 Vision is not the only sense associated with physical attractiveness and partner preference. Body odor signals a variety of information on matters such as eating habits, hygiene, health, and more. Based on a survey of hundreds of college students, men rated visual and smell information as being equally important for selecting a lover, while women considered to have their potential mates smell to be the single most important variable, in other words, women ranked body odor as more important for attraction than looks. I've talked about the concern around aluminum-containing antiperspirants. What can we do to make ourselves smell better? Clinical studies dating back to the 1950s show that chlorophyll can be used to improve body odors. This led to a wave of commercial chlorophyll deodorant products, but as one chlorophyll scientist lamented, because of the unfounded fantastic and sometimes completely idiotic claims made for chlorophyll by the promotion in advertising men, the buying public as well as the scientist will remain skeptical. And rightly so. To be an effective deodorant chlorophyll has to be taken internally at doses that far exceed those found in so-called deodorizing chewing gums and lozenges, studies showing the elimination of detectable underarm odors use doses on the order of 100 milligrams a day. In other words, the amount of chlorophyll one could get in about a third of a bunch of raw spinach. So before slathering aluminum onto your skin, I recommend first trying to deodorize from the inside out by eating a big salad every day, which may improve your body odor two ways, hitting the chlorophyll threshold and improving your health. There is a scent to disease. Some diseases result in a characteristic odor emanating from sick individuals. For example, tuberculosis of the throat makes you smell like stale beer. Typhoid makes you smell like baked bread, that doesn't sound so bad, though yellow fever makes you smell like a butcher's shop. But it's not just infection. I mean, evolutionarily, wouldn't it be advantageous if you could smell the first signs of inflammation, immune system activation, to stay away from people before they become contagious? What this team of researchers did was inject people with endotoxin, which is a highly inflammatory component of certain bacterial cell walls, caused a big spike of internal inflammation. And the question is, could you smell it on people? Within just a few hours, endotoxin exposed individuals had a more aversive body odor relative to when they were exposed to a placebo. A significantly less pleasant body odor within hours. Moreover, the more inflamed they got, the worse they smelled, providing the first experimental evidence that we could smell inflammation on people. And guess where endotoxins are found in the food supply? Where bacteria are found in meat, and they're not destroyed by cooking. I have a whole series of videos about that. We know meat causes inflammation, so does that mean it makes people smelly? You don't know until you put it to the test. The effective meat consumption on body odor attractiveness. Not just body odor, but body odor attractiveness. For two weeks, male odor donors were placed on a diet that included meat, or excluded meat, a no meat diet. And then during the final 24 hours, they had pads taped into their armpits to collect their body odor. Then the researchers just needed some judges to sniff the pads from each of the men. So fresh odor samples, hot off the pits, less than an hour old, were assessed for their pleasantness, attractiveness, masculinity, and intensity by 30 women. A month later, the study was repeated with the same guys, but now following the other diet. The same poor women were used as judges. The men, incidentally, were paid 2,000 in check currency for their time, and potential inconvenience caused by the prescribed diet. But the women who had to sniff all those armpit pads, the raters were not paid for their participation though, did get a chocolate bar after the second session. So, who had the most pleasant, the most attractive body odor? The results showed that the odor of donors went on the non-meat diet was judged as significantly more attractive, more pleasant, and less intense. No difference was noted for masculinity. The researchers concluded that meat may have a negative impact on perceived body odor hedonicity. In other words, those even more plant-based evidently smell significantly more pleasurable.