of style?". It stated that, based on Medicare data, the U.S. heart-attack hospitalization rate declined by 23% from 2002 to 2007. Also, a study based on 3 million members of a northern California health plan showed a 24% drop in heart attack hospitalizations between 1999 and 2008. While an increasing number of people are diagnosed with heart disease, fewer are dying from it - heart attack deaths have been declining in the U.S. for the past 40 years.

The article conjectures that, "Maybe decades of efforts to eat right and exercise more, stop smoking, lower LDL cholesterol levels, and control blood pressure are working." This appears only partially true. Yes, fewer Americans smoke, and Lipitor, a medication for reducing LDL and total cholesterol, is the most prescribed drug in the U.S. Many people are also taking blood pressure medication. Yet, there is little evidence that people are "eating right" as fast-food consumption and obesity continue to increase. Also, various national campaigns, such as the American College of Sports Medicine's Healthy People 2000, have failed dismally to get people to exercise more. Thus, it appears that the reduction in heart attacks is less due to anything that requires will power than to modern medicine. Another possible factor is reduced stress, as the economy was doing well over the study period. It remains to be seen what the recession and high unemployment rate will do to the heart attack rate. Hopefully, and emphasis on family and personal fulfillment and relationships will help keep stress to a minimum, even in the face of economic difficulties.

The reduction in heart attacks is encouraging, yet it would be even better if people became healthier through lifestyle changes such as exercise and good nutrition.

Avoiding or Lessening the Effects of a Stroke

An article in the May 2010 issue of the NIH (National Institutes of Health) News in Health describes how to avoid a stroke or, if you have one, how to recognize it and take immediate action to completely avoid, or at least lessen any lasting effects.

A stroke is a failure of normal blood flow to the brain, which can damage and destroy brain cells. There are two types of stroke:

• Ischemic Stroke - the arteries feeding the brain are blocked, usually by a blood clot
• Hemorrhagic stroke - broken or leaking blood vessels fail to supply oxygen to brain cells

Ischemic stroke accounts for about 80%, and hemorrhagic stroke about 20% of cases. Unfortunately, the treatment for the two types of stroke are opposite, so treating for the wrong kind of stroke can actually increase the damage to brain cells.

Signs of an ischemic stroke include sudden weakness or numbness of the face, arm, or leg, especially if it occurs on one side of the body, and/or difficulty in walking, talking, seeing and thinking. If you have any of these symptoms, it is important to be taken to an emergency room immediately (don’t drive yourself) because clot-busting drugs, if taken within 3 hours of the onset of symptoms, can stop brain damage. Unfortunately, only 2% of stroke victims actually get this effective treatment within the optimal time window. If given too late, the drug can actually increase damage. It is also important to get prompt treatment even if symptoms disappear quickly, because mini-strokes, also called transient ischemic attacks (TIAs), are a sign that a major stroke may occur soon afterwards.

The most common symptom of hemorrhagic stroke is a very sudden and painful headache, and prompt surgery may be required to repair a damaged blood vessel feeding the brain.
 
Some cases of partial or complete paralysis on one side of the face are not caused by stroke but by Bell’s Palsy, a nerve disorder that is, in most cases, temporary. However, only a medical professional can distinguish between Bell’s Palsy and a stroke. In both illnesses, immediate treatment produces the best outcome, so an emergency room visit is required in either case.

A healthy lifestyle can lessen your risk of a stroke. By exercising, eating healthfully (especially limiting foods high in saturated fat, cholesterol, and sodium), not smoking, and keeping your weight under control you can dramatically reduce your risk of a stroke. Our web site has more specific details on avoiding a stroke.
 
Bottom Line
To greatly reduce your risk of a stroke, follow a healthy lifestyle. But if you do develop stroke symptoms, seek immediate medical attention to avoid permanent damage and long-term disability.

Can Omega-3 Oils Deter Aging?

An interesting article appeared in the April 2010 Nutrition Action Health Letter that reported on a study of 600 San Francisco area residents with heart disease. Those with the highest blood levels of the Omega-3 fats, DHA and EPA, had the least telomere shortening, while those with the lowest blood levels had the most shortening. This is important because telomeres are the end-sections of chromosomes that become shorter as we age, eventually triggering genes that bring about symptoms of aging. These results were independent of other factors that might affect risk, like blood pressure, body weight, smoking history and exercise participation. The health letter recommends eating fatty fish like salmon twice a week and the American Heart Association recommends that people with heart disease take one 1,000 mg fish oil capsule daily. More than 3,000 mg per day may cause bleeding.

NOTE: This was a cross-sectional study. More definitive conclusions about the effects of Omega-3 fats on telomeres would be gained from prospective studies in which half the subjects are randomly assigned to eat high Omega-3 diets for several years while the other half are assigned to eat low Omega-3 diets, and the effects on their telomere shortening are observed. Of course, it is still a good idea to eat fatty fish because of the abundant existing evidence of it's disease-deterring qualities. Also, some of the countries with the longest life spans have high percapita fish consumption.

Longer-Interval Run Training Shows Beneficial Cholesterol Effect

Introduction
The two major fractions of blood cholesterol are low-density-lipoprotein (LDL) cholesterol and high-density-lipoprotein (HDL) cholesterol. LDL increases the risk of heart-disease because it is readily deposited in arterial walls and can result in a blood clot that shuts off the blood supply to the heart muscle. In contrast, LDL removes cholesterol from arterial walls. The ratio of total cholesterol (TC) to HDL cholesterol is a risk-index for heart-disease. The higher the ratio, the greater the risk. The average ratio is 4.5, but doctors recommend it be below 4.0 and preferably below 3.0.

Endurance exercise has been shown to improve the TC/HDL ratio, but interval training (sprint running interspersed with rest periods) has not been shown effective in this regard. However, a recent study by Musa et al. (Journal of Strength and Conditioning Research, vol 23, no 2, 2009, pages 587-592) showed that interval training using longer running intervals (500 meters ~ half-mile) can be effective for improving the ratio.

Experimental Procedure
20 college age males ran 4 half-mile intervals at high intensity (90% of max heart rate) seperated by rest periods equal in time (3-5 min) to the running intervals, 3 times a week for 8 weeks. Their TC/HDL ratio improved by 18%, reducing their risk of heart-disease by an estimated 37%. The training also improved their 2.4 km (1.5 mi) running time by 9%.

Bottom Line
Interval training using running distances of 0.5 miles and rest periods equal to run time can effectively enhance blood cholesterol profiles, reducing risk for heart-disease. Thus, for individuals healthy enough to withstand the strain of high-intensity running, longer-distance interval training can have a valuable place in a physical fitness program.

Smoking Rises Among U.S. Adults

The U.S. government Centers for Disease Control has reported that, for the first time since 1994, the percentage of adults who smoke has increased over the previous year - from 19.8% to 21.0%. For men, the rate is 23.1% and for women it is 18.3%. The increase ended a steady decline in smoking from about 40% in the 1960s. The highest rate is among people aged 25-44 and the lowest by far is among people over 65 (many smokers likely die before reaching that age). American Indians and Inuits (Eskimos) have the highest rate of any group while Asians have the lowest rate by far. As to education, more than 40% of those with a GED degree smoke, while less than 6% of those with graduate degrees do. The smoking rate is more than 50% higher for people below the poverty line than those above it. The U.S. states with the highest percentages of smokers are West Virginia, Indiana, and Kentucky, while the states with the lowerst percentages of smokers are Utah, California, and New Jersey.

Perhaps the economic recession and its associated stress have driven people to smoke, or at least driven those who had quit back into smoking. The entertainment industry doesn't help any, as leading men and women are frequently depicted smoking, as if this makes them sexier or tougher. The upward trend is unfortunate because, according to the CDC, "cigarette smoking is the leading cause of preventable death in the United States, accounting for approximately 443,000 deaths or 1 of every 5 deaths in the United States each year." In addition, smoking drains a considerable amount of money from family budgets, worsening financial pressures.

We must continue to seek other ways of dealing with stress than smoking. Exercise is a great stress-reducer. It is very difficult to think about one's problems while lifting a heavy weight, pushing oneself on a treadmill, keeping up with a strenuous exercise class or playing with one's team against tough competition. In addition, exercise leads to feelings of relaxation and well-being. There are several approaches to quitting smoking. Our web site provides a listing of the methods proven most effective.

Places Where People Live Long - What They Have In Common

Dan Buettner, in his book, "The Blue Zones: Lessons for Living Longer from the People Who've Lived the Longest" reveals the factors in common among cultures that have very long life expectancies. In his lecture, televised on CNN, he delves into the cultures of the highlands of Sardinia (which has the longest male life-expectancy), Okinawa (which has the longest female life-expectancy) and Seventh-Day Adventists (who have the longest life-expectancy in the U.S.). There are 9 factors that he states are common to all these societies:

Move Naturally
1) In these societies, people don't perform programmed exercise. They just exercise as part of their daily lives. Okinawans get up off the floor 40+ times a day. Sardinians walk and garden a lot. Seventh Day Adventists take nature walks regularly. The common denominator seems to be a large volume of low-level physical activity.

Right Outlook
2) Downshift daily: That means to take some time daily to calm down, meditate, contemplate, or pray.
3) Purpose now: Have a purpose in living, either work, taking care of others, creating something beautiful, etc.

Eating Wisely
4) Wine in moderation (although the 7th Day Adventists discourage alcohol consumption)
5) Plant-based diet: Meat may be consumed but in relatively small quantities.
6) 80% Full Rule: Stop eating when you feel 80% full.

Connect
7) Loved ones come first
8) Belong to supportive groups
9) Right Tribe: Associate with other people who have good living habits