El estudio comparó un grupo de 500 mujeres que habían sido recientemente diagnosticadas de cáncer de mama con un grupo de 500 mujeres de la misma edad que no tenían el cáncer.
Los investigadores encontraron que las mujeres que habían amamantado más de tres niños o habían dado el pecho al primer hijo más de 13 meses tenían la mitad de riesgo de desarrollar cáncer de mama que las que nunca habían dado el pecho.
![IntraMed](data:image/svg+xml,<?xml version="1.0" encoding="UTF-8"?>%0A<svg id="Capa_1" xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 1080 315">%0A <defs>%0A <style>%0A .st0 {%0A fill-rule: evenodd;%0A }%0A%0A .st0, .st1 {%0A fill: %23002bc7;%0A }%0A%0A .st2 {%0A fill: %23fff;%0A }%0A </style>%0A </defs>%0A <g>%0A <circle class="st2" cx="141.5" cy="179.93" r="135.02"/>%0A <g>%0A <path class="st2" d="M350.28,126.97v106.62c0,7-4.04,11.22-10.41,11.22s-10.5-4.22-10.5-11.22v-106.62c0-7,4.13-11.22,10.5-11.22s10.41,4.22,10.41,11.22Z"/>%0A <path class="st2" d="M459.96,184.86v49.09c0,6.82-4.04,10.86-10.23,10.86s-10.14-4.04-10.14-10.86v-47.03c0-13.28-6.73-20.28-20.73-20.28-7.81,0-15.53,2.15-20.19,4.85v62.47c0,6.82-4.04,10.86-10.23,10.86s-10.14-4.04-10.14-10.86v-66.68c0-6.37,1.35-9.24,7.09-12.21,5.38-3.14,18.49-8.17,33.48-8.17,26.66,0,41.11,14.36,41.11,37.96Z"/>%0A <path class="st2" d="M505.83,137.92v10.68h24.14c7,0,10.59,3.59,10.59,9.42s-3.59,9.33-10.59,9.33h-24.14v45.05c0,9.78,3.86,14.09,12.74,14.09,4.76,0,8.08-1.08,10.77-1.98,2.15-.72,3.95-1.52,6.28-1.52,4.58,0,8.44,3.77,8.44,9.06s-3.14,8.08-7.99,9.96c-5.21,1.97-11.76,3.59-18.76,3.59-19.03,0-31.86-10.86-31.86-31.23v-76.47c0-6.82,3.95-10.77,10.14-10.77s10.23,3.95,10.23,10.77Z"/>%0A <path class="st2" d="M559.96,233.95v-55.73c0-19.3,11.76-31.32,30.69-31.32,6.01,0,11.22.72,15.17,1.89,5.83,1.61,9.87,4.67,9.87,10.32,0,6.28-4.22,9.87-8.44,9.87-1.97,0-3.41-.36-4.85-.72-3.05-.81-5.92-1.26-9.69-1.26-8.44,0-12.39,4.04-12.39,12.39v54.57c0,6.82-3.95,10.86-10.14,10.86s-10.23-4.04-10.23-10.86Z"/>%0A <path class="st2" d="M624.04,214.83c0-15.08,11.76-28.9,36.08-28.9,7.81,0,14.72.99,22.89,3.14v-7.45c0-10.86-5.74-16.25-20.28-16.25-6.37,0-12.74,1.62-16.69,3.23-2.69.99-5.21,1.88-7.45,1.88-4.76,0-8.53-3.68-8.62-8.71,0-4.22,2.24-7.54,7.81-9.69,6.19-2.6,15.8-5.21,26.48-5.21,24.5,0,38.41,11.04,38.41,35.27v46.13c0,3.68-.99,5.56-3.77,7.45-5.65,3.86-19.57,9.87-37.87,9.87-23.78,0-36.98-13.37-36.98-30.78ZM662.73,228.84c7.27,0,14.81-2.06,20.28-4.94v-20.19c-7.45-2.24-13.55-3.23-20.37-3.23-12.83,0-19.21,6.28-19.21,14.36,0,8.89,7.54,14,19.3,14Z"/>%0A <path class="st2" d="M724.12,235.12c0-.81.09-2.06.18-2.78l13.73-96.57c2.15-15.17,9.51-20.01,20.1-20.01,9.51,0,16.78,3.95,19.66,19.12l18.4,85.71c.45,1.62.72,2.33,1.98,2.33,1.35,0,1.7-.72,2.06-2.42l18.31-85.62c2.87-15.17,10.05-19.12,19.57-19.12,10.68,0,17.95,4.85,20.01,20.1l13.73,96.03c.18,1.44.27,2.24.27,3.32,0,5.84-3.95,9.6-9.69,9.6-6.55,0-10.14-3.5-10.86-10.05l-12.12-94.86c-.27-1.89-.72-2.51-1.88-2.51-.99,0-1.53.45-1.88,2.15l-19.57,88.22c-2.42,11.58-8.53,17.05-18.13,17.05-10.23,0-15.71-5.57-18.22-17.14l-19.48-88.04c-.45-1.62-.99-2.24-1.79-2.24-1.17,0-1.71.72-1.97,2.6l-11.85,94.78c-.81,6.64-4.31,10.05-10.41,10.05s-10.14-3.59-10.14-9.69Z"/>%0A <path class="st2" d="M891.08,208.91c-.63-6.73-.63-17.68-.09-23.96,2.06-22.17,18.04-37.87,42.18-37.87s39.67,16.06,39.67,39.67v5.3c0,9.87-1.97,11.31-10.86,11.31h-51.88c0,1.26,0,2.6.09,3.86.72,12.03,9.96,20.01,24.32,20.01,7.9,0,13.91-1.71,18.85-3.68,2.96-1.08,4.85-2.06,7.45-2.06,4.85,0,8.44,3.14,8.44,8.44.09,5.12-3.77,8.08-7.54,9.78-6.91,3.32-16.78,5.92-27.64,5.92-24.5,0-41.01-15.08-42.99-36.71ZM954,188.81c1.26-15.44-7.81-24.32-21.45-24.32s-21.54,8.98-22.35,22.08c0,.72-.09,1.53-.09,2.24h43.89Z"/>%0A <path class="st2" d="M1074.18,125.17v102.85c0,3.95-1.08,5.92-3.86,7.81-5.83,3.86-20.1,9.78-37.16,9.78-23.87,0-39.22-14.81-41.19-36.17-.72-7.27-.72-19.21,0-26.39,1.97-21.36,17.32-36.17,39.4-36.17,8.17,0,16.78,2.06,22.44,4.85v-26.57c0-6.82,3.95-10.86,10.23-10.86s10.14,4.04,10.14,10.86ZM1033.97,225.87c6.91,0,15.53-2.06,19.83-5.11v-49c-4.31-3.05-12.93-5.12-19.83-5.12-13.37,0-20.73,7.99-21.81,19.75-.54,6.55-.45,13.82,0,19.74,1.08,11.76,8.44,19.75,21.81,19.75Z"/>%0A </g>%0A <g>%0A <path class="st1" d="M101.42,217.17c0-.64.07-1.63.14-2.2l10.87-76.46c1.71-12.01,7.53-15.85,15.92-15.85,7.53,0,13.29,3.13,15.56,15.14l14.57,67.86c.36,1.28.57,1.85,1.56,1.85,1.07,0,1.35-.57,1.63-1.92l14.5-67.79c2.27-12.01,7.96-15.14,15.49-15.14,8.46,0,14.21,3.84,15.85,15.92l10.87,76.04c.14,1.14.21,1.78.21,2.63,0,4.62-3.13,7.6-7.67,7.6-5.19,0-8.03-2.77-8.6-7.96l-9.59-75.11c-.21-1.49-.57-1.99-1.49-1.99-.78,0-1.21.36-1.49,1.71l-15.49,69.85c-1.92,9.17-6.75,13.5-14.36,13.5-8.1,0-12.44-4.41-14.43-13.57l-15.42-69.71c-.36-1.28-.78-1.78-1.42-1.78-.92,0-1.35.57-1.56,2.06l-9.38,75.04c-.64,5.26-3.41,7.96-8.24,7.96s-8.03-2.84-8.03-7.67Z"/>%0A <path class="st1" d="M90.62,131.29v84.42c0,5.54-3.2,8.88-8.24,8.88s-8.31-3.34-8.31-8.88v-84.42c0-5.54,3.27-8.88,8.31-8.88s8.24,3.34,8.24,8.88Z"/>%0A </g>%0A <g>%0A <path class="st0" d="M74.36,202.14c19.92.79,54.3-4.62,92.4-15.33,58-16.32,102.67-38.77,99.76-50.15-2-7.85-26.05-8.39-59.77-2.65,23.98-2.82,37.51-1.37,39.11,4.9,2.82,11.03-37.79,32.76-93.95,48.56-1.26.35-2.51.7-3.76,1.04,0,0,0,0-.01,0-13.29,3.95-50.37,13.62-73.78,13.62Z"/>%0A <path class="st0" d="M191.55,191.02c-13.03,4.75-27.19,9.32-42.09,13.5-70.38,19.79-130.56,23.59-134.41,8.48-2.65-10.4,20.1-26.01,58.76-41.85-26.73,12.73-38.09,24.13-35.96,32.45,3.73,14.63,59.37,10.95,127.5-8.22,36.59-10.29,68.58-22.95,89.79-34.73-9.63,6.73-23.48,14.01-40.32,21.2-4.91,2.44-18.07,7.34-23.28,9.16Z"/>%0A </g>%0A </g>%0A</svg>%0A)