Can whole milk reduce the risk of diabetes?

New research suggests that whole-fat dairy products -- generally shunned by health experts -- contain a fatty acid that may lower the risk of type 2 diabetes.

The fatty acid is called trans-palmitoleic acid, and people with the highest blood levels of this fatty acid reduce their odds of diabetes by 62 percent compared to those with the lowest blood levels of it.

In addition, "people who had higher levels of this fatty acid had better cholesterol and triglyceride levels, lower insulin resistance and lower levels of inflammatory markers," said study author Dr. Dariush Mozaffarian, co-director of the program in cardiovascular epidemiology at Brigham and Women's Hospital and Harvard School of Public Health.

Whole milk has more trans-palmitoleic acid than 2 percent milk, and 2 percent milk has more of this fatty acid than does skim milk.

Should you start drinking whole milk?

Mozaffarian said it's difficult to know exactly how many servings of dairy it would take to get to the highest levels of trans-palmitoleic acid, but said it was likely three to five servings a day, depending on the type of dairy consumed.

However, he said, it's too soon to make any dietary recommendations based on the results of just this finding.

"This study confirms that something about dairy is linked very strongly to a lower risk of diabetes, but no single study should be enough to change guidelines," he said, adding that he hopes this study will spur more research.

Tell you doctor.

Stay active, fight diabetes

The Centers for Disease control predicts that as many as one in three American adults may have diabetes by 2050 as the number of diabetes patients doubles or triples over the next 40 years.

There's one simple thing you can do -- exercise.

People with Type 2 diabetes should get 150 minutes of aerobic exercise a week, according to a new recommendation a committee that wrote a position paper for the American College of Sports Medicine and the American Diabetes Association.

"There is probably not a better medicine out there for people with diabetes than exercise," said Sheri Colberg-Ochs, an Old Dominion University exercise science professor and chair of the committee.

They also recommended that diabetics not let more than two days pass between exercise because frequent activity is key to keeping blood glucose levels from rising.

The first line of treatment of diabetes should be lifestyle changes, such as improving diet and exercise habits, Colberg-Ochs said. "The medications are supplemental to that. You should not take the medications until you make the lifestyle changes." Many people can come off medications, especially if they start making the changes early in their diagnosis.

Even a little bit of activity counts. The 150 minutes of recommended exercise could come in 10-minute bursts throughout the week.

"Weeding, washing your dishes counts, and is very important in people with diabetes," she said. "People think of it as they join the gym or they don't do anything. There are a lot of things in between."

Weight training works against diabetes

A new study predicts that half of Americans will be diagnosed with diabetes by 2020. So that's you or somebody you love.


Here's a strategy for preventing it. A new study suggests that when it comes to exercise, the combination of aerobics and weight lifting is better than either activity alone at lowering blood sugar in diabetes patients.

That doesn't mean double the time spent exercising, however. The study found that doing both types of exercise — some days spent doing cardio, and other days lifting weights — was effective, even if patients' total exercise time did not differ.

To figure out which type of exercise was most effective, researchers recruited 262 sedentary adults with diabetes for a nine-month study. The volunteers were randomly assigned to one of four groups: aerobic exercise only (about 150 minutes of walking on a treadmill per week), resistance training only (upper- and lower-body exercises on weight machines three days per week), aerobic exercise plus weights (two weekly sessions of weight training plus cardio on other days, with total exercise time roughly equaling the other groups), and no exercise.

The researchers found that participants in the combination group were able to lower their blood levels of HbA1C (an indicator of blood sugar) by 0.34%, compared with the aerobics- and weights-only groups, who lowered their HbA1C levels by 0.24% and 0.16%, respectively. The only change that was statistically significant from the control group's, however, was that of the combination exercise group.

Participants in the combination-exercise group lowered the amount of diabetes medication they needed on average. They were also the only ones to lose weight out of all the groups. And while all groups lost some fat mass, the combination-exercise group and lost the most compared with the control group.

"The biggest consumer of blood sugar is skeletal muscle, and anything you do to improve the health of your muscles will help control your use of blood sugar," said the study's lead author, Dr. Timothy Church, director of preventive medicine research at the Pennington Biomedical Research Center at Louisiana State University System.

How to walk your way to health

Research shows that starting a walking program can help people with type 2 diabetes achieve tighter glucose control, Johns Hopkins reports, but everyone can benefit.

A study by Italian researchers found that sedentary diabetes participants who began walking about 30 minutes a day lowered their hemoglobin A1c levels by 0.4% after two years. The walkers also experienced marked improvements in cholesterol, triglycerides (a type of fat in the blood), protective high-density lipoprotein (HDL) cholesterol, and blood pressure.

Most people with diabetes can follow the American Heart Association and American College of Sports Medicine recommendation to get at least 30 minutes of moderate physical activity on most, and preferably all, days of the week or at least 20 minutes of vigorous aerobic activity three days a week. "Moderate" activity is defined as equivalent to walking at a pace of 3 to 4 miles per hour.

How do you know if you're getting the benefit?

Try to achieve a "target heart range" that's between 50 and 70% of your maximum heart rate (MHR), which is an estimate of how fast your heart would beat at the very peak of physical exertion. This formula may seem a bit complicated at first, but it can help you find an appropriate walking pace for your age that provides solid health benefits.

I've done this and it's not as complicated as it sounds. The heart rate monitor I bought a few years ago even did the calculation for me.

• First, determine your MHR by subtracting your age from the number 220. MHR is 158 (220-62 = 158).

• Now determine your target heart range by first multiplying your MHR by 0.5 then multiplying it by 0.7. Example: If you are 62, your target heart range during exercise is between 79 and 111 beats per minute (158 x 0.5 = 79; 158 x 0.7 = 111). Once you know your target heart range, stop in the middle of your next walk and check your heart rate. Using your middle and index fingers, find your pulse at the base of your wrist or on the side of your neck. Count the beats for 15 seconds (the first beat counts as zero). Take the total and multiply by four to determine your heart rate. Are you within your target heart range?
   
• When first starting out, aim for the low end of your target heart range. Once you have checked your heart rate during exercise a few times you will come to know what the proper intensity feels like.

As an alternative to using this formula, you can purchase a heart rate monitor, which does the work for you. Or you can follow some simple rules of thumb that will keep you moving at a healthy clip:

• Walk as though you're running late to catch a bus or plane, but not so fast that you can't talk and keep up a conversation.

• If you don't break a sweat during a workout, chances are you aren't walking fast enough.

• Start counting. According to a study in the American Journal of Preventive Medicine, walking at a pace equal to roughly 100 steps per minute produces a moderate degree of physical exertion. (If keeping track of steps is too hard, use a pedometer.)

Eating to prevent diabetes

The Mediterranean diet -- high in vegetables, fibre-rich grains, legumes, fish and plant-based sources of unsaturated fat -- particularly olive oil and nuts -- while being low in red meat and high-fat dairy -- may help prevent diabetes.

Spanish researchers studying more than 400 adults found that those following the traditional diet were less likely to develop diabetes over four years -- even without counting calories or shedding weight.

The participants were randomly assigned to one of three diets: a Mediterranean diet with emphasis on more consumption of olive oil, the same diet with a focus on getting unsaturated fats from nuts, and a diet cutting all types of fat. After four years, 10 to 11 percent of those in the two Mediterranean groups had developed diabetes, compared to 18 percent of those in the low-fat diet group.

But don't rule out exercise and calories: when the researchers accounted for a number of other factors, such as the participants' weight, smoking history and reported exercise levels, the Mediterranean diet itself was linked to 52 percent reduction in diabetes risk compared to the low-fat diet.

Why fish oil protects against diabetes

You've heard that fish oil is good for you for a lot of reasons, but nobody ever knew exactly why. Now some scientists have discovered that omega-3 fatty acids reduce inflammation that can lead to diabetes.

By studying fat tissue in the mice consuming fish oil, researchers found that omega-3 fatty acids seem to act on a particular receptor on cells, GPR120, which, when activated, blocks inflammatory processes.
Chronic inflammation can lead to insulin resistance, a precursor to diabetes.

"If we can fix the inflammation part, it's possible that we could prevent insulin resistance or even ameliorate diabetes," said study co-author Saswata Talukdar, a post-doctoral fellow at University of California, San Diego.

Here's more of the science.

Fat tissue contains macrophages, immune system cells that gobble up bacteria, clear out cellular debris and help rid the body of infection. But macrophages found in fat can also have a downside. When macrophages "go rogue," Talukdar said, they produce cytokines and other pro-inflammatory proteins.

A build up of cytokines can result in a "signaling cascade," that eventually leads to low-grade, chronic inflammation and insulin resistance, Talukdar said. In people with insulin resistance, cells are unable to properly utilize insulin, which regulates blood sugar levels. That can lead to type 2 diabetes, which is often linked to obesity.

While studying fat tissue, researchers found that omega-3 fatty acids, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), acted on the specific receptor, GPR120 (for G protein-coupled receptor), found on the surface of macrophages.

The GPR120 receptor is found only on pro-inflammatory macrophages in mature fat cells, according to the study. Exposure to omega-3 fatty acids activates the receptor, which reduces the runaway pro-inflammatory cascade.

This study focused on diabetes, but omega-3 fatty acids may also help with other diseases in which inflammation plays a role, including cancer and cardiovascular disease, researchers said.


Being appropriately cautious, the researchers said it is not guaranteed that the same result would be found in humans.

The National Institutes of Health has a lot of information on omega-3s here, including dosing information.

For healthy adults with no history of heart disease, the American Heart Association recommends eating fish at least two times per week. In particular, fatty fish are recommended, such as anchovies, bluefish, carp, catfish, halibut, herring, lake trout, mackerel, pompano, salmon, striped sea bass, tuna (albacore), and whitefish. It is also recommended to consume plant-derived sources of α-linolenic acid, such as tofu/soybeans, walnuts, flaxseed oil, and canola oil. The World Health Organization and governmental health agencies of several countries recommend consuming 0.3-0.5 grams of daily EPA + DHA and 0.8-1.1 grams of daily α-linolenic acid. A doctor and pharmacist should be consulted for dosing for other conditions.