ReportWire

Tag: bone loss

  • Does Marijuana Affect Weight Gain or Bone Density?  | NutritionFacts.org

    Does Marijuana Affect Weight Gain or Bone Density?  | NutritionFacts.org

    Are the apparent adverse effects of heavy cannabis use on the bone just due to users being thinner? 

    It’s been recognized for decades that cigarette smoking can have “a major effect” on bone health, “increasing the lifetime risk of hip fracture by about half.” It also appears to impair bone healing, so much so that surgeons ask if they should discriminate against smokers because their bone and wound-healing complication rates are so high. What about smoking marijuana?

    As I discuss in my video Effects of Marijuana on Weight Gain and Bone Density, “There is accumulating evidence to suggest that cannabinoids [cannabis compounds] and their receptors play important roles in bone metabolism by regulating bone mass, bone loss, and bone cell function.” Okay, but are they “friend or foe?” 

    “Results from research on cannabinoids and bone mineral density in rodent models have been inconsistent. Some studies show increased bone formation, others have demonstrated accelerated bone loss, and yet others have shown no association. This variation in results may be due [in part] to differences in the mouse strain, sex, age…” If you can’t even extrapolate from one mouse to another, how can you extrapolate from mice to human beings?

    What if you just measure cannabis use and bone mineral density in people? Researchers tested thousands of adults and asked them about their cannabis use. There did not appear to be any link between the two, which is a relief. However, in this study, “heavy” cannabis use was defined as just five or more days of use in the previous 30 days. The researchers didn’t ask beyond that, so, theoretically, someone who smoked just five joints in their entire life could be categorized as a “heavy user” if they happened to use it five times in the last four weeks.

    How about cannabis use on 5,000 separate occasions over a lifetime? Now that’s a heavy user—decades of regular use. In that case, heavy use was “associated with low bone mineral density and an increased risk of fractures”—about double the fracture rate presumably due to lower bone density in the hip and spine, although heavy cannabis users were also thinner on average, and thinner people have lighter bones.

    Hip fracture risk goes down as our weight goes up. Nearly half of underweight women have osteoporosis, but less than 1 percent of obese women do, which makes total sense. Being obese forces our body to make our bones stronger to carry around all of that extra weight. That’s why weight-bearing exercise is so important to constantly put stress on our skeleton. When it comes to our bones, it’s use it or lose it. That’s why astronauts can lose a percent of their bone mass every month in “long-duration spaceflight.” Their bodies aren’t stupid. Why waste all that energy making a strong skeleton if you aren’t going to put any weight on it? 

    So, maybe the reason heavy cannabis users have frailer bones is because they tend to be about 15 pounds lighter. Wait a second. Marijuana users are slimmer? What about the munchies? “The lower BMI that was observed in heavy cannabis users at first sight seems counterintuitive,” given marijuana’s appetite stimulation, but this isn’t the first time this has been noted. 

    “Popular culture commonly depicts marijuana users as a sluggish, lethargic, and unproductive subculture of compulsive snackers,” and marijuana has indeed been found to increase food intake. A single hit can increase appetite, so you’d expect obesity rates to rise in states that legalized it. But, if anything, the rise in obesity appeared to slow after medical marijuana laws were passed, whereas it appeared to just keep rising in other states, as you can see in the graph below and at 3:45 in my video. 

    The reason pot smokers may be slimmer is because of the effect of smoked marijuana on metabolism. We’ve known for more than nearly 40 years that within 15 minutes of lighting up, our metabolic rate goes up by about 25 percent and stays there for at least an hour, as you can see below and at 4:04 in my video. So, that may be playing a role. 

    Is that why heavy cannabis use is associated with lower bone mineral density and increased risk of fractures? Because users just aren’t as overweight? No. Even when taking BMI into account, heavy cannabis use appears to be “an independent predictor” of weaker bones.

    I originally released a series of marijuana videos in a webinar and downloadable digital DVD. There are still a few videos coming out over the next year, but if you missed any of the already published ones, see the related posts below. 

    For more on bone health, check out the related posts below. 

    Michael Greger M.D. FACLM

    Source link

  • Any Pitfalls with Restricting Calories?  | NutritionFacts.org

    Any Pitfalls with Restricting Calories?  | NutritionFacts.org

    How may we preserve bone and mass on a low-calorie diet? 
     
    One of the most consistent benefits of calorie restriction is that blood pressure improves in as little as one or two weeks. Blood pressure may even be normalized in a matter of weeks and blood pressure pills discontinued. Unfortunately, this can work a little too well and cause orthostatic intolerance, which can manifest as lightheadedness or dizziness upon standing and, in severe cases, may cause fainting, though staying hydrated can help. 
     
    What about loss of muscle mass? In the CALERIE trial, which I profile in my video Potential Pitfalls of Calorie Restriction, 70 percent of the body weight the subjects lost was fat and 30 percent was lean body mass. So, they ended up with an improved body composition of about 72 percent lean mass compared to 66 percent in the control group, as you can see at 0:51 in my video. And, even though leg muscle mass and strength declined in absolute terms, relative to their new body size, they generally got stronger. 

    Is there any way to preserve even more lean mass, particularly among older individuals who naturally tend to lose muscle mass with age? Increased protein intakes are commonly suggested, but most studies fail to find a beneficial effect on preserving muscle strength or function whether you’re young or old, active or sedentary. For example, during a 25 percent calorie restriction, researchers randomized overweight older men and women to either a normal-protein diet with 4 grams for every ten pounds of body weight or a high-protein diet with about 8 grams per ten pounds. That doubling of protein intake had no discernible effect on lean body mass, muscle strength, or physical performance. As you can see below and at 1:48 in my video, most such studies found the same lack of benefit, but when they’re all put together, one can tease out a small advantage of about one or two pounds of lean mass over an average of six months. 

    Unfortunately, high protein intake during weight loss has also been found to have “profound” negative metabolic effects, including undermining the benefits of weight loss on insulin sensitivity. As you can see in the graph below and at 2:14 in my video, if you lose 20 pounds, you can dramatically improve your body’s ability to handle blood sugars, compared to subjects in a control group who maintained their weight. But, if you lose the exact same amount of weight on a high-protein diet, getting about an extra 30 grams a day, it’s like you never lost any weight at all. 


    Though you can always bulk back up after weight loss, the best way to preserve muscle mass during weight loss is to exercise. The CALERIE study had no structured exercise component, and, similar to bariatric surgery, about 30 percent of the weight loss was lean mass. In contrast, that proportion was only about 16 percent of The Biggest Loser contestants, chalked up to their “vigorous exercise program.” Resistance training even just three times a week can prevent more than 90 percent of lean body mass loss during calorie restriction. 
     
    The same may be true of bone loss. Lose weight through calorie restriction alone, and you experience a decline in bone mineral density in fracture risk sites, such as the hip and spine. In the same study, though, those randomized to lose weight with exercise did not suffer any bone loss. The researchers concluded: “Our results suggest that regular EX [exercise] should be included as part of a comprehensive weight loss program to offset the adverse effects of CR [caloric restriction] on bone.” 
     
    It’s hard to argue with calls for increased physical activity, but even without an exercise regimen, the “very small” drop in bone mineral density in the CALERIE trial might only increase a ten-year risk of osteoporotic fracture by about 0.2 percent. The benefits of calorie restriction revealed by the study included improvements in blood pressure and cholesterol, as you can see in the graph below and at 3:54 in my video, as well as improved mood, libido, and sleep. These would seem to far outweigh any potential risks. The fact that a reduction in calories seemed to have such wide-ranging benefits on quality of life led commentators in the AMA’s internal medicine journal to write: “The findings of this well-designed study suggest that intake of excess calories is not only a burden to our physical homeostasis [or equilibrium], but also on our psychological well-being.” 
     


    Check out my other videos on calorie restriction, fasting, intermittent fasting, and time-restricted eating in the related videos below. 

     

    Michael Greger M.D. FACLM

    Source link

  • Muscle Shrinkage and Bone Loss on Keto Diets?  | NutritionFacts.org

    Muscle Shrinkage and Bone Loss on Keto Diets?  | NutritionFacts.org

    Ketogenic diets have been found to undermine exercise efforts and lead to muscle shrinkage and bone loss. 
     
    An official International Society of Sports Nutrition position paper covering keto diets notes the “ergolytic effect” of keto diets on both high- and low-intensity workouts. Ergolytic is the opposite of ergogenic. Ergogenic means performance-boosting, whereas ergolytic means performance-impairing. 
     
    For nonathletes, ketosis may also undermine exercise efforts. Ketosis was correlated with increased feelings of “perceived exercise effort” and “also significantly correlated to feelings of ‘fatigue’ and to ‘total mood disturbance,’” during physical activity. “Together, these data suggest that the ability and desire to maintain sustained exercise might be adversely impacted in individuals adhering to ketogenic diets for weight loss.” 
     
    You may recall that I’ve previously discussed that shrinkage of measured muscle mass among CrossFit trainees has been reported. So, a ketogenic diet may not just blunt the performance of endurance athletes, but their strength training as well. As I discuss in my video Keto Diets: Muscle Growth and Bone Density, study participants performed eight weeks of the battery of standard upper and lower body training protocols, like bench presses, pull-ups, squats, and deadlifts, and there was no surprise. You boost muscle mass—unless you’re on a keto diet, in which case there was no significant change in muscle mass after all that effort. Those randomized to a non-ketogenic diet added about three pounds of muscle mass, whereas the same amount of weight lifting on the keto diet tended to subtract muscle mass by about 3.5 ounces on average. How else could you do eight weeks of weight training and not gain a single ounce of muscle on a ketogenic diet? Even keto diet advocates call bodybuilding on a ketogenic diet an “oxymoron.” 
     
    What about bone loss? Sadly, bone fractures are one of the side effects that disproportionately plague children placed on ketogenic diets, along with slowed growth and kidney stones. Ketogenic diets may cause a steady rate of bone loss as measured in the spine, presumed to be because ketones are acidic, so keto diets can put people in what’s called a “chronic acidotic state.” 
     
    Some of the case reports of children on keto diets are truly heart-wrenching. One nine-year-old girl seemed to get it all, including osteoporosis, bone fractures, and kidney stones, then she got pancreatitis and died. Pancreatitis can be triggered by having too much fat in your blood. As you can see in the graph below and at 2:48 in my video, a single high-fat meal can cause a quintupling of the spike in triglycerides in your bloodstream within hours of consumption, which can put you at risk for inflammation of the pancreas.  

    The young girl had a rare genetic disorder called glucose transporter deficiency syndrome. She was born with a defect in ferrying blood sugar into her brain. That can result in daily seizures starting in infancy, but a ketogenic diet can be used as a way to sneak fuel into the brain, which makes a keto diet a godsend for the 1 in 90,000 families stricken with this disorder.

    As with anything in medicine, it’s all about risks versus benefits. As many as 30 percent of patients with epilepsy don’t respond to anti-seizure drugs. Unfortunately, the alternatives aren’t pretty and can include brain surgery that implants deep electrodes through the skull or even removes a lobe of your brain. This can obviously lead to serious side effects, but so can having seizures every day. If a ketogenic diet can help with seizures, the pros can far outweigh the cons. For those just choosing a diet to lose weight, though, the cost-benefit analysis would really seem to go the other way. Thankfully, you don’t need to mortgage your long-term health for short-term weight loss. We can get the best of both worlds by choosing a healthy diet, as I discussed in my video Flashback Friday: The Weight Loss Program That Got Better with Time.
     
    Remember the study that showed the weight loss was nearly identical in those who had been told to eat the low-carb Atkins diet for a year and those told to eat the low-fat Ornish diet, as seen below and at 4:18 in my video? The authors concluded, “This supports the practice of recommending any diet that a patient will adhere to in order to lose weight.” That seems like terrible advice. 

    There are regimens out there like “The Last Chance Diet which consisted of a low-calorie liquid formula made from leftover byproducts from a slaughterhouse [that] was linked to approximately 60 deaths from cardiovascular-related events.” An ensuing failed lawsuit from one widower laid the precedent for the First Amendment protection for those who produce deadly diet books. 

    It’s possible to construct a healthy low-carb diet or an unhealthy low-fat one—a diet of cotton candy would be zero fat—but the health effects of a typical low-carb ketogenic diet like Atkins are vastly different from a low-fat plant-based diet like Ornish’s. As you can see in the graph below and at 5:26 in my video, they would have diametrically opposed effects on cardiovascular risk factors in theory, based on the fiber, saturated fat, and cholesterol contents of their representative meal plans. 

    And when actually put to the test, low-carb diets were found to impair artery function. Over time, blood flow to the heart muscle itself is improved on an Ornish-style diet and diminished on a low-carb one, as shown below and at 5:44 in my video. Heart disease tends to progress on typical weight-loss diets and actively worsens on low-carb diets, but it may be reversed by an Ornish-style diet. Given that heart disease is the number one killer of men and women, “recommending any diet that a patient will adhere to in order to lose weight” seems irresponsible. Why not tell people to smoke? Cigarettes can cause weight loss, too, as can tuberculosis and a meth habit. The goal of weight loss is not to lighten the load for your pallbearers. 

     
    For more on keto diets, see my videos on the topic. Interested in enhancing athletic performance? Check out the related videos below. 

    Michael Greger M.D. FACLM

    Source link