(Health Secrets) Many parents wonder how to advise their daughters who are ready for contraceptives. The consequences of not using contraceptives can be life altering, but so can the consequences of using them. To make it even more complicated, recent research has shown that contraceptive use during adolescence prevents peak bone mass acquisition, leading to significantly increased risk of osteoporosis and fractures later in life.
As reported in the journal Contraception, researchers designed a four year follow-up study with 122 adolescent women ranging in ages from 12 to 19. The collected data was divided into three groups based on estrogen-progestin contraceptive use: nonusers, those with 1-2 years of use, and those with more than 2 years of use. Height, weight, and the amount of exercise as well as bone mineral content of the lumbar spine and femoral neck (found where the femur joins the hip) were measured repeatedly.
The researchers found a significant trend showing less of an increase in the mean adjusted bone mineral content of the lumbar spine in the group who had used a contraceptive for more than 2 years compared with the two other groups. These findings led the researchers to conclude that estrogen-progestin contraceptive preparations suppress normal bone mineral accrual.
The hormones used in contraceptives are synthetic or semi-synthetic, and differ in molecular structure from the hormones naturally made by the female body. They are hormone drugs, not natural hormones or bioidentical hormones.
During the period from childhood to early adulthood, minerals are deposited in bone as the skeleton grows. The highest rates of bone growth occur during infancy and again in the pubertal growth spurt. During adolescence the speed of bone growth doubles, and around 40% of peak bone mass is created. By the age of about 20, up to 95% of peak bone mass is attained.
As the journey through the 20’s continues, bone mass starts to decline. Minerals and the collagen matrix begin to be removed from bone more rapidly than new bone tissue is added. By old age, women have typically lost half of their trabecular and one-third of their cortical bone.
It can be clearly seen that the amount of bone achieved at peak bone mass dictates the amount of bone to be had throughout the rest of life. There is increasing evidence that the groundwork for the development of osteoporosis is laid during the period of childhood and adolescence. Researchers are now at work determining the extent to which the diet and lifestyle choices we make for our children can predict their fracture risk later in life.
What is already known is that a balanced diet of mineral rich whole foods sets the stage for optimal peak bone mass growth. This outcome can be negatively affected by the consumption of foods that deplete the mineral content of the skeleton such as soft drinks that are high in phosphorus, eating products made with soy, or by lack of exercise. And now we know that this outcome is also dependent on lifestyle choices such as the choice to use contraceptives. These research findings suggest that the incredible rise in the rates of diagnosed osteoporosis may be directly tied to the huge increase in use of contraceptives in the last 40 years.
The above noted study lends additional support to the conclusions of previous research. In 2001, the Canadian Medical Association reported research to assess the relation between oral contraceptive use and bone mineral density in a population based national sample of women aged 25-45. Premenopausal women who had been enrolled in the Canadian Multi-Centre Osteoporosis Study were classified as having ever been users of oral contraceptives, or as having never been users of oral contraceptives. Data was obtained through extensive questionnaires and by measuring participants’ weight, height and the bone mineral density of lumbar vertebrae and of the proximal femur.
Of the sample of 524 women, whose mean age was 36.3 years, 454 had used oral contraceptives. The mean age when they started using the contraceptives was 19.8, and the mean duration of use was 6.8 years. There was no difference between the groups in age, age at menarche, parity, current calcium intake, exercise, body mass index, irregular cycles, or amenorrhea. However, the mean bone mineral density was 2.3-3.7% lower in contraceptive users, and significantly lower in the spine and trachanter.
A study reported in the 1995 journal Contraception was designed to investigate bone metabolism in young women taking an oral contraceptive for over 5 years. Two hundred healthy women between 19 and 22 years of age were divided into two groups. Group A received an oral contraceptive, Group B did not receive any treatment. All the subjects underwent a bone mass density evaluation of spinal level at baseline and every 12 months during the 5 years.
Results indicated that Group A did not show any significant bone mineral density change after 5 years on oral contraceptive treatment, while Group B showed a significant increase in bone mass content at the end of the time of observations (+7.8% after 5 years).