Dr. Rhonda Patrick, PhD, is an American biochemist who has done extensive research on aging, cancer, and nutrition. Her groundbreaking work includes studies of how vitamin and mineral inadequacies impact metabolism, inflammation, DNA, and aging, and whether supplementation can reverse the damage. In addition, she has investigated the role of vitamin D in brain function and behavior. Her stated goal is to “encourage the wider public to think about health and longevity using a proactive, preventative approach.” She is the host of the Found My Fitness podcast.
In an extended conversation for an episode of the Tim Ferriss Show, Dr. Patrick took questions from listeners about the best practices for fasting, the minimum effective dose for the benefits of sauna, and much more. Below is an excerpt of the discussion, edited by Outside.
Can you summarize the best practices for time-restricted eating?
Time-restricted eating is the idea that by constraining our eating within a certain window ranging from eight to 12 hours per day—usually earlier in the day to align better with our circadian rhythm—we stand to benefit in a variety of ways. On the more extreme end, you’re engaging in what’s well known in fitness as 16:8 intermittent fasting. But simply maintaining a slightly more conservative time window for eating than you usually do has started to show advantages as well. Animals that have been limited to a nine- to 12-hour window in which they can eat have attained some pretty amazing benefits, including decreased fat mass, increased lean muscle mass, reduced inflammation, and protection from obesity.
How you choose to act on this information is ultimately dictated by life circumstances. The flexibility of my schedule has made implementing time-restricted eating easier. I aim for a ten-hour eating window and a 14-hour nighttime fasting window. I follow the same procedure on days I sleep in, even though some animal research shows that this pattern has benefits even if you cheat on the weekend. I chose a ten-hour window because it’s a sufficiently tight window of time to likely confer some of the advantages of time-restricted eating without being unduly burdensome. Stretching for the nine-hour or even eight-hour window, however, may appeal to some people. Animal research has shown an aerobic endurance benefit for time-restricted feeding in the nine-hour range, but not for shorter fasts. But, I think there’s still a lot of room for more emerging research in this area to teach us things that may be important.
Can you share your thoughts on benefits of saunas?
Some of the positive benefits of sauna use on heart health are similar to the benefits seen with regular physical exercise. Heart rate can increase up to 100 beats per minute during moderate sauna bathing sessions and up to 150 beats per minute during more intense warm sauna use. And 150 beats per minute corresponds to moderate-intensity physical exercise, which, as we already know, has a positive effect on cardiovascular health.
As for the types of saunas, we have a few options available. Infrared saunas don’t get quite as hot and are often limited to about 140 degrees Fahrenheit or 60 Celsius. For reasons of practicality and because I believe that benefits from the sauna are primarily conferred directly by heat, I tend to prefer a hotter sauna. But it seems reasonable that making other adjustments, like preceding the sauna session with light cardio, for example, might help make up for the differences. It’s hard to know for absolute certain, but I’m optimistic.
All of that said, try to exercise good judgment. Even if you don’t think you have a medical condition that could increase your risks to heat stress, it’s worth checking in with a doctor before becoming some mega sauna enthusiast. Heat is no joke and it’s important that you don’t hurt yourself.
Besides a low-carb diet (which reduces inflammation), what is the most effective non-pharmaceutical pain reliever for people suffering from arthritis or sports injuries?
Many NSAIDs (non-steroidal anti-inflammatory drugs) that are used for mild pain relief are actually not especially safe to take on a daily basis. This is even more true for people that tend to take them in larger-than-recommended doses, which is why the FDA recently strengthened their warning that NSAIDs, with exception to aspirin, significantly increase the risk of heart attack or stroke even with short-term use. As an alternative to the use of NSAIDs, however, I’ve found the compound curcumin is actually very helpful. It exhibits a pretty diverse array of potentially beneficial properties, but its activity can be limited unless you try to make it more bioavailable. There are a few formulations that attempt to do that, but the one I’ve found to be the most interesting is known as Meriva, which has been shown to exhibit certain pain-relieving properties.
How can we identify trustworthy supplement brands?
One thing you can do is make sure that the product is certified by NSF International, or the National Sanitary Foundation, which independently tests and certifies dietary supplements and nutritional products, and ensures that they don’t contain undeclared ingredients or contaminants. While being in the NSF database is a good sign, not being in it isn’t a deal breaker. So, here’s another option: Look for products that are USP-certified. The USP, which stands for the United States Pharmacopeial Convention, is a scientific nonprofit that sets standards for the quality and purity of dietary supplements that are manufactured, distributed, and consumed worldwide. In the United States, the FDA relies on standards the USP has developed.
What small lifestyle change leads to the biggest impact on health and wellbeing?
I think for people starting from ground zero, one of the easiest change to make with the biggest impact is to cut out refined sugar. The second easiest thing you can do is to begin doing time-restricted eating within a nine- to 12-hour time frame, in accordance with circadian rhythm where, unless you are a night shift worker, you try to eat your meals earlier in the day as possible.
The third huge lifestyle change that can make a big, big difference is simply doing whatever it takes to triple the amount of vegetables you take in on a daily basis. Finally, number four, which I think can have a potentially big impact for many people, is taking a vitamin D supplement.