In conclusion, increasing intake of purified proteins from either animal or plant sources increases renal net acid excretion, which in turn increases urinary calcium. The effects of a protein on urinary calcium and bone metabolism are reduced by other nutrients found in that protein source, such as phosphorus in meat and K plus base in legumes, respectively. The effect of a diet pattern on calcium excretion is not only affected by the amount of protein but is also modified by other dietary constituents such as calcium, potassium, phosphorus, isoflavones, antioxidants, salt, oxalate, phytates and caffeine. Animal and plant foods may have different effects on bone health, although these effects are mainly attributable to other constituents of the food and diet, not protein.
Everybody wants to live a long and healthy life. So, expanding one’s lifespan is a goal anybody would go for. Of course, there is no formula that guarantees a long life. However, there are criterions which put into practice get very close to achieve this goal. Starting with regular physical activity, avoiding stressful mindsets and particularly following proper diet habits account for a long and healthy life. Against this background, some of the world’s top-notch medical doctors examined whether there is a link of animal and plant-based protein intake to the risk for mortality. Their conclusion should be a warning signal for some to radically change their diet habits before it’s too late.
Urinary calcium excretion is strongly related to net renal acid excretion. The catabolism of dietary protein generates ammonium ion and sulfates from sulfur-containing amino acids. Bone citrate and carbonate are mobilized to neutralize these acids, so urinary calcium increases when dietary protein increases. Common plant proteins such as soy, corn, wheat and rice have similar total S per g of protein as eggs, milk and muscle from meat, poultry and fish. Therefore increasing intake of purified proteins from either animal or plant sources similarly increases urinary calcium. The effects of a protein on urinary calcium and bone metabolism are modified by other nutrients found in that protein food source. For example, the high amount of calcium in milk compensates for urinary calcium losses generated by milk protein. Similarly, the high potassium levels of plant protein foods, such as legumes and grains, will decrease urinary calcium. The hypocalciuric effect of the high phosphate associated with the amino acids of meat at least partially offsets the hypercalciuric effect of the protein. Other food and dietary constituents such as vitamin D, isoflavones in soy, caffeine and added salt also have effects on bone health. Many of these other components are considered in the potential renal acid load of a food or diet, which predicts its effect on urinary acid and thus calcium. “Excess” dietary protein from either animal or plant proteins may be detrimental to bone health, but its effect will be modified by other nutrients in the food and total diet.
Design, Setting, and Participants This prospective cohort study of US health care professionals included 131 342 participants from the Nurses’ Health Study (1980 to end of follow-up on June 1, 2012) and Health Professionals Follow-up Study (1986 to end of follow-up on January 31, 2012). Animal and plant protein intake was assessed by regularly updated validated food frequency questionnaires. Data were analyzed from June 20, 2014, to January 18, 2016.