Does diet cause osteoporosis? Can a good diet clear up osteoporosis or mitigate it? The answers are not as clear as you might think. http://www.ncbi.nlm.nih.gov/pubmed/14972062
Medical and scientific opinion about the connection between nutrition and osteoporosis has changed over the years. No one questions that proper nutrition can contribute to good health and reducing the risk of all sorts of illnesses. Doctors will tell you to consume plenty of calcium but few serious researchers in this field think calcium in the diet will prevent osteoporosis. The most they will say is that not consuming enough calcium increases the risk of the disease.
The Mayo Clinic website lists low calcium intake as a risk factor for osteoporosis. Low calcium consumption is a risk factor alongside smoking and a sedentary lifestyle. Eating disorders and high alcohol consumption are also risk factors.
The Institute of Medicine establishes guidelines for nutrient targets and widely referenced “recommended daily allowances” of many dietary constituents. The RDA for adults is 1 gram of calcium per day (1000 mg/day). For women past age 50 and men past age 70 the RDA rises 20% (1200 mg/day). Good sources of calcium include milk products (all types of milk, yogurt, cheese) and green vegetables (kale, brocolli, spinach). Some tofus are made with calcium sulfate and hence have lots of calcium and many food products (orange juice, breakfast cereal) are fortified with calcium.
Vitamin D can be produced in the skin, in response to sunlight (or specifically the UV-B spectrum, wavelength 290–315 nm). In light-skinned people, only 10 minutes of sun exposure can product 5000 units. Diet can also be a source of Vitamin D. The experts recommended daily intake of vitamin D differs for different ages, but in all cases it is less than 1000 units per day. Dieticians distinguish between two main forms of vitamin D: D2 (ergocalciferol, derived from plant sources) and D3 (cholecalciferol). Inside the body, in the bloodstream, it is best to have the vitamin D level higher than 30 ng/mL to keep parathormone concentration at the right level so bone density does not decline.
Can you take in too much calcium? Yes, but generally your digestive system will absorb a lower percentage of the available calcium as intake rises, so your body corrects somewhat. Really high supplementation of calcium could lead to kidney damage and "calcium deposition" seen in people who abuse antacid tablets. Calcium compounds can deposit in the muscles, kidneys, arteries, and gall bladder. Analysis of health studies has shown that calcium supplements increase the risk of heat disease.
Will eating a diet high in calcium and Vitamin D prevent osteoporosis? Not necessarily. Will eating a diet low in calcium result in osteoporosis? Not necessarily, either. Epidemiologists have not been able to establish either of those things. The best they can say is that calcium and Vitamin D consumption reduce your risk for osteoporosis. And when it comes to treating osteoporosis, nobody says that diet is enough by itself and that high calcium diets will reverse the condition.
The National Osteoporosis Foundation cautions against taking more supplemental calcium than you need. There is not even agreement among authorities about how much calcium a person should consume and whether supplements are needed. Although the US government's RDA is 1000 mg/day and up, in the UK the RDA is 700 mg/day and the World Health Organization is only 400-500 mg/day.
In a 2000 paper a Creighton University scientists said "evidence firmly establishes that high calcium intakes promote bone health" (http://www.ncbi.nlm.nih.gov/pubmed/10759135) and it doesn’t appear
to matter whether the calcium comes from pills (supplements) or from regular foods that have calcium in them. It also appears that dietary calcium provides more benefit to young adults than to older ones.
A meta-analysis published in 2010 concluded that calcium supplements had little effect on osteoporosis risk and raised the risk of heart attacks.
The United States Preventive Services Task Force put serious doubt into calcium supplements. In a 2013 statement they said otherwise low risk postmenopausal women do not need to take supplements of calcium or Vitamin D. Premenopausal women and men of all ages were also said to not need to take the supplements. The task force felt there was insufficient evidence that these supplements prevented fractures. The added risk of kidney stones, although small, was felt to outweigh the benefits.
A diet high in fruits and vegetables seems to improve markers of bone health. Many studies have shown this. Whether vegetables can help prevent onset on osteoporosis is not clear, but it is considered possible. Of course, there are other benefits to eating a lot of fruits and vegetables.
Doctors sometimes tell osteoporosis patients to take protein supplements, especially if they have had a fracture.
Magnesium is an important nutrient for bone health. Dietary magnesium stimulates the body's production of the hormone calcitonin. Getting enough magnesium can help lower the risk of heart attack, kidney stones, and osteoporosis. One idea gaining favor is that the ratio of calclium in the diet (and bloodstream) to other minerals is important in bone health.
Other questions of nutrition – consumption of micronutrients – might be good for you, but there is even less evidence that they influence incidence of osteoporosis.
Some communities put fluoride in their water, and there has been
interest in this increasing or decreasing the risk for osteoporosis.
A Lancet study concluded minimal effect on bone fracture risk. Another study concluded
"there was no clear evidence of other potential adverse effects."
Advocates of a so-called alkaline diet claim that you can adjust the pH in your body with your diet. The body is quite well buffered and there are mechanism to maintain the pH within a narrow range. More sophisticated alkaline diet boosters say the diet reduces the load on the buffering systems and results in less depletion of valuable minerals. This would include calcium in the bones, which is said to be depleted by a more acidic diet. The alkaline diet is claimed by some to prevent osteoporosis.
The Journal of Environmental and Public Health published an article recently looking at the question. It concluded that alkaline diets can result in a higher urine pH and less calcium in the urine, but that "there is no substantial evidence that this improves bone health or protects from osteoporosis".
Manifestations of the "alkaline diet" are often high in fruits and vegetables, and most Americans could probably stand to eat more fruits and vegetables as it is. There appears to be little science behinds these claims, but a plant-rich diet is said to increase the ratio of potassium to sodium in the body and this is said to keep muscle tissue and reduce hypertension. Advocates also claim this diet will induce the body to produce more human growth hormone and increase the availability of magnesium in the body that ends up helping various physiological functions.
Considered pseudo-science, the alkaline diet is not seriously considered viable by most dietitians or doctors.
An Egyptian study in rats suggests that olive oil can help slow down bone loss in patients with osteoporosis.
The U.S. Department of Agriculture reports that people in the Navajo nation tend to have lower rates of osteoporosis than the general US population despite consuming low quantities of dairy products. An article on their website talks about speculation that the local water supply on the Navajo reservation has high mineral content.
Sources for information on page: AHRQ.gov, Centers for Disease Control, National Institutes of Health, Washington Post