Staying Well-Hydrated Is Very Closely Linked to Longevity, According to New Research—RDs Explain Why

News flash: It might finally be time to invest in one of those cheugy (but cute) gallon-sized motivational water bottles to stay adequately hydrated throughout the day.

After all, we already know how challenging meeting our daily water intake goals can be (not to mention how important staying well-hydrated is for nearly every bodily function). But this week, a new study was published further showing that good hydration is closely linked to healthy aging—which just might be the science-backed evidence we’ve been waiting for to encourage us to stay on top of our hydration game from now on.

According to a National Institutes of Health study published in the journal eBioMedicine, “adults who stay well-hydrated appear to be healthier, develop fewer chronic conditions, such as heart and lung disease, and live longer than those who may not get sufficient fluids.” The study analyzed serum sodium level data—the concentration of sodium in the blood, which goes up when fluid intake goes down—and various indicators of health from 11,255 adults over a 30-year period.

The result? Adults with serum sodium levels at the higher end of a normal range were more likely to develop chronic conditions and show signs of advanced biological aging than those with serum sodium levels in the medium range. Additionally, adults with higher levels had a higher risk of dying at a younger age.

We spoke with two registered dietitians that shared why maintaining optimal hydration levels is essential for healthy aging and imperative for several bodily functions, plus their take on the evidence this new study presents.

Why is optimal hydration so important for healthy aging?

According to Christina Manian, RDN, a Boulder-based registered dietitian and sustainable food systems professional, water is one of the most important components that make up the human body. “Hydration is incredibly important for so many reasons, especially considering the face that our bodies are comprised of somewhere between 45 to 75 percent water,” Manian says. To put it simply, the water we consume throughout the day helps regulate just about every key bodily function.

“Some benefits of staying well hydrated include optimal digestion and nutrient delivery to cells, regulation of body temperature, and improved joint lubrication,” Manian says. “Proper hydration also helps all of our organs function most optimally, especially our heart, kidneys, and brain— keeping headaches at bay and improving cognition, memory, and mood.” But that’s not all; according to Manian, hydration gives our organs a leg up in carrying out natural detoxification processes, which is the body’s process of removing toxic substances.

Lauren Manaker, MS, RDN, LD, CLEC, CPT, a registered dietitian based in Charleston, firmly agrees, adding that while hydration is an aspect of our diet that is incredibly important, it remains to be one that many have trouble with. “Unfortunately, many of us are chronically dehydrated,” Manaker says. In fact, research estimates that about 75 percent of Americans are chronically dehydrated. This becomes even more prevalent (and risky) as we age, especially for adults over 60, because the body retains a lower water volume, and the thirst sensation decreases as we grow older.

Having trouble discerning whether you’re dehydrated, just really thirsty, or both? Signs that your body is lacking hydration include joint pain, stiffness or cramping in your muscles and ligaments, dry mouth and skin, and darker, more concentrated urine (and less of it).

How can we apply these findings to our daily routine?

Although the study presents valid information and generally good news when it comes to longevity-boosting habits that are easy to adopt into our daily routines, Manaker notes that there are a few things to keep in mind before you start chugging copious amounts of H2O. “This study is observational in nature, and the sample size is relatively small,” Manaker explains. But that’s not to say the findings aren’t valid. On the contrary, she says that the data highlights just how impactful proper hydration is for our overall health and that following the advice that is implied by these findings comes with little risk (if any).

According to Natalia Dmitrieva, PhD, a study author and researcher in the Laboratory of Cardiovascular Regenerative Medicine at the National Heart, Lung, and Blood Institute (NHLBI), part of NIH, “people can safely increase their fluid intake to meet recommended levels, which can be done with water as well as other fluids, like juices, or vegetables and fruits with a high water content.” You could even crack open a coconut, as one of the prime benefits of coconut water is keeping your body hydrated.

But exactly how much water should we be drinking? The National Academies of Medicine suggests that most women consume around six to nine cups of fluids daily and eight to 12 cups for men. Of course, those with underlying health conditions should seek professional medical guidance to determine their proper fluid intake quantities.

An RD shares the top hydrating foods to help meet your hydration goals: