Can you preserve your fertility as a woman for longer through your lifestyle?
Studies show that a healthy weight is measurably linked to better fertility. Whether changing your lifestyle actively preserves egg supply for longer is not yet known with certainty.
Excess weight is the lifestyle factor with the most supporting evidence. Women with a higher BMI tend to have fewer eggs in their ovaries on average, and the hormone levels that reflect egg supply are lower, although this link has not been found in every study. More concretely: among women trying IVF, those with obesity (BMI 30 or above) have roughly a 15% lower chance of a live birth than women with a healthy weight. Whether losing weight actually reverses this effect has not yet been properly studied.
Diet plays a less clear-cut role. Healthy eating patterns such as the Mediterranean diet did not appear to be linked to a better egg supply in studies of women attending a fertility centre. What does seem to matter are harmful substances released when food is cooked at very high temperatures (grilling, high-heat frying) and also through smoking, but that evidence comes largely from cell and animal studies and has not yet translated well to people. Having an adequate vitamin D level is linked to better IVF outcomes in a small number of studies, but this has not yet been confirmed in well-designed intervention studies in healthy women.
Environmental factors also count, even if you only have partial control over them. Exposure to heavy metals in the environment is consistently linked in multiple studies to a lower egg supply and an earlier menopause. Fine particles and nitrogen oxides in polluted air show a similar pattern: nine out of twelve available studies found lower hormone levels at higher levels of exposure. So-called 'forever chemicals' (found in, among other things, non-stick coatings and water-repellent clothing) appear to lower oestrogen levels, but that evidence is contradictory.
The honest answer is that researchers assume that addressing these factors slows the ageing of the ovaries, but there is no study yet that proves this with certainty. What you can do right now: maintaining a healthy weight has the most supporting evidence, avoiding smoking is consistent with the broader evidence, and limiting unnecessary exposure to environmental pollution is sensible, even though your influence over that as an individual is limited.
This answer draws on several overview studies and one summary of 21 studies on IVF outcomes in obesity. Most findings come from studies in which women were followed over time without anyone being randomly assigned to a group, so cause and effect are rarely proven. The researchers themselves note that intervention evidence, that is, studies showing that lifestyle change actually preserves fertility, is lacking. The evidence on weight and IVF outcome is the strongest; the evidence on diet, vitamins and environmental factors is still thin or contradictory.
Does a long life come at the cost of fertility?
Genetic research shows a small trade-off in men: higher testosterone is linked to slightly more children and a slightly shorter lifespan. In women this testosterone effect has not been found, although fertility does decline clearly with age.
Can you delay menopause with lifestyle or diet?
Avoiding smoking, eating less red meat, and eating more citrus fruit and oily fish appear to have a favourable influence on the age of menopause. However, evidence from controlled experiments is still entirely lacking.
What does chronic sleep deprivation do to your fertility?
Chronic sleep deprivation and frequent insomnia have been linked in several large studies to a lower chance of conception and more reproductive problems. If you want to become pregnant, getting regular and sufficient sleep is a concrete starting point, even though causality has not yet been definitively proven.
Can hormones explain why women live longer on average than men?
Sex hormones likely contribute to women's longer lifespan, but they do not fully explain the difference. Social factors also play a role, and the hormonal protection has a clear downside after the menopause.
What does pregnancy do to your hormone balance in the long run?
Pregnancy and breastfeeding bring measurable, sometimes long-lasting hormonal changes, of which the genital and urinary complaints caused by oestrogen loss are the best documented. Knowing what to expect makes it easier to talk about these issues and seek help.
Can stress make you infertile?
Extreme or prolonged stress that disrupts the menstrual cycle can harm fertility; whether ordinary daily stress causes infertility has not been demonstrated. If you notice your cycle becoming irregular due to stress, discuss it with your doctor.